How to volume match using ADC?

[Eskamobob1]

Hello everyone,

I seem to be drawing a blank trying to search this one up. I would like to volume match amps/dacs/chains to subjectively ABX them. I am fairly sure I have seen it mentioned several times you can do this using an ADC, but I can't for the life of me find a guide on how to do it. If it can't be done with an adc, what is the best way to do it? Oscilloscope? Thanks for your time.

-esk

Edit: the ADC i have on hand is a motu M2 I use for my mic in case that changes anything too significantly

 

[Purité Audio]

A millivolt meter measuring at the dacs output, to .1dB.
Keith

 

[Atanasi]

You can use REW, generating a test signal and checking the levels.

 

[Pdxwayne]

I use loopback with ADC. REW to DAC -> DAC to ADC -> REW.

Using Focusrite Scarlett Solo as ADC, I was able to check very small volume difference and thus was able to match the volume.

Note that using freq sweep also helps with matching the filter being used. You want to also match filter as close as possible when doing blind tests.

 

[Eskamobob1]

Ok, so basucaly just grab a multi-meter and match the rms voltage of a test signal (pink noise? 1khz sin?) as closely as possible? Guess that makes a ton of sense. Not realy sure why I was thinking I had to use an adc looming back at it.

 

[Blumlein 88]

As others say, REW or other software or online sources for test signals. Put say 440 hz or 1 khz thru, and measure with a voltmeter at the speaker terminals. Match volume within .1 db or within 1%.

 

[Eskamobob1]

I use loopback with ADC. REW to DAC -> DAC to ADC -> REW.

Using Focusrite Scarlett Solo as ADC, I was able to check very small volume difference and thus was able to match the volume.

Note that using freq sweep also helps with matching the filter being used. You want to also match filter as close as possible when doing blind tests.

I havent played with REW at all. Will it allow me to use both inputs of the m2 simultaneously to match directky without having to switch off?

Edit: I just realized mic inputs are unbalanced. So do I need to use both inputs simultanously to even measure balanced output?

Edit2: bad with words this morning. They are mono, not unbalanced

 

[Atanasi]

Edit: I just realized mic inputs are unbalanced. So do I need to use both inputs simultanously to even measure balanced output?

Edit2: bad with words this morning. They are mono, not unbalanced

I think mono is enough if you want to ABX components. Channel balance is typically good, and if differences become audible because of channel balance, it's fair.

 

[Pdxwayne]

I havent played with REW at all. Will it allow me to use both inputs of the m2 simultaneously to match directky without having to switch off?

Edit: I just realized mic inputs are unbalanced. So do I need to use both inputs simultanously to even measure balanced output?

Edit2: bad with words this morning. They are mono, not unbalanced

My adc is mono too. So I just measure the channel one by one.

I did find out that one of my DAC has channel imbalance of ~0.2db using this loopback way.