Posted by Rick Merrill on 08/28/07 18:34

Richard Crowley wrote:
> "Rick Merrill" wrote ...
>> There is one more tiny thing: the feed is Mono while the camcorder is
>> Stereo. Right now we have both L and R inputs wired together in the
>> stereo jack from the Mono feed. Suppose I put the L and R Mic In in
>> series?
>
> Perhaps you meant to put them in parallel. You can't
> put them in "series". Feeding a mono signal into both
> channels is a very common practice. Sometimes we
> feed the house mix into one channel and a live mic
> into the other channel. That gives you independent
> redundancy, and the POV of the live audience. In some
> cases (such as rock music performances), the direct
> feed from the PA system is too "dry" and doesn't include
> the non-amplified instruments, or the audience reaction,
> etc.
>
>> That would increase the Mic in impedance by 4x.
>
> Putting two impedances in series increases the total
> impedance by 2x, and putting them in parallel makes
> the total 1/2 the individual impedances. But you can't
> put the mic inputs in "series" unless you use a pair of
> isolation transformers, etc.

If you Could put them in series (presently in parallel) then
the change would be 2x/(1/2).

> Padding the mixer line-level output down to mic level
> should not be dependent on the input impedance of
> the camcorder. So impedance is a very minor factor
> in your situation as you have explained it here.
>
>> Would that be a step in the right direction?
>
> Padding the line level down to mic level would be the
> right direction. Using shielded cable would definitely
> be the right direction.
>
> You could even consider recording the audio on some
> other machine (that doesn't have AGC), but we don't
> know what your production flow is and whether you
> could accommodate separate sound recording? And
> we don't even know what you are producing and how
> much of a problem the "pumping" is?

it's not much of a problem - just an annoyance to those
of us who hear it / watch it.

The dual input idea is a great one - and easy to mix in post, if I remember!

Where can I get a nice, flexible shielded cable? Anybody got 25' to spare?

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