[LAU] Terrible mic ground noise

[jonetsu at teksavvy.com]

Le 01-04-2013 05:50, Fons Adriaensen a écrit :
> On Sun, Mar 31, 2013 at 09:59:11PM -0700, Len Ovens wrote:
>
>> You are getting sound from your mic... therefore it must be a 
>> dynamic mic.
>> It is quite possible that whatever I looked up on m-audio's website 
>> is not
>> what you have. So it is not worth worrying about getting phantom 
>> power to
>> it if it is working without it.

> I wouldn't be so sure. Electret mics can in theory produce a tiny 
> signal
> even without power, but I don't think that's the case. More probably 
> the
> mic pics ups some signal from the amplifier/speaker by magnetic 
> induction.

I've uploaded a music sketch on Youtube (first time - only a black 
screen + music) at:

http://youtu.be/Iu5U8GxG6Rg

Acoustic guitar and bass are recorded using the Pulsar mic w/o phantom 
power.  The acoustic bass is actually doubling the guitar line a bit 
later.  The main bass is keyboard.

It's a sketch, not really meant for presenting anywhere.  It has 
repetitions and is used for the idea to develop further.  If you listen 
until the end you'll hear he general direction.

> Regarding using the city water (or central heating pipes, or 
> whatever) as
> a security ground: DON'T DO THAT. It would be illegal in almost all 
> places,
> and you could easily kill or injure yourself or others if anything 
> goes wrong.

That sounds like a good advice.  In case something shorts at the 
electrical side then this would be reflected immediately in the water 
pipes, probably of the whole house.  Although the setup is all connected 
to a sturdy power bar featuring a breaker which should operate within 
milliseconds, the principle by itself is not a safe one - thanks for 
reminding about that.

So the mystery remains about how can a phantom-powered mic pick up 
acoustic sounds at a respectable level without being powered.