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CategoryLast Update
[All Projects] RevOS - MIUI2019-03-07 11:08
ReporterinvitadoAssigned ToBadWolf 
Status closedResolutionfixed 
Summary0000164: Redmi Note 4 snapdragon (mido): horrible sound quality in phone calls via external loudspeaker
DescriptionSince the new update 9.1.15 (first one switching from China base to global base), the sound of the external speaker during phone calls has become very bad, much too loud (not really possible to reduce the volume) and very distorted!

This phenomenon is exactly the same as it occurs in all the roms I tested during the past few months! I think, Revolution OS took the sound code/sound manipulations directly from

This bad sound quality does NOT occur in the most recent China developer rom (9.1.17) and it did not occur in the developer roms of the past few months I tested!

The bad sound quality is not present in the Global developer roms either!

It is specific to roms and now to Revolution OS, too.

According to some searching I did it may be specific to mido - because the few people that talk about this issue all use mido!
Steps To Reproduce- use a redmi note 4 snapdragon device
- use Revolution OS 9.1.15 (or just for the record: roms)
- make phone calls
- use the external loudspeaker (you get really loud sound that is distorted, the sound volume can hardly be diminished)

Additional Information- no such problems in the former 8.12.6 Revolution OS
- no such problems in current and earlier China roms
- no such problems in current and earlier Global roms
DeviceXiaomi Redmi Note 4 (snapdragon version)
Telegram UserFred



2019-01-26 19:15

viewer   ~0000170

This problem is solved!

I found the source of the issue, it is these two (or, perhaps, only one of them) entries in build.prop that obviously stem from

If I modify these entries and substitute them by the corresponding lines in the china roms (and also the 8.12.6 revolution os), in-call sound via the external loudspeaker is good again! No more extreme volume (much too loud), no more distortion.

The good entries should be:

This is valid for "mido" - I do not know if other devices suffer from the same issue...


2019-01-26 19:16

viewer   ~0000171

I forgot to add that the previous comment also came from me, Fred. :-)


2019-02-04 02:19

viewer   ~0000174

Great news!
You announced that the sound issue will be dealt with in the next version of Revolution OS in February 2019.

But please be aware, like I said before, that this issue may be "mido specific". Many Xiaomi users complain about sound issues like low volume and such - but these users have different devices and perhaps, the build.prop changes in your current version benefit them, whilst they are harmful for mido users.

I only write this expecting users complaining after the reversal of the build.prop changes. I suggest, you better test the changes with mido and with other devices. Thanks.



2019-03-07 11:08

administrator   ~0000422

Added to all devices on new version of ROS (9.3.7)

Issue History

Date Modified Username Field Change
2019-01-18 16:52 invitado New Issue
2019-01-26 19:15 invitado Note Added: 0000170
2019-01-26 19:16 invitado Note Added: 0000171
2019-02-04 02:19 invitado Note Added: 0000174
2019-03-07 11:08 BadWolf Assigned To => BadWolf
2019-03-07 11:08 BadWolf Status new => closed
2019-03-07 11:08 BadWolf Resolution open => fixed
2019-03-07 11:08 BadWolf Note Added: 0000422
2019-09-04 15:38 BadWolf Category Revolution OS - MIUI => RevOS - MIUI