Using REW with either Apollo Twin or Avid HD IO

Sound-Guy123

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Hi,

I'm in the process of trying to take some acoustic measurements to determine what treatment I need in my mix room. I'm speaking to GIK acoustics and they recommended I take a measurement of the response of the room using REW. I'm a professional sound engineer so I can usually get these sorts of things to work without too much trouble but I'm really struggling to get REW to work.

I'm attempting to calibrate my soundcard (as this is the recommended first step in the GIK tutorial) but both on my main rig (AVID HD IO) and on a laptop with an Apollo Twin, I can't get REW to see the input signal. In both instances the input is metering on the interface from the sine tone coming down the loop back connection, but regardless of how I set the Input drop downs I just can't get it to meter within REW.

I would appreciate any and all help that can be offered as I really just want to get on with measuring my room and specing out the required treatment.

Thanks in advance,

Jonathan
 

John Mulcahy

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Which OS? On windows the Java drivers cannot see multichannel inputs or outputs, only stereo pairs, so best using the ASIO driver option on Windows. All should work OK on macOS. The soundcard won't need calibrating but going through the motions is a good way to make sure there is no monitoring, the input must not get fed back to the output.
 

Sound-Guy123

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Which OS? On windows the Java drivers cannot see multichannel inputs or outputs, only stereo pairs, so best using the ASIO driver option on Windows. All should work OK on macOS. The soundcard won't need calibrating but going through the motions is a good way to make sure there is no monitoring, the input must not get fed back to the output.

Hey,

Thanks for responding!

Tried it on both a dustbin Mac Pro running High Sierra (10.13.6 / REW V5.19) with Avid HD IO and a Macbook Pro running El Capitan (10.11.3 / REW 5.19). The two setups are physically completely separate (different audio cabling) and in both instance the interfaces are metering the input but I can't get REW to see it.

i'm sure the soundcards are both perfectly flat, but given that I can't get REW to see any input signal I'm a bit stuck.

Cheers,

Jonathan
 

DanDan

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I have a MacPro HDIO High Sierra. I rarely, almost never use Loopback. Even if you want to include that for precise timing, multiple sweeps, or whatever, ignore it for now. I would try to 'prime' the OS using AudioMidi Setup, maybe even Sound Prefs. Get it playing back REW signals, Spotify etc. etc. Then get the input going, again you may have to just try everything in AudioMidi and in REW.
For reassurance try the onboard Line/Headphone outs for playback and the onboard mic on the MacBook.
 

Sound-Guy123

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I have a MacPro HDIO High Sierra. I rarely, almost never use Loopback. Even if you want to include that for precise timing, multiple sweeps, or whatever, ignore it for now. I would try to 'prime' the OS using AudioMidi Setup, maybe even Sound Prefs. Get it playing back REW signals, Spotify etc. etc. Then get the input going, again you may have to just try everything in AudioMidi and in REW.
For reassurance try the onboard Line/Headphone outs for playback and the onboard mic on the MacBook.


Hey thanks for replying,

I'm not bothered about using loopback per se, but attempting to is demonstrating to me that I can't get audio into REW through any of my available interfaces. What do you mean by 'prime the OS'? I can get the inbuilt microphone in my Mac Pro to register input in REW, but that's obviously not suitable for connecting a measurement microphone to....
 

Sound-Guy123

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I have a MacPro HDIO High Sierra. I rarely, almost never use Loopback. Even if you want to include that for precise timing, multiple sweeps, or whatever, ignore it for now. I would try to 'prime' the OS using AudioMidi Setup, maybe even Sound Prefs. Get it playing back REW signals, Spotify etc. etc. Then get the input going, again you may have to just try everything in AudioMidi and in REW.
For reassurance try the onboard Line/Headphone outs for playback and the onboard mic on the MacBook.

Here's a screenshot with REW set to use the AVID HD IO for both the input and output paths. The output path is working fine and is spitting 1kHz down channel 2 (this seems to be the default for some reason?) but the input is actually my display microphone (even though the input device is set to AVID HD IO).
 

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DanDan

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I have been at this a while. Chasing Loopback is not helpful. In Studio terms we want to establish Record and Play, without Direct Monitoring! Back in the day, REW would not play nice with Mac at all, thus FuzzMeasure. Also Digidesign/Avid interfaces have historically been reluctant to take over the job of SoundCard in Macs. I suspect the UAD uses third party drivers, so I would park that for the moment.
Always and ever, if there is a MacBook or iMac with built in Mic, I have found it useful to first 'go native'. Get REW running using the onboard mic and speakers. Then introduce one new aspect at a time. e.g a different input chain, say Decent Mic, External Pre, Built In Line Input.
When you try to get an external interface to join the party, AudioMidi Setup is the leg opener. It has commands to instruct the OS to 'use this device for sound input' Ditto output. Make sure the Interface, OS, and REW are all on the same sample rate.
 

Sound-Guy123

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I have been at this a while. Back in the day, REW would not play nice with Mac at all, thus FuzzMeasure. Also Digidesign/Avid interfaces have historically been reluctant to take over the job of SoundCard in Macs. I suspect the UAD uses third party drivers, so I would park that for the moment.
Always and ever, if there is a MacBook or iMac with built in Mic, I have found it useful to first 'go native'. Get REW running using the onboard mic and speakers. Then introduce one new aspect at a time. e.g a different input chain, say Decent Mic, External Pre, Built In Line Input.
When you try to get an external interface to join the party, AudioMidi Setup is the leg opener. It has commands to instruct the OS to 'use this device for sound input' Ditto output.

Sure. I'm wondering if using the HD IO for this task is a fool's errand. What sort of interface have you had luck with on Mac? Presumably cheap simple stuff that doesn't use third party drivers. I could borrow a focusrite scarlett for the job. Any experience with that and REW?
 

John Mulcahy

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Try the current beta and see if that works any better, but I've used interfaces with 18 inputs and 20 outputs on macOS without encountering any problems.
 

DanDan

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You may have better luck with a genuinely class compliant interface. However, nothing is more 'native' than the onboard I/O. The sound quality of those on the MacPro is perfectly good enough for the quest at hand.
Normally I would fire up REW and get into AudioMidiSetup etc. etc. but I am in the middle of a Mastering session. I have a complex I/O here using Dirac Live via LineIn. Simply put, while working, can't touch the OS, too many bits and bobs each one capable of rendering silence or worse.
But rest assured, the HDIO can be used with REW.
 
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