Necessary Interface and Microphone for REW on macOS

[rkilbashian]

Hello All,

First time post for me so hopefully I can get pointed in the right directions. I have a nice project studio with three different pair of reference monitors and I run several different DAW's. My main audio interface is a Universal Audio Apollo x6. My speakers use a couple of different applications to tune the monitors; 1) Genelec GLM 4.1 and IK Multimedia ARC 3.

I would like to try using REW and other than installing it on macOS Catalina I need setup material so if anyone can point me to that I'd appreciate it. My main question (for now) is this...
Do I need to purchase another calibration microphone specific to REW or can I use the microphone that came with both my Genelec and IK Multimedia applications? Will REW detect and use the low-impedance condenser microphones plugged into my Universal Audio Apollo x6 interface to calibrate?

Thanks for helping to get me underway?

Best,

Rick

 

[DanDan]

Some guides to REW and acoustic measurement

AustinJerry's guide has good coverage of using USB microphones.

www.avnirvana.com

 

[rkilbashian]

Fantastic - thanks for getting me going. Do you know if the calibration microphones I use with m y Universal Audio Apollo audio interface will suffice?

 

[DanDan]

You are welcome. I don't know about the Mics associated with the Genelec and ARC systems. Hopefully they are just affordable generic omni condensers. There can be issues with the intermediate software drivers coupled to the Interfaces. Sadly. Give it a go. You do not need Loopback Calibration. REW welcomes Mic Cal flles, which make a cheap mic flat. I generally recommend the UMIK-1 or Dayton, both USB Mics. Playback using the onboard computer headphone output. No Interface or other intermediates.

 

[DJMact]

Hi,
Just a heads up on the IK MultiMedia mics that come with the ARC software and the MTM monitors. They are not flat response and there are no calibration files. Some have speculated that they are "tweaked" with a proprietary curve that the ARC can manage and this is for piracy protection.

I use a Dayton EMM-6 that comes with a calibration file through a Universal Audio Apollo Twin (mic input).

I can't post links at this time but if you search gearspace.com for "Input on REW measurement"
there is a thread on using REW with the IK MEMs mic and some attempts at a calibration file.

 

[DanDan]

Well spotted and said. The new mic which comes with ARC is a MEMS device.......very far from flat, not useable outside of ARC really.

 

[rkilbashian]

Oh boy,

Can you clarify what this means please? So again, I use ARC 3 with their MEMS mic for calibrating my Adam Audio as well as JBL's monitors only. The Genelec GLM and mic are used solely to calibrate my Genelec monitors.
Why would the MEMS mic be anything except flat and how would it benefit their ARC software?

 

[DanDan]

MEMS mics are far from flat, but they are very consistent. The ARC software has the required quite strong correcting curve built in.

Fresh From the Bench: IK Multimedia ARC 2.5 MEMS Test Microphone

For the Test & Measurement Focus published in audioXpress March 2018, two of our authors tackled IK Multimedia’s ARC 2.5 room correction system. In this article Stuart Yaniger tested the new MEMS measurement microphone available with IK Multimedia’s ARC 2.5 System. The microphone is built around...

audioxpress.com

 

[rkilbashian]

I had no idea they built it up that way? Any idea why? Given they're writing their code for a calibration mic why wouldn't they OEM a flat mic and built ARC without a need to have an offset correction? All the more reason for me to look at more closely and dig in to REW. My problem is I don't know where to start. As an example, I run macOS Catalina and my Mac connects to a Universal Audio Apollo x6 interface via Thunderbolt 3. That breaks out into a monitor management controller that feeds three separate pair of studio monitors. So when I say I don't know where to begin I mean what additional equipment would I need? Does a calibration mic connect to my audio interface or directly to my Mac? Can I calibrate with either test tones or Pink Noise from within one of my DAW's; Pro Tools, LUNA or Logic X?
I appreciate your hand-holding DD.

Best,

Rick

 

[sam_adams]

MEMS mics are consistent in their response because they are essentially 'machined' as they are a semiconductor device as opposed to hand-assembled electret condensers. Characterization of one from a production run would be applicable to the rest within a certain margin of error. Article on basic principles of MEMS devices.

The MEMS device in the ARC3 mic is probably the Knowles SPH1642HT5H-1. Since the consistency in the response of the device is well characterized, there is no real need for any calibration file.

Here's a brief tutorial on the MEMS devices from ST Micro.

Another device that you may recognize that employs MEMS mics is the MiniDSP UMIK-X mic array.

 

[rkilbashian]

Hi. I just read the article you posted from Audioxpress regarding ARC 2.5 and found it interesting. They did release ARC 3 (3.0.2 current build) using the same MEMS so I don't know how improved this is. Maybe you know? I can say that it is a convenient tool to have in my studio in that after the room is analyzed the results are embedded in their plugin which is then instantiated in my DAW. At that time mixing or mastering factors in the room correction. Of course their plugin is disabled prior to Export / Bouncing the mix.

 

[DanDan]

You are welcome Rick. I suspect your Genelec Mic is fine for use with REW. There are Primers and Guides in the REW support section, including my Primer. It is often simpler to buy a USB mic and use the Mac Headphone output rather than dealing with an Interface and drivers.
Note the MEMS mic is about 6dB off at HF and 10dB at LF. They certainly need FR Correction.
They are consistent, which cheap mics such as the Behringer are not.

 

[rkilbashian]

I'm impressed with your devotion to getting someone new up and running so a big thanks.
I can say that for whatever reason I have been happy with the Genelec GLM platform; their mic and software so I have faith in it. I do know that IK Multimedia ARC does allow for 3rd party mics as long as there is a calibration file I can load. So having said that, is there a particular mic you'd recommend (with cal file) that I could try with ARC and REW?
Again, thanks!!

 

[rkilbashian]

Hi DanDan,

Could you recommend 1-2 Calibration Mic's that would come with associated Cal files?

Best regards,

Rick

 

[DanDan]

Sure. Sorry I meant to point out this to your earlier. Should answer most questions for start up. I would add the new Neumann Measurement mic.

Some guides to REW and acoustic measurement

AustinJerry's guide has good coverage of using USB microphones.

www.avnirvana.com