Using measurement mic without an audio interface

[Volutrik]

Is it viable to use a measurement microphone without an audio interface, like using an XLR to USB adapter, for example? Asides from buying the mic itself, buying an audio interface just to perform a measurement that'll be done once is kind of overkill imo. Thanks.

 

[masterhw]

Get a UMIK-1, it has the ADC inboard and is natively USB.

The challenge when using a XLR mic with a cheap interface is you can never really measure beyond the limits of the interface’s ADC. Not a huge deal for REW measurements, but still I would stick to the UMIK which is made for this.

 

[staticV3]

Is it viable to use a measurement microphone without an audio interface, like using an XLR to USB adapter, for example?

If the XLR to USB adapter has known good frequency response, then sure.

Asides from buying the mic itself, buying an audio interface just to perform a measurement that'll be done once is kind of overkill imo. Thanks.

That's why USB measurement mic's like the miniDSP UMIK exist

 

[Keith_W]

An audio interface is an incredibly versatile piece of kit. You can use it for all sorts of things, not just for taking measurements. You can also:

- take measurements that are not possible with a USB mic. Like loopback measurements.
- use it as a headphone amp
- use it as a DAC
- send audio from other audio equipment to your PC, e.g. from a TV, or from a turntable
- send audio from one program to another, e.g. from Youtube to an audio recorder of your choice. Or from REW to a convolver.
- plug all sorts of microphones into it and use it to record music, podcasts, etc.
- mix audio from different sources. For example, gaming with a commentary.

If all you want to do is take measurements, then get a USB mic. But I can tell you from personal experience that the very modest additional outlay for a XLR mic + audio interface is most definitely worth it. USB mics are one trick ponies compared to an audio interface.

 

[Volutrik]

If the XLR to USB adapter has known good frequency response, then sure.


That's why USB measurement mic's like the miniDSP UMIK exist

Will using an iPhone to EQ everything below 500Hz do the trick? I just wanted to control the lows. Thanks.

 

[DVDdoug]

Will using an iPhone to EQ everything below 500Hz do the trick? I just wanted to control the lows. Thanks.

It's not calibrated* so the frequency response won't be flat. But somebody knowledgeable... I don't remember who... said that room modes are a lot worse than microphones so you don't really need a calibrated mic. (I think he was talking about the lower frequencies.) ...Your ears can pick-out the worst problems if you know the frequencies you're listening to.

I'm not sure if it's easy to use a phone with REW (or other measurement software).

One advantage to a USB measurement mic is that frequency response and SPL are both calibrated. It's not always important to know but with an analog mic and interface there is no known relationship between dB SPL and digital dBFS levels unless you do your own calibration with an SPL meter. And you have to re-calibrate every time you touch the gain knobs.

I don't fully-trust iPhone SPL apps because the microphone's sensitivity will vary from unit-to-unit and there are different models of iPhones, etc.





* Measurement mics aren't necessarily super-flat but they are individually measured and you get a calibration-correction file (tied to the mic's serial number) that you can use in REW.

 

[staticV3]

Will using an iPhone to EQ everything below 500Hz do the trick? I just wanted to control the lows. Thanks.

Afaik Apple offer official correction curves which Apps like HouseCurve use to provide somewhat accurate response measurements with the mics built into iPhones .

Though IIRC, even those correction curves are in some cases problematic.

In the end, I've yet to see a comprehensive measurement test of iPhone mics + Apple correction curves, compared against reference mics.

Though what you can be sure of is that, even in the case of suboptimal iPhone frequency response, the error will be a gentle shelf or Pass filter.

High-Q room modes will still be captured more or less faithfully.

 

[Volutrik]

Afaik Apple offer official correction curves which Apps like HouseCurve use to provide somewhat accurate response measurements with the mics built into iPhones .

Though IIRC, even those correction curves are in some cases problematic.

In the end, I've yet to see a comprehensive measurement test of iPhone mics + Apple correction curves, compared against reference mics.

Though what you can be sure of is that, even in the case of suboptimal iPhone frequency response, the error will be a gentle shelf or Pass filter.

High-Q room modes will still be captured more or less faithfully.

I was considering buying an iMM6, but i dont know if my phone's jack input will modify the microphones frequency response. The USB C version of it would be better and solve this problem?

 

[boxerfan88]

Will using an iPhone to EQ everything below 500Hz do the trick? I just wanted to control the lows. Thanks.

For a rough cut adjustment, it should be good enough. Room modes are quite obvious as they have ridiculously high peaks/dips. If possible use another brand phone to cross-check. Finally your ear-brain system will tell you if the adjustment sounds good or not. Pink noise as your test signal.

 

[No. 5]

Is it viable to use a measurement microphone without an audio interface, like using an XLR to USB adapter, for example? Asides from buying the mic itself, buying an audio interface just to perform a measurement that'll be done once is kind of overkill imo. Thanks.

Measurement microphones that use an XLR connection will also require phantom power. Be sure to check that any adapter that you are looking at provides this, the few that I have looked at do not but I have not looked very hard. Second, without a real mic preamp in the signal chain, the actual signal level going into the computer may be very low as a microphone's output level tends to be quite a bit lower than line level.

Will using an iPhone to EQ everything below 500Hz do the trick? I just wanted to control the lows. Thanks.

For what you want to do that should be fine. As is using your phone's built in microphone. As has noted by others in this thread, you don't need a calibrated mic to see the major room effects that will affect sound quality. I've measured a few mobile devices and they were generally flat down to 30-40Hz. So as long as you don't get too hung up in the slope of frequency response, a phone and pink noise is just fine.

Just use the right software. A lot of them use very short FFT lengths and ridiculously high refresh rates. I use Mobile Tools by AudioControl on my iPad and find it very useful, but I'm sure that there are other good choices out there.

 

[staticV3]

The USB C version of it would be better and solve this problem?

The USB version, just the a miniDSP UMIK, would remove the ADC characteristics of the phone/computer/interface from the equation, as that's built into the microphone.