This is the review and measurements of the audio performance of LG G7 ThinQ smartphone. It was purchased by my son a couple of weeks ago. It retails for USD $750. Its claim to fame is inclusion of an ESS quad (four paralleled) DACs ES9218P with integrated headphone amplifier.There are actually two DACs in there with Quad DAC by default not selected.I suspect they don't leave it as default because it uses more power and would hurt benchmarks and battery life.It even has fancy audiophile reconstruction filter choices:Default was "short" (apodizing) filter. As seen above, we did our testing using Sharp filter.Is this all fluff or does it perform? Let's find out.Let's start with our usual dashboard view of a 24-bit, 1 kHz tone at 44.1 kHz sampling:Wow, that is impressive. SINAD (signal above power of noise+distortion) is in desktop DAC category:As shown above, the standard DAC is no slouch either, clocking at 105 dB in SINAD.Both leave my Samsung S8+ deep in the dust at just 89 dB...Dynamic Range (SNR) is pretty good with both DACs:The Standard DAC has lower output though:Just 0.8 volts output? That is darn anemic but more on that later.In preparing for these measurements, I assumed that LG was not thoughtful enough to have its media player bypassing the Android audio stack. So we downloaded the USB Audio Pro player for $8 and gave that a try. Performance was initially disappointing:No matter what we tried, we could not get better numbers. Indeed none of the settings in the player made any difference! Hearing that the LG G7 supports MQA, on a whim, we tried that option in the player:That did the trick:This shows that the Android audio pipeline is limited to 16 bits so best to avoid it if you can. Fortunately the LG player does that and therefore, there is no need to buy USB Audio Pro (unless you like its interface better).All was not perfect here. LG has some screwy logic where it examines the impedance of the headphone and messes with the output level and hence power. This was not always consistent. We managed to get outputs as high as 2 volts RMS but other times, it would step down to 1.5 or even 1 volt. After a while, we managed to get consistent outputs resulting in these power numbers relative to load (just a volume step below clipping):As we see, the headphone amp does not like low impedances. It sharply drops output voltage resulting in very low power outputs. This is the opposite of external headphone amplifiers where lowering the load impedance increases their output power.Output impedance was a low 1.6 ohm:Channel balance was of course perfect due to digital volume control:I did some brief testing with two of my headphones. Using the HifiMan HE-400i, the output was very anemic. Its 35 ohm impedance forces the headphone amp to clamp down resulting in too little power. Switching to Sennheiser HD-650 results in a far more satisfying experience given its 300 ohm output. Mind you, it is not super loud but good. My Etymotic ER4 SR produced decent levels too but still not loud enough.The LG G7 ThinQ DAC produces exemplary performance. It destroys the Samsung S8+. I was impressed that they paired good playback software with the hardware to make sure the Android limitations of 16 bit audio don't get in the way. Even its non-quad DAC produces class leading results.The weak point is the headphone amplifier which has a mind of its own and severely limits output power into small load impedances. As such an external portable headphone amp would be necessary for proper performance for most headphones. No need to augment it with a DAC though as the LG G7 DAC outperforms just about all the portable DACs.While I have only tested two modern smartphones so far, theWell done LG!-------------As always, questions, comments, recommendations, etc. are welcome.If you like this review, please consider donating funds to support these reviews using Patreon ( https://www.patreon.com/audiosciencereview ), or upgrading your membership here though Paypal ( https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ).