Q: Electro-Voice RE-20, Lack of Bass Response

Archived from groups: rec.audio.tech (More info?)

I was given the task of repairing two E-V RE-20 mics from one of our radio
stations.
One of the units had broken wires internally due to the base being twisted
around. The other was missing a ground and was returned for noise.

I fixed the ground problem and that mic sounds fine. But the other mic with
the broken wire (at the base XLR connector) works after repair but has no
low end. I checked the rolloff switch and found that not to be the cause, as
switching it on worsens the problem, switching it to flat just returns to
generally lacking in bass.

I noted that the two mic capsules were wired differently. The mic that
sounds fine was wired such that all the connections were on the terminals on
the same side of the capsule. The other mic has one wire on each opposite
side. There are two possible connections. So I tried changing the wiring to
match the other mic, but the output was nearly nonexistent. All other
connections at the transformer in the base were identical.

I inspected the capsule and saw nothing out of the ordinary. No pinholes in
the diaphragm. Nothing interfering with the movement of such, as far as I
can tell.

Does anyone familiar with this mic have any ideas what else might be causing
one of the two to have such radically attenuated bass?

--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
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