It's oh so quiet - Audio Express + SM7B (noob alert)

[pedro01]

Hi

I'm pretty new to all this, so prepare to suck in deep breaths as I walk all over the terminology.

I've got myself a new Shure SM7B and an Audio Express. I do a lot of internet based radio shows and webinars and wanted to upgrade from the poor sound I get from headsets (plus I am male and wanted new toys). Plus I am in a "2 pin" country and my PC isn't earthed and there was buzzing on the sound card.

So I'm set up - but the mic is so quiet. I'm testing it on Skype and recording software called Audacity. This is with the USB connection to the PC.

On the recording software, I select "MOTU Mic/Instrument 1-2" or "MOTU Mix 1 Return 1-2" either way, the audio is barely audible.

Both seem to be set to 100% output in Windows...



I've tested both the MIC and the MIC/Audio Express wired up to an AMP and that seems to be OK - although hardly what I need.

I can also hook it up to my PCs sound card (and suffer the buzzing) and I think I'm getting a boost there.

When I plug the mic in - it only gives me 22bB of trim control, which I presume is because that's just for condenser mics.

I'm at a loss here. Is this a matter of needing more kit or is this combination something that should give me reasonable output for use in PC recording applications?



Any thoughts would be appreciated.

Cheers

Pete

[mikehalloran]

OK, I assume that you have the Mic gain turned up all the way on the Audio Express, right?

The SM7 is well known to have low output relative to most other dynamic mics. If your setup is otherwise ok, try one of these phantom powered level boosters—it takes its power from the Audio Express:

http://www.sweetwater.com/store/detail/CLZCloud

I bought one to use with my ribbon mics and to correct the impedance mismatch typical of Shure dynamics such as the SM57/58 (they perform much better with a 600 Ohm input—typical mixers are 1300–2400 Ohm). I plan to buy a second soon.

In addition to impedance matching (this also benefits the SM7), there is a switchable 12dB/25dB boost. I find the ideal setting 1/3 the way between 350–1.5k Ohm for Shure dynamics and expect that this would be true for a SM7, also.

The CL-1 is a 25dB boost unit only but it's half the price and very popular in this application.
http://www.sweetwater.com/store/detail/CL1Cloud

[pedro01]

Thanks

The bizarre thing is that the manual says that 60db of gain is available.

And it is - you can see it on CueMix - 60db available - but that drops to 22db available the moment I plug the mic in.

The phantom power button is also disabled the moment I plug the mic in. It's as if it's detecting the mic and deciding that the additional gain shouldn't be available....

Now my pre-amp needs a pre-amp... Jeez....

[mikehalloran]

The bizarre thing is that the manual says that 60db of gain is available.

And it is - you can see it on CueMix - 60db available - but that drops to 22db available the moment I plug the mic in.

I'm not saying that there is a setting that hasn't been overlooked—only that I don't see one.

I would call MOTU support and see if this is something that they can troubleshoot over the phone.

[mikehalloran]

If you can get the immediate level issue fixed, you can make a passive impedance converter to smooth out the response with a 1k potentiometer, a couple of XLR jacks and a metal project box. It drops the level about -2dB.

[pedro01]

Will do - here's a video of how the gain drops when you plug in the mic...



11 seconds - see the gain drop...

[reedster]

Are you using an cable with XLR on both ends to plug in?

If it's TRS the gain drops...

[pedro01]

Are you using an cable with XLR on both ends to plug in?

If it's TRS the gain drops...

That's it!

Thanks for that - it was the wrong sort of cable - I went down to the music store, got a cable with XLR both ends and it works a treat.

Muchos Gracias!

Told you I was a noob.