Absolute Bluetooth Volume in Android

[Jaysound]

Is leaving Absolute Bluetooth Volume in Android enabled, as it is by default, innocuous if no blatant audio issues are occurring, or is it detrimental to SQ to have the phone's volume output go down along with the Bluetooth volume?

It's more convenient to have it enabled, I guess, which is why it's on by default.

Yet I've heard that some audiophiles say that when there's a chain of audio devices it's best to have the first output device -- the phone in this case -- at max volume, and then adjust the second output device -- the Bluetooth headphones or adapter(s) in this case -- to the desired volume level, so you get the max original sound to work with. Absolute Bluetooth Volume obviously has to be disabled in Developer Options to achieve this.

There's also the question of how well Absolute Bluetooth Volume works with various volume level settings with the given devices -- how well they synchronize various volume levels. (Samsung S24 Ultra and Shure TW2 Bluetooth adapters.)

 

[jsmiller58]

Is leaving Absolute Bluetooth Volume in Android enabled, as it is by default, innocuous if no blatant audio issues are occurring, or is it detrimental to SQ to have the phone's volume output go down along with the Bluetooth volume?

It's more convenient to have it enabled, I guess, which is why it's on by default.

Yet I've heard that some audiophiles say that when there's a chain of audio devices it's best to have the first output device -- the phone in this case -- at max volume, and then adjust the second output device -- the Bluetooth headphones or adapter(s) in this case -- to the desired volume level, so you get the max original sound to work with. Absolute Bluetooth Volume obviously has to be disabled in Developer Options to achieve this.

There's also the question of how well Absolute Bluetooth Volume works with various volume level settings with the given devices -- how well they synchronize various volume levels. (Samsung S24 Ultra and Shure TW2 Bluetooth adapters.)

I disable absolute volume for the reason you stated. An imperfect analogy would be as follows... what would result in the best quality 1. Amplify a normal voice or 2. Amplify a faint voice. The faint voice likely has lost resolution and amplifying it cannot bring that resolution back.

 

[bigshot]

As long as it doesn’t clip down the line.

 

[gregorio]

what would result in the best quality 1. Amplify a normal voice or 2. Amplify a faint voice.

Neither, they would result in the same audible quality. Of course, it would depend on how faint the voice, how much amplification and the noise floor of the recording/system. If the voice is faint enough and the amplification is great enough to make the noise floor audible then #1 would most likely be the best audible quality but could under certain conditions still be the same or potentially worse (if clipping occurs for example).

Is leaving Absolute Bluetooth Volume in Android enabled, as it is by default, innocuous if no blatant audio issues are occurring, or is it detrimental to SQ to have the phone's volume output go down along with the Bluetooth volume?

In theory you should be perfectly OK to lower the phone’s volume, as long as it’s not by a large amount and you’re not having to set your Bluetooth device near its max volume to compensate. This theory might not occur in practice though, it depends on your specific Android device and your specific Bluetooth device.

G

 

[jsmiller58]

Neither, they would result in the same audible quality. Of course, it would depend on how faint the voice, how much amplification and the noise floor of the recording/system. If the voice is faint enough and the amplification is great enough to make the noise floor audible then #1 would most likely be the best audible quality but could under certain conditions still be the same or potentially worse (if clipping occurs for example).

You might be right, of course. However one thing you might have trouble reproducing is the dynamic range.

 

[gregorio]

However one thing you might have trouble reproducing is the dynamic range.

Why?

G

 

[bigshot]

What’s the difference between automatically normalizing the track with absolute volume, or normalizing manually using your volume control. It seems to me that auto normalization wouldn’t make any difference, and it would make the levels consistent. But maybe I’m misunderstanding because I don’t have android.

 

[jsmiller58]

Why?

G

The skeptics might be right - I guess I have read this in many forums and took it for granted. I am going to try the experiment of setting a relatively low volume on the source (DAP or phone) and amplifying at the receiver (dongle) and compare to maxing at the source with lower amplification at the receiver for similar volume levels - of course volume matching will be hit or miss.

I’ll report back what I find. Would be great for others to do as well!

 

[gregorio]

The skeptics might be right - I guess I have read this in many forums and took it for granted.

That’s often the problem in the audiophile community. While there is sometimes just silly made-up or deliberately misrepresented nonsense, quite often it’s a case of some element of truth but the actual consequences are misunderstood (or again, deliberately misrepresented). Bluetooth codecs do have a limited dynamic range; with 24bit we’ve got around 144dB dynamic range and 16bit gives us about 96dB, while Bluetooth codecs give us somewhere around 110dB to about 85dB depending on the codec, obviously that’s a reduction in the available dynamic range. However, the dynamic range of the medium is irrelevant, what’s relevant is the dynamic range of what we’re reproducing. In the case of music recordings the dynamic range is genre dependant, typically it’s around 40dB for popular genres and can be as much as about 60dB for some orchestral symphonic recordings. In an handful of extremely rare cases it can be as much as about 70dB.

Therefore, even in the worse case (most dynamic recording and least dynamic codec) we should still have around 10dB to play with, lowering the volume of the source and in the vast majority of cases considerably more. Of course, a weak signal and/or a particularly poor implementation in a particular device will lower the bit rate and therefore reduce the dynamic range further but in normal use there won’t be a problem unless you’re playing especially dynamic symphonies and/or lowering the source volume very significantly.

I’ll report back what I find.

That would be interesting, although without proper volume matching it won’t be particularly useful.

G

 

[bigshot]

I've noticed that most of the time, audiophile misconceptions are a matter of scale. There's an assumption that better numbers mean better sound, but the truth is that some things are big and obvious, and some things are so small there's no way any human could perceive them. It helps to know what the numbers represent so you don't chase down unnecessary rabbit holes.

 

[jsmiller58]

Just another opinion from someone (not sure at all how definitive this would be considered) - https://www.makeitsoundgreat.com/source-volume-vs-speaker-volume-control/

“So, in conclusion, you should generally source volume (computer, phone, etc.) up or close to 100% and use the speaker, receiver, or amplifier volume knob to adjust the loudness to comfort.”

 

[gregorio]

Just another opinion from someone (not sure at all how definitive this would be considered) - https://www.makeitsoundgreat.com/source-volume-vs-speaker-volume-control/

Not a great article, there’s some factual inaccuracies and as is commonly the case in audiophile articles, “can” is often incorrectly interpreted to mean “will” and therefore what should be “impossible” or “only in very extreme specific cases” becomes “quite possibly”.

“So, in conclusion, you should generally source volume (computer, phone, etc.) up or close to 100% and use the speaker, receiver, or amplifier volume knob to adjust the loudness to comfort.”

Despite my previous sentence the quoted conclusion is a good basic rule of thumb, although the statement prior: “it’s fine to reduce the volume on your source to 70%-90% max and turn the amplifier level volume knob a little higher.” is also true and “it’s fine” can be interpreted as “no audible difference”. With Bluetooth codecs you have a little less dynamic range to play with, so 70% might, with some very dynamic recordings, be a little too much.

G