help with REW and umik 1.

[Ema79]

Good morning everyone, I recently got the Rew and the Umik 1 microphone. I recently removed the preamp from the audio chain, and I don't have a sound card on my PC, but I imagine there shouldn't be any problems with the Umik 1 microphone. However, when I try to calibrate the sound card, it gives me an error message: "excessive variation in measurement."
Unfortunately, I don't have variable gain on my DAC, only a fixed 5.2V output with digital volume. Is it possible to equalize the levels by adjusting the microphone? If so, how? Thanks everyone.

 

[Keith_W]

It's not clear whether you are using motherboard sound on your PC or a third party DAC. Either way, it can't be calibrated.

The usual way to calibrate a sound card is to connect the output to the input with a cable. REW sends a test signal and generates a calibration file from that.

Since your output (PC or DAC or whatever) is different to your input (UMIK1) there is no way to calibrate your sound card.

 

[staticV3]

In other words: you cannot (easily) use soundcard calibration with the UMIK, as soundcard calibration is intended to be used like this:

REW->DAC (Line out)->ADC (Line in)->REW.

You cannot play the soundcard calibration through a speaker and microphone. It's not designed for that and will throw that error.

To use soundcard calibration, you'd have to plug out the UMIK, temporarily use a Line in recording device with known flat frequency response (so that only your Line out nonlinearities are corrected), then save the calibration, plug the UMIK back in, and start measuring.

That's a bit of a pain, and honestly unnecessary with the majority of Line outs.

Unless it's a very old, or very cheap Line out device, it's totally fine to assume that it has flat frequency response and to proceed without soundcard calibration.

For reference, here's a Loopback of my decade old gaming motherboard:


This is perfectly flat enough for loudspeaker measurements without soundcard calibration.

If you're sceptical of your Line out device, then you can buy a $10 Apple headphone adapter as your soundcard for measuring speakers with the UMIK.
It has ruler flat frequency response.