diff --git a/src/pipecat/services/asyncai/tts.py b/src/pipecat/services/asyncai/tts.py
index d4e2eabdc..3b1296752 100644
--- a/src/pipecat/services/asyncai/tts.py
+++ b/src/pipecat/services/asyncai/tts.py
@@ -9,8 +9,8 @@
 import asyncio
 import base64
 import json
-from dataclasses import dataclass, field
-from typing import Any, AsyncGenerator, Mapping, Optional, Self
+from dataclasses import dataclass
+from typing import Any, AsyncGenerator, Optional
 
 import aiohttp
 from loguru import logger
@@ -27,7 +27,7 @@ from pipecat.frames.frames import (
     TTSStoppedFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import AudioContextTTSService, TextAggregationMode, TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -75,28 +75,9 @@ def language_to_async_language(language: Language) -> Optional[str]:
 
 @dataclass
 class AsyncAITTSSettings(TTSSettings):
-    """Settings for Async AI TTS services.
+    """Settings for Async AI TTS services."""
 
-    Parameters:
-        output_container: Audio container format (e.g. "raw").
-        output_encoding: Audio encoding format (e.g. "pcm_s16le").
-        output_sample_rate: Audio sample rate in Hz.
-    """
-
-    output_container: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    output_encoding: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    output_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-
-    @classmethod
-    def from_mapping(cls, settings: Mapping[str, Any]) -> Self:
-        """Construct settings from a plain dict, destructuring legacy nested ``output_format``."""
-        flat = dict(settings)
-        nested = flat.pop("output_format", None)
-        if isinstance(nested, dict):
-            flat.setdefault("output_container", nested.get("container"))
-            flat.setdefault("output_encoding", nested.get("encoding"))
-            flat.setdefault("output_sample_rate", nested.get("sample_rate"))
-        return super().from_mapping(flat)
+    pass
 
 
 class AsyncAITTSService(AudioContextTTSService):
@@ -176,9 +157,6 @@ class AsyncAITTSService(AudioContextTTSService):
             model="async_flash_v1.0",
             voice=None,
             language=None,
-            output_container=container,
-            output_encoding=encoding,
-            output_sample_rate=0,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -215,6 +193,11 @@ class AsyncAITTSService(AudioContextTTSService):
         self._api_version = version
         self._url = url
 
+        # Init-only audio format config (not runtime-updatable).
+        self._output_container = container
+        self._output_encoding = encoding
+        self._output_sample_rate = 0  # Set in start()
+
         self._receive_task = None
         self._keepalive_task = None
 
@@ -262,7 +245,7 @@ class AsyncAITTSService(AudioContextTTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.output_sample_rate = self.sample_rate
+        self._output_sample_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -319,9 +302,9 @@ class AsyncAITTSService(AudioContextTTSService):
                 "model_id": self._settings.model,
                 "voice": {"mode": "id", "id": self._settings.voice},
                 "output_format": {
-                    "container": self._settings.output_container,
-                    "encoding": self._settings.output_encoding,
-                    "sample_rate": self._settings.output_sample_rate,
+                    "container": self._output_container,
+                    "encoding": self._output_encoding,
+                    "sample_rate": self._output_sample_rate,
                 },
                 "language": self._settings.language,
             }
@@ -567,9 +550,6 @@ class AsyncAIHttpTTSService(TTSService):
             model="async_flash_v1.0",
             voice=None,
             language=None,
-            output_container=container,
-            output_encoding=encoding,
-            output_sample_rate=0,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -602,6 +582,11 @@ class AsyncAIHttpTTSService(TTSService):
         self._base_url = url
         self._api_version = version
 
+        # Init-only audio format config (not runtime-updatable).
+        self._output_container = container
+        self._output_encoding = encoding
+        self._output_sample_rate = 0  # Set in start()
+
         self._session = aiohttp_session
 
     def can_generate_metrics(self) -> bool:
@@ -630,7 +615,7 @@ class AsyncAIHttpTTSService(TTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.output_sample_rate = self.sample_rate
+        self._output_sample_rate = self.sample_rate
 
     @traced_tts
     async def run_tts(self, text: str, context_id: str) -> AsyncGenerator[Frame, None]:
@@ -653,9 +638,9 @@ class AsyncAIHttpTTSService(TTSService):
                 "transcript": text,
                 "voice": voice_config,
                 "output_format": {
-                    "container": self._settings.output_container,
-                    "encoding": self._settings.output_encoding,
-                    "sample_rate": self._settings.output_sample_rate,
+                    "container": self._output_container,
+                    "encoding": self._output_encoding,
+                    "sample_rate": self._output_sample_rate,
                 },
                 "language": self._settings.language,
             }
diff --git a/src/pipecat/services/azure/tts.py b/src/pipecat/services/azure/tts.py
index f4aa85dbc..112459c5a 100644
--- a/src/pipecat/services/azure/tts.py
+++ b/src/pipecat/services/azure/tts.py
@@ -73,7 +73,6 @@ class AzureTTSSettings(TTSSettings):
 
     Parameters:
         emphasis: Emphasis level for speech ("strong", "moderate", "reduced").
-        language: Language for synthesis. Defaults to English (US).
         pitch: Voice pitch adjustment (e.g., "+10%", "-5Hz", "high").
         rate: Speech rate adjustment (e.g., "1.0", "1.25", "slow", "fast").
         role: Voice role for expression (e.g., "YoungAdultFemale").
@@ -83,7 +82,6 @@ class AzureTTSSettings(TTSSettings):
     """
 
     emphasis: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    language: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     pitch: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     rate: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     role: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
@@ -143,7 +141,6 @@ class AzureBaseTTSService:
         *,
         api_key: str,
         region: str,
-        voice: str = "en-US-SaraNeural",
     ):
         """Initialize Azure-specific configuration.
 
@@ -152,7 +149,6 @@ class AzureBaseTTSService:
         Args:
             api_key: Azure Cognitive Services subscription key.
             region: Azure region identifier (e.g., "eastus", "westus2").
-            voice: Voice name to use for synthesis. Defaults to "en-US-SaraNeural".
         """
         self._api_key = api_key
         self._region = region
@@ -343,7 +339,7 @@ class AzureTTSService(TTSService, AzureBaseTTSService):
         )
 
         # Initialize Azure-specific functionality from mixin
-        self._init_azure_base(api_key=api_key, region=region, voice=default_settings.voice)
+        self._init_azure_base(api_key=api_key, region=region)
 
         self._speech_config = None
         self._speech_synthesizer = None
@@ -842,7 +838,7 @@ class AzureHttpTTSService(TTSService, AzureBaseTTSService):
         )
 
         # Initialize Azure-specific functionality from mixin
-        self._init_azure_base(api_key=api_key, region=region, voice=default_settings.voice)
+        self._init_azure_base(api_key=api_key, region=region)
 
         self._speech_config = None
         self._speech_synthesizer = None
diff --git a/src/pipecat/services/deepgram/sagemaker/tts.py b/src/pipecat/services/deepgram/sagemaker/tts.py
index 9457cc1db..0129abedb 100644
--- a/src/pipecat/services/deepgram/sagemaker/tts.py
+++ b/src/pipecat/services/deepgram/sagemaker/tts.py
@@ -14,7 +14,7 @@ streaming audio output.
 
 import asyncio
 import json
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Any, AsyncGenerator, Optional
 
 from loguru import logger
@@ -33,20 +33,16 @@ from pipecat.frames.frames import (
 )
 from pipecat.processors.frame_processor import FrameDirection
 from pipecat.services.aws.sagemaker.bidi_client import SageMakerBidiClient
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import TTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
 
 @dataclass
 class DeepgramSageMakerTTSSettings(TTSSettings):
-    """Settings for Deepgram SageMaker TTS service.
+    """Settings for Deepgram SageMaker TTS service."""
 
-    Parameters:
-        encoding: Audio encoding format (e.g. "linear16").
-    """
-
-    encoding: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class DeepgramSageMakerTTSService(TTSService):
@@ -107,10 +103,9 @@ class DeepgramSageMakerTTSService(TTSService):
         voice = voice or "aura-2-helena-en"
 
         default_settings = DeepgramSageMakerTTSSettings(
-            model=voice,
+            model=None,
             voice=voice,
             language=None,
-            encoding=encoding,
         )
         if settings is not None:
             default_settings.apply_update(settings)
@@ -126,6 +121,7 @@ class DeepgramSageMakerTTSService(TTSService):
 
         self._endpoint_name = endpoint_name
         self._region = region
+        self._encoding = encoding
 
         self._client: Optional[SageMakerBidiClient] = None
         self._response_task: Optional[asyncio.Task] = None
diff --git a/src/pipecat/services/deepgram/tts.py b/src/pipecat/services/deepgram/tts.py
index b54cd23dc..95db998e2 100644
--- a/src/pipecat/services/deepgram/tts.py
+++ b/src/pipecat/services/deepgram/tts.py
@@ -11,7 +11,7 @@ for generating speech from text using various voice models.
 """
 
 import json
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Any, AsyncGenerator, Optional
 
 import aiohttp
@@ -30,7 +30,7 @@ from pipecat.frames.frames import (
     TTSStoppedFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import TTSService, WebsocketTTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -47,13 +47,9 @@ except ModuleNotFoundError as e:
 
 @dataclass
 class DeepgramTTSSettings(TTSSettings):
-    """Settings for Deepgram TTS service.
+    """Settings for Deepgram TTS service."""
 
-    Parameters:
-        encoding: Audio encoding format (linear16, mulaw, alaw).
-    """
-
-    encoding: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class DeepgramTTSService(WebsocketTTSService):
@@ -105,10 +101,9 @@ class DeepgramTTSService(WebsocketTTSService):
 
         # 1. Initialize default_settings with hardcoded defaults
         default_settings = DeepgramTTSSettings(
-            model="aura-2-helena-en",
+            model=None,
             voice="aura-2-helena-en",
             language=None,
-            encoding=encoding,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -132,6 +127,7 @@ class DeepgramTTSService(WebsocketTTSService):
 
         self._api_key = api_key
         self._base_url = base_url
+        self._encoding = encoding
 
         self._receive_task = None
         self._context_id: Optional[str] = None
@@ -236,7 +232,7 @@ class DeepgramTTSService(WebsocketTTSService):
             # Build WebSocket URL with query parameters
             params = []
             params.append(f"model={self._settings.voice}")
-            params.append(f"encoding={self._settings.encoding}")
+            params.append(f"encoding={self._encoding}")
             params.append(f"sample_rate={self.sample_rate}")
 
             url = f"{self._base_url}/v1/speak?{'&'.join(params)}"
@@ -422,10 +418,9 @@ class DeepgramHttpTTSService(TTSService):
         """
         # 1. Initialize default_settings with hardcoded defaults
         default_settings = DeepgramTTSSettings(
-            model="aura-2-helena-en",
+            model=None,
             voice="aura-2-helena-en",
             language=None,
-            encoding=encoding,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -447,6 +442,7 @@ class DeepgramHttpTTSService(TTSService):
         self._api_key = api_key
         self._session = aiohttp_session
         self._base_url = base_url
+        self._encoding = encoding
 
     def can_generate_metrics(self) -> bool:
         """Check if the service can generate metrics.
@@ -476,7 +472,7 @@ class DeepgramHttpTTSService(TTSService):
 
         params = {
             "model": self._settings.voice,
-            "encoding": self._settings.encoding,
+            "encoding": self._encoding,
             "sample_rate": self.sample_rate,
             "container": "none",
         }
diff --git a/src/pipecat/services/elevenlabs/tts.py b/src/pipecat/services/elevenlabs/tts.py
index 2447427ab..c22455e7a 100644
--- a/src/pipecat/services/elevenlabs/tts.py
+++ b/src/pipecat/services/elevenlabs/tts.py
@@ -201,9 +201,6 @@ class ElevenLabsTTSSettings(TTSSettings):
         style: Style control for voice expression (0.0 to 1.0).
         use_speaker_boost: Whether to use speaker boost enhancement.
         speed: Voice speed control (0.7 to 1.2).
-        auto_mode: Whether to enable automatic mode optimization.
-        enable_ssml_parsing: Whether to parse SSML tags in text.
-        enable_logging: Whether to enable ElevenLabs logging.
         apply_text_normalization: Text normalization mode ("auto", "on", "off").
     """
 
@@ -212,9 +209,6 @@ class ElevenLabsTTSSettings(TTSSettings):
     style: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     use_speaker_boost: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speed: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    auto_mode: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    enable_ssml_parsing: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    enable_logging: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     apply_text_normalization: Literal["auto", "on", "off"] | None | _NotGiven = field(
         default_factory=lambda: NOT_GIVEN
     )
@@ -228,8 +222,6 @@ class ElevenLabsTTSSettings(TTSSettings):
         {"stability", "similarity_boost", "style", "use_speaker_boost", "speed"}
     )
 
-    _aliases: ClassVar[Dict[str, str]] = {"voice_id": "voice"}
-
 
 @dataclass
 class ElevenLabsHttpTTSSettings(TTSSettings):
@@ -255,8 +247,6 @@ class ElevenLabsHttpTTSSettings(TTSSettings):
         default_factory=lambda: NOT_GIVEN
     )
 
-    _aliases: ClassVar[Dict[str, str]] = {"voice_id": "voice"}
-
 
 def calculate_word_times(
     alignment_info: Mapping[str, Any],
@@ -430,6 +420,11 @@ class ElevenLabsTTSService(AudioContextTTSService):
             model="eleven_turbo_v2_5",
         )
 
+        # Track init-only URL params through the override chain
+        _auto_mode = True
+        _enable_ssml_parsing = None
+        _enable_logging = None
+
         # 2. Apply direct init arg overrides (deprecated)
         if voice_id is not None:
             _warn_deprecated_param("voice_id", ElevenLabsTTSSettings, "voice")
@@ -456,11 +451,11 @@ class ElevenLabsTTSService(AudioContextTTSService):
                 if params.speed is not None:
                     default_settings.speed = params.speed
                 if params.auto_mode is not None:
-                    default_settings.auto_mode = str(params.auto_mode).lower()
+                    _auto_mode = str(params.auto_mode).lower()
                 if params.enable_ssml_parsing is not None:
-                    default_settings.enable_ssml_parsing = params.enable_ssml_parsing
+                    _enable_ssml_parsing = params.enable_ssml_parsing
                 if params.enable_logging is not None:
-                    default_settings.enable_logging = params.enable_logging
+                    _enable_logging = params.enable_logging
                 if params.apply_text_normalization is not None:
                     default_settings.apply_text_normalization = params.apply_text_normalization
                 if _pronunciation_dictionary_locators is None:
@@ -485,6 +480,11 @@ class ElevenLabsTTSService(AudioContextTTSService):
         self._api_key = api_key
         self._url = url
 
+        # Init-only WebSocket URL params (not runtime-updatable).
+        self._auto_mode = _auto_mode
+        self._enable_ssml_parsing = _enable_ssml_parsing
+        self._enable_logging = _enable_logging
+
         self._output_format = ""  # initialized in start()
         self._voice_settings = self._set_voice_settings()
         self._pronunciation_dictionary_locators = _pronunciation_dictionary_locators
@@ -518,20 +518,7 @@ class ElevenLabsTTSService(AudioContextTTSService):
         return language_to_elevenlabs_language(language)
 
     def _set_voice_settings(self):
-        ts = self._settings
-        voice_setting_keys = [
-            "stability",
-            "similarity_boost",
-            "style",
-            "use_speaker_boost",
-            "speed",
-        ]
-        voice_settings = {}
-        for key in voice_setting_keys:
-            val = getattr(ts, key, None)
-            if val is not None:
-                voice_settings[key] = val
-        return voice_settings or None
+        return build_elevenlabs_voice_settings(self._settings)
 
     async def _update_settings(self, delta: TTSSettings) -> dict[str, Any]:
         """Apply a settings delta, reconnecting as needed.
@@ -670,13 +657,13 @@ class ElevenLabsTTSService(AudioContextTTSService):
             voice_id = self._settings.voice
             model = self._settings.model
             output_format = self._output_format
-            url = f"{self._url}/v1/text-to-speech/{voice_id}/multi-stream-input?model_id={model}&output_format={output_format}&auto_mode={self._settings.auto_mode}"
+            url = f"{self._url}/v1/text-to-speech/{voice_id}/multi-stream-input?model_id={model}&output_format={output_format}&auto_mode={self._auto_mode}"
 
-            if self._settings.enable_ssml_parsing:
-                url += f"&enable_ssml_parsing={self._settings.enable_ssml_parsing}"
+            if self._enable_ssml_parsing:
+                url += f"&enable_ssml_parsing={self._enable_ssml_parsing}"
 
-            if self._settings.enable_logging:
-                url += f"&enable_logging={self._settings.enable_logging}"
+            if self._enable_logging:
+                url += f"&enable_logging={self._enable_logging}"
 
             if self._settings.apply_text_normalization is not None:
                 url += f"&apply_text_normalization={self._settings.apply_text_normalization}"
diff --git a/src/pipecat/services/fish/tts.py b/src/pipecat/services/fish/tts.py
index af02b4e99..78b021c51 100644
--- a/src/pipecat/services/fish/tts.py
+++ b/src/pipecat/services/fish/tts.py
@@ -52,25 +52,19 @@ class FishAudioTTSSettings(TTSSettings):
     """Settings for Fish Audio TTS service.
 
     Parameters:
-        fish_sample_rate: Audio sample rate sent to the API.
         latency: Latency mode ("normal" or "balanced"). Defaults to "normal".
-        format: Audio output format.
         normalize: Whether to normalize audio output. Defaults to True.
         prosody_speed: Speech speed multiplier (0.5-2.0). Defaults to 1.0.
         prosody_volume: Volume adjustment in dB. Defaults to 0.
         reference_id: Reference ID of the voice model.
     """
 
-    fish_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     latency: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    format: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     normalize: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     prosody_speed: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     prosody_volume: int | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     reference_id: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
-    _aliases: ClassVar[Dict[str, str]] = {"voice_id": "voice", "sample_rate": "fish_sample_rate"}
-
     @classmethod
     def from_mapping(cls, settings: Mapping[str, Any]) -> Self:
         """Construct settings from a plain dict, destructuring legacy nested ``prosody``."""
@@ -179,9 +173,7 @@ class FishAudioTTSService(InterruptibleTTSService):
         default_settings = FishAudioTTSSettings(
             model="s1",
             voice=None,
-            fish_sample_rate=0,
             latency="normal",
-            format=output_format,
             normalize=True,
             prosody_speed=1.0,
             prosody_volume=0,
@@ -228,6 +220,10 @@ class FishAudioTTSService(InterruptibleTTSService):
         self._receive_task = None
         self._request_id = None
 
+        # Init-only audio format config (not runtime-updatable).
+        self._fish_sample_rate = 0  # Set in start()
+        self._output_format = output_format
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -262,7 +258,7 @@ class FishAudioTTSService(InterruptibleTTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.fish_sample_rate = self.sample_rate
+        self._fish_sample_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -312,9 +308,9 @@ class FishAudioTTSService(InterruptibleTTSService):
 
             # Send initial start message with ormsgpack
             request_settings = {
-                "sample_rate": self._settings.fish_sample_rate,
+                "sample_rate": self._fish_sample_rate,
                 "latency": self._settings.latency,
-                "format": self._settings.format,
+                "format": self._output_format,
                 "normalize": self._settings.normalize,
                 "prosody": {
                     "speed": self._settings.prosody_speed,
diff --git a/src/pipecat/services/google/tts.py b/src/pipecat/services/google/tts.py
index 22ba47821..7cf2ee996 100644
--- a/src/pipecat/services/google/tts.py
+++ b/src/pipecat/services/google/tts.py
@@ -494,7 +494,6 @@ class GoogleHttpTTSSettings(TTSSettings):
             Range [0.25, 2.0].
         volume: Volume adjustment (e.g., "loud", "soft", "+6dB").
         emphasis: Emphasis level for the text.
-        language: Language for synthesis. Defaults to English.
         gender: Voice gender preference.
         google_style: Google-specific voice style.
     """
@@ -506,7 +505,6 @@ class GoogleHttpTTSSettings(TTSSettings):
     emphasis: Literal["strong", "moderate", "reduced", "none"] | None | _NotGiven = field(
         default_factory=lambda: NOT_GIVEN
     )
-    language: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     gender: Literal["male", "female", "neutral"] | None | _NotGiven = field(
         default_factory=lambda: NOT_GIVEN
     )
@@ -520,11 +518,9 @@ class GoogleStreamTTSSettings(TTSSettings):
     """Settings for Google streaming TTS service.
 
     Parameters:
-        language: Language for synthesis. Defaults to English.
         speaking_rate: The speaking rate, in the range [0.25, 2.0].
     """
 
-    language: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speaking_rate: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
 
@@ -533,13 +529,11 @@ class GeminiTTSSettings(TTSSettings):
     """Settings for Gemini TTS service.
 
     Parameters:
-        language: Language for synthesis. Defaults to English.
         prompt: Optional style instructions for how to synthesize the content.
         multi_speaker: Whether to enable multi-speaker support.
         speaker_configs: List of speaker configurations for multi-speaker mode.
     """
 
-    language: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     prompt: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     multi_speaker: bool | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speaker_configs: list[dict[str, Any]] | None | _NotGiven = field(
diff --git a/src/pipecat/services/gradium/tts.py b/src/pipecat/services/gradium/tts.py
index 3befb4505..2ade14367 100644
--- a/src/pipecat/services/gradium/tts.py
+++ b/src/pipecat/services/gradium/tts.py
@@ -6,7 +6,7 @@
 
 import base64
 import json
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Any, AsyncGenerator, Optional
 
 from loguru import logger
@@ -22,7 +22,7 @@ from pipecat.frames.frames import (
     TTSStartedFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import AudioContextTTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -40,13 +40,9 @@ SAMPLE_RATE = 48000
 
 @dataclass
 class GradiumTTSSettings(TTSSettings):
-    """Settings for the Gradium TTS service.
+    """Settings for the Gradium TTS service."""
 
-    Parameters:
-        output_format: Audio output format.
-    """
-
-    output_format: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class GradiumTTSService(AudioContextTTSService):
@@ -108,7 +104,6 @@ class GradiumTTSService(AudioContextTTSService):
             model="default",
             voice="YTpq7expH9539ERJ",
             language=None,
-            output_format="pcm",
         )
 
         # 2. Apply direct init arg overrides (deprecated)
diff --git a/src/pipecat/services/groq/tts.py b/src/pipecat/services/groq/tts.py
index 6f9a610e2..18b623fc8 100644
--- a/src/pipecat/services/groq/tts.py
+++ b/src/pipecat/services/groq/tts.py
@@ -9,7 +9,7 @@
 import io
 import wave
 from dataclasses import dataclass, field
-from typing import AsyncGenerator, ClassVar, Dict, Optional
+from typing import AsyncGenerator, Optional
 
 from loguru import logger
 from pydantic import BaseModel
@@ -39,16 +39,10 @@ class GroqTTSSettings(TTSSettings):
     """Settings for the Groq TTS service.
 
     Parameters:
-        output_format: Audio output format.
         speed: Speech speed multiplier. Defaults to 1.0.
-        groq_sample_rate: Audio sample rate.
     """
 
-    output_format: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speed: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    groq_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-
-    _aliases: ClassVar[Dict[str, str]] = {"voice_id": "voice", "sample_rate": "groq_sample_rate"}
 
 
 class GroqTTSService(TTSService):
@@ -122,9 +116,7 @@ class GroqTTSService(TTSService):
             model="canopylabs/orpheus-v1-english",
             voice="autumn",
             language="en",
-            output_format=output_format,
             speed=1.0,
-            groq_sample_rate=sample_rate,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
diff --git a/src/pipecat/services/inworld/tts.py b/src/pipecat/services/inworld/tts.py
index f650ce620..a1421b2ab 100644
--- a/src/pipecat/services/inworld/tts.py
+++ b/src/pipecat/services/inworld/tts.py
@@ -71,8 +71,6 @@ class InworldTTSSettings(TTSSettings):
     """Settings for Inworld TTS services.
 
     Parameters:
-        audio_encoding: Audio encoding format (e.g. LINEAR16).
-        audio_sample_rate: Audio sample rate in Hz.
         speaking_rate: Speaking rate for speech synthesis.
         temperature: Temperature for speech synthesis.
         auto_mode: Whether to use auto mode. Recommended when texts are sent
@@ -84,8 +82,6 @@ class InworldTTSSettings(TTSSettings):
         timestamp_transport_strategy: Strategy for timestamp transport ("ASYNC" or "SYNC").
     """
 
-    audio_encoding: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    audio_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speaking_rate: float | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     temperature: float | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     auto_mode: bool | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
@@ -93,7 +89,6 @@ class InworldTTSSettings(TTSSettings):
     timestamp_transport_strategy: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
     _aliases: ClassVar[Dict[str, str]] = {
-        "voice_id": "voice",
         "voiceId": "voice",
         "modelId": "model",
         "applyTextNormalization": "apply_text_normalization",
@@ -107,8 +102,6 @@ class InworldTTSSettings(TTSSettings):
         flat = dict(settings)
         nested = flat.pop("audioConfig", None)
         if isinstance(nested, dict):
-            flat.setdefault("audio_encoding", nested.get("audioEncoding"))
-            flat.setdefault("audio_sample_rate", nested.get("sampleRateHertz"))
             flat.setdefault("speaking_rate", nested.get("speakingRate"))
         return super().from_mapping(flat)
 
@@ -184,8 +177,6 @@ class InworldHttpTTSService(TTSService):
             model="inworld-tts-1.5-max",
             voice="Ashley",
             language=None,
-            audio_encoding=encoding,
-            audio_sample_rate=0,
             speaking_rate=None,
             temperature=None,
             timestamp_transport_strategy="ASYNC",
@@ -239,6 +230,10 @@ class InworldHttpTTSService(TTSService):
 
         self._cumulative_time = 0.0
 
+        # Init-only audio format config (not runtime-updatable).
+        self._audio_encoding = encoding
+        self._audio_sample_rate = 0  # Set in start()
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -254,7 +249,7 @@ class InworldHttpTTSService(TTSService):
             frame: The start frame.
         """
         await super().start(frame)
-        self._settings.audio_sample_rate = self.sample_rate
+        self._audio_sample_rate = self.sample_rate
 
     async def stop(self, frame: EndFrame):
         """Stop the Inworld TTS service.
@@ -334,8 +329,8 @@ class InworldHttpTTSService(TTSService):
         logger.debug(f"{self}: Generating TTS [{text}] (streaming={self._streaming})")
 
         audio_config = {
-            "audioEncoding": self._settings.audio_encoding,
-            "sampleRateHertz": self._settings.audio_sample_rate,
+            "audioEncoding": self._audio_encoding,
+            "sampleRateHertz": self._audio_sample_rate,
         }
         if self._settings.speaking_rate is not None:
             audio_config["speakingRate"] = self._settings.speaking_rate
@@ -611,8 +606,6 @@ class InworldTTSService(AudioContextTTSService):
             model="inworld-tts-1.5-max",
             voice="Ashley",
             language=None,
-            audio_encoding=encoding,
-            audio_sample_rate=0,
             speaking_rate=None,
             temperature=None,
             apply_text_normalization=None,
@@ -686,6 +679,10 @@ class InworldTTSService(AudioContextTTSService):
         # Track the end time of the last word in the current generation
         self._generation_end_time = 0.0
 
+        # Init-only audio format config (not runtime-updatable).
+        self._audio_encoding = encoding
+        self._audio_sample_rate = 0  # Set in start()
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -701,7 +698,7 @@ class InworldTTSService(AudioContextTTSService):
             frame: The start frame.
         """
         await super().start(frame)
-        self._settings.audio_sample_rate = self.sample_rate
+        self._audio_sample_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -1051,8 +1048,8 @@ class InworldTTSService(AudioContextTTSService):
             context_id: The context ID.
         """
         audio_config = {
-            "audioEncoding": self._settings.audio_encoding,
-            "sampleRateHertz": self._settings.audio_sample_rate,
+            "audioEncoding": self._audio_encoding,
+            "sampleRateHertz": self._audio_sample_rate,
         }
         if self._settings.speaking_rate is not None:
             audio_config["speakingRate"] = self._settings.speaking_rate
diff --git a/src/pipecat/services/kokoro/tts.py b/src/pipecat/services/kokoro/tts.py
index 60dfb65ce..0646923f3 100644
--- a/src/pipecat/services/kokoro/tts.py
+++ b/src/pipecat/services/kokoro/tts.py
@@ -7,7 +7,7 @@
 """Kokoro TTS service implementation using kokoro-onnx."""
 
 import os
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from pathlib import Path
 from typing import AsyncGenerator, Optional
 
@@ -23,7 +23,7 @@ from pipecat.frames.frames import (
     TTSStartedFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -91,13 +91,9 @@ def language_to_kokoro_language(language: Language) -> str:
 
 @dataclass
 class KokoroTTSSettings(TTSSettings):
-    """Settings for the Kokoro TTS service.
+    """Settings for the Kokoro TTS service."""
 
-    Parameters:
-        lang_code: Kokoro language code for synthesis.
-    """
-
-    lang_code: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class KokoroTTSService(TTSService):
@@ -156,7 +152,6 @@ class KokoroTTSService(TTSService):
             model=None,
             voice=None,
             language=language_to_kokoro_language(Language.EN),
-            lang_code=language_to_kokoro_language(Language.EN),
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -168,9 +163,7 @@ class KokoroTTSService(TTSService):
         if params is not None:
             _warn_deprecated_param("params", KokoroTTSSettings)
             if not settings:
-                lang_code = language_to_kokoro_language(params.language)
-                default_settings.language = lang_code
-                default_settings.lang_code = lang_code
+                default_settings.language = language_to_kokoro_language(params.language)
 
         # 4. Apply settings delta (canonical API, always wins)
         if settings is not None:
@@ -181,8 +174,6 @@ class KokoroTTSService(TTSService):
             **kwargs,
         )
 
-        self._lang_code = default_settings.lang_code
-
         model_file = Path(model_path) if model_path else KOKORO_CACHE_DIR / "kokoro-v1.0.onnx"
         voices = Path(voices_path) if voices_path else KOKORO_CACHE_DIR / "voices-v1.0.bin"
 
@@ -196,6 +187,17 @@ class KokoroTTSService(TTSService):
         """Indicate that this service supports TTFB and usage metrics."""
         return True
 
+    def language_to_service_language(self, language: Language) -> str:
+        """Convert a Language enum to kokoro-onnx language format.
+
+        Args:
+            language: The language to convert.
+
+        Returns:
+            The kokoro-onnx language code.
+        """
+        return language_to_kokoro_language(language)
+
     @traced_tts
     async def run_tts(self, text: str, context_id: str) -> AsyncGenerator[Frame, None]:
         """Synthesize speech from text using kokoro-onnx.
@@ -215,7 +217,7 @@ class KokoroTTSService(TTSService):
             yield TTSStartedFrame(context_id=context_id)
 
             stream = self._kokoro.create_stream(
-                text, voice=self._settings.voice, lang=self._lang_code, speed=1.0
+                text, voice=self._settings.voice, lang=self._settings.language, speed=1.0
             )
 
             async for samples, sample_rate in stream:
diff --git a/src/pipecat/services/lmnt/tts.py b/src/pipecat/services/lmnt/tts.py
index 58468bc00..9ee6d8d60 100644
--- a/src/pipecat/services/lmnt/tts.py
+++ b/src/pipecat/services/lmnt/tts.py
@@ -7,7 +7,7 @@
 """LMNT text-to-speech service implementation."""
 
 import json
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Any, AsyncGenerator, Optional
 
 from loguru import logger
@@ -17,14 +17,13 @@ from pipecat.frames.frames import (
     EndFrame,
     ErrorFrame,
     Frame,
-    InterruptionFrame,
     StartFrame,
     TTSAudioRawFrame,
     TTSStartedFrame,
     TTSStoppedFrame,
 )
 from pipecat.processors.frame_processor import FrameDirection
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import InterruptibleTTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -75,13 +74,9 @@ def language_to_lmnt_language(language: Language) -> Optional[str]:
 
 @dataclass
 class LmntTTSSettings(TTSSettings):
-    """Settings for LMNT TTS service.
+    """Settings for LMNT TTS service."""
 
-    Parameters:
-        format: Audio output format. Defaults to "raw".
-    """
-
-    format: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class LmntTTSService(InterruptibleTTSService):
@@ -130,7 +125,6 @@ class LmntTTSService(InterruptibleTTSService):
             model="blizzard",
             voice=None,
             language=self.language_to_service_language(language),
-            format="raw",
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -156,6 +150,7 @@ class LmntTTSService(InterruptibleTTSService):
         )
 
         self._api_key = api_key
+        self._output_format = "raw"
         self._receive_task = None
         self._context_id: Optional[str] = None
 
@@ -262,7 +257,7 @@ class LmntTTSService(InterruptibleTTSService):
             init_msg = {
                 "X-API-Key": self._api_key,
                 "voice": self._settings.voice,
-                "format": self._settings.format,
+                "format": self._output_format,
                 "sample_rate": self.sample_rate,
                 "language": self._settings.language,
                 "model": self._settings.model,
diff --git a/src/pipecat/services/minimax/tts.py b/src/pipecat/services/minimax/tts.py
index 2be25aef9..efe8c1fd9 100644
--- a/src/pipecat/services/minimax/tts.py
+++ b/src/pipecat/services/minimax/tts.py
@@ -12,7 +12,7 @@ for streaming text-to-speech synthesis.
 
 import json
 from dataclasses import dataclass, field
-from typing import Any, AsyncGenerator, ClassVar, Dict, Mapping, Optional, Self
+from typing import Any, AsyncGenerator, Mapping, Optional, Self
 
 import aiohttp
 from loguru import logger
@@ -100,10 +100,6 @@ class MiniMaxTTSSettings(TTSSettings):
             "disgusted", "surprised", "calm", "fluent").
         text_normalization: Enable text normalization (Chinese/English).
         latex_read: Enable LaTeX formula reading.
-        audio_bitrate: Audio bitrate in bps.
-        audio_format: Audio output format.
-        audio_channel: Number of audio channels.
-        audio_sample_rate: Audio sample rate in Hz.
         language_boost: Language boost string for multilingual support.
     """
 
@@ -114,14 +110,8 @@ class MiniMaxTTSSettings(TTSSettings):
     emotion: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     text_normalization: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     latex_read: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    audio_bitrate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    audio_format: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    audio_channel: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    audio_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     language_boost: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
-    _aliases: ClassVar[Dict[str, str]] = {"voice_id": "voice"}
-
     @classmethod
     def from_mapping(cls, settings: Mapping[str, Any]) -> Self:
         """Construct settings from a plain dict, destructuring legacy nested dicts.
@@ -140,13 +130,6 @@ class MiniMaxTTSSettings(TTSSettings):
             flat.setdefault("text_normalization", voice.get("text_normalization"))
             flat.setdefault("latex_read", voice.get("latex_read"))
 
-        audio = flat.pop("audio_setting", None)
-        if isinstance(audio, dict):
-            flat.setdefault("audio_bitrate", audio.get("bitrate"))
-            flat.setdefault("audio_format", audio.get("format"))
-            flat.setdefault("audio_channel", audio.get("channel"))
-            flat.setdefault("audio_sample_rate", audio.get("sample_rate"))
-
         return super().from_mapping(flat)
 
 
@@ -258,10 +241,6 @@ class MiniMaxHttpTTSService(TTSService):
             emotion=None,
             text_normalization=None,
             latex_read=None,
-            audio_bitrate=128000,
-            audio_format="pcm",
-            audio_channel=1,
-            audio_sample_rate=0,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -335,6 +314,12 @@ class MiniMaxHttpTTSService(TTSService):
         self._base_url = f"{base_url}?GroupId={group_id}"
         self._session = aiohttp_session
 
+        # Init-only audio format config
+        self._audio_bitrate = 128000
+        self._audio_format = "pcm"
+        self._audio_channel = 1
+        self._audio_sample_rate = 0  # Set in start()
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -361,7 +346,7 @@ class MiniMaxHttpTTSService(TTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.audio_sample_rate = self.sample_rate
+        self._audio_sample_rate = self.sample_rate
         logger.debug(f"MiniMax TTS initialized with sample_rate: {self.sample_rate}")
 
     @traced_tts
@@ -399,10 +384,10 @@ class MiniMaxHttpTTSService(TTSService):
 
         # Build audio_setting dict for API
         audio_setting = {
-            "bitrate": self._settings.audio_bitrate,
-            "format": self._settings.audio_format,
-            "channel": self._settings.audio_channel,
-            "sample_rate": self._settings.audio_sample_rate,
+            "bitrate": self._audio_bitrate,
+            "format": self._audio_format,
+            "channel": self._audio_channel,
+            "sample_rate": self._audio_sample_rate,
         }
 
         # Create payload from settings
diff --git a/src/pipecat/services/neuphonic/tts.py b/src/pipecat/services/neuphonic/tts.py
index f6cc6bf68..da14ec2e5 100644
--- a/src/pipecat/services/neuphonic/tts.py
+++ b/src/pipecat/services/neuphonic/tts.py
@@ -80,13 +80,9 @@ class NeuphonicTTSSettings(TTSSettings):
 
     Parameters:
         speed: Speech speed multiplier. Defaults to 1.0.
-        encoding: Audio encoding format.
-        sampling_rate: Audio sample rate.
     """
 
     speed: float | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    encoding: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    sampling_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
 
 class NeuphonicTTSService(InterruptibleTTSService):
@@ -160,8 +156,6 @@ class NeuphonicTTSService(InterruptibleTTSService):
             voice=None,
             language=self.language_to_service_language(Language.EN),
             speed=1.0,
-            encoding=encoding,
-            sampling_rate=sample_rate,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -200,6 +194,8 @@ class NeuphonicTTSService(InterruptibleTTSService):
         self._receive_task = None
         self._keepalive_task = None
         self._context_id: Optional[str] = None
+        self._encoding = encoding
+        self._sampling_rate = sample_rate
 
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
@@ -327,8 +323,8 @@ class NeuphonicTTSService(InterruptibleTTSService):
             tts_config = {
                 "lang_code": self._settings.language,
                 "speed": self._settings.speed,
-                "encoding": self._settings.encoding,
-                "sampling_rate": self._settings.sampling_rate,
+                "encoding": self._encoding,
+                "sampling_rate": self._sampling_rate,
                 "voice_id": self._settings.voice,
             }
 
@@ -503,8 +499,6 @@ class NeuphonicHttpTTSService(TTSService):
             voice=None,
             language=self.language_to_service_language(Language.EN) or "en",
             speed=1.0,
-            encoding=encoding,
-            sampling_rate=sample_rate,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -536,6 +530,7 @@ class NeuphonicHttpTTSService(TTSService):
         self._api_key = api_key
         self._session = aiohttp_session
         self._base_url = url.rstrip("/")
+        self._encoding = encoding
 
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
@@ -629,7 +624,7 @@ class NeuphonicHttpTTSService(TTSService):
         payload = {
             "text": text,
             "lang_code": self._settings.language,
-            "encoding": self._settings.encoding,
+            "encoding": self._encoding,
             "sampling_rate": self.sample_rate,
             "speed": self._settings.speed,
         }
diff --git a/src/pipecat/services/resembleai/tts.py b/src/pipecat/services/resembleai/tts.py
index f0a8a988a..e1c1cf68a 100644
--- a/src/pipecat/services/resembleai/tts.py
+++ b/src/pipecat/services/resembleai/tts.py
@@ -8,8 +8,8 @@
 
 import base64
 import json
-from dataclasses import dataclass, field
-from typing import AsyncGenerator, ClassVar, Dict, Optional
+from dataclasses import dataclass
+from typing import AsyncGenerator, Optional
 
 from loguru import logger
 
@@ -23,7 +23,7 @@ from pipecat.frames.frames import (
     TTSStartedFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import AudioContextTTSService
 from pipecat.utils.tracing.service_decorators import traced_tts
 
@@ -38,22 +38,9 @@ except ModuleNotFoundError as e:
 
 @dataclass
 class ResembleAITTSSettings(TTSSettings):
-    """Settings for Resemble AI TTS service.
+    """Settings for Resemble AI TTS service."""
 
-    Parameters:
-        precision: PCM bit depth (PCM_32, PCM_24, PCM_16, or MULAW).
-        output_format: Audio format (wav or mp3).
-        resemble_sample_rate: Audio sample rate sent to the API.
-    """
-
-    precision: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    output_format: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    resemble_sample_rate: int | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-
-    _aliases: ClassVar[Dict[str, str]] = {
-        "voice_id": "voice",
-        "sample_rate": "resemble_sample_rate",
-    }
+    pass
 
 
 class ResembleAITTSService(AudioContextTTSService):
@@ -100,21 +87,12 @@ class ResembleAITTSService(AudioContextTTSService):
             model=None,
             voice=None,
             language=None,
-            precision="PCM_16",
-            output_format="wav",
-            resemble_sample_rate=22050,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
         if voice_id is not None:
             _warn_deprecated_param("voice_id", ResembleAITTSSettings, "voice")
             default_settings.voice = voice_id
-        if precision is not None:
-            default_settings.precision = precision
-        if output_format is not None:
-            default_settings.output_format = output_format
-        if sample_rate is not None:
-            default_settings.resemble_sample_rate = sample_rate
 
         # 3. No params for this service
 
@@ -133,6 +111,11 @@ class ResembleAITTSService(AudioContextTTSService):
         self._api_key = api_key
         self._url = url
 
+        # Init-only audio format config (not runtime-updatable).
+        self._precision = precision or "PCM_16"
+        self._output_format = output_format or "wav"
+        self._resemble_sample_rate = 0  # Set in start()
+
         self._websocket = None
         self._request_id_counter = 0
         self._receive_task = None
@@ -174,9 +157,9 @@ class ResembleAITTSService(AudioContextTTSService):
             "data": text,
             "binary_response": False,  # Use JSON frames to get timestamps
             "request_id": self._request_id_counter,  # ResembleAI only accepts number
-            "output_format": self._settings.output_format,
-            "sample_rate": self._settings.resemble_sample_rate,
-            "precision": self._settings.precision,
+            "output_format": self._output_format,
+            "sample_rate": self._resemble_sample_rate,
+            "precision": self._precision,
             "no_audio_header": True,
         }
 
@@ -190,7 +173,7 @@ class ResembleAITTSService(AudioContextTTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.resemble_sample_rate = self.sample_rate
+        self._resemble_sample_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
diff --git a/src/pipecat/services/rime/tts.py b/src/pipecat/services/rime/tts.py
index 613d58f3a..04ebcd5fc 100644
--- a/src/pipecat/services/rime/tts.py
+++ b/src/pipecat/services/rime/tts.py
@@ -76,8 +76,6 @@ class RimeTTSSettings(TTSSettings):
     """Settings for Rime WS JSON and HTTP TTS services.
 
     Parameters:
-        audioFormat: Audio output format.
-        samplingRate: Audio sample rate.
         segment: Text segmentation mode ("immediate", "bySentence", "never").
         speedAlpha: Speech speed multiplier (mistv2 only).
         reduceLatency: Whether to reduce latency at potential quality cost (mistv2 only).
@@ -91,8 +89,6 @@ class RimeTTSSettings(TTSSettings):
         top_p: Cumulative probability threshold (arcana only, 0.0-1.0).
     """
 
-    audioFormat: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    samplingRate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     segment: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     speedAlpha: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     reduceLatency: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
@@ -113,16 +109,12 @@ class RimeNonJsonTTSSettings(TTSSettings):
     """Settings for Rime non-JSON WS TTS service.
 
     Parameters:
-        audioFormat: Audio output format.
-        samplingRate: Audio sample rate.
         segment: Text segmentation mode ("immediate", "bySentence", "never").
         repetition_penalty: Token repetition penalty (1.0-2.0).
         temperature: Sampling temperature (0.0-1.0).
         top_p: Cumulative probability threshold (0.0-1.0).
     """
 
-    audioFormat: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    samplingRate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     segment: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     repetition_penalty: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     temperature: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
@@ -230,8 +222,6 @@ class RimeTTSService(AudioContextTTSService):
         default_settings = RimeTTSSettings(
             model="arcana",
             voice=None,
-            audioFormat="pcm",
-            samplingRate=0,  # updated in start()
             language=None,
             segment=None,
             inlineSpeedAlpha=None,
@@ -293,6 +283,10 @@ class RimeTTSService(AudioContextTTSService):
             **kwargs,
         )
 
+        # Init-only audio format fields (not runtime-updatable)
+        self._audio_format = "pcm"
+        self._sampling_rate = 0  # updated in start()
+
         if not text_aggregator:
             # Always skip tags added for spelled-out text
             # Note: This is primarily to support backwards compatibility.
@@ -342,8 +336,8 @@ class RimeTTSService(AudioContextTTSService):
         params: dict[str, Any] = {
             "speaker": self._settings.voice,
             "modelId": self._settings.model,
-            "audioFormat": self._settings.audioFormat,
-            "samplingRate": self._settings.samplingRate,
+            "audioFormat": self._audio_format,
+            "samplingRate": self._sampling_rate,
         }
         if self._settings.language is not None:
             params["lang"] = self._settings.language
@@ -437,7 +431,7 @@ class RimeTTSService(AudioContextTTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.samplingRate = self.sample_rate
+        self._sampling_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -737,8 +731,6 @@ class RimeHttpTTSService(TTSService):
             model="mistv2",
             voice=None,
             language="eng",
-            audioFormat="pcm",
-            samplingRate=0,
             segment=None,
             speedAlpha=None,
             reduceLatency=None,
@@ -789,6 +781,9 @@ class RimeHttpTTSService(TTSService):
         self._session = aiohttp_session
         self._base_url = "https://users.rime.ai/v1/rime-tts"
 
+        # Init-only audio format fields (not runtime-updatable)
+        self._audio_format = "pcm"
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -974,8 +969,6 @@ class RimeNonJsonTTSService(InterruptibleTTSService):
         default_settings = RimeNonJsonTTSSettings(
             voice=None,
             model="arcana",
-            audioFormat=audio_format,
-            samplingRate=sample_rate,
             language=None,
             segment=None,
             repetition_penalty=None,
@@ -1017,6 +1010,11 @@ class RimeNonJsonTTSService(InterruptibleTTSService):
             settings=default_settings,
             **kwargs,
         )
+
+        # Init-only audio format fields (not runtime-updatable)
+        self._audio_format = audio_format
+        self._sampling_rate = sample_rate
+
         self._api_key = api_key
         self._url = url
         # Add any extra parameters for future compatibility
@@ -1053,7 +1051,7 @@ class RimeNonJsonTTSService(InterruptibleTTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.samplingRate = self.sample_rate
+        self._sampling_rate = self.sample_rate
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -1101,8 +1099,8 @@ class RimeNonJsonTTSService(InterruptibleTTSService):
             settings_dict = {
                 "speaker": self._settings.voice,
                 "modelId": self._settings.model,
-                "audioFormat": self._settings.audioFormat,
-                "samplingRate": self._settings.samplingRate,
+                "audioFormat": self._audio_format,
+                "samplingRate": self._sampling_rate,
             }
             if self._settings.language is not None:
                 settings_dict["lang"] = self._settings.language
diff --git a/src/pipecat/services/sarvam/tts.py b/src/pipecat/services/sarvam/tts.py
index cf00dd8c7..659a58bdd 100644
--- a/src/pipecat/services/sarvam/tts.py
+++ b/src/pipecat/services/sarvam/tts.py
@@ -250,7 +250,6 @@ class SarvamHttpTTSSettings(TTSSettings):
     """Settings for Sarvam HTTP TTS service.
 
     Parameters:
-        language: Sarvam language code.
         enable_preprocessing: Whether to enable text preprocessing. Defaults to False.
             **Note:** Always enabled for bulbul:v3-beta (cannot be disabled).
         pace: Speech pace multiplier. Defaults to 1.0.
@@ -263,16 +262,13 @@ class SarvamHttpTTSSettings(TTSSettings):
         temperature: Controls output randomness for bulbul:v3-beta (0.01 to 1.0).
             Lower values = more deterministic, higher = more random. Defaults to 0.6.
             **Note:** Only supported for bulbul:v3-beta. Ignored for v2.
-        sample_rate: Audio sample rate.
     """
 
-    language: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     enable_preprocessing: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     pace: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     pitch: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     loudness: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     temperature: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    sarvam_sample_rate: int | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
 
 
 @dataclass
@@ -280,19 +276,12 @@ class SarvamTTSSettings(TTSSettings):
     """Settings for Sarvam WebSocket TTS service.
 
     Parameters:
-        language: Sarvam language code (e.g. ``"hi-IN"``).  Uses the standard
-            ``TTSSettings.language`` field.
-        speech_sample_rate: Audio sample rate as string.
         enable_preprocessing: Enable text preprocessing. Defaults to False.
             **Note:** Always enabled for bulbul:v3-beta.
         min_buffer_size: Minimum characters to buffer before generating audio.
             Lower values reduce latency but may affect quality. Defaults to 50.
         max_chunk_length: Maximum characters processed in a single chunk.
             Controls memory usage and processing efficiency. Defaults to 150.
-        output_audio_codec: Audio codec format. Options: linear16, mulaw, alaw,
-            opus, flac, aac, wav, mp3. Defaults to "linear16".
-        output_audio_bitrate: Audio bitrate (32k, 64k, 96k, 128k, 192k).
-            Defaults to "128k".
         pace: Speech pace multiplier. Defaults to 1.0.
             - bulbul:v2: Range 0.3 to 3.0
             - bulbul:v3-beta: Range 0.5 to 2.0
@@ -307,12 +296,9 @@ class SarvamTTSSettings(TTSSettings):
 
     _aliases: ClassVar[Dict[str, str]] = {"target_language_code": "language"}
 
-    speech_sample_rate: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     enable_preprocessing: bool | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     min_buffer_size: int | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     max_chunk_length: int | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    output_audio_codec: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
-    output_audio_bitrate: str | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     pace: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     pitch: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
     loudness: float | None | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
@@ -587,7 +573,6 @@ class SarvamHttpTTSService(TTSService):
             frame: The start frame containing initialization parameters.
         """
         await super().start(frame)
-        self._settings.sarvam_sample_rate = self.sample_rate
 
     @traced_tts
     async def run_tts(self, text: str, context_id: str) -> AsyncGenerator[Frame, None]:
@@ -881,12 +866,9 @@ class SarvamTTSService(InterruptibleTTSService):
             model="bulbul:v2",
             voice="anushka",
             language="en-IN",
-            speech_sample_rate="22050",
             enable_preprocessing=False,
             min_buffer_size=50,
             max_chunk_length=150,
-            output_audio_codec="linear16",
-            output_audio_bitrate="128k",
             pace=1.0,
             pitch=None,
             loudness=None,
@@ -901,6 +883,10 @@ class SarvamTTSService(InterruptibleTTSService):
             _warn_deprecated_param("voice_id", SarvamTTSSettings, "voice")
             default_settings.voice = voice_id
 
+        # Init-only audio format fields (not runtime-updatable)
+        output_audio_codec = "linear16"
+        output_audio_bitrate = "128k"
+
         # 3. Apply params overrides — only if settings not provided
         if params is not None:
             _warn_deprecated_param("params", SarvamTTSSettings)
@@ -916,9 +902,9 @@ class SarvamTTSService(InterruptibleTTSService):
                 if params.max_chunk_length is not None:
                     default_settings.max_chunk_length = params.max_chunk_length
                 if params.output_audio_codec is not None:
-                    default_settings.output_audio_codec = params.output_audio_codec
+                    output_audio_codec = params.output_audio_codec
                 if params.output_audio_bitrate is not None:
-                    default_settings.output_audio_bitrate = params.output_audio_bitrate
+                    output_audio_bitrate = params.output_audio_bitrate
                 if params.pace is not None:
                     default_settings.pace = params.pace
                 if params.pitch is not None:
@@ -943,7 +929,6 @@ class SarvamTTSService(InterruptibleTTSService):
         # Set default sample rate based on model if not specified
         if sample_rate is None:
             sample_rate = self._config.default_sample_rate
-            default_settings.speech_sample_rate = str(sample_rate)
 
         # Set default voice based on model if not specified via any mechanism
         if voice_id is None and (settings is None or settings.voice is NOT_GIVEN):
@@ -986,6 +971,11 @@ class SarvamTTSService(InterruptibleTTSService):
             **kwargs,
         )
 
+        # Init-only audio format fields (not runtime-updatable)
+        self._speech_sample_rate = str(sample_rate)
+        self._output_audio_codec = output_audio_codec
+        self._output_audio_bitrate = output_audio_bitrate
+
         # WebSocket endpoint URL with model query parameter
         self._websocket_url = f"{url}?model={resolved_model}"
         self._api_key = api_key
@@ -1022,7 +1012,7 @@ class SarvamTTSService(InterruptibleTTSService):
         await super().start(frame)
 
         # WebSocket API expects sample rate as string
-        self._settings.speech_sample_rate = str(self.sample_rate)
+        self._speech_sample_rate = str(self.sample_rate)
         await self._connect()
 
     async def stop(self, frame: EndFrame):
@@ -1140,12 +1130,12 @@ class SarvamTTSService(InterruptibleTTSService):
         config_data = {
             "target_language_code": self._settings.language,
             "speaker": self._settings.voice,
-            "speech_sample_rate": self._settings.speech_sample_rate,
+            "speech_sample_rate": self._speech_sample_rate,
             "enable_preprocessing": self._settings.enable_preprocessing,
             "min_buffer_size": self._settings.min_buffer_size,
             "max_chunk_length": self._settings.max_chunk_length,
-            "output_audio_codec": self._settings.output_audio_codec,
-            "output_audio_bitrate": self._settings.output_audio_bitrate,
+            "output_audio_codec": self._output_audio_codec,
+            "output_audio_bitrate": self._output_audio_bitrate,
             "pace": self._settings.pace,
             "model": self._settings.model,
         }
diff --git a/src/pipecat/services/xtts/tts.py b/src/pipecat/services/xtts/tts.py
index adf11da6a..ea7cb0b8b 100644
--- a/src/pipecat/services/xtts/tts.py
+++ b/src/pipecat/services/xtts/tts.py
@@ -10,7 +10,7 @@ This module provides integration with Coqui XTTS streaming server for
 text-to-speech synthesis using local Docker deployment.
 """
 
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import AsyncGenerator, Dict, Optional
 
 import aiohttp
@@ -25,7 +25,7 @@ from pipecat.frames.frames import (
     TTSStartedFrame,
     TTSStoppedFrame,
 )
-from pipecat.services.settings import NOT_GIVEN, TTSSettings, _NotGiven, _warn_deprecated_param
+from pipecat.services.settings import TTSSettings, _warn_deprecated_param
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language, resolve_language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -72,13 +72,9 @@ def language_to_xtts_language(language: Language) -> Optional[str]:
 
 @dataclass
 class XTTSTTSSettings(TTSSettings):
-    """Settings for XTTS TTS service.
+    """Settings for XTTS TTS service."""
 
-    Parameters:
-        base_url: Base URL of the XTTS streaming server.
-    """
-
-    base_url: str | _NotGiven = field(default_factory=lambda: NOT_GIVEN)
+    pass
 
 
 class XTTSService(TTSService):
@@ -123,7 +119,6 @@ class XTTSService(TTSService):
             model=None,
             voice=None,
             language=self.language_to_service_language(language),
-            base_url=base_url,
         )
 
         # 2. Apply direct init arg overrides (deprecated)
@@ -140,6 +135,10 @@ class XTTSService(TTSService):
             settings=default_settings,
             **kwargs,
         )
+
+        # Init-only fields (not runtime-updatable)
+        self._base_url = base_url
+
         self._studio_speakers: Optional[Dict[str, Any]] = None
         self._aiohttp_session = aiohttp_session
 
@@ -175,7 +174,7 @@ class XTTSService(TTSService):
         if self._studio_speakers:
             return
 
-        async with self._aiohttp_session.get(self._settings.base_url + "/studio_speakers") as r:
+        async with self._aiohttp_session.get(self._base_url + "/studio_speakers") as r:
             if r.status != 200:
                 text = await r.text()
                 await self.push_error(
@@ -203,7 +202,7 @@ class XTTSService(TTSService):
 
         embeddings = self._studio_speakers[self._settings.voice]
 
-        url = self._settings.base_url + "/tts_stream"
+        url = self._base_url + "/tts_stream"
 
         payload = {
             "text": text.replace(".", "").replace("*", ""),