# REW and Digidesign Interfaces



## PTRust (May 24, 2009)

I am not having much luck using my m-box as the audio interface. I'm currently running a 2.4 ghz Macbook/4 gig ram. It has pro-tools installed but I doubt its conflicting with it. 

Is there anybody else out there having success with a similar setup?

:scratchhead:


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## brucek (Apr 11, 2006)

Generally as long as your Mac has an Intel processor, you're OK, as REW only works on Intel Macs.

The problem with M-box is that it only uses ASIO drivers (I believe). REW requires the use of WDM drivers.

brucek


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## PTRust (May 24, 2009)

More specifically it seems the problem is a feedback loop caused by an inability to mute the monitoring of the input signal. I don't have an answer. Any ideas?

:scratchhead:


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## Barish (May 20, 2009)

I have tested a commercial studio's control room with success today using a Macbook Pro 2.4GHz (MB133B/A with OS X 10.5.6) and an M-Box Mini + PTLE 7.4.2. The trick is that you need to launch Pro Tools along with REW in order to control the M-Box, since the Digi drivers won't let you control the interface from System Preferences Sound Pane.

- Just launch PTLE and start a new session with two mono audio input tracks assigned to either of the inputs, and a stereo master fader, all set to 0dB. Mute the input tracks so that they don't relay what's at the input to the output, and then leave it as it is all throughout the test.

- Set the Output from REW settings panel to Java Audio Engine, and the Input to M-Box Mic Input.

- Connect the mic to the M-Box as usual and turn the direct monitoring knob full-clockwise to Input (opposite end of Mix).

- Calibrate the soundcard using the utility below the same panel and off you go.

Good luck.

B.


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## PTRust (May 24, 2009)

Great answer, why didn't I think of that. Can't wait to try it.

Thanks!


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## Barish (May 20, 2009)

No bother. The REW is free, and so is the supplementary advice :T



brucek said:


> The problem with M-box is that it only uses ASIO drivers (I believe). REW requires the use of WDM drivers.
> 
> brucek


FYI, there is no such thing as WDM for Macs. There's just Core Audio drivers. WDM is for Windows platforms. I even doubt that there is an ASIO driver protocol for OS X platform, cos I've never heard of it.

Digidesign products use Core Audio drivers in OS X.

Cheers.

B.


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## brucek (Apr 11, 2006)

Great, thanks for the answers Barish. My Mac knowledge is about zero, so I always appreciate any Mac guy helping out.

brucek


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## Barish (May 20, 2009)

My pleasure. Thanks for maintaining such a great board. It's very helpful and full of valuable information :T

Cheers.

B.


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## Barish (May 20, 2009)

Tried the same setup again today. You don't even need to launch PTLE. Just adjust the settings in REW and on M-Box unit as above and carry on. The mic appears on the left channel on M-Box Mini.

B.


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## PTRust (May 24, 2009)

I'm sorry I feel like an idiot here but I'm still getting a feedback loop. I opened up PTLE as per your instructions set the mbox's mix knob full clockwise and set the REW input/ouput settings as discussed but still getting a loop. In fact turning down the input signal knob does nothing.
Let me ask which out (L or R) are you connecting to which input (1 or 2).


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## Barish (May 20, 2009)

Then make sure all the on-board mic in, line in and speaker outs are either muted, or at the minimum from the System Preferences Sound Panel when working, because in a few occasions I caught them working (and affecting the result) along with M-box Mini.

Other than that, it really is as simple as I've explained above. Put the mic in, press the phantom power button in, pad out, turn the direct monitoring knob to full right to All Input, go to settings, select Java Core Audio as Output and Digidesign M-Box as Input (default inputs, as there are no other inputs anyway), then select Left channel as "the" channel, untick the Left channel loopback calibration thingie (cos L channel is busy with the mic signal now), and check the I/O gain to -12dBFS/-18dBFS parity, then calibrate the SPL, then set the target level according to the speaker type and then click Measure and get the snapshot. I don't know what else to say.

B.


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## PTRust (May 24, 2009)

Thanks, that's about as detailed as you can get. Do you run the calibrate function first by patching the output of the mbox into the input?


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## brucek (Apr 11, 2006)

> Do you run the calibrate function first by patching the output of the mbox into the input?


You _must _do this first to obtain a soundcard calibration file.

brucek


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## PTRust (May 24, 2009)

I figured that calibration was necessary but I guess my question is which outputs and inputs to use. Remember the mbox is not labeled L and R on the inputs but 1 and 2. I guess I can assume that input 1 (the only mic input) will be referred to as L in REW? 

Because this is where I am experiencing the feedback loop. I haven't even gotten to hook a mic up to it yet.

Thanks for your patience!


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## brucek (Apr 11, 2006)

> but I guess my question is which outputs and inputs to use


Like many higher end soundcards, a 1 and 2 are used in place of right and left. You have to establish which is which, since REW selects the channel to use with an R and L designation.

Make sure you don't check the "Use Left Channel as Calibration reference" box.

You may select either Right or Left channel to use for the calibration - it matters not. What does matter is that once you have created the soundcard calibration file, then the channel it was created on must be used for the mic and output to your system.



> I haven't even gotten to hook a mic up to it yet


As well you shouldn't until the soundcard calibration file is created and you confirm that the file is good by doing a measure of the loopback cable. It (of course) should now measure flat from 2-20000Hz because any inadequacies of the soundcard are compensated by the soundcard cal file.

Once you've accomplished that, it's a simple matter of removing the loopback cable and hook up your mic and system to do a measurement.

Set speaker type.
Run Check Levels.
Run Calibrate.
Set measure limits (i.e 0-200Hz for a sub , 0-20000 for full system)
Measure.

That's it.

brucek


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## PTRust (May 24, 2009)

I appreciate it. Let me fool with it tonight and I'll let you know how it turns out.

Thanks again!


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## PTRust (May 24, 2009)

Still having problems. I noticed that I'm not getting a clean sine wave. I patched the output of the mbox into my mixer and just ran the signal generator and realized that I'm getting a very modulated strange signal. This is not an overload problem as I adjusted levels to make sure I wasn't clipping anything.


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## Barish (May 20, 2009)

Try selecting the MBox as default Audio In and Out device from System Preferences > Sound and then selecting Default device option in REW menu.

By the way I can confirm that the internal oscillator of the REW sends absolute garbage out of the right channel. The L signal is fine, but R signal is totally distorted.

I'm not sure if this is caused by an internal driver conflict or not, but whatever the signal type, be it Pink Noise or sweep, the R channel signal is not usable at all.

I've checked it both on my MBP + MBox mini system, and MacPro + HD Accel + 192I/O system. I could replicate the same symptoms on both systems.

Someone should let the developers know about this.

I could provide further evidence to track the fault if needed.

B.


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## brucek (Apr 11, 2006)

> By the way I can confirm that the internal oscillator of the REW sends absolute garbage out of the right channel.


Thousands have used REW without having this problem, so it's a bit confusing that you have this trouble?

I'll inform the author of REW of your problem.

brucek


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## Barish (May 20, 2009)

Thanks Bruce. What I'll do is, I'll record the outputs on another recorder over the weekend and post the files along with full setting snapshots and may be someone else can replicate it that way as well.

At first I thought perhaps it was something to do with my MBox but when I installed the REW onto the other MacPro + PTHD system the result was just the same.

PC versions might not have this problem, but Mac version seems to have it.

B.


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## JohnM (Apr 11, 2006)

I guess it depends which Mac and which soundcard  I test on a Mac Mini using the onboard sound and an Edirol USB card, both channels are OK. Will be interesting to see the captured data.


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## PTRust (May 24, 2009)

Posting a sound file of this is a good idea. I would like you to hear what I'm hearing also. I'm new to the board how would you suggest I do that?


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## JohnM (Apr 11, 2006)

If you don't have a web account you can post files to you are welcome to email me the file at [email protected] - 20MB limit for that. Just to repeat one thing though: there is a known issue with PowerPC-based Macs that results in incorrect byte ordering of the output signal, that problem does not occur with the earlier REW V3.11 (although that has its own limitations on the Mac).


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## Barish (May 20, 2009)

Hi John, thanks for chiming in. No worries about the webspace. I have over 1TB of that with some 3Tb monthly BW or something so that should do. I also happen to own and administer Turkey's leading pro-audio forums at http://www.muziktek.net . I'm commuting at the moment, but I'll print and post the wave files immediately as soon as I get back to the studio. But if you'd like to have them unpublished I'd understand and comply with that too.

Cheers.

B.


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## JohnM (Apr 11, 2006)

Posting the files would be great Barish, thanks.


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## PTRust (May 24, 2009)

Great! I will send you an mp3 of the 1k tone from REW and as a reference the same tone from pro tools. Both will be going thru identical signal chains. 

By the way I'm using an intel based mac.


Thanks


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## JohnM (Apr 11, 2006)

PTRust said:


> Great! I will send you an mp3 of the 1k tone from REW and as a reference the same tone from pro tools. Both will be going thru identical signal chains.


Thanks, got those. First interesting thing is they are at 48kHz, the Mac only seems to support 44.1kHz for Java output using the Javasound classes, so there may be an issue there - might explain the tone difference you mentioned as there could be some low quality rate conversion happening somewhere. Worth trying to run the setup at 44.1k and see if that helps. The second odd thing is that the right channel shows lots of dropouts at irregular intervals. What's odd about that is REW only generates and processes stereo signals, so anything happening on a single channel must be after the signal has left REW. The JavaSound classes are also set up for the stereo signals REW generates, so not sure where the mono differences occur.


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## PTRust (May 24, 2009)

Sorry I tracked the tones into a session that was at 48k and forgot to convert it to 44.1. 

I guess we can just use the L output for the testing process since we don't need the output signal in stereo anyway.

I'm really looking forward to using the program for my new control room setup and I'll keep fooling until I get it.

Thanks


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## TheIncredibleMass (Nov 4, 2009)

Hi,

I'm COMPLETELY new to all of this, and to be honest am getting rather confused. I've only just set up my first speakers and am looking to eq my room and have been recommended this program from other forums. 
I'm using a Digidesign 003 rack and Genelec 8020b speakers with a Macbook Pro 15.4".
There are a variety of outputs and inputs on my 003 and I'm not sure which ones to use. I read somewhere that it's ideal to use the line levels instead of the balanced TRS or XLR connections, but there is only one RCA in and out on the 003, when I tried to run the test it didn't seem to work, although I'm not altogether sure what results I'm meant to be seeing in the first place! Sorry if I'm come across as an idiot, my brain is a little fried right now. onder: 
I read the previous information about the Mbox Mini, and that doesn't seem to have any RCA connections either, so how does that work?? Is it actually ok to use the balanced connections?? 

This program seems to be the perfect tool once you get it working properly, and I'm desperate to get there! 

Thanks for any help anyone can offer...

Chris


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## brucek (Apr 11, 2006)

> I'm using a Digidesign 003 rack


Is this not a firewire connection to your MAC?

If so, REW does not work with MAC using firewire connected soundcards (it's a MAC/Java problem).

brucek


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## TheIncredibleMass (Nov 4, 2009)

.... No wonder!! 

Thanks for the help!


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