Is REW right for this?

[dcaton]

Total newbie in this area. My only experience with room correction is with a Yamaha AV receiver that came with a calibration mike. I'm a software programmer by trade and know very little about audio other than some basic concepts, and reading the REW manual makes my eyes bleed. Don't know what details I can skip over and what I really need to take the time to understand. I don't even know if REW is the right program for this.

I want to do room correction, but not on an AV system. I have a virtual pipe organ setup, using Hauptwerk software, running on Windows 10 with 64gb ram. The audio interface is a 24-channel Motu 24ao connected via USB. I am using 15 outputs. 12 Monoprice 8" studio monitors, a SVS PB12-NSD subwoofer, and 2 outputs for a headphone amp. The Hauptwerk software is configured for 12 channel output (6 stereo pairs), the sub gets a mix of all 12 channels and the headphones get a mix of all L and R outs.

The Motu24ao is a professional DAC with 24 outputs and no inputs. Actually there are 48 (I think) channels of optical inputs but I think they're for chaining other output devices into the 24ao's virtual mixing console. I also have a miniDSP UMIK-1.

The Motu24ao has its own ASIO driver, but since it has no inputs if I select this driver in REW the UMIK-1 doesn't show up. In order to see the USB mic I have to choose the Java driver, but then I can only see outputs 1 and 2 of the Motu, not all 24.

I'm not really sure how to go about calibrating a multi channel setup like this. Do you calibrate one speaker at a time, or the entire setup as a whole? This is not a surround configuration, there are 6 monitors in a stack on each side of the console. For room correction measurement, should I set up the routing in Motu for two input channels and route L to 6 monitors and R to the other six, and a combined LR to the sub?

Once I set up the correct configuration of inputs/outputs, then what? How do I apply whatever correction REW creates to the audio output? The Motu 24ao has a 4 band parametric EQ on each input channel; would that work? Hauptwerk has the ability to apply an IR, but that's intended for reverbs and has its own IR file format. And even if I used that for room correction, then I would lose the ability to apply reverb to "dry" organ sample sets. Would I need to use a DAW or VST host like Reaper or Cantable and run Hauptwerk's output through that (it can act as a VST) and then apply room eq though some IR plug in? Is there some other room correction sw that would be better suited for this? I looked at Dirac but that appears to be geared towards a normal AV setup.

Thanks in advance for any advice.

 

[John Mulcahy]

To access all the channels of the interface you would need to use an ASIO wrapper like FlexASIO or ASIO4All. Could treat each stack as a single speaker and EQ all channels the same using the Motu's EQ, probably the most straightforward approach.

 

[dcaton]

Yes, but when using an ASIO driver (either the Motu supplied one or ASIO4All) it doesn't see the USB mic. My interface has no inputs, only outputs. The input to the interface is generated by the Hauptwerk software program, and it has no ability to mix in a physical device.

 

[John Mulcahy]

ASIO wrappers like ASIO4All or FlexASIO combine multiple physical devices into a single pseudo device accessible over ASIO. If you don't see the UMIK in ASIO4All likely explanations are you haven't selected it in the ASIO4All panel or the sample rate is not set to 48 kHz. There is a guide to using ASIO4All with a UMIK in the Downloads section.

 

[dcaton]

Yes, the sample rate is set to 96k since that's what I'm using with Hauptwerk. Will set to 48k and check the control panel. Thanks for the tip. I used to use ASIO4All before Motu had their own ASIO driver (or maybe it was buggy, I don't remember exactly why).

Assuming I get ASIO4All to work, would you still recommend treating multiple monitors as a stack and setting same EQ for all? In general, is it safe to assume that the freq response differences between individual speakers or monitors of the same brand and model are insignificant? Given of course that they're all in approximately the same location in the room.

 

[John Mulcahy]

Yes, should be fine to treat them as a stack.