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Bill Graham Bill Graham is offline
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Default Gain Change on Shure MX418

mcp6453 wrote:
We did our annual music awards show last month. It's the one where we
always have problems with the lectern mic. This year was as bad as it
has ever been. The show owners insisted on using a Shure MX418 with
an inline preamp. That mic was WAY too much output. It constantly
overloaded the mic preamp on the house Yamaha digital console.
Unfortunately, the FOH guy didn't know how to operate the board, so
when the idiot presenters got too close to the mic, it was really
distorted.

The FOH guy kept saying the mic was overloading internally, that the
problem could not be the board. Since I have little to no say, I just
went with it. The mics are all split with one feed going to the
monitor/multitrack recorder and the other feed going to the house.
Towards the end of the show, I walked backstage to listen to the
multitrack feed. Even with the performers deep throating the SM58
wireless mics, the feed was clean and clear. That's when I knew the
Yamaha preamps had to be overloaded. (The mics were rented from a
sound company. The theater provides the house sound and the
"engineer". You'd think they'd have at least spoken to each other
before the show.)

On to my question. The Shure MX418 spec sheet says that the output
level can be set to 0, but it is shipped as +12. In looking at the
spec sheet, it appears that the gain changes require soldering
surface mount resistors:

http://tinyurl.com/mx418

If I'm reading that correctly, it's at least a little misleading to
suggest that the gain can be readily changed. (They didn't say that,
but that's what it sounds like.) Heck, if you can open a U47 or a
KMS105, you can change the gain with a soldering iron and the right
resistors.

These mics really suck for this application. If I participate in the
show again, I think I'm going to get my hands on an AKG D880 that
Scott recommends. Or a Sennheiser 421 that can take an idiot
screaming into it.

Is there an inline XLR attenuator that passes phantom?


Yes. There are several. Here is one:
http://www.bhphotovideo.com/c/produc...ca_AT8202.html