[SeeSax]

Have you tried it with a mojo yet?  I can't find a way to get past the phone's auto re-sampling to 96kHz, it's annoying me now!!


I agree with your review though, great phone so far!  Feels a lot better than I was expecting it to as well.

I'll give that a try today but that probably requires USB Audio Player Pro. I've never been able to bypass that on any Android phone without it unfortunately.

 

[jamestux]

I'll give that a try today but that probably requires USB Audio Player Pro. I've never been able to bypass that on any Android phone without it unfortunately.

I can't use UAPP, I'm assuming that it's not been certified for Nougat yet. I have it on multiple Marshmallow devices already but it just doesn't appear yet on the Pixel

 

[wersus]

Has anyone tested how badly is the hiss with Shure SE846? Especially with quiet classical music? Will I be shocked after V10?

 

[reginalb]

Well, it plays high resolution files, if that's your thing, but output impedance is clearly a little bit high:
 
Google Pixel XL with Unique Melody Merlin load:
 

 

  Okay, Folks. A bit more in depth this time now that I've had more than two hours with the Pixel XL. 
 
Test IEMs: MusicMaker Shockwave III
Test music: Tidal Hi-Fi (various songs)
 
Audio Quality (the most important, right?): I can now detect substantial differences in the sound signature between this and my S7 Edge (Exynos with the "Lucky" DAC chip). While volume levels are nearly identical, the bass on the Pixel is much more profound and bordering on "boomy" in comparison. I have found this to be the case with non-Aqstic run of the mill Qualcomm DAC chips and I don't think this is much different. I found the same on my HTC 10 in comparison as well. Mid range is probably the most similar frequency range on the two and I find it pleasant, nothing to complain about. Treble is probably where the biggest difference lies and this is probably the only letdown for me: it is rolled off compared to both the iPhone 7 and the S7 Edge. For those who are treble sensitive, this might be a blessing. For me, I love my treble and even on some of the brightest equipment that people complain about, I enjoy it. The silver lining is that I can REALLY crank it up with the SW3 IEMs, but, I still found myself wanting a bit more treble extension. SQ-wise the treble is fine, no sibilance, no grain per-se, I just want more of it. Background noise is nicely silent and I heard no hiss with Sony XBA-300, Shockwave III or HiFiMan RE-600. Overall, I find this to be a very pleasant-sounding phone with a slightly "consumer" sound signature for lack of a better word. I do not think it competes with my old V10 or G5 with HiFi module, but for how much I love the phone I find the sound quality great and perfectly tolerable. After all, I have a Chord Mojo or an elaborate desktop rig if I really need to split hairs. 
 
Camera: This thing is FAST. They weren't kidding with their demos and I love that it's always shooting in HDR with no speed penalty. It's also very cool how it has no bulge on the back and it's very noticeable. The double press on the power button is not as elegant as the quick launch on the iPhone or S7, but it gets the job done and the camera makes up with it with speed. Images look great, very neutral and accurate color and plenty of sharpness. Overall no complaints and it's really nice to see a Google phone finally live up to most of the hype. It's not going to replace a DSLR though (and I laugh that Apple thinks the iPhone 7 Plus can). 
 
Everything Else: I really like the new version of Android. It's fast, fluid, zero lag and it's just overall a breath of fresh air. I like the new launcher, but I found myself stumbling to get to my apps a few times in the beginning. The Google Assistant to me doesn't offer a ton more functionality than the older Google Now, but it's a nice update and fun to play with. More of a novelty right now, but, it has potential. I never thought I would write something like this, but I think my absolute favorite part of the software are the new wallpapers. Google has finally tapped into the LOADS of beautiful images they have and you have probably 200 choices (or more) for wallpapers. I know this is minor and possibly comical, but my wife and I were enamored last night browsing through all of them available. Really, really well-done. Also, this phone doesn't feel any bigger than the S7 Edge. My concern, based on Phone Arena's size comparison, would be that it was simply too large. It feels about the same and very usable. Battery life was great the first day, but I'll reserve judgement. It also seems to pick up a stronger signal than my S7 Edge did. 
 
Overall: I love it. I love it so much that I listed my S7 Edge on Swappa this morning. While the S7 Edge might be a bit more elegant and have preferable sound quality to some, I absolutely love "stock" Android and I am all in for Google's latest phone. Yes, it's expensive, but it is a step in the right direction that I want to support. 
 
Cheers friends, 
 
-Collin-

 
Boomy bass is likely due to the output impedance, you can see above a low impedance load, it's pretty flat unloaded:
 

 
By the way, a bit better with a 32‎Ω load:

 
Similar loads on a ZX1 and an AK300
 

 

 

[NullZero]

Some really useful data by 'chdloc' over at XDA (not me):
http://forum.xda-developers.com/pixel-xl/how-to/headphone-output-objective-data-audio-t3488211
 

Introduction
I created this thread to post and discuss measurements and data related to audio fidelity of the headphone output. Note that audio fidelity does not automatically correlate with audio quality. Audio quality is a very subjective measure. Some people like their audio to be very bass heavy while others prefer accentuated mids and/or highs. Yet others (like myself) enjoy a very "neutral" sound signature. Audio fidelity -- at least the way I define it -- on the other hand can be measured: Audio data is fed to the DAC/amp and measured at the output. For perfect fidelity, the recorded output is identical to the input. Of course, this ideal cannot be achieved. Deviations from the ideal can be measured, documented, and discussed. Particularly, not all deviations from the ideal are actually audible. I predict some heated discussions on audibility in this thread going forward...   

Test Equipment
The device under test (DUT) is a Pixel XL that sports a Qualcomm WCD9335 codec/amp discrete audio chip. The headphone output is split with a Y-wire. One signal path goes into the measurement rig, a Rohde & Schwarz UPV Audio Analyzer. Depending on the measurement, the other end either stays open (not connected or N/C) or connected to my Sennheiser IE800 IEMs. Those IEMs have a virtually frequency-independent impedance of 16 Ohm, a sensitivity of 125 dB/Vrms at 1 kHz, and a ruler-flat phase response. These IEMs are not only one of the best "sounding" headphones I know, but actually very easy to drive as the specs that I've listed show.
 
Test Signals
For the tests conducted so far, I have used two signals that I created with Matlab:
 

1. stereo wave file with full-scale (0 dBFS) 1 kHz sine wave in the left channel and silence (zeros) in the right channel (16 bit, 48 kHz sampling rate)
2. stereo wave file with white noise mastered to take advantage of the full dynamic range (16 bit, 48 kHz sampling rate)

These signal were played with the stock Android music player, with all audio effects disabled.
In some cases I swapped the Pixel XL with an iPhone 5s for comparison purposes. All other hardware stayed the same.
 
Measurement Results
This section summarizes the measurements detailed in the second post.
 
Output Impedance
The Pixel's output impedance was measured to be 4.8 Ohm. To compare, the output impedance of the iPhone 5s' amp is 2.0 Ohm.
 
Comments: The Pixel's output impedance violates the often-quoted 1/8 rule in some cases. The rule says that most amps work best with headphones that have an impedance that is at least eight times its own output impedance. According to this rule, headphones should ideally have an impedance of more than 40 Ohm. Nevertheless, the amp seems to work with my 16 Ohm IEMs without any issues (other than the level drop, see below). The reason, I think, is that my IEMs make use of a single dynamic driver rather than multiple balanced armature ones like many other IEMs. Multiple balanced armature drivers are much harder to drive and may cause minor problems (slight modification of the frequency response) with the amp in the Pixel
 
Frequency Response
The frequency response is ruler flat, whose shape does not change at all once my IEMs are plugged in a load. The gain dropped by 2.3 dB after plugging in the headphones. The reason for this drop is the interaction of the headphone's impedances with the output impedance of the amp. Higher impedance headphones will see a smaller drop in volume when plugged into the Pixel.
The channel imbalance is a negligible 0.1 dB at 1 kHz.
 
Comments: As discussed above, the only potential issue I can see here is that the combination of this amp with low-impedance multiple armature-based IEMs may lead to slight modifications in the overall frequency response, maybe on the order of +/- 2 dB.
 
Maximum output level
When the volume on the Pixel is turned up all the way, the maximum attainable output voltage with a full-scale 1 kHz sine wave is 0.427 Vrms, without any load attached. I have found that the output volume was capped digitally to -7 dBFS in the mixer by Google. The maximum theoretically attainable output voltage of virtually any DAC/amp combo devices is 1 Vrms.  Once a custom recovery has been made available for the Pixel, it should be trivial to boost its maximum output voltage to 1 Vrms.
 
Comments: No issues here.
 
Volume level steps with volume rocker
As discussed above, at max volume the Pixel delivers 0.427 Vrms, which is volume step 15.
Lowering the output volume from the maximum setting, 15, with the volume rocker results in the following steps (rounded):
Volume setting: 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
Change in gain: 0dB, -3dB, -3dB,-3dB,-3dB,-3dB,-3dB,-4dB,-4dB,-3dB,-4dB,-4dB,-4dB,-7dB,-7dB,-54dB
 
Noise Floor
The noise floor was measured to be 115 dB, which gives a theoretical dynamic range of 115 dB.
 
Comments: No issues here.
 
Total Harmonic Distortion + Noise (THD+N)
Measurements of THD+N were done on both iPhone 5s and Pixel at their respective maximum volume as well at a volume setting that corresponds to an output voltage of around 20 mV, with which the IE800 would produce around 90 dB SPL: Pixel at 20 mV: THD+N is -71.4 dB Pixel @ max volume: THD+N is -81.3 dB iPhone 5s at 20 mV: THD+N is -78.7 dB iPhone 5s @ max volume: THD+N is -84.1 dB
 
Comments: By comparing the plots in the second post, it can be seen that the Pixel has higher non-linear distortions than the iPhone 5s, especially at low output voltages. The reason for this is that Google and I believe any other Android manufacturer opts to maximize analog gain while controlling overall level with digital gain only. This is not ideal. It would be better to hit the codec with the highest digital gain possible (but no more than 0 dB), keep the analog gain low initially and control overall loudness with the analog gain only. This way the full dynamic range of the DAC can be utilized. This is the paradigm that virtually any home/car stereo systems utilizes. Based on the plots below, I'm guessing that Apple is doing it, too.
 
 
Stereo Crosstalk
Stereo crosstalk very much depends on the interaction of amp, headphone, and analog circuit design of the phone. Here, at least on the surface, the Pixel does not seem to be showing strong numbers. With my headphones attached and throughout the volume range offered by the Pixel, I measured the stereo crosstalk to be 45 dB. I compared this number with the iPhone 5s. Interestingly, stereo crosstalk on the iPhone shows a strong dependence on the playback level. Again with the IEMs attached the crosstalk ranged from 43 dB at the lower volume settings up to 60 dB at the higher end. I repeated the measurements with full-size cans, the Sennheiser HD 540 (300 Ohm). With those headphones attached, the stereo crosstalk of both the iPhone 5s and the Pixel are north of 80 dB.
 
Comments: To put things into perspective, though, at the playback levels that in the long run do not cause permanent hearing loss (less than 90 dB SPL at the ear drum) with the IEMs, both iPhone 5s and Pixel have very similar stereo crosstalk performance, i.e. around 45 dB. Carefully controlled double-blind tests should be considered to determine at what point crosstalk actually becomes audible.
 
Comments on the Pixel mixer
There is one thing that strikes me after having examined the Pixel mixer (/system/etc/mixer_paths.xml): The amplifier is setup as "CLS_H_LOHIFI" and not as "CLS_H_HIFI", which is the default for the WCD9335 in general and the HTC10 in particular. While I don't know what exactly the differences between those two settings are, I will play around with them as soon as a custom recovery becomes available.
 
 
Supporting graphs
Pixel "frequency response" at 20 mV output voltage. Note that the 2.3 dB level drop to to the presence of the IE800 has been compensated for:

Pixel "frequency response" at maximum output voltage. Note that the 2.3 dB level drop to to the presence of the IE800 has been compensated for:

Pixel THD+N at 20 mV output voltage (only the left graph is relevant):

Pixel THD+N at maximum output voltage (only the left graph is relevant):

iPhone 5s THD+N at 20 mV output voltage (only the left graph is relevant):

iPhone 5s THD+N at maximum output voltage (only the left graph is relevant):

 

[SeeSax]

So I'm back after a few more days and my initial assessment is largely still true, but, things have become more apparent. There is a definite lack of treble energy in comparison to the iPhone 7 and the bass is still "boomy" and not as tight as the iPhone. This is not bad, per se, but it's an easily recognizable difference and that may not suit some folks. Unfortunately, I really like my treble and have never found any earphones to be too sibilant or have too much treble. I find that the Pixel does not suit my style as much as I would like, but, the phone is still good enough for me to keep. I really, really want to try the V20 as I remember having zero complaints about the sound of the V10 and G5/HiFi module. Even with my brightest headphones (MDR-EX1000, DQSM D2, Shockwave 3), I am wishing for more treble on the Pixel. 
 
-Collin-

 

[MosIncredible]

The GSM review is here. 
 
http://www.gsmarena.com/google_pixel_xl-review-1513p7.php
 

Audio quality is good, not quite the best

When plugged into an active external amplifier, the Google Pixel XL posted excellent scores top to bottom and garnished them with very high volume levels. Certainly one of the best performers on the market here.

 

Plugging in a pair of headphones causes moderate damage to stereo quality and introduces a tiny bit of extra distortion. Neither is too big a deal, but when coupled with the loudness drop to just above average you are no longer looking at a class-leading performer.

And now here go the results so you can do your comparison.

 

 

[Mariano3113]

Some really useful data by 'chdloc' over at XDA (not me):
http://forum.xda-developers.com/pixel-xl/how-to/headphone-output-objective-data-audio-t3488211

Have my Pixel Rooted and took a snippet of Pixel mixel_path.xml

Seems to have lowered Bass roominess, but about to install Elemental Kerbal and tweak audio that way.

(Viper4 Android failed to install driver even with BusyBox installed. Same with SElinux mode changer also failing.)

Will play around with some tweaks this week.

Edit:
Missed a another XML edit: "RX HPH Mode" value="CLS_H_LP" compared to HTC 10 & Note 7 (Snapdragon) "RX HPH Mode" value="CLD_H_HIFI"
Before:


After:

 

[Emerald Core]

Pixel is more of everything except being ultimate entertainment device like some competition. 

 

[Mariano3113]

Pixel is more of everything except being ultimate entertainment device like some competition. 

Entertainment is a rather broad category.

Google is making big promises with Daydream.

I can't speak in regards to gaming.(I don't play mobile games)

As far as Audio and Movies: After some 'Root' tweaks the audio is how I remember Snapdragon Note 7; so I am satisfied. (Maybe the HIFI settings were overlooked by Pixel staff)

Movies performance for me seems fine: I have them stored on a USB 3 flash drive. (Makes it easier to use USB OTG to watch on different devices)

Definitely not the media content device that the LG V20 is in regards to audio DAC and recording Audio. (But I don't think LG is attempting to do VR, definitely not Daydream given missing spec prerequisites.)

Apple seems like a step backwards if looking at iPod with Phone capabilities: removal of headphone jack and no-video out of old.(I suppose they just want Apple TV/Chromecast to be the transport....fully embracing Wireless except for Charging.)
LOL of the next iPhone has no ports at all: I will give them a thumbs up: Wireless or contact charging and continuation of no headphone jack. They can go back to proprietary PC connections, while toting a full wireless Phone.

Samsung and HTC both removed IR blasters and HTC moved away from front facing stereo speakers which seems backwards. Plus removal of headphone jack on new HTC Bolt, ugh.

Samsung seems closest to Pixel in terms of entertainment: albeit with expandable storage catering to Audio and Movies. Also their audio was better out of the box: clearly a more polished device.

(Aside from Note 7 debacle)

 

[SeeSax]

Entertainment is a rather broad category.

Google is making big promises with Daydream.

I can't speak in regards to gaming.(I don't play mobile games)

As far as Audio and Movies: After some 'Root' tweaks the audio is how I remember Snapdragon Note 7; so I am satisfied. (Maybe the HIFI settings were overlooked by Pixel staff)

Movies performance for me seems fine: I have them stored on a USB 3 flash drive. (Makes it easier to use USB OTG to watch on different devices)

Definitely not the media content device that the LG V20 is in regards to audio DAC and recording Audio. (But I don't think LG is attempting to do VR, definitely not Daydream given missing spec prerequisites.)

Apple seems like a step backwards if looking at iPod with Phone capabilities: removal of headphone jack and no-video out of old.(I suppose they just want Apple TV/Chromecast to be the transport....fully embracing Wireless except for Charging.)
LOL of the next iPhone has no ports at all: I will give them a thumbs up: Wireless or contact charging and continuation of no headphone jack. They can go back to proprietary PC connections, while toting a full wireless Phone.

Samsung and HTC both removed IR blasters and HTC moved away from front facing stereo speakers which seems backwards. Plus removal of headphone jack on new HTC Bolt, ugh.

Samsung seems closest to Pixel in terms of entertainment: albeit with expandable storage catering to Audio and Movies. Also their audio was better out of the box: clearly a more polished device.

(Aside from Note 7 debacle)

 
I've been following XDA and just saw that the phones can be rooted (even the Verizon one). Can you give a bit more detail in the root tweaks? Previously, I've modified the "mixer_paths" file to get more volume on Snapdragon DACs and would be very curious if that is the case on the Pixel too. I saw some posts about higher volume just not being enabled from the factory. Any info would be awesome - thank you!
 
-Collin-

 

[Mariano3113]

I've been following XDA and just saw that the phones can be rooted (even the Verizon one). Can you give a bit more detail in the root tweaks? Previously, I've modified the "mixer_paths" file to get more volume on Snapdragon DACs and would be very curious if that is the case on the Pixel too. I saw some posts about higher volume just not being enabled from the factory. Any info would be awesome - thank you!

-Collin-

To make things easier I restarted settings without my convoluted adb commands.

Not sure if you have Elemental Kernel Manager ($3 from market) but if you want to tweak Color Calibration and use UI audio gains, it will be easier to use conjunction with Flashing Elemental Kernel for Pixel or Pixel XL.

After obtaining Root (and flashing Kernel).

I installed BusyBox (/su/xbin)

Next, I made audio Digital gains of +1DB for both channels in Elemental Kernel Manager.

Then using a Root Explorer (I used ES File Explorer)I navigated to /system/etc/mixer_paths.xml and used ES file editor to make changes.

From my above screenshots: there is one entry that is "CLS_H_LP" near the top about 65 lines down from the top that I changed to "CLS_H_HIFI" to match Note 7 and HTC 10 Snapdragon Aqstic.

Then there is a "CLS_H_LOHIFI" about 240 up from the end of the mixer XML file that I also changed to "CLS_H_HIFI".

Then I saved edited file.


After that I rebooted and checked file to make sure changes were committed.

Perceived to have removed the slight bass roominess.

I am pretty sure you can change the audio levels in the .xml if you need more listening volume.


I'm curious now to see if APTX-HD can be enabled since it should be supported by choose, just not being implemented.

Currently it feels like Google optimized software for what it deemed most important and even though there is Hardware there to support Aqstic driver and should also be there for APTX-HD; I feel like Google brushed over those.

(Unless they are planning an update to address those shortcomings when Daydream debuts, or after.)

-Mariano

P.S.- I did use Terminal Emulator to enable my Hotspot.

 

[SeeSax]

To make things easier I restarted settings without my convoluted adb commands.

Not sure if you have Elemental Kernel Manager ($3 from market) but if you want to tweak Color Calibration and use UI audio gains, it will be easier to use conjunction with Flashing Elemental Kernel for Pixel or Pixel XL.

After obtaining Root (and flashing Kernel).

I installed BusyBox (/su/xbin)

Next, I made audio Digital gains of +1DB for both channels in Elemental Kernel Manager.

Then using a Root Explorer (I used ES File Explorer)I navigated to /system/etc/mixer_paths.xml and used ES file editor to make changes.

From my above screenshots: there is one entry that is "CLS_H_LP" near the top about 65 lines down from the top that I changed to "CLS_H_HIFI" to match Note 7 and HTC 10 Snapdragon Aqstic.

Then there is a "CLS_H_LOHIFI" about 240 up from the end of the mixer XML file that I also changed to "CLS_H_HIFI".

Then I saved edited file.


After that I rebooted and checked file to make sure changes were committed.

Perceived to have removed the slight bass roominess.

I am pretty sure you can change the audio levels in the .xml if you need more listening volume.


I'm curious now to see if APTX-HD can be enabled since it should be supported by choose, just not being implemented.

Currently it feels like Google optimized software for what it deemed most important and even though there is Hardware there to support Aqstic driver and should also be there for APTX-HD; I feel like Google brushed over those.

(Unless they are planning an update to address those shortcomings when Daydream debuts, or after.)

-Mariano

P.S.- I did use Terminal Emulator to enable my Hotspot.

 
Super helpful. Pretty involved, I think I will leave the phone alone for now since it is plenty loud with all my IEMs. It would be nice to have less of the bass effect you mentioned, but I will see if I can build up the courage. I'm not a stranger to rooting/flashing/etc. but those were my younger crazier years
 
-Collin-

 

[Mariano3113]

Super helpful. Pretty involved, I think I will leave the phone alone for now since it is plenty loud with all my IEMs. It would be nice to have less of the bass effect you mentioned, but I will see if I can build up the courage. I'm not a stranger to rooting/flashing/etc. but those were my younger crazier years

-Collin-

To be honest the only part that is worrisome is the editing of the XML as there is a lot of lines to look at.

I do highly suggest unlocking Bootloader as that is prerequisite to "Flash Official Factory Images" in case the need arises.

Current Root method does not include a Custom recovery so it is just simply running a single adb command in CMD (if Windows).

After Root you could cheat with XML by saving a copy to PC and editing the file and then saving it back to correct location on device. (Also allows you to save it for others to use of also using Pixel XL)

 

[SeeSax]

To be honest the only part that is worrisome is the editing of the XML as there is a lot of lines to look at.

I do highly suggest unlocking Bootloader as that is prerequisite to "Flash Official Factory Images" in case the need arises.

Current Root method does not include a Custom recovery so it is just simply running a single adb command in CMD (if Windows).

After Root you could cheat with XML by saving a copy to PC and editing the file and then saving it back to correct location on device. (Also allows you to save it for others to use of also using Pixel XL)

 
When I tried this on an older Motorola phone, the system was "read-only" and the XML file kept reverting back to stock. Will I face that with this method? It was pretty frustrating
 
-Collin-