yashsingh1/xdaforums huggingface dataset:
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I asked my friend [MENTION=2760454]chdloc[/MENTION] and here is his response.

Incidentally, he has a PhD in electrical engineering and specializes in high end acoustics.

What that user links to mostly pertains to loudspeakers and only to a much lesser degree to headphones.

For loudspeakers, it is certainly true that a lot of air needs to be moved to produce low frequencies. Lorentz' law states that

force = (magnetic flux density)*(electric current)*(length of voice coil conductor)

This force is then exerted onto a membrane that moves the air. The more air is moved the louder (and potentially lower in frequency) it is.

Hence, it is actually more important for an amplifier to be able to deliver current rather than voltage. (Other important factors that impact the quality of low-frequency sound reproduction are the linearity of the magnetic field at the limits of excursion and the motor's thermal behavior.)

All of this is much less important for headphones as the drivers are extremely close to our ears, so the membranes don't have to move nearly as much, Also, the nearfield effect helps a lot with the low frequencies.

Unless a headphone amp engages its current limiter there should not be a problem. You can probably measure the linearity (presence of a limiter) of the amp driving a load quite easily: start with a low-level (low-frequency?) signal and increase the digital gain at set gain intervals. If the output level keeps increasing at the same intervals, then you know the amp is linear. Do this until get to max digital gain.

I will do some low frequency measurements with my Sennheiser 800s and report back.

Maybe we will both learn something.
[Google Pixel 2 XL Themes, Apps, and Mods] BaronInkjet:
[MENTION=281070]bjrmd[/MENTION]

One interesting test is to flip on the Spotify bass boost switch. The overall volume will immediately go down.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
It looks like about 80 % is correct--starts to go up after that--this is pretty good at 78%
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Spotify may volume normalize the tracks to prevent clipping-I would not put much validity in that observation.

Test of both HTC Dac and Google's

Compare no load vs HD 800s, both at max android volume and just manipulate the Dac gain from 50% to max.

Full scale 40 Hz sine

Conclusion--

Excellent linearity on both with no noticeable drop off at low frequency bass. The perceived sound was of excellent fidelity.
[Google Pixel 2 XL Themes, Apps, and Mods] BaronInkjet:
Whatever you say, [MENTION=281070]bjrmd[/MENTION]. :) I do appreciate your work helping us to understand the issues with the Google dongle and Android driver. Those were invaluable! :good:
[Google Pixel 2 XL Themes, Apps, and Mods] Telperion:
Awesome, thanks! I'm using 77% and the quality is excellent.

If anybody wants a tester song with pristine mastering, use Take The Power Back by Rage Against The Machine. The intro is perfect for testing audio equipment and settings. Many years ago this was recommended to me by an audio technician who set up large-scale concert rigs, it was his go-to song for checking out the sound prior to the shows.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I come from a very academic background (double boarded physician for many years). Part of my job has been to separate fact from misinformation based on objective research. With the help of some very smart people, I have learned something about limiting factors in audio fidelity and simply want to put that information out there. So if someone has a subjective opinion on how something sounds, that's fine, but it's opinion only. I know the manufacturers of expensive audio gear try to avoid this approach (remember the Nwavguy).

Thanks
[Google Pixel 2 XL Themes, Apps, and Mods] jasenko:
I had some other issues with Magisk and finally removed the root and returned to stock :(

At least I was able to test and enjoy for a little while. The best thing I learned out of it, Google dongle DAC is a beast, and by far the best value for money. I even preferred it to Dragonfly Black for rock music (dragonfly seems to cut the "edges" a little bit and mellows sharp and aggressive sounds).

Back to Dragonfly Black and USB Audio Player Pro combo for me... (until Google figures this out)
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I did some detailed looking at current limitation, seems we are pretty much in the clear.
[Google Pixel 2 XL Themes, Apps, and Mods] *justintime*:
Great addition for Audiophiles......

I have got one problem on Oreo it alway downmix to 48khz/24 bits....it's always using the inbuilt DAC. I have tried with every usb player out there.

Soundabout isnt working on Oreo.

Anything i could try here?
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
The Pixel 2 doesn't have an onboard Dac.

You are limited to Bluetooth or a USB Dac.
[Google Pixel 2 XL Themes, Apps, and Mods] *justintime*:
Yes i believe the U11 either. I phrased it wrong.
[Google Pixel 2 XL Themes, Apps, and Mods] willdo7474:
It does have an onboard DAC. How else would there be sound from the speakers? The onboard DAC just isn't used by the headphones.
[Google Pixel 2 XL Themes, Apps, and Mods] qnord:
Just wanted to share that this worked to significantly increase volume of Dragonfly Red on my Z3C as well. Thanks for sharing
[Google Pixel 2 XL Themes, Apps, and Mods] darjin77:
I installed version 33 APK on my taimen Pixel 2 XL (rooted with Magisk) (using DAC headphone connector that came with the phone). Had some strange issues where DAC increase/decrease wouldn't work, profiles wouldn't delete, USB Gain Control pop up wouldn't appear. Uninstalled, rebooted, and installed version 34. Now all of those features work properly.

Feature request: Enable/Disable so that I can hear the difference from before the mod was applied. Otherwise I'm not sure if it actually sounds better or just placebo.

Thanks!
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
To see how stock would sound/perform, all you need to do is set the Dac gain to max on the sliders. Using the Google dongle it would be 175 out of 175. I need to update the OP with V34.

So in most cases, the stock default Pixel Dac gain is set to max
[Google Pixel 2 XL Themes, Apps, and Mods] Telperion:
In future versions, can the app be updated to not show the splash screen when plugging in a recognized device with a profile?
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Sure, good idea.

Will try for this week.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
This version has a toggle for the popup, just click once to turn on/off.

It is on the main menu, you can get to it via the gain slider screen, press the 3 dot menu.

Also some bug fixes, support for Razer Dac, Realtec Dac, Dragonfly Black.
[Google Pixel 2 XL Themes, Apps, and Mods] Telperion:
Looks great, thanks!
[Google Pixel 2 XL Themes, Apps, and Mods] dricacho:
Just installed this in my Pixel 2XL. The volume gain seems to work although adjusting DAC, I couldn't really tell the difference. Also, choosing SPL Graph and turning on the visualizer doesn't do anything. I installed the v35.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Are you certain that you installed the correct tinymix file in the Download folder and it was automatically copied into the sbin folder on a reboot?
[Google Pixel 2 XL Themes, Apps, and Mods] dricacho:
I downloaded the tinymix.rar file, extracted tinymix from it and copied it into the Download folder and ensured that there is no file extension. How do I verify that it is copied into the sbin folder? Where is the sbin folder located? Also, I installed v35 and the SPL Graph is now coming up but no graph plots.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
It should be in the root folder /Sbin with the Magisk files.

Lets get the sound working first, then we'll work on the Spl.
[Google Pixel 2 XL Themes, Apps, and Mods] Sui77:
Hi!

I've got an Pixel 2 XL as a replacement for my Pixel XL (lucky man), but only the bare handset.

Now I have to buy a Dongle for using a 3,5mm headphone while cycling.

Which dongle would be the bets option? Google/HTC/???

THX
[Google Pixel 2 XL Themes, Apps, and Mods] BR7fan:
Your Pixel 2 XL didn't come with one? Mine did
[Google Pixel 2 XL Themes, Apps, and Mods] Sui77:
No, I got a replacement device, bare device without charger, dongle, etc
[Google Pixel 2 XL Themes, Apps, and Mods] BR7fan:
I just caught that,to late to edit lol
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I wrote up a comparison:

https://xdaforums.com/pixel-2-xl/how-to/pixel-usb-c-audio-measurements-t3691535

My favorite is the Google Dac dongle. It is based on a custom Realtec chip with great measurements.

It also is the lowest price, so you can get a spare or two.
[Google Pixel 2 XL Themes, Apps, and Mods] jtf420:
Sorry for the n00b questions, OP

1. Is this distortion problem Pixel 2 XL - Taimen specific? Or extends to Pixel 2 - Walleye as well?

2. You have mentioned U11 should have tinymix32 and the Pixel 2 XL the regular 64bit one. If the sound distortion problem extends to Pixel 2 - Walleye, which tinymix should be used?

Please forgive my questions but the phone model names and the mod file names have confused me.

I would like to thank you for the mod and the research. It was a very satisfying read! Best regards to you!
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Hi, I am happy to help.

The "distortion" banding is a function of how the Android os handles Dac gain. Instead of gradually increasing digital gain on the Dac, the OS sets it at max, then uses another gain control (the volume steps) to get a final output.

Unfortunately, setting the Dac digital gain to max is not optimal for distortion. This will occur on all stock Android devices. I just don't think optimal audio quality was high on the priority list at Google.

The Pixel 2 XL and the Pixel 2, should be treated as the same so use the 64 bit file.
[Google Pixel 2 XL Themes, Apps, and Mods] blyndfyre:
Which model of Schiit DAC do you have.

How is your Pixel 2 XL connected to the DAC?
[Google Pixel 2 XL Themes, Apps, and Mods] Jayme Helgerud:
I have the original Fulla which has been replaced by the Fulla 2. I'm using the included (with the pixel 2) USB C to USB adapter. The original Fulla is mini USB so I use a mini USB to USB cable which goes into the Pixel adapter.

In my case I did not go out and get anything certified for USB 2 or 3. This may or may not matter. I was a little surprised it worked first try given the ancient tech of the mini USB.
[Google Pixel 2 XL Themes, Apps, and Mods] blyndfyre:
I have been hesitating to get the Shiit Fulla 2 but you have given me a bit of confidence. I'm pretty surprised the USB C to USB adapter included with the Pixel 2 XL works.

I'm not rooted so I assume my digital signal out to the Shiit DAC won't be as good without rooting and using the audio control mod?
[Google Pixel 2 XL Themes, Apps, and Mods] Jayme Helgerud:
Actually the overall resolution is really good according to others with more wisdom in these forums. The advantage to rooting has more to do with altering the audio profiles of your streaming music....nothing beats viper4android replacing the sound FX for google play music or other streaming.

But if you own your music and can download a HD file then you can use Power Amp or other reputable apps to output HD music to your headphones using the Google DAC dongle or something like schiit or dragonfly. That said even crap mp3 files sound great on my Fulla and high quality headphones.
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
I tried this app on my U11 yesterday and it worked in the beginnign then the app stopped showing and when I unplug/plug the dongle it will say /proc/asound/card1/stream0 no such file or directory.

And yes tinymix is in the download folder
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
That error may mean that the dongle is not getting recognized.

Does it work if you uninstall my app?
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
Weirdly enough it worked by itself when I went to jogging, at first the volume was too low even though V4A and volume was at max, then I realized it's perhaps the dongle app and it launched ,changed the max power and sound was perfect :good:
[Google Pixel 2 XL Themes, Apps, and Mods] iridium7777:
i wrote this in another thread -- but is there a modified rom that would prevent android from upsampling 44.1 into 48KHz?

Specifically i'm looking for something that would have a system wide driver installed for natural bit-perfect pass through like the USB Pro Player allows inside its app only.

thanks

---------- Post added at 10:20 PM ---------- Previous post was at 10:20 PM ----------

i wrote this in another thread -- but is there a modified rom that would prevent android from upsampling 44.1 into 48KHz?

Specifically i'm looking for something that would have a system wide driver installed for natural bit-perfect pass through like the USB Pro Player allows inside its app only.

thanks
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
So all is working now?

I am not sure what if any interaction with viper there potentially could be.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I too have been looking for the same thing for years.

Another weird compromise by Google.

The sample rate is hard coded into audioflinger.

Only a custom driver like Neutron can bypass that.

Even if you used Neutron as such, you would lose notification sounds while playing music.
[Google Pixel 2 XL Themes, Apps, and Mods] iridium7777:
Neurtron only seems to play local music, there are no streaming options unless you're running your own server, is that correct?

I use USBPP because at least it allows for Tidal stream (i only have 64gb model so i'm not loading any music locally, i only stream), so i've been using that.

either way, i'd gladly lose notifications during music if i could have bit perfect path-through only any audio app, without running something sandboxed.

i really wonder if it's not possible to implement in a rom or if no one really cares enough to implement it?
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
Ok today I plugged the dongle:

-It worked

-I have set to max

-Went to save the settings by tapping the 3 dots

-The app window disappeared and I got a loop of messages like ''reading device'' ,''HTC'' ''settings unknown''

-Try to re-open the window of the app by tapping on the app's icon but no joy

-FC the app on purpose and re*-opened it, the messages loop came back and no window

-Unplugged the dongle and re-plugged it, the app didn't recognize it anymore :eek:
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
It would be great if that could be done but both I and [MENTION=2760454]chdloc[/MENTION] have done extensive testing of the built in resampler and there is no detectable distortion or compromise of signal. There must be some increased cpu utilization but how much is hard to say.

Bottom line-you won't hear the difference.
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I suspect there is some weird interaction with Viper +/- the U11.

Not sure what else to try. The app works fine with Pixel 1 and 2 for most folks.
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
I could bring back the app window by going to the statusbar :)

Though how to save the settings and make them the default when plugging the dongle?
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Give me a bit to look at this in more detail.
[Google Pixel 2 XL Themes, Apps, and Mods] iridium7777:
how and what did you (guys) test? with regards to the raw vs. reprocessed stream? what was measured -- can i read about it somewhere?
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Here are some old sweep tests I ran a few years ago looking at the resampler in the Sony M4 vs Note2 (native 44.1)

The top is the M4, then the N2 converting 44.1 to 48K (much banding distortion), then N2 native 44.1(no resample) then the N2 using Voodoo oversample option. You can see that the M4 (44.1 to 48k) is close to the N2. The oversample option in Voodoo sound made it worse.

The next was a look at the Neutron high vs low quality resampler vs a native 48 k sweep on the Note 4:

The top is Neutron high quality (partly cut window), then low quality sampler (more banding) then a 48K sweep (native).

Bottom line, after this I kind of gave up on pushing the issue although I wholly agree with you.

We also looked at some 1 Khz sine testing, maybe a couple of dB difference in harmonic banding (out of 80 dB from the peak signal).
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
I have made a few clean ups and disabled ambient notification (Pixel 2 only theoretically).

Try this version and let me know.

When you plug the dongle in, the initial window will give you a menu for transfer to the headphone screen to put in your data and settings as well.
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
Thanks!

It's better, though I still don't know how to save the settings as if I couldn't find a save option and if I tap on headhone,I add the name of my iem then enter the app will close, when I open it again the DAC level is back to the lowest even if I pick my iem name again
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
When you choose the "headphone" menu, you get to this screen:

Then enter all data including the start volume and percent gain, press enter and it should save. Are you saying that it does not?
[Google Pixel 2 XL Themes, Apps, and Mods] vegetaleb:
Actually the numbers were not right, for example in the beginning I used DAC 14 and it saved it to 2, then I saw the max % thingy and used 100% it saved it to 1, then saved it to 99 and it saved it to the max being 14, though volume sticks to 15 whatever I put 22 or 25
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
A few thoughts.

If your device only has 15 or 20 volume steps, don't go above the limit. The new pixel has 25, but the HTC may not.

The initial Dac gain on the entry screen above is a percent for a reason. All of the Dacs have a different gain range (Google is 175, Dragonfly 64, HTC 14). So when I wrote this, I needed to be somewhat creative in making it work for multiple Dac units.

So if you have an HTC Dac and choose 50%, that translates to a Dac gain of 7 (which is what you may be seeing. If you save it to 100 (or close due to rounding), then 14 will be the max gain achieved.
[Google Pixel 2 XL Themes, Apps, and Mods] swieder711:
I have a few Shure headsets with mic (and 2.5mm plugs). I like to use them for phone calls. To get these headsets to work with my old Moto X Pure phone, I needed to add an inline impedance adapter. I also have a 2.5mm to 3.5mm converter. It is a bit of a mess, but I like the boom mic on Shure headset!

I see an adjustment for impedance in the screen for the headphone adjustments of your app. If I want to use the Shure headset with a Pixel 2 XL phone. Do you think that your app would remove the need for the inline impedance adapter?
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
The impedance "adjustments" are for the app to know the impedance of the headphone in order to accurately predict the SPL.

So, no- if you need more impedance this won't help.

Be aware that using an inline impedance adapter raises the impedance of the player, not the headphones. If you are using multidriver iem's with variable impedance(like my SE846) this will worsen the frequency response.
[Google Pixel 2 XL Themes, Apps, and Mods] flummi3000:
I also got the shure se846, would you share your settings?

Gesendet von meinem HTC U11 mit Tapatalk
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
You bet:

Se846 - initial volume 23, initial gain .46 = 46percent
[Google Pixel 2 XL Themes, Apps, and Mods] flummi3000:
Thanks. I am not sure but I think I read your review at Amazon about the db magix ac3c amp. Was about to buy it, because it sounded pretty good but 40ohm impendence is a bit high for shure se846.

Gesendet von meinem HTC U11 mit Tapatalk
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Absolutely, the frequency response curve would he dramatically altered.

Believe it or not, the cheap stock Google adapter is quite good.

I just got a set of Mee aptx Bluetooth cables with mmcx connectors to use with the se846. The frequency response curve was unchanged, so the output impedance should be low.

I'll try to write up a review for everyone.
[Google Pixel 2 XL Themes, Apps, and Mods] DMechnikov:
Thank you for this, it’s brilliant! I seem to have a knack for getting IEMs that are much to loud at the lowest volume on my phones, and I had the same issue with my Shure SE215s connected to the Pixel 2. Set them up at 22% gain for the DAC, and things are perfect for quiet listening.
[Google Pixel 2 XL Themes, Apps, and Mods] Freak07:
Hey [MENTION=281070]bjrmd[/MENTION]

I just wanted to drop you a huge thanks from a fellow audio guy! I managed to get my hands on a HTC U12+ and your mod works there still flawless with the 32bit tinymix binary!

I can enjoy my dragonfly red again to the fullest thanks to you!

Have a great day and keep up the good work :)

So somehow having usb c and the dragonfly is also an advantage because I can just carry my good audio from one phone to another!

Thanks again!
[Google Pixel 2 XL Themes, Apps, and Mods] cmh714:
Quick post since I am about to play with this, the tinymix file did NOT copy over automatically. I had to do it myself. No biggie. And that was trying the v.36 apk.....

Just copied it myself and changed the permissions accordingly.

Thanks for the work!!!

---------- Post added at 11:16 AM ---------- Previous post was at 10:29 AM ----------

OK, not hearing or seeing the changes as described....Pixel 2 XL, rooted, app and tinymix installed. This test is with the Google adapter that came with the Pixel and Bose QC3 headphones. I generally use PowerAmp but for HD I use USB Pro Audio mostly.

The UI renders and I configure but ONLY the device volume is working. Nothing on the DAC side....but if I read/understood correctly that is built-in to the dongle. Can someone confirm for me? I will try and dig up my v1 DragonFly to see if I can get that working.....assuming it will work on an old Black DF....
[Google Pixel 2 XL Themes, Apps, and Mods] bjrmd:
Something isn't right if you need to manually copy tinymix. Remember that the tinymix file doesn't stick on a reboot, so my app is designed to automatically copy it from the download folder on each restart.

Also, the symptoms you describe mean that tinymix isn't working (so only Android volume is changing).

Double check that tinymix is the correct bit version and download it again. Also reinstall the app and make sure it gets permission for root.

Here is tinymix for the Pixel XL 2. Just unzip and place in download folder.
[Google Pixel 2 XL Themes, Apps, and Mods] cmh714:
Absolutely will give all of the above a try....however, I ONLY had to do the copy once, but I always have tinymix in /sbin after reboots so only the first copy seems to have failed on me for whatever reason. Going to try this version of tinymix to see if I goofed on the first d/l.

Stay tuned, will be in touch.....but regardless, appreciate the work still!