My experience with different Roms and headphone audio.

[senny22]

So I've been on pretty much every rom and so I will share my experience with each of them considering headphone audio quality, sound, and volume. I've used my HD 598 and Momentum in-ears on each Rom with no sound effect on.

Stock marshmallow G (And a room that was based on stock U): well I actually found that the sound on marshmallow is one of the best on both super and standard setting with a clean and flat signal but on the European (G model) the volume is very very low which is a big downside of marshmallow on G model.
TL;DR: Good clean sound, extremely low volume on G model.


Stock nougat, both G and U: here I found the sound on both G and U to be the same which is probably true since the "mixer_paths" were identical. IMO the sound was somewhat muffled with the super setting turned on along with it having a 10k+ boost which made for artificial highs in some music. Changing to standard solved the sound issues but then the sound was once again very low in volume output.
TL;DR: Super: Muddy bass, boosted top frequencys. Standard: Clean sound, low volume.


Lineage OS/Resurrection Remix: once again identical sound and identical "mixer_paths" files. On these Roms the sound is very strong and significantly louder than on any stock Rom. However, I found the sound to be very muffled with alot off boosted bass despite no sound effects being on or installed. I didn't like the like the sound on these Rims at all and couldn't really here any improvement​ over my old Nexus in sound quality since the boosted bass just took over and sort of layer on top of all the other frequencys.
TL;DR: Very loud signal with lack of quality due to very boosted bass.

Nucler Rom: Now we are talking. I feel like this Rom has the best of both Lineage and stock. The sound is just as loud as on Lineage/RR but the boosted bass is no more. I found this Rom to have just as a flat and clean signal as atleast stock nougat and probably as good as stock marshmallow on the U model but with a stronger and louder sound.
TL;DR: Loud volume output with a clean and flat signal.

If I were to recommend a Rom based on headphone audio qualty it would be either Stock marshmallow or Nuclear with Nuclear having a louder volume output and stock marshmallow having the option to use the super setting which I believe is just a tuning from ZTE to make the sound perceived as better with just boosted bass and treble and also a louder volume which is all classic tricks companies use to simulate high quality sound.

 

[QAM]

Hola
Very well put together write up. I am sure that this is especially useful for other audiophiles like yourself, particularly given that sound output from this device was a main selling point / feature for many.

That aside we must also give credit to the likes of people like Carl @Unjustified Dev, @DrakenFX, the mysterious anonymous dev (who was kind enough to fix the sound issue for third party ROMs) and a few others. Without their hard work and time we would still have piss poor audio on this relatively decent device.

"So what you want me to do 'bout that?"

 

[cfbruck]

Yeah, thanks for the write up!

Another tip for those of us who have been somewhat disappointed by the audio on this device (which after all is selling as a hifi-phone; the meizu pro 5 I had before was way way better...)

Try an audio mod called Ainur Pandora, here on xda. Its not an enhancement or equalizer thing, but rather an audiophile mod, changing audio libs or something (no idea how it works) to use the hardware better. For me it was a big improvement, at bit like changing the mixer paths file that you suggested earlier, but better. I'm starting to feel satisfied with the sound now, the weak point being the treble quality I think, but that is probably inherent in the hardware implementation.

 

[mcsti]

Yeah, thanks for the write up!

Another tip for those of us who have been somewhat disappointed by the audio on this device (which after all is selling as a hifi-phone; the meizu pro 5 I had before was way way better...)

Try an audio mod called Ainur Pandora, here on xda. Its not an enhancement or equalizer thing, but rather an audiophile mod, changing audio libs or something (no idea how it works) to use the hardware better. For me it was a big improvement, at bit like changing the mixer paths file that you suggested earlier, but better. I'm starting to feel satisfied with the sound now, the weak point being the treble quality I think, but that is probably inherent in the hardware implementation.

Can Ainur Pandora be installed on Stock ROM or the ROM should definitely be LOS based?

 

[senny22]

Thanks

 

[senny22]

Yeah, thanks for the write up!

Another tip for those of us who have been somewhat disappointed by the audio on this device (which after all is selling as a hifi-phone; the meizu pro 5 I had before was way way better...)

Try an audio mod called Ainur Pandora, here on xda. Its not an enhancement or equalizer thing, but rather an audiophile mod, changing audio libs or something (no idea how it works) to use the hardware better. For me it was a big improvement, at bit like changing the mixer paths file that you suggested earlier, but better. I'm starting to feel satisfied with the sound now, the weak point being the treble quality I think, but that is probably inherent in the hardware implementation.

Will try thanks.

 

[cfbruck]

Can Ainur Pandora be installed on Stock ROM or the ROM should definitely be LOS based?

I tried on both stock and LOS, clear difference on both so it seems to work with both. With the mod I actually preferred LOS.

The same developer also has another mod that is called Nero which is supposed to bypass a lot of stuff and send the audio signal directly to the dac. Sounds good in theory I think, but I couldn't tell any difference at all, not sure if it installed correctly. If anyone tries it gets it to work/notices any difference it would be interesting to hear.

 

[MaxRink]

Has any1 tried los vs stock with extremely high sensitivity iems?
I notice a rather high noise floor on stock, with both dacs

Gesendet von meinem ZTE A2017G mit Tapatalk

 

[eMadman]

Your post touches on some of my bluetooth audio "issues" on LOS. The volume curve is not even at the lower registers and on low impedence headphones, can easily get to the point of causing clipping and hearing damage at just 50% volume. There's a huge jump in volume from a volume of 3-4 over bluetooth that I can't seem to figure out how to manage.

You can see my research in my post in the Lineage thread here: https://forum.xda-developers.com/showpost.php?p=71934393&postcount=2344

Do you have any thoughts on how i can modify LOS to account for this?
@MaxRink - LOS on stock with my low impedence IEMs (Shure SE 425) direct to the headphone port works great. The volume curve is well balanced with stock lineage OS, but you should be able to mess with audio_policy_volumes.xml to get the curve to your linking.

 

[MaxRink]

thats actually not my issue
my issue is, that i have a rather huge ammount of background noise which especially noticeable when listening to speech at lower volumes. iot might be an opamp issue tho

 

[senny22]

Has any1 tried los vs stock with extremely high sensitivity iems?
I notice a rather high noise floor on stock, with both dacs

Gesendet von meinem ZTE A2017G mit Tapatalk

No hiss on any rom with my momentum in ears but they aren't really that sensitivity either.

 

[senny22]

Your post touches on some of my bluetooth audio "issues" on LOS. The volume curve is not even at the lower registers and on low impedence headphones, can easily get to the point of causing clipping and hearing damage at just 50% volume. There's a huge jump in volume from a volume of 3-4 over bluetooth that I can't seem to figure out how to manage.

You can see my research in my post in the Lineage thread here: https://forum.xda-developers.com/showpost.php?p=71934393&postcount=2344

Do you have any thoughts on how i can modify LOS to account for this?
@MaxRink - LOS on stock with my low impedence IEMs (Shure SE 425) direct to the headphone port works great. The volume curve is well balanced with stock lineage OS, but you should be able to mess with audio_policy_volumes.xml to get the curve to your linking.

I have noticed that the absolute Max volume on stock is the same volume as ~75% on LOS based Roms so I don't think that it all lies in the volume curve settings. I didn't push the volume above 75% on LOS because I didn't want to risk damaging my headphone although that's probably very unlikely.

 

[dyonoctis]

I think that I've read in the german forum that the super was indeed a switch for the ak4490, while the ak4691 is used for everything else. If you are using bluetooth, the phone will use the ak4691 (the super switch doesn't work on bluetooth) same for dolby.

 

[awsomjgp]

I tried on both stock and LOS, clear difference on both so it seems to work with both. With the mod I actually preferred LOS.

The same developer also has another mod that is called Nero which is supposed to bypass a lot of stuff and send the audio signal directly to the dac. Sounds good in theory I think, but I couldn't tell any difference at all, not sure if it installed correctly. If anyone tries it gets it to work/notices any difference it would be interesting to hear.

Same, tried on RR and noticed a huge difference. Made it sound louder and clearer.

Edit: At least on the speakers, haven't tried headphones.

 

[senny22]

I think that I've read in the german forum that the super was indeed a switch for the ak4490, while the ak4691 is used for everything else. If you are using bluetooth, the phone will use the ak4691 (the super switch doesn't work on bluetooth) same for dolby.

Interesting. Do you know which of the DAC/amps are in use in AOSP ROMs?

 

[dyonoctis]

It seems that the jack output on los is using the ak4490 all the time, and the ak4691 for the other stuff. The snapdragon dac isn't utilised at all according to what they said on the german forum.
you can find this in Los mixer file:
<!-- Hi-Fi Audio -->
<ctl name="AKM HIFI Switch Sel" value="ak4961" />
<ctl name="AKM HIFI Switch Mute" value="off" />
<ctl name="AKM HIFI PW" value="off" />
<ctl name="AK4490 BICK Frequency Select" value="48fs" />
<ctl name="AK4490 Lch Digital Volume" value="0" />
<ctl name="AK4490 Rch Digital Volume" value="0" />

I just wish that zte could have more polished their software when it comes to audio. compared to the Lg V20 or even some android chinese DAP it feels so basic...

 

[senny22]

It seems that the jack output on los is using the ak4490 all the time, and the ak4691 for the other stuff. The snapdragon dac isn't utilised at all according to what they said on the german forum.
you can find this in Los mixer file:
<!-- Hi-Fi Audio -->
<ctl name="AKM HIFI Switch Sel" value="ak4961" />
<ctl name="AKM HIFI Switch Mute" value="off" />
<ctl name="AKM HIFI PW" value="off" />
<ctl name="AK4490 BICK Frequency Select" value="48fs" />
<ctl name="AK4490 Lch Digital Volume" value="0" />
<ctl name="AK4490 Rch Digital Volume" value="0" />

I just wish that zte could have more polished their software when it comes to audio. compared to the Lg V20 or even some android chinese DAP it feels so basic...

Do you know why the value on the last two lines is at 0 if it's that DAC that's in use?

 

[dyonoctis]

Do you know why the value on the last two lines is at 0 if it's that DAC that's in use?

I honestly don't know why. But the stock file show the same lines with the same value.

 

[senny22]

I honestly don't know why. But the stock file show the same lines with the same value.

Ahh ok thanks.

 

[cfbruck]

Tried some more - RR rom 7.1.2 with beast mode kernel and the Ainur Pandora gives me the best sound. (Better than nuclear I'd say).