diff --git a/apps/beep.c b/apps/beep.c
index 25b5e0e391..62ebf2c3f9 100644
--- a/apps/beep.c
+++ b/apps/beep.c
@@ -97,7 +97,7 @@ void beep_play(unsigned int frequency, unsigned int duration,
     beep_get_more(&start, &size);
 
     mixer_channel_set_amplitude(PCM_MIXER_CHAN_BEEP, MIX_AMP_UNITY);
-    mixer_channel_play_data(PCM_MIXER_CHAN_BEEP,
-                            beep_count ? beep_get_more : NULL,
-                            start, size);
+    static struct mixer_play_cbs cbs;
+    cbs.get_more = beep_count ? beep_get_more : NULL;
+    mixer_channel_play_data(PCM_MIXER_CHAN_BEEP, &cbs, start, size);
 }
diff --git a/apps/pcmbuf.c b/apps/pcmbuf.c
index 6bd39d4dc0..e9e05bc5c0 100644
--- a/apps/pcmbuf.c
+++ b/apps/pcmbuf.c
@@ -29,6 +29,7 @@
 #include "pcmbuf.h"
 #include "dsp-util.h"
 #include "playback.h"
+#include "dsp_core.h"
 #include "codec_thread.h"
 
 /* Define LOGF_ENABLE to enable logf output in this file */
@@ -836,6 +837,12 @@ static void pcmbuf_pcm_callback(const void **start, size_t *size)
     }
 }
 
+static void pcmbuf_sampr_callback(uint32_t sampr)
+{
+    struct dsp_config* dsp = dsp_get_config(CODEC_IDX_AUDIO);
+    dsp_configure(dsp, DSP_SET_OUT_FREQUENCY, sampr);
+}
+
 /* Force playback */
 void pcmbuf_play_start(void)
 {
@@ -845,8 +852,11 @@ void pcmbuf_play_start(void)
         chunk_widx != chunk_ridx)
     {
         current_desc = NULL;
-        mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, pcmbuf_pcm_callback,
-                                NULL, 0);
+        static const struct mixer_play_cbs cbs = {
+            .get_more = pcmbuf_pcm_callback,
+            .sampr_changed = pcmbuf_sampr_callback,
+        };
+        mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
     }
 }
 
diff --git a/apps/plugin.h b/apps/plugin.h
index 4eb83fbad5..f0491f4ece 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -782,7 +782,7 @@ struct plugin_api {
     void (*mixer_channel_calculate_peaks)(enum pcm_mixer_channel channel,
                                           struct pcm_peaks *peaks);
     void (*mixer_channel_play_data)(enum pcm_mixer_channel channel,
-                                    pcm_play_callback_type get_more,
+                                    const struct mixer_play_cbs* cbs,
                                     const void *start, size_t size);
     void (*mixer_channel_play_pause)(enum pcm_mixer_channel channel, bool play);
     void (*mixer_channel_stop)(enum pcm_mixer_channel channel);
diff --git a/apps/plugins/doom/i_sound.c b/apps/plugins/doom/i_sound.c
index 78780dd9b3..068aa915c5 100644
--- a/apps/plugins/doom/i_sound.c
+++ b/apps/plugins/doom/i_sound.c
@@ -466,7 +466,10 @@ void I_SubmitSound(void)
    if (!enable_sound)
       return;
 
-   rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &get_more, NULL, 0);
+   static const struct mixer_play_cbs cbs = {
+       .get_more = get_more,
+   };
+   rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 }
 
 void I_ShutdownSound(void)
diff --git a/apps/plugins/midi/midiplay.c b/apps/plugins/midi/midiplay.c
index d19ff7888b..2a6e579b9c 100644
--- a/apps/plugins/midi/midiplay.c
+++ b/apps/plugins/midi/midiplay.c
@@ -507,6 +507,10 @@ UNUSED_ATTR static int find_min_sampr_ge_22(void)
     return ret;
 }
 
+static const struct mixer_play_cbs mixer_cbs = {
+    .get_more = get_more,
+};
+
 static int midimain(const void * filename)
 {
     int a, notes_used, vol;
@@ -625,7 +629,7 @@ static int midimain(const void * filename)
 #endif
 
     rb->pcmbuf_fade(false, true);
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &mixer_cbs, NULL, 0);
 
     while (!quit)
     {
@@ -684,7 +688,7 @@ static int midimain(const void * filename)
 #endif
                 midi_debug("Rewind to %d:%02d\n", playing_time/60, playing_time%60);
                 if (is_playing)
-                    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+                    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &mixer_cbs, NULL, 0);
                 break;
             }
 
@@ -706,7 +710,7 @@ static int midimain(const void * filename)
 #endif
                 midi_debug("Skip to %d:%02d\n", playing_time/60, playing_time%60);
                 if (is_playing)
-                    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+                    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &mixer_cbs, NULL, 0);
                 break;
             }
 
diff --git a/apps/plugins/mikmod/mikmod.c b/apps/plugins/mikmod/mikmod.c
index 782153f8e5..a482ace68b 100644
--- a/apps/plugins/mikmod/mikmod.c
+++ b/apps/plugins/mikmod/mikmod.c
@@ -292,6 +292,10 @@ static void get_more(const void** start, size_t* size)
 #endif
 }
 
+static const struct mixer_play_cbs mixer_cbs = {
+    .get_more = get_more,
+};
+
 static void showinfo(void)
 {
     char statustext[LINE_LENGTH];
@@ -600,10 +604,9 @@ static void applysettings(void)
         }
 
         // MikMod_Reset("");  BROKEN!
-
         rb->mixer_channel_stop(PCM_MIXER_CHAN_PLAYBACK);
-	rb->mixer_set_frequency(md_mixfreq);
-	rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+        rb->mixer_set_frequency(md_mixfreq);
+        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &mixer_cbs, NULL, 0);
     }
 
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
@@ -810,7 +813,7 @@ static int playfile(char* filename)
         display = DISPLAY_INFO;
         Player_Start(module);
         rb->pcmbuf_fade(false, true);
-        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &mixer_cbs, NULL, 0);
     }
 
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
diff --git a/apps/plugins/mpegplayer/pcm_output.c b/apps/plugins/mpegplayer/pcm_output.c
index 5e95d16316..6ce603ac9c 100644
--- a/apps/plugins/mpegplayer/pcm_output.c
+++ b/apps/plugins/mpegplayer/pcm_output.c
@@ -173,6 +173,10 @@ static void get_more(const void **start, size_t *size)
         pcmbuf_read = pcmbuf_written;
 }
 
+static const struct mixer_play_cbs mixer_cbs = {
+    .get_more = get_more,
+};
+
 /** Public interface **/
 
 /* Return a buffer pointer if at least size bytes are available and if so,
@@ -236,8 +240,7 @@ void pcm_output_flush(void)
 
     /* Restart if playing state was current */
     if (status == CHANNEL_PLAYING)
-        rb->mixer_channel_play_data(MPEG_PCM_CHANNEL,
-                                    get_more, NULL, 0);
+        rb->mixer_channel_play_data(MPEG_PCM_CHANNEL, &mixer_cbs, NULL, 0);
 }
 
 /* Seek the reference clock to the specified time - next audio data ready to
@@ -318,8 +321,7 @@ void pcm_output_play_pause(bool play)
         if (play)
         {
             rb->mixer_channel_set_amplitude(MPEG_PCM_CHANNEL, MIX_AMP_UNITY);
-            rb->mixer_channel_play_data(MPEG_PCM_CHANNEL,
-                                        get_more, NULL, 0);
+            rb->mixer_channel_play_data(MPEG_PCM_CHANNEL, &mixer_cbs, NULL, 0);
         }
     }
 }
diff --git a/apps/plugins/pacbox/pacbox.c b/apps/plugins/pacbox/pacbox.c
index 34f103039d..e024c6d493 100644
--- a/apps/plugins/pacbox/pacbox.c
+++ b/apps/plugins/pacbox/pacbox.c
@@ -407,8 +407,11 @@ static void start_sound(void)
 
     wsg3_set_sampling_rate(caps->samprs[sr_index]);
 
+    static const struct mixer_play_cbs cbs = {
+        .get_more = get_more,
+    };
     rb->mixer_set_frequency(caps->samprs[sr_index]);
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 
     sound_playing = true;
 }
diff --git a/apps/plugins/pdbox/PDa/src/s_audio_rockbox.c b/apps/plugins/pdbox/PDa/src/s_audio_rockbox.c
index 5f82f6d393..fd3c764645 100644
--- a/apps/plugins/pdbox/PDa/src/s_audio_rockbox.c
+++ b/apps/plugins/pdbox/PDa/src/s_audio_rockbox.c
@@ -181,7 +181,10 @@ int rockbox_send_dacs(void)
     if(!playing && outbuf_fill > 0)
     {
         /* Start playing. */
-        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, pdbox_get_more, NULL, 0);
+        static const struct mixer_play_cbs cbs = {
+            .get_more = pdbox_get_more,
+        };
+        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 
         /* Set status flag. */
         playing = true;
diff --git a/apps/plugins/rockboy/rbsound.c b/apps/plugins/rockboy/rbsound.c
index 60f877471e..7d10dbdb83 100644
--- a/apps/plugins/rockboy/rbsound.c
+++ b/apps/plugins/rockboy/rbsound.c
@@ -73,7 +73,10 @@ int rockboy_pcm_submit(void)
 
     if(newly_started)
     {
-        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &get_more, NULL, 0);
+        static const struct mixer_play_cbs cbs = {
+            .get_more = get_more,
+        };
+        rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
         newly_started = false;
     }
 
diff --git a/apps/plugins/sdl/src/audio/rockbox/SDL_rockboxaudio.c b/apps/plugins/sdl/src/audio/rockbox/SDL_rockboxaudio.c
index bfa5802ddf..2ffcda6b46 100644
--- a/apps/plugins/sdl/src/audio/rockbox/SDL_rockboxaudio.c
+++ b/apps/plugins/sdl/src/audio/rockbox/SDL_rockboxaudio.c
@@ -288,7 +288,10 @@ static int ROCKBOXAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
 
     rbaud_underruns = 0;
 
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+    static const struct mixer_play_cbs cbs = {
+        .get_more = get_more,
+    };
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 
     /* We're ready to rock and roll. :-) */
     return(0);
diff --git a/apps/plugins/test_sampr.c b/apps/plugins/test_sampr.c
index 4c39ba3515..dfaea58183 100644
--- a/apps/plugins/test_sampr.c
+++ b/apps/plugins/test_sampr.c
@@ -237,7 +237,10 @@ static void play_tone(bool volume_set)
                                       IF_PRIO(, PRIORITY_PLAYBACK)
                                       IF_COP(, CPU));
 
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+    static const struct mixer_play_cbs cbs = {
+        .get_more = get_more,
+    };
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 
 #ifndef HAVE_VOLUME_IN_LIST
     if (volume_set)
diff --git a/apps/plugins/xrick/system/syssnd_rockbox.c b/apps/plugins/xrick/system/syssnd_rockbox.c
index 74edd98140..ec8886f881 100644
--- a/apps/plugins/xrick/system/syssnd_rockbox.c
+++ b/apps/plugins/xrick/system/syssnd_rockbox.c
@@ -222,8 +222,11 @@ void syssnd_update(void)
 
         if (!isAudioPlaying && fillCount > 0)
         {
+            static const struct mixer_play_cbs cbs = {
+                .get_more = get_more,
+            };
             isAudioPlaying = true;
-            rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+            rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
         }
     }
 }
diff --git a/apps/plugins/xworld/sys.c b/apps/plugins/xworld/sys.c
index 50c0c64e0b..a8c2d695fe 100644
--- a/apps/plugins/xworld/sys.c
+++ b/apps/plugins/xworld/sys.c
@@ -1029,7 +1029,10 @@ void sys_startAudio(struct System* sys, AudioCallback callback, void *param)
     audio_param = param;
     audio_sys = sys;
 
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, NULL, 0);
+    static const struct mixer_play_cbs cbs = {
+        .get_more = get_more,
+    };
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, NULL, 0);
 }
 
 void sys_stopAudio(struct System* sys)
diff --git a/apps/plugins/zxbox/spsound.c b/apps/plugins/zxbox/spsound.c
index 602030361f..4b38e68171 100644
--- a/apps/plugins/zxbox/spsound.c
+++ b/apps/plugins/zxbox/spsound.c
@@ -212,7 +212,10 @@ static void write_buf(void){
                     = my_buf[j+10] = my_buf[j+11] \
                     = (((byte)sp_sound_buf[i])<<8) >> settings.volume;
 
-    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, get_more, (unsigned char*)(my_buf),TMNUM*4*3*2);
+    static const struct mixer_play_cbs cbs = {
+        .get_more = get_more,
+    };
+    rb->mixer_channel_play_data(PCM_MIXER_CHAN_PLAYBACK, &cbs, (unsigned char*)(my_buf),TMNUM*4*3*2);
 
 #if 0
     /* can use to save and later analyze what we produce */
diff --git a/apps/voice_thread.c b/apps/voice_thread.c
index b31bc5bc76..3e83138d6c 100644
--- a/apps/voice_thread.c
+++ b/apps/voice_thread.c
@@ -245,8 +245,10 @@ static void voice_start_playback(void)
     struct voice_pcm_frame *frame =
         &voice_buf->frames[voice_buf->frame_out % VOICE_FRAMES];
 
-    mixer_channel_play_data(PCM_MIXER_CHAN_VOICE, voice_pcm_callback,
-                            frame->pcm, frame->size);
+    static const struct mixer_play_cbs cbs = {
+        .get_more = voice_pcm_callback,
+    };
+    mixer_channel_play_data(PCM_MIXER_CHAN_VOICE, &cbs, frame->pcm, frame->size);
 }
 
 /* Stop the voice channel */
diff --git a/docs/PLUGIN_API b/docs/PLUGIN_API
index d86fcbf335..4a895cc0a3 100644
--- a/docs/PLUGIN_API
+++ b/docs/PLUGIN_API
@@ -1607,9 +1607,9 @@ size_t mixer_channel_get_bytes_waiting(enum pcm_mixer_channel channel)
     \return
     \description
 
-void mixer_channel_play_data(enum pcm_mixer_channel channel, pcm_play_callback_type get_more, const void *start, size_t size)
+void mixer_channel_play_data(enum pcm_mixer_channel channel, const struct mixer_play_cbs* cbs, const void *start, size_t size)
     \param channel
-    \param get_more
+    \param cbs
     \param start
     \param size
     \description
diff --git a/firmware/export/pcm_mixer.h b/firmware/export/pcm_mixer.h
index 6dcbb9e4d4..99ded55082 100644
--- a/firmware/export/pcm_mixer.h
+++ b/firmware/export/pcm_mixer.h
@@ -96,8 +96,13 @@ enum channel_status
 /** Public interfaces **/
 
 /* Start playback on a channel */
+struct mixer_play_cbs {
+    void (*get_more)(const void **start, size_t *size);
+    void (*sampr_changed)(uint32_t sampr);
+};
+
 void mixer_channel_play_data(enum pcm_mixer_channel channel,
-                             pcm_play_callback_type get_more,
+                             const struct mixer_play_cbs* cbs,
                              const void *start, size_t size);
 
 /* Pause or resume a channel (when started) */
diff --git a/firmware/pcm_mixer.c b/firmware/pcm_mixer.c
index a0d26fc86d..f093084572 100644
--- a/firmware/pcm_mixer.c
+++ b/firmware/pcm_mixer.c
@@ -42,12 +42,12 @@ static unsigned int mix_frame_size = MIX_FRAME_SAMPLES*4;
 /* Descriptor for each channel */
 struct mixer_channel
 {
-    const void *start;               /* Buffer pointer */
-    size_t size;                     /* Bytes remaining */
-    size_t last_size;                /* Size of consumed data in prev. cycle */
-    pcm_play_callback_type get_more; /* Registered callback */
-    enum channel_status status;      /* Playback status */
-    uint32_t amplitude;              /* Amp. factor: 0x0000 = mute, 0x10000 = unity */
+    const void *start;                    /* Buffer pointer */
+    size_t size;                          /* Bytes remaining */
+    size_t last_size;                     /* Size of consumed data in prev. cycle */
+    const struct mixer_play_cbs* cbs;     /* Registered callbacks */
+    enum channel_status status;           /* Playback status */
+    uint32_t amplitude;                   /* Amp. factor: 0x0000 = mute, 0x10000 = unity */
     chan_buffer_hook_fn_type buffer_hook; /* Callback for new buffer */
 };
 
@@ -154,9 +154,9 @@ fill_frame:
 
         if (chan->size == 0)
         {
-            if (chan->get_more)
+            if (chan->cbs->get_more)
             {
-                chan->get_more(&chan->start, &chan->size);
+                chan->cbs->get_more(&chan->start, &chan->size);
                 ALIGN_AUDIOBUF(chan->start, chan->size);
             }
 
@@ -287,14 +287,14 @@ static void mixer_start_pcm(void)
 
 /* Start playback on a channel */
 void mixer_channel_play_data(enum pcm_mixer_channel channel,
-                             pcm_play_callback_type get_more,
+                             const struct mixer_play_cbs* cbs,
                              const void *start, size_t size)
 {
     struct mixer_channel *chan = &channels[channel];
 
     ALIGN_AUDIOBUF(start, size);
 
-    if (!(start && size) && get_more)
+    if (!(start && size) && cbs && cbs->get_more)
     {
         /* Initial buffer not passed - call the callback now */
         pcm_play_lock();
@@ -304,7 +304,7 @@ void mixer_channel_play_data(enum pcm_mixer_channel channel,
         pcm_play_unlock(); /* Allow playback while doing callback */
 
         size = 0;
-        get_more(&start, &size);
+        cbs->get_more(&start, &size);
         ALIGN_AUDIOBUF(start, size);
     }
 
@@ -317,7 +317,7 @@ void mixer_channel_play_data(enum pcm_mixer_channel channel,
         chan->start = start;
         chan->size = size;
         chan->last_size = 0;
-        chan->get_more = get_more;
+        chan->cbs = cbs;
 
         mixer_activate_channel(chan);
         chan_call_buffer_hook(chan);
@@ -464,11 +464,36 @@ void mixer_set_frequency(unsigned int samplerate)
 
     if (samplerate == mixer_sampr)
         return;
-
-    /* All data is now invalid */
-    mixer_reset();
     mixer_sampr = samplerate;
 
+    for (size_t i = 0; i < ARRAYLEN(active_channels) && active_channels[i]; i += 1)
+    {
+        struct mixer_channel* chan = active_channels[i];
+
+        /* Notify upstreams */
+        if (chan->cbs)
+        {
+            if (chan->cbs->sampr_changed)
+            {
+                chan->cbs->sampr_changed(samplerate);
+            }
+            if (chan->cbs->get_more)
+            {
+                /* Remake buffer */
+                const void *start = NULL;
+                size_t size;
+                chan->cbs->get_more(&start, &size);
+                if (start && size) {
+                    chan->start = start;
+                    chan->size = size;
+                    chan->last_size = 0;
+                } else {
+                    channel_stopped(chan);
+                }
+            }
+        }
+    }
+
     /* Work out how much space we really need */
     if (samplerate > SAMPR_96)
         mix_frame_size = 4;
diff --git a/firmware/usbstack/usb_audio.c b/firmware/usbstack/usb_audio.c
index f8d431705f..fd135cf7a3 100644
--- a/firmware/usbstack/usb_audio.c
+++ b/firmware/usbstack/usb_audio.c
@@ -1337,7 +1337,10 @@ bool usb_audio_fast_transfer_complete(int ep, int dir, int status, int length)
             logf("usbaudio: prebuffering done");
             playback_audio_underflow = false;
             usb_rx_overflow = false;
-            mixer_channel_play_data(PCM_MIXER_CHAN_USBAUDIO, playback_audio_get_more, NULL, 0);
+            static const struct mixer_play_cbs cbs = {
+                .get_more = playback_audio_get_more,
+            };
+            mixer_channel_play_data(PCM_MIXER_CHAN_USBAUDIO, &cbs, NULL, 0);
         }
         restore_irq(oldlevel);
         retval =  true;