How does digital audio amplification work?

[RadiatingLight]

When playing music through a Bluetooth speaker, I can choose a volume on my phone to transmit to the speaker, which then has it's own on-board volume. obviously, the speaker's volume control is using an AMP on analog audio, like normal, but how does my phone transmit different volumes of music over Bluetooth, which is a digital form of communication? Is there a way to amplify audio without turning it into analog signal?

[79wjd]

Your phone probably includes volume information in the stream -- it doesn't actually transmit the data differently. (Thats my assumption anyway)

 

Phone: Here's Song X. The user has the volume set to 50%. 

Speaker: Thank You, I will play Song X at myVolume*(50% volume). 

 

[Guest]

The level of the digital signal is changed via DSP before it is sent. Same thing as with the windows mixer or youtube volume control.

[RadiatingLight]

1 minute ago, djdwosk97 said:

Your phone probably includes volume information in the stream -- it doesn't actually transmit the data differently. (my guess anyway)

Hm...

one sec let me test something

[RadiatingLight]

@SSL @djdwosk97

Yep. You're right. it just gets transmitted as a volume variable along with the music.

I can confirm because I just checked with my shitty Chinese Bluetooth speaker. at the same volume level, using the internal AMP with phone at minimum volume / using the Phone volume with speaker at minimum, audio quality is the same (that is to say, shit in both cases, but equally shit in both scenarios)

 

EDIT: This is all wrong

[Guest]

1 minute ago, RadiatingLight said:

@SSL @djdwosk97

Yep. You're right. it just gets transmitted as a volume variable along with the music.

 

I don't think that's correct and that isn't what I said above.

[RadiatingLight]

Just now, SSL said:

 

I don't think that's correct and that isn't what I said above.

Oh, sorry. didn't read your post above correctly.

so there IS a way to amplify audio digitally without it going through an analog phase?

[Guest]

1 minute ago, RadiatingLight said:

Oh, sorry. didn't read your post above correctly.

so there IS a way to amplify audio digitally without it going through an analog phase?

 

No. Volume control doesn't have any effect on amplification.

[RadiatingLight]

Just now, SSL said:

 

No. Volume control doesn't have any effect on amplification.

What? I don't understand what you're talking about.

my original question was how a digital device can amplify audio without a DAC → AMP → ADC Process (which would be bad for audio quality I assume)

[Guest]

2 minutes ago, RadiatingLight said:

What? I don't understand what you're talking about.

my original question was how a digital device can amplify audio without a DAC → AMP → ADC Process (which would be bad for audio quality I assume)

 

I don't know what's so difficult to understand. Volume. Control. Does not. Affect amplification.

 

That is to say, amplification is a separate process from volume control.

[RadiatingLight]

1 minute ago, SSL said:

 

I don't know what's so difficult to understand. Volume. Control. Does not. Affect amplification.

 

That is to say, amplification is a separate process from volume control.

Forgive me for being a noob in the audiophile community, but what separates the two? as far as I understand, making an audio track louder is amplifying the audio, is it not?

[Guest]

1 minute ago, RadiatingLight said:

Forgive me for being a noob in the audiophile community, but what separates the two? as far as I understand, making an audio track louder is amplifying the audio, is it not?

 

No. Amplification involves taking a low-level, low-power signal, called "line-level" and amplifying it so that it can drive a load.

 

Signals are transmitted at line-level to conserve power and materials; a high-level signal requires more substantial cabling and electronic considerations to manage.

 

Volume control is attenuation. It is applied to the signal before amplification.