Automatic Mixers

[NewYorkDave]

I've been tasked with the design of a simple audio system for a small
courtroom enviromment. The system is for recording/transcription
purposes only, not for sound reinforcement. The sources will be eight
phantom-powered microphones (probably small PZMs) plus occasionally a
line-level signal from a speakerphone. This is a "set and forget" type
of application, with no skilled operator available during the
proceedings, so it seems to call for an automatic mixer.

This kind of system isn't my specialty--I'm a studio engineer--and
although I can read all the brochures I want online, I'd like to hear
brand/model recommendations from those who've used automatic mixers in
the real world. Thanks in advance.

[Blackburst]

Shure SCM-810(? I think)

Stunningly good. 8 inputs, rackmount. Opens the mike with the highest amplitude
(usually nearest to the source) and attenuates all others. When another person
speaks, it opens THAT mike and gradually attenuates the last mic.

This unit is great at defeating the problems of multiple open mikes, phase
cancellation and comb-filtering. The net effect is the best possible sound with
no operator necessary.

I installed 2 of these units (16 inputs) in a City Council chamber known for
atrocious audio, to feed TV and radio: 10 councillors, president, city clerk,
guest podium, 2 wireless and an aux in. Everbody is thrilled at the increase in
quality - nice, close-up sound, and lightning-quick response when a new person
speaks.

These things should be standard issue for radio, TV and PA applications.


Caveat: You mention using PZMs. This unit works best with directional, close-up
mikes. I'm not sure how effective it would be at picking the right mike if
they're all PZMs.

Specify the Shure. Do NOT use the BiAmp model - it is only a gated mixer, much
less effective. I got burned on these, and had to pay a restock fee.

[Scott Dorsey]

Blackburst > wrote:
>Shure SCM-810(? I think)
>
>Stunningly good. 8 inputs, rackmount. Opens the mike with the highest amplitude
>(usually nearest to the source) and attenuates all others. When another person
>speaks, it opens THAT mike and gradually attenuates the last mic.

I will second that. The other one I would recommend is the model that AKG
used to sell, which I think Lectrosonics is now selling. I am not sure who
really makes it, but it does not clatter and the noise floor on it does not
pump too outrageously. Very nice for round table discussions.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."