# M-audio mobile pre +ECM 8000 issues



## Jason Schultz (Jul 31, 2007)

I plan on REW using an M-audio mobile pre with the ECM 8000 mic but I am not getting anywhere. I think I've connected it all correctly. I can play sound from i- tunes through the M-audio sound card and can hear sound through my speakers but i cannot get any sound from my mic (or another mic for that matter) I assume that i should be able to hear my voice through the speakers as well but this is not happening. Does any body know what could be wrong?

PS tried both windows XP and vista 32 sp1 thanks guys

Jason


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## brucek (Apr 11, 2006)

Did you first successfully create a soundcard calibration file?

brucek


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## Jason Schultz (Jul 31, 2007)

Hi Bruce. I tried to do this using the loopback connection but the bar indicators showing input levels remained at -73 DB


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## brucek (Apr 11, 2006)

> I tried to do this using the loopback connection but the bar indicators showing input levels remained at -73 DB


Then there is no use carrying on until that problem is solved.
Tell me about the loopback connection you used to run the soundcard calibration routine.

brucek


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## kjgarrison (Nov 17, 2007)

Not a hijacking. Thread appears to be abandoned, so it's a salvage operation.

I have the same equipment, including the Behringer ECM8000. Also, Win XP Pro SP3.

I have read much of what has been said in other threads about the issue of calibration of the card given the problem that the M-Audio does not have XLR (or any balanced for that matter) output.

Tried to do a sound card calibration by using [1/4" stereo jack <>RCA cable<>1/4" stereo jack] for the loopback connection.

Problem is that the input level is too low. The part where the input and output levels are supposed to be adjusted until they are within 3dB of each other and within the range of -12dB to -3dB (or something like that) is where I have my problem. My output *[Edit: input]* scale is only showing ~ -35dB. I tried either R or L channel. No difference. I have tried all combinations of inputs and outputs, including the one on the front of the unit.

I have set the sliders to max in Windows as well as the M-Audio MobilePre. I've fiddled with the gain on the M-Aud and can get outputs way up in the +20dB range (worsening the gap between input and output of course)

Any ideas?


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## brucek (Apr 11, 2006)

> 1/4" stereo jack <>RCA cable<>1/4" stereo jack


The 1/4" output port on the Mobile is unbalanced and the 1/4" input port is balanced, so using stereo plugs is not correct.

You need to use 1/4" TS plugs, to resolve this. Simple solution would be to get the TS to RCA adapters and use an RCA cable.

brucek


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## kjgarrison (Nov 17, 2007)

brucek said:


> The 1/4" output port on the Mobile is unbalanced and the 1/4" input port is balanced, so using stereo plugs is not correct.
> 
> You need to use 1/4" TS plugs, to resolve this. Simple solution would be to get the TS to RCA adapters and use an RCA cable.
> 
> brucek


Thank you!

I don't think I had the drivers/installation of the M-Audio MobilePre right, so I uninstalled and re-installed with the latest drivers which is for XP SP2 and SP3.

And ...

I was suspicious that my plugs were not what I needed, so before I even read this I got the "mono" (which I believe is the same as TS) plugs and tried the set up. Funny thing: it didn't work. Then I tried using the stereo plugs again and it worked. Can't figure it out. I need to play around more. One of the issues is that control settings are called different things.

But I did go all the way through the process of calibrating the card, calibrating the SPL, and doing a few runs with my subwoofer.

My current wish is just to measure how effective the EQ that my AVR comes with is (Audyssey MultiEQ XT). I would like to send L and R signal to the AVR and then measure the sub alone, the fronts alone, and the 2.1 in combination with various crossovers. I'm thinking that there may be room issues, for example, with the mains that using a slightly higher crossover to the sub would fix, since the sub is in-between. Or vice versa. Not sure how to hook things up to accomplish this. Specifically, I'm not sure how to connect the M-Audio to the AVR. If I have to limit the connection to one wire, then maybe someplace there is a way to send "mono" input to the AVR and have it distribute the signal to L, R, and/or sub.


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## brucek (Apr 11, 2006)

> I got the "mono" (which I believe is the same as TS) plugs


Correct. TS stands for tip and sleeve. The TRS (what you have called stereo) stands for tip, ring, sleeve.

In a TS plug, the tip is the unbalanced (+) plus signal and the sleeve is the ground. 
With the TRS plug, the tip is the (+) positive balanced signal, the ring is the (-) balanced signal and the sleeve is the ground. Standard practice is to use a TS plug in a TRS jack if you want to unbalance the signal (for connecting to an already unbalanced interface). The TS plug shorts the sleeve (ground) and the ring (-) signal together to unbalance the balanced connection.



> Specifically, I'm not sure how to connect the M-Audio to the AVR. If I have to limit the connection to one wire, then maybe someplace there is a way to send "mono" input to the AVR and have it distribute the signal to L, R, and/or sub.


Simple. Connect the mono channel (left or right line-out) from REW to your AUX or CD input of the AVR with a Y-splitter. Then place the AVR in stereo and enable your bass management crossover in the AVR (i.e. small mains). Now if you want to check the sub alone, you remove the mains speaker wires (with the power off). The other speakers won't be active in stereo.
If you want to test the mains by themselves, simply turn off the sub. If you want the mains + sub, connect the mains speakers and turn on the sub.

brucek


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## kjgarrison (Nov 17, 2007)

brucek said:


> Correct. TS stands for tip and sleeve. The TRS (what you have called stereo) stands for tip, ring, sleeve.
> 
> In a TS plug, the tip is the unbalanced (+) plus signal and the sleeve is the ground.
> With the TRS plug, the tip is the (+) positive balanced signal, the ring is the (-) balanced signal and the sleeve is the ground. Standard practice is to use a TS plug in a TRS jack if you want to unbalance the signal (for connecting to an already unbalanced interface). The TS plug shorts the sleeve (ground) and the ring (-) signal together to unbalance the balanced connection.
> ...


You make it simple, and that is a gift.

Thank you! :hail:


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## Jason Schultz (Jul 31, 2007)

Hi KJg. Thanks for outlining your experiences with M-Audio Mobile etc. Sounds like you got your rig working ok finally. I have same set up as you and same problems also. I've gotten as far as completing the sound card cal file. I think I fluked that actually. but The next step is causing me grief, the checking levels process. I cannot seem to get any input readings when I start the pink noise test. I am using the main speakers to set levels. I'm using the same type of connections as when I did the sound card cal file. I am using the same (right) channel but now input is from ECM8000 instead of sound card. I can get output figures but no input. my souncards controls are at max (input and output) REW cannot find any input controls for me to use to boost input either. Any ideas? please


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## kjgarrison (Nov 17, 2007)

Jason Schultz said:


> Hi KJg. Thanks for outlining your experiences with M-Audio Mobile etc. Sounds like you got your rig working ok finally. I have same set up as you and same problems also. I've gotten as far as completing the sound card cal file. I think I fluked that actually. but The next step is causing me grief, the checking levels process. I cannot seem to get any input readings when I start the pink noise test. I am using the main speakers to set levels. I'm using the same type of connections as when I did the sound card cal file. I am using the same (right) channel but now input is from ECM8000 instead of sound card. I can get output figures but no input. my souncards controls are at max (input and output) REW cannot find any input controls for me to use to boost input either. Any ideas? please


Hope this doesn't insult you, but did you turn the phantom power for your mic ON?


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## Jason Schultz (Jul 31, 2007)

yes I did. no insult taken. I expect the problem will be somthing simple like that( i hope so). Maybe Brucek will chime in again?
Connection wise I am using a TRS/RCA plug from the left output of my soundcard, going into AVR. Mic is going into right channel of Y adaptor into stereo 3.5mm input.
I can hear pink noise at 75 dB from speakers but mic is picking up zilch.


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## Jason Schultz (Jul 31, 2007)

Correction those plugs are TS plugs and not TRS 
Jason


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## Jason Schultz (Jul 31, 2007)

OK I've worked out the problem !

If you are using the ECM8000 with M-Audio mobile pre:
When measuring speakers (not soundcard measurement) you must plug the mic into the XLR mic inputs on the rear because it has a gain control which you need. Channel 2 on rear corresponds to the Right channel on REW input. I've now got my measurement levels sorted!


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## kjgarrison (Nov 17, 2007)

Yep. Where did you have the XLR plugged into before????


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## Jason Schultz (Jul 31, 2007)

I still had it set up as in the sound card measurement set up where it states you must use line level inputs. nowhere does it say to reverse this. anyay i'm happy now things are moving along nicely


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