Mic Preamp/USB interface Suggestions for Loudspeaker Measurement

[Joseph Crowe]

I’m looking for recommendations on a good mic preamp/USB interface for loudspeaker measurement. My Scarlett Solo bottoms out at -90dB IMD from my testing which is also documented by Virtins test report.
This is the bottleneck in my measurement system.

Thanks

 

[CristianoLO]

Take a look here https://www.audiosciencereview.com/forum/index.php?pages/Reviews/
Filter by ADC, order by SINAD
And about your microphone? It have good specs?

 

[Blumlein 88]

I don't think you are going to find any speakers with that low of an imd reading. So it's not really a bottle neck. If you also want electronic measurements, Motu is good for the money.

 

[DVDdoug]

Usually, the room noise is worse than preamp noise. Unless you have a soundproof studio or anechoic chamber.

But speakers are normally measured at louder volumes where a little background noise isn't a problem.

 

[Joseph Crowe]

Take a look here https://www.audiosciencereview.com/forum/index.php?pages/Reviews/
Filter by ADC, order by SINAD
And about your microphone? It have good specs?

Thanks, I took a look but I don't see a mic preamp. The microphone is an ACO Pacific 7052PH. I don't believe it to be the bottleneck simply because I'm hitting a brick wall at -90dB and Virtins indicates -90dB in their test for the Scarlett Solo.

I don't think you are going to find any speakers with that low of an imd reading. So it's not really a bottle neck. If you also want electronic measurements, Motu is good for the money.

Really? I routinely get -85dB on my loudspeaker measurements for IMD.

Usually, the room noise is worse than preamp noise. Unless you have a soundproof studio or anechoic chamber.

But speakers are normally measured at louder volumes where a little background noise isn't a problem.

I have a unique situation where I live way out in the country and my house is dead quiet. I've found that small changes in IMD at low level is a good metric when evaluating smaller changes to a loudspeaker design.

 

[Blumlein 88]

Which imd frequencies are you using? If it's the 4:1 ratio with tones far apart then each tone is likely on different speakers due to the crossover. If it's tones 1:1 close together that is surprising the results are that good.

 

[Joseph Crowe]

Which imd frequencies are you using? If it's the 4:1 ratio with tones far apart then each tone is likely on different speakers due to the crossover. If it's tones 1:1 close together that is surprising the results are that good.

I’m doing 12 band per octave multitone in ARTA.

 

[Joseph Crowe]

Recently I tested the distortion on the Focusrite Scarlett Solo. I looped its line level output into its XLR mic input and ran test tones in ARTA. The dynamic range is only 85dB. I then repeated the test but with the Topping D10S DAC feeding the Scarlett’s XLR mic input. Dynamic range improved to 90dB. The Topping D10S should be about 110dB based on Amir’s tests. So I believe the S/N on the Scarlett’s outputs are 85dB while its XLR input is 90dB. I at least have a method now to objectively measure the preamp’s distortion. One option I’m looking at is the Universal Audio Apollo DuoX interface with a claimed distortion of 115dB

Apollo Twin X | Desktop Thunderbolt 3 Audio Interface | Universal Audio

Apollo Twin X allows musicians and producers to easily track, overdub, and mix with elite-class A/D and D/A conversion, two Unison-enabled preamps, and available DUO or QUAD Core realtime UAD plug-in processing

www.uaudio.com

There is also the Cosmos ADC with 127dB SNR but it has no phantom power for my mic. It’s also out of stock.

Cosmos ADC | index

e1dashz.wixsite.com

 

[CristianoLO]

Apollo it is a great choice also RME