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Re: inverting a track on a stereo recording to increase gain....huh?

Subject: Re: inverting a track on a stereo recording to increase gain....huh?
From: "Scott Fraser" scottbfraser
Date: Sat May 4, 2013 8:09 am ((PDT))
< I have been making some frog recordings with a Sennheiser K6/ME66 shotgun=
 into a LS-11 recorder. I recently purchased a 90 elbow microphone plug
extension for the recorder to stop me from bending plugs. Recently a new pr=
oblem has arisen. When I import the recordings into
Audacity, I can't get the gain up high enough even though there is plenty o=
f gain in the recording as far as I can tell.
Doing a little research on the internet, I saw a suggestion to split the st=
ereo track, invert one of the two resulting tracks, then recombine the two
tracks back into a new stereo track. Surprisingly (to me) this works like a=
 charm. I now have plenty of gain.
I have no idea what "inverting&quot; the right channel does, or why this wo=
rks, and might not understand if you explained it to me. But what can I do =
to avoid having to do this?
If I record directly off the LS-11 built in mics, I have no such problem. >

What this reveals is that your cable is mis-wired for the application. Your=
 cable is taking a balanced mono signal into unbalanced inputs & sending th=
e opposing polarity components (+ & -) to separate channels, as if they wer=
e stereo channels. Your resulting tracks are out of polarity & thus combine=
 destructively, resulting in a cancellation of the signal. When you invert =
the polarity of one of the stereo channels, proper polarity is restored & i=
t sounds as it should. What you need is a cable which unbalances the output=
 of the Sennheiser by connecting pins 1 & 3 together. So the wiring would b=
e: XLR pins 1 & 3 tied together connected to the sleeve of the mini plug, &=
 XLR pin 2 connected to the tip of the mini plug, with the ring left unconn=
ected. Or the mini plug tip & ring tied together if you want to fill both s=
tereo channels with the mono signal.
If this is overly technical, another approach is to split your stereo track=
 & simply discard one of the channels. You have a mono signal from the Senn=
heiser & there is no reason to use 2 channels to contain the same, yet out =
of polarity, signal.

Scott Fraser








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