New Bluetooth Bt4 Multimedia Volume Issue On Mi4c


Apr 19, 2014
Bug still present on Libra beta 6.5.5 observed on 2 Mi4c 32GB.

This bug was introduced on libra Rom, between 6.3.3 I was running previously (BT multimedia volume control by the phone was OK with all my peripherals) and version 6.4.14.
It is now still present on all intermediate versions (as for 6.4.27), up to the latest 6.5.5 , my recent update.
But not observed on 2 Mi4i running official Xiaomi stable global or beta global 6.4.27

This volume problem occurs only with my excellent Xiaomi BT4 stereo speaker.(SKU:QBH4041CN)...

Volume adjustment achieved on the V+/ V- Mi4c buttons do not operate properly with Xiaomi BT4 speaker since recent upgrades. Slight effective volume modifications around an average value forced by the internal volume settings of the speaker are only obtained when adjusting the volume on the Mi4c.
Not possible to reach an effective 100% or 0% volume on the speaker, despite display on the phone vary between 0% and 100%..

With the Mi4c 6.5.5 rom, the volume buttons V+/ V- of the Xiaomi BT4 speaker are modifying the displayed multimedia sound level on the screen of the Mi4c, and action on the phone volume V+/V- buttons try to do the opposite in the speaker volume settings.
Erratic volume control.
Speaker impose its internal volume into the phone..
--> Conflict...

No volume control problem observed with a Bluedio BT Headset and a Philips SHB9100 BT headset...
Volume adjustment accessible on these BT peripherals remains local and do not modify the multimedia volume settings in the displayed phone volume and in the parameters menu..
(These peripherals are only BT3)
--> No conflict with the phone media volume control.
Volume adjustment achieved by the Mi4c still goes from 0% up to 100% on these peripherals without problem...

But I can not say if this problem comes from the original Mi4c Libra beta Rom version from Xiaomi, before the translation achieved by, or if it was introduced by during Rom recompilation after translation.
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