diff --git a/config/youtube.ini b/config/youtube.ini
index 8d97b54..edee910 100644
--- a/config/youtube.ini
+++ b/config/youtube.ini
@@ -18,6 +18,9 @@ enable_demucs = 是
 # 是 = 有显卡则用 GPU；否 = 强制 CPU；无显卡时自动回退到 CPU
 demucs_use_gpu = 是
 
-# 人声混合比例（0.5-1.0），改善人声自然度，减少尖锐感
-# 0.85 = 85%人声+15%其他（推荐，更自然）；1.0 = 纯人声（可能尖锐）
-demucs_vocal_mix = 0.85
\ No newline at end of file
+# 人声混合比例（0.5-1.0），改善自然度、减少尖锐
+# 0.75 = 75%人声+25%混合（推荐）；1.0 = 纯人声
+demucs_vocal_mix = 0.75
+
+# 混合来源：bass=低音（无混响无重复）；other=其他（可能带混响导致重复感）
+demucs_mix_source = bass
\ No newline at end of file
diff --git a/demucs_pipeline.py b/demucs_pipeline.py
index 7f28470..c828214 100644
--- a/demucs_pipeline.py
+++ b/demucs_pipeline.py
@@ -75,10 +75,11 @@ DEMUCS_CHUNK_SEC = 2.0
 BYTES_PER_SAMPLE = 2
 
 
-def _demucs_separate_vocals(model, audio_chunk, device, vocal_mix_ratio=1.0):
+def _demucs_separate_vocals(model, audio_chunk, device, vocal_mix_ratio=1.0, mix_source="bass"):
     """
     对音频块进行人声分离，返回人声轨道。
-    vocal_mix_ratio: 1.0=纯人声；0.85=85%人声+15%other（更自然，减少尖锐感）
+    vocal_mix_ratio: 1.0=纯人声；0.75=75%人声+25%混合（更自然）
+    mix_source: "bass"=与低音混合(少混响无重复感)；"other"=与其他混合(可能带混响)
     """
     import torch
     # audio_chunk: numpy or tensor, shape (channels, samples)
@@ -93,17 +94,17 @@ def _demucs_separate_vocals(model, audio_chunk, device, vocal_mix_ratio=1.0):
     with torch.no_grad():
         out = apply_model(model, wav, device=device, progress=False, overlap=0.25)
     # out: (batch, sources, channels, samples)
-    # sources: [drums, bass, other, vocals]
+    # sources: [drums=0, bass=1, other=2, vocals=3]
     vocals = out[0, 3]
     if vocal_mix_ratio >= 1.0:
         return vocals.cpu().numpy()
-    # 混合 other 以保留更自然的人声，减少纯人声的尖锐感
-    other = out[0, 2]
-    mixed = vocals * vocal_mix_ratio + other * (1.0 - vocal_mix_ratio)
+    # 混合 bass 或 other：bass 无混响、无重复感；other 可能带混响导致"重复一遍"
+    blend = out[0, 1] if mix_source == "bass" else out[0, 2]
+    mixed = vocals * vocal_mix_ratio + blend * (1.0 - vocal_mix_ratio)
     return mixed.cpu().numpy()
 
 
-def _run_demucs_worker(audio_read_pipe, audio_write_socket, model, device, stop_event, vocal_mix_ratio=1.0):
+def _run_demucs_worker(audio_read_pipe, audio_write_socket, model, device, stop_event, vocal_mix_ratio=1.0, mix_source="bass"):
     """Demucs 工作线程：从 FFmpeg 读音频，分离人声，写入 socket"""
     import numpy as np
     chunk_samples = int(DEMUCS_SAMPLE_RATE * DEMUCS_CHUNK_SEC * DEMUCS_CHANNELS)
@@ -131,7 +132,7 @@ def _run_demucs_worker(audio_read_pipe, audio_write_socket, model, device, stop_
                 arr = np.frombuffer(chunk, dtype=np.int16)
                 arr = arr.reshape(-1, DEMUCS_CHANNELS).T.astype(np.float32) / 32768.0
                 try:
-                    vocals = _demucs_separate_vocals(model, arr, device, vocal_mix_ratio)
+                    vocals = _demucs_separate_vocals(model, arr, device, vocal_mix_ratio, mix_source)
                     # float -> s16le
                     out = (vocals * 32768).astype(np.int16).tobytes()
                     try:
@@ -150,7 +151,7 @@ def _run_demucs_worker(audio_read_pipe, audio_write_socket, model, device, stop_
             try:
                 arr = np.frombuffer(buf, dtype=np.int16)
                 arr = arr.reshape(-1, DEMUCS_CHANNELS).T.astype(np.float32) / 32768.0
-                vocals = _demucs_separate_vocals(model, arr, device, vocal_mix_ratio)
+                vocals = _demucs_separate_vocals(model, arr, device, vocal_mix_ratio, mix_source)
                 out = (vocals * 32768).astype(np.int16).tobytes()
                 audio_write_socket.sendall(out)
             except Exception:
@@ -178,7 +179,8 @@ def run_demucs_pipeline(
     stream_ended_exception,
     cleanup_proc_fn,
     stderr_reader_fn,
-    vocal_mix_ratio: float = 0.85,
+    vocal_mix_ratio: float = 0.75,
+    mix_source: str = "bass",
     stats_interval_sec: int = 10,
 ):
     """
@@ -194,8 +196,9 @@ def run_demucs_pipeline(
 
     device = next(model.parameters()).device
     device_str = "cuda" if "cuda" in str(device) else "cpu"
-    mix_info = "纯人声" if vocal_mix_ratio >= 1.0 else f"{int(vocal_mix_ratio*100)}%人声+{int((1-vocal_mix_ratio)*100)}%其他"
-    print(f"[INFO] Demucs 人声分离已启用 ({device_str})，模式: {mix_info}")
+    src_name = "低音" if mix_source == "bass" else "其他"
+    mix_info = "纯人声" if vocal_mix_ratio >= 1.0 else f"{int(vocal_mix_ratio*100)}%人声+{int((1-vocal_mix_ratio)*100)}%{src_name}"
+    print(f"[INFO] Demucs 人声分离已启用 ({device_str})，模式: {mix_info}，低通 9kHz 降尖锐")
 
     # TCP 服务器用于音频（跨平台）
     server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -271,7 +274,7 @@ def run_demucs_pipeline(
         "-x264-params", "force-cfr=1:scenecut=0:open_gop=0:sync-lookahead=0",
         "-pix_fmt", "yuv420p",
         "-c:a", "aac", "-b:a", "128k", "-ar", "48000", "-ac", "2",
-        "-af", "aresample=async=1:first_pts=0",
+        "-af", "lowpass=f=9000,aresample=async=1:first_pts=0",
         "-flags", "+global_header", "-flvflags", "no_duration_filesize",
         "-f", "flv", youtube_rtmp,
     ]
@@ -339,7 +342,7 @@ def run_demucs_pipeline(
         # 注意：proc_a 输出到 stdout，我们读。conn 是 FFmpeg 作为 client 连上来的，所以 FFmpeg 在读，我们写 conn。
         demucs_thread = threading.Thread(
             target=_run_demucs_worker,
-            args=(proc_a.stdout, conn[0], model, device, stop_event, vocal_mix_ratio),
+            args=(proc_a.stdout, conn[0], model, device, stop_event, vocal_mix_ratio, mix_source),
             daemon=True,
         )
         demucs_thread.start()
diff --git a/douyin_youtube_ffplay.py b/douyin_youtube_ffplay.py
index c230433..0ba6e54 100644
--- a/douyin_youtube_ffplay.py
+++ b/douyin_youtube_ffplay.py
@@ -104,7 +104,8 @@ def start_douyin_youtube_ffplay(
 
     enable_demucs = False
     demucs_use_gpu = True
-    demucs_vocal_mix = 0.85  # 0.85=人声更自然，1.0=纯人声（可能尖锐）
+    demucs_vocal_mix = 0.75  # 0.75=更自然少尖锐；1.0=纯人声
+    demucs_mix_source = "bass"  # bass=无混响无重复；other=可能带混响
     video_bitrate_mbps = 4.5  # 优先画质，YouTube 720p 推荐 4-4.5
     stats_interval_sec = 10  # 推流状态日志间隔
     if os.path.exists(config_file):
@@ -125,6 +126,9 @@ def start_douyin_youtube_ffplay(
                             demucs_vocal_mix = v
                     except ValueError:
                         pass
+                elif key_lower == "demucs_mix_source":
+                    if val.lower() in ("bass", "other"):
+                        demucs_mix_source = val.lower()
                 elif key_lower == "video_bitrate_mbps":
                     try:
                         v = float(val)
@@ -145,7 +149,7 @@ def start_douyin_youtube_ffplay(
             # 兼容：若上面未匹配到 key，取第一个非配置项的值作为 stream key
             if youtube_rtmp == rtmp_base + default_key:
                 for k, v in config.items("youtube"):
-                    if k.strip().lower() not in ("enable_demucs", "demucs_use_gpu", "demucs_vocal_mix", "video_bitrate_mbps", "stats_interval_sec") and v.strip():
+                    if k.strip().lower() not in ("enable_demucs", "demucs_use_gpu", "demucs_vocal_mix", "demucs_mix_source", "video_bitrate_mbps", "stats_interval_sec") and v.strip():
                         v = v.strip()
                         youtube_rtmp = v if v.startswith("rtmp://") else rtmp_base + v
                         print(f"[INFO] 从 {config_file} 读取 YouTube stream key: {youtube_rtmp}")
@@ -532,6 +536,7 @@ def start_douyin_youtube_ffplay(
                             cleanup_proc_fn=cleanup_proc,
                             stderr_reader_fn=_stderr_reader_thread,
                             vocal_mix_ratio=demucs_vocal_mix,
+                            mix_source=demucs_mix_source,
                             stats_interval_sec=stats_interval_sec,
                         )
                     except StreamEnded: