LG V20 Sound Quality
Oct 4, 2017 at 3:53 PM Post #2,960 of 4,141
Great, thanks. Looks like UAPP improved. Last time I tested its switches were not working as expected.
BTW, I assume you are playing lossless content, right?

Yes the files are all originally FLAC encoded. But at this point in the decode, lossy or lossless are the same PCM 44.1 stream handed off to android since the app is doing the file level decode. And even MP3 files all decode to the original PCM rate (usually 44.1)
 
Oct 4, 2017 at 4:00 PM Post #2,961 of 4,141
I've had some time to get used to the sound now and overall this is a stunning musical device. Especially considering it's not really a musical device....

The sound is absolutely grainless, punchy, detailed and smooth as silk. Still think there's a hint of sterility/coldness, but it's not as bad as I thought it was during my initial impression (I had a headache brewing that day that didn't help). It's not the best I've heard in the my life, but damn... I can probably live with this thing the rest of my life and be moderately happy.

On another note, I hooked it up to my Auralic Taurus amp and while it made a difference it wasn't as big as I expected. Both the DAC and amp inside this device are very good.

I have to agree 100%. This is why I think the LG V20 is such a steal right now, just as a DAP -- even forgetting it is a very good smartphone. Some of the magic we are hearing in the V20 is because of the Pro (latest gen) core used in the 9218. It just has amazing resolution and inner detail. Part of it is the great design of the Class-G headphone amp in the part. Simplicity has its virtues, and as discrete designs are best of breed -- it is astounding how much performance comes out of this singular IC solution with a very basic design.
 
Oct 4, 2017 at 4:19 PM Post #2,962 of 4,141
does anyone know if adjusting the balanced knobs in the high res sound settings would improve sound quality? i heard decreasing both to -3dB or -6dB would increase dynamic range

Are you talking about the Hi-fi DAC volume knobs under sound settings? These are actuated automatically everytime you change the android master volume toggle on the physical phone. It is just a way to control left and right balance independently. They in-turn all act on the AVC where the volume is lowered in the analog domain entirely in the Hi-Fi DAC. So lowering the volume will lower the noise floor by the same amount. I dont see how it can improve DNR though, because max volume was just decreased by that same amount. The great thing here is that bit depth is not touched as in digital volume attenuation. That is at least my understanding...please correct me if I am wrong.
 
Oct 4, 2017 at 4:46 PM Post #2,963 of 4,141
Are you talking about the Hi-fi DAC volume knobs under sound settings? These are actuated automatically everytime you change the android master volume toggle on the physical phone. It is just a way to control left and right balance independently. They in-turn all act on the AVC where the volume is lowered in the analog domain entirely in the Hi-Fi DAC. So lowering the volume will lower the noise floor by the same amount. I dont see how it can improve DNR though, because max volume was just decreased by that same amount. The great thing here is that bit depth is not touched as in digital volume attenuation. That is at least my understanding...please correct me if I am wrong.

i don't get how volume can affect bit depth. how loud does it have to be to experience 24-bit or 1 bit DSD? (by loud i mean both in dB and in the volume number on the phone)
 
Oct 4, 2017 at 4:58 PM Post #2,964 of 4,141
i don't get how volume can affect bit depth. how loud does it have to be to experience 24-bit or 1 bit DSD? (by loud i mean both in dB and in the volume number on the phone)

The way traditional digital volume controls work (including the way the Snapdragon ASICs work) is simply truncating the bit depth. With each digit you drop you increase the attenuation of the resulting signal by several DB. Remembering that bit depth is the way all dynamics are conveyed in PCM. With AVC in the Hi-Fi DAC bit depth is retained, and attenuation is done entirely in the analog domain (like a potentiameter does). It is done in the IC still, but on the analog signal before it exits to the headphone jack.

There are ways around stopping loss of quality with digital volume controls.....especially by padding the 16 bit word to 24 bits... or even 32 (as in modern DACs). Thus reducing the low order bits isnt actually touching the original signal. But this doesnt have the benefit of reducing noise floor as AVC does as the volume drops.

With DSD it is much trickier --- because we have to peel back the onion even further to understand better what is going on. Realizing that even PCM gets converted inside the DAC to a pseudo DSD stream. This is the way all Delta-Sigma style DACs work. So even with PCM we are listening to DSD really. with DSD natively rendered (cant access this yet on the 9218 in the V20), the pipleline is more simple. But whenever we listen to DSD today, it is converted to PCM first....treated exactly like a native PCM stream from that point -- including the seemingly redundant conversion back to DSD inside that Delta-Sigma DAC.
 
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Oct 4, 2017 at 5:37 PM Post #2,965 of 4,141
The way traditional digital volume controls work (including the way the Snapdragon ASICs work) is simply truncating the bit depth. With each digit you drop you reduce the attenuation of the resulting signal by several DB. Remembering that bit depth is the way all dynamics are conveyed in PCM. With AVC in the Hi-Fi DAC bit depth is retained, and attenuation is done entirely in the analog domain (like a potentiameter does). It is done in the IC still, but on the analog signal before it exits to the headphone jack.

There are ways around stopping loss of quality with digital volume controls.....especially by padding the 16 bit word to 24 bits... or even 32 (as in modern DACs). Thus reducing the low order bits isnt actually touching the original signal. But this doesnt have the benefit of reducing noise floor as AVC does as the volume drops.

With DSD it is much trickier --- because we have to peel back the onion even further to understand better what is going on. Realizing that even PCM gets converted inside the DAC to a pseudo DSD stream. This is the way all Delta-Sigma style DACs work. So even with PCM we are listening to DSD really. with DSD natively rendered (cant access this yet on the 9218 in the V20), the pipleline is more simple. But whenever we listen to DSD today, it is converted to PCM first....treated exactly like a native PCM stream from that point -- including the seemingly redundant conversion back to DSD inside that Delta-Sigma DAC.
i did notice that when i increased the AVC from -6 back to 0 the sound had a larger soundstage and better instrument separation and less distorted and my digital volume is usually always at 45-65 on the volume meter. what settings do you recommend though? (on the AVC + digital volume)
 
Oct 4, 2017 at 5:46 PM Post #2,966 of 4,141
i did notice that when i increased the AVC from -6 back to 0 the sound had a larger soundstage and better instrument separation and less distorted and my digital volume is usually always at 45-65 on the volume meter. what settings do you recommend though? (on the AVC + digital volume)

The whole thing is quite elegantly simple. The only way to attenuate the signal is via AVC in the Hi-Fi DAC. What the digital volume control does is act as a an input to the AVC. Since all the controls in the phone are digital.... once the Hi-Fi DAC is enabled (not greyed out) the Digital volume control is fed to the inputs of the 9218 to control the AVC. Think of a remote controlled motorized potentiometer in a larger Preamp. The Remote is digital, the remote actuator is digital, but ultimately the volume control is implemented in the analog domain. A digitally-controlled analog attenuator. The knobs in the sound settings and the rocker on the side of the phone control the same input for AVC.
 
Oct 5, 2017 at 1:47 AM Post #2,967 of 4,141
Yes the files are all originally FLAC encoded. But at this point in the decode, lossy or lossless are the same PCM 44.1 stream handed off to android since the app is doing the file level decode. And even MP3 files all decode to the original PCM rate (usually 44.1)
well...actually not always the same, that depends on the app, the system and the content.

mp3/aac/flac/etc. can be played as raw bitstream and decoded by hardware codec (lower power consumption and sometimes better quality)
or as PCM stream and decoded by application processor (better compatibility and easier for post processing)

android supports both. the only way to find out which path is used for a certain scenario is by testing.
 
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Oct 5, 2017 at 4:14 AM Post #2,970 of 4,141
For some reason, my V20 went into high impedance with EMX500 earbuds yesterday, which are very efficient. They sounded better than in low impedance, obviously much louder (could only go up to 50/75 and even then was unbearingly loud). I don't quite know if the quality is objectively better, but it did appear to be bassier, which regular low impedance lacks a bit. I wish we had manual control over this, less so for IEMs, but earbuds and some overears would benefit I'm sure.
 

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