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We purchased this camera for training video. The audio quality with
its built-in is good as advertised. When we tried to use an external
mic, the volume was really low at ~ -40db. What is your experience on
this? I wonder if we got a lemon.

THANKS!

liu wrote:
> We purchased this camera for training video. The audio quality with
> its built-in is good as advertised. When we tried to use an external
> mic, the volume was really low at ~ -40db. What is your experience on
> this? I wonder if we got a lemon.
>
> THANKS!

http://www.zoom.co.jp/english/products/q3hd/

"Input LINE IN (1/8" Stereo phone jack)"

That's not much to go on, but that implies a line level microphone,
which might be about 1V rms or so. It also doesn't state
whether it provides mic bias, to power a condenser mic
(similar to the two condensers mounted in the upper housing).

There are some suggested voltage values here, for line level.

http://en.wikipedia.org/wiki/Line_level

USA professional audio +4 dBu 1.228 Vrms (approximate)
Consumer audio −10 dBV 0.316 Vrms

The Zoom product should make statements along those lines,
to help consumers.

It could mean, you're missing a microphone preamp in your kit bag.
A preamp may be necessary, to get from microphone level to line level.

Paul