M-Audio MobilePre and REW

[Nat Ward]

For some reason the brain really isn't working today. I've been searching to determine the best way to setup up a measurement system and need help with cabling. I will be using the M Audio MobilePre and Behringer ECM8000. The feedback loop for soundcard calibration with REW has me confused, and dictates other cables I should use. The MobilePre has the following inputs/outputs:

Inputs
1. XLR (x2)
2. 1/4" balanced (x2)
3. 1/8" strereo mic

Outputs
1. 1/4" unbalanced (x2)
2. 1/8" stereo
3. 1/8" headphone

What combination of cables should I use for
1. mic to MobilePre
2. MobilePre to surround sound processor

This is probably the easiest thing to answer but all diagrams I've seen have the Radio Shack meter running to the 1/8" input to the sound card, nothing about a mic and XLR inputs, etc. Thanks a bunch.
Nat

[Kal Rubinson]

I use an XLR-XLR microphone cable and a 1/4"phone to RCA cable for output to pre/pro.

Kal

[ThomasW]

You need a standard mic cable to go from the ECM8000 to either channel mic XLR input on the MobilePre

Use a mono 1/4" to RCA adaptor to get from the MobilePre 1/4" output to the input of your processor.

You'll need a "Y" adaptor if you want to feed both channels of the processor with the mono out from the MobilePre

The loopback is done connecting channel 1 out to channel 2 in, that's done using the 1/4" connections. So you again you'll need either mono 1/4" to RCA adaptors or a cable with mono 1/4" connectors on both ends.

[Nat Ward]

Awesome guys, thanks for the help. Off to spend some money!

[dynamowhum]

Talk about a timely thread. I just got word my M-audio unit just shipped. Thanks once again for the fine input Thomas.
By the way why would you want to use both sides of the processor in a mono situation?

[ThomasW]

By the way why would you want to use both sides of the processor in a mono situation?

Because some people don't understand that it is mono and or they aren't sure what to do with left and right inputs.... :B

[dynamowhum]

Thomas covering all the bases :B

[Nat Ward]

Soundcard Calibration

I ended up grabbing a set of 1/4mono to RCA adapters from Radio Shack. I'm attempting to calibrate the soundcard now and keep getting a funky curve. I've tried a few RCA cables and swapping adapters from input to output in attempt to see if a good connection will help, and every time I get some sort of resonance. I only bought the normal adapters, not the gold ones, not sure about their quality. Any input? I might buy a 1/4 to 1/4 cable and see if the lack of adapters helps.
Nat

Image not available

[Mudjock]

You might try making sure that direct monitoring is switched off in the M-Audio software control panel. Otherwise, try adjusting the gain to see what effect it has on the resonanace.

[ThomasW]

It's not the adaptors, no you don't need the gold ones or to make up/buy special cables

In the beginning I had one that looked like that too. Unfortunately I can't remember what I did to change it. I old enough that my brain's RAM buffers are full, so I forget things like this..... :roll:

Seems like it was reversing the input/output channels, lowering the level setting on the MobilePre knob, puttering around with REQW settings or something like that.

If I get some free time later today I'll pull mine out and see if I can duplicate the problem.

[Nat Ward]

Thanks. I picked up a 1/4 to 1/4 cable and tried again - still a funky response. I installed the software (I'd read that it wasn't needed to taking measurements elsewhere) and things now look good. I tried with monitoring muted and not muted - still get a good response. I don't know what did it, but I'm now getting a good cal response. I'm going to keep setting things up to play around, I might try uninstalling the drivers later to see if that's what did it. Thanks again guys!
Nat

[Nat Ward]

After hours and hours of staring at the computer (really, I'm not this dumb) I think I finally have things up and running. The second sweep (the one you run through automatic measure following calibration) shows a perfectly straight line, which I'm not sure is correct - that's my only remaining issue. I was able to run some sweeps and they look pretty close to the ones I manually took with the Radio Shack meter, so I've got that going for me. I had to crank the output knob on the MobilePre to get REW to get a clean input, I hope that isn't an issue. Ugh, no more for a few days.