Question for audio experts

[adam1330]

I have got a bullet cam set up in my car, with all the related gubbins, including an external(from the camcorder) microphone. When I am recording, I am getting a really low sound level, the only way to hear anything on playback is to increase the gain when I am editing the footage. I think I could solve this by using a pre-amp when recording.

My question is, would the quality be better recording with a pre-amp, so the level is correct in the first place and doesn't need editing, or is it just as good to not use a pre-amp, and fiddle with the gain during editing?

I would rather not have to use a pre-amp, as it is one more thing to remember to plug in, but if it would be better, then I will.

[simpo two]

Maybe the mic doesn't give enough output (mV)? See if you can find a better one maybe.
Just an idea!

[GetCarter]

I had similar problems with audio and bullet cam.

You could try one of those cheap mics with a battery from Dixons or the like - that will probably give you more gain. I found things became distorted though. To be honest, if you can 'fix it in the mix' then I'd carry on with what works.

One thing to check - most digi cameras have a Db +3 -3 cut / boost (a software thing)... check out the manual, you may be able to record stuff louder onto tape.

Steve

[meeja]

simpo two said:

Maybe the mic doesn't give enough output (mV)? See if you can find a better one maybe. Just an idea!

Could be that you are using a microphone that requires Phantom Power, or is battery powered.

If the Phantom Power is not there, or the battery is dead, you will get poor quality audio as a result.

[Alanq]

If you’re using the analogue AV inputs then the camcorder is expecting to see line level audio at this point, whereas the signal from a mic is much less. You need a gizmo called a microphone pre-amplifier to boost the mic signal up to line level.

[adam1330]

Thanks for the replies. I think I may just continue tweaking the sound in the editing, it's only in-car footage so I will most probably be overlaying it with music when I edit it anyway.

[meeja]

adam1330 said:

I will most probably be overlaying it with music when I edit it anyway.

....having paid for the appropriate licence from MCPS first of course......

[KITT]

Alanq said:

You need a gizmo called a microphone pre-amplifier to boost the mic signal up to line level.

Sorry to hi-jack the thread but does anyone know where I can get one of these from and as cheap as possible?

[GetCarter]

If you buy a cheap mic from your local electronics store, and it needs a battery, it will effectively have one built in.

That's the cheapest way of doing it.

[Alanq]

All condensor (electret) mics need power to work. This can come from either an internal battery or they be “phantom” powered by the camcorder. In either case the mic signal will still not be “line-level”. If you plug them into a mic input they’ll work fine but if you plug them into an AV input (eg when used with a bullet cam) then the signal will be way too feint and you’ll need a separate pre-amplifier. They’re not that cheap though, stereo ones about £70. Or any cheap battery powered audio mixer would do just as well.