diff --git a/audio.c b/audio.c
index 008dc79..13070c8 100644
--- a/audio.c
+++ b/audio.c
@@ -173,7 +173,7 @@ void AUDIO_PlayBeep(beep_type_t Beep)
 			break;
 	}
 
-	BK4819_StartTone1(ToneFrequency, 96, false, false);
+	BK4819_StartTone1(ToneFrequency, 10, false, false);
 
 	SYSTEM_DelayMs(2);
 	GPIO_SetBit(&GPIOC->DATA, GPIOC_PIN_SPEAKER);
diff --git a/driver/bk4819.c b/driver/bk4819.c
index 0a8b389..d6b3321 100644
--- a/driver/bk4819.c
+++ b/driver/bk4819.c
@@ -816,19 +816,16 @@ void BK4819_EnableDTMF(void)
 
 void BK4819_StartTone1(const uint16_t frequency, const unsigned int level, const bool tx, const bool tx_unmute)
 {
+//	(void)tx_unmute;
+
 	GPIO_ClearBit(&GPIOC->DATA, GPIOC_PIN_SPEAKER);
-	SYSTEM_DelayMs(2);
 
-//	BK4819_SetAF(BK4819_AF_MUTE);
-	BK4819_SetAF(BK4819_AF_BEEP);
-//	BK4819_SetAF(BK4819_AF_TONE);
+	SYSTEM_DelayMs(1);
 
-	BK4819_EnterTxMute();
+	// mute TX
+	BK4819_write_reg(0x50, (1u << 15) | 0x3B20);
 
-	if (level > 0)
-		BK4819_write_reg(0x70, BK4819_REG_70_ENABLE_TONE1 | ((level & 0x7f) << BK4819_REG_70_SHIFT_TONE1_TUNING_GAIN));
-	else
-		BK4819_write_reg(0x70, 0);
+	BK4819_write_reg(0x70, BK4819_REG_70_ENABLE_TONE1 | ((level & 0x7f) << BK4819_REG_70_SHIFT_TONE1_TUNING_GAIN));
 
 	BK4819_write_reg(0x30, 0);
 
@@ -865,23 +862,29 @@ void BK4819_StartTone1(const uint16_t frequency, const unsigned int level, const
 
 	BK4819_write_reg(0x71, scale_freq(frequency));
 
+	SYSTEM_DelayMs(1);
+
+//	BK4819_SetAF(tx ? BK4819_AF_BEEP : BK4819_AF_TONE);
+	BK4819_SetAF(BK4819_AF_TONE);  // RX
+//	BK4819_SetAF(BK4819_AF_BEEP);  // TX
+
 	if (tx_unmute)
-		BK4819_ExitTxMute();
+		BK4819_write_reg(0x50, 0x3B20);   // 0011 1011 0010 0000
 
-	SYSTEM_DelayMs(2);
-
-	if (!tx && level > 0)
-		GPIO_SetBit(&GPIOC->DATA, GPIOC_PIN_SPEAKER);
+	GPIO_SetBit(&GPIOC->DATA, GPIOC_PIN_SPEAKER);
 }
 
 void BK4819_StopTones(const bool tx)
 {
 	GPIO_ClearBit(&GPIOC->DATA, GPIOC_PIN_SPEAKER);
-	SYSTEM_DelayMs(2);
+
+	SYSTEM_DelayMs(1);
 
 	BK4819_SetAF(BK4819_AF_MUTE);
 
-	BK4819_EnterTxMute();
+//	BK4819_EnterTxMute();
+
+	SYSTEM_DelayMs(1);
 
 	BK4819_write_reg(0x70, 0);
 
@@ -917,6 +920,8 @@ void BK4819_StopTones(const bool tx)
 		0);
 	}
 
+	SYSTEM_DelayMs(1);
+
 	BK4819_ExitTxMute();
 }
 
diff --git a/firmware.bin b/firmware.bin
index f0f0880..c3ad7a2 100644
Binary files a/firmware.bin and b/firmware.bin differ
diff --git a/firmware.packed.bin b/firmware.packed.bin
index f9fa9ec..56d1a46 100644
Binary files a/firmware.packed.bin and b/firmware.packed.bin differ
diff --git a/functions.c b/functions.c
index af0d45b..9b3cc3c 100644
--- a/functions.c
+++ b/functions.c
@@ -267,7 +267,7 @@ void FUNCTION_Select(function_type_t Function)
 				if (g_current_vfo->channel.mdc1200_mode == MDC1200_MODE_BOT || g_current_vfo->channel.mdc1200_mode == MDC1200_MODE_BOTH)
 				{
 					#ifdef ENABLE_MDC1200_SIDE_BEEP
-//						BK4819_StartTone1(880, 20, true, false);
+//						BK4819_StartTone1(880, 10, true, false);
 //						SYSTEM_DelayMs(120);
 //						BK4819_StopTones(true);
 					#endif
@@ -276,7 +276,7 @@ void FUNCTION_Select(function_type_t Function)
 					BK4819_send_MDC1200(MDC1200_OP_CODE_PTT_ID, 0x80, g_eeprom.config.setting.mdc1200_id, true);
 
 					#ifdef ENABLE_MDC1200_SIDE_BEEP
-						BK4819_StartTone1(880, 20, true, false);
+						BK4819_StartTone1(880, 10, true, false);
 						SYSTEM_DelayMs(120);
 						BK4819_StopTones(true);
 					#endif
diff --git a/radio.c b/radio.c
index 04e7b3c..8b7868b 100644
--- a/radio.c
+++ b/radio.c
@@ -1215,7 +1215,7 @@ void RADIO_tx_eot(void)
 		BK4819_send_MDC1200(MDC1200_OP_CODE_POST_ID, 0x00, g_eeprom.config.setting.mdc1200_id, false);
 
 		#ifdef ENABLE_MDC1200_SIDE_BEEP
-			BK4819_StartTone1(880, 30, true, false);
+			BK4819_StartTone1(880, 10, true, false);
 			SYSTEM_DelayMs(120);
 			BK4819_StopTones(true);
 		#endif