Wavering signal while micing acoustic closely with LDCs

Archived from groups: rec.audio.pro (More info?)

Hello, I have recorded an acoustic guitar and I was trying out several mics
and placement. Two different mics, both Large Diaphragm Condensers, both
placed about 6 inches from the sound hole, tracked with a nice
distinguishable tremolo effect ( a wavering signal, not a wavering
frequency ). Distant micing could not reproduce this, and other dynamic
mics and small condensers could not pick up this nuance. (The mics were an
MK-319 and a ADK A51s, incidentally.) It seems the entire spectrum is
wavering, but it could be just the low end, hard to tell.

I tried it with a tube pre and with just my mixer, and the same thing.

I think it is a property of the acoustic guitar when mic'd at 6 inches, the
sound waves must vary that strongly. Anyway, I LIKE the effect, and was
wondering if anyone else has experienced this, and if so, 1.) what causes
it, and 2.) have you ever heard it in a song?
re there any other things I should look out for when doing this?

Thanks!

Archived from groups: rec.audio.pro (More info?)

On Fri, 03 Sep 2004 22:52:44 GMT, "Ted Lachance" <tlachance@yahoo.com>
wrote:

>Hello, I have recorded an acoustic guitar and I was trying out several mics
>and placement. Two different mics, both Large Diaphragm Condensers, both
>placed about 6 inches from the sound hole, tracked with a nice
>distinguishable tremolo effect ( a wavering signal, not a wavering
>frequency ). Distant micing could not reproduce this, and other dynamic
>mics and small condensers could not pick up this nuance. (The mics were an
>MK-319 and a ADK A51s, incidentally.) It seems the entire spectrum is
>wavering, but it could be just the low end, hard to tell.
>

<snip>

It's mic placement. At 6", the player's right hand is probably
passing in front of the mic and causing the effect you describe.



Rick Ruskin
Lion Dog Music - Seattle WA
http://liondogmusic.com

Archived from groups: rec.audio.pro (More info?)

On Sat, 04 Sep 2004 01:08:39 +0000, Ted Lachance wrote:

> Me again.
>
> I should clarify : How can one mic be out of phase?
>
> The frequency of vibrato is much higher that the movement of my hands, and I
> strum behind the sound anyway.
>
> - Ted

Sorry, thought you had two mics up.
It's obviously doppler distortion.

(Runs and hides...)

Archived from groups: rec.audio.pro (More info?)

Ted,

If it's not caused by the player's hand blocking the sound into the mike,
then it's probably a beat frequency effect. I bet you'll hear the exact same
thing if you put your ear close to the guitar. The solution is change the
strings and tune the guitar carefully.

--Ethan

Archived from groups: rec.audio.pro (More info?)

On Sat, 4 Sep 2004 11:17:54 -0400, agent86 wrote
(in article <SCk_c.15893$Np2.11994@bignews4.bellsouth.net> ):

> Ted Lachance wrote:
>
>> Hello, I have recorded an acoustic guitar and I was trying out several
>> mics
>> and placement. Two different mics, both Large Diaphragm Condensers, both
>> placed about 6 inches from the sound hole, tracked with a nice
>> distinguishable tremolo effect ( a wavering signal, not a wavering
>> frequency ). Distant micing could not reproduce this, and other dynamic
>> mics and small condensers could not pick up this nuance. (The mics were
>> an
>> MK-319 and a ADK A51s, incidentally.) It seems the entire spectrum is
>> wavering, but it could be just the low end, hard to tell.
>>
>> I tried it with a tube pre and with just my mixer, and the same thing.
>>
>> I think it is a property of the acoustic guitar when mic'd at 6 inches,
>> the
>> sound waves must vary that strongly. Anyway, I LIKE the effect, and was
>> wondering if anyone else has experienced this, and if so, 1.) what causes
>> it, and 2.) have you ever heard it in a song?
>> re there any other things I should look out for when doing this?
>
>
> There's not by chance a ceiling fan in the room is there? Just checking.
>
> I've also gotten tremolo effects from strings that were too old. If this
> is the case, it will be more pornounced on single note playing than on
> strumming, and won't affect all strings equally.
>

OR.....you're using an expander or gate and some structure borne vibration is
causing the circuit to shimmy.

I had that once with an attic fan that was two floors above my recording
space. Turn the fan off and the shimmy went away.

Regards,

Ty Ford



-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com

Archived from groups: rec.audio.pro (More info?)

"Ty Ford" <tyreeford@comcast.net> wrote in message
news:8tWdnWZmGKzuw6bcRVn-qw@comcast.com...
> On Sat, 4 Sep 2004 11:17:54 -0400, agent86 wrote
> (in article <SCk_c.15893$Np2.11994@bignews4.bellsouth.net> ):
>
> > Ted Lachance wrote:
> >
> >> Hello, I have recorded an acoustic guitar and I was trying out
several
> >> mics
> >> and placement. Two different mics, both Large Diaphragm Condensers,
both
> >> placed about 6 inches from the sound hole, tracked with a nice
> >> distinguishable tremolo effect ( a wavering signal, not a wavering
> >> frequency ). Distant micing could not reproduce this, and other
dynamic
> >> mics and small condensers could not pick up this nuance. (The mics
were
> >> an
> >> MK-319 and a ADK A51s, incidentally.) It seems the entire spectrum is
> >> wavering, but it could be just the low end, hard to tell.
> >>
> >> I tried it with a tube pre and with just my mixer, and the same thing.
> >>
> >> I think it is a property of the acoustic guitar when mic'd at 6
inches,
> >> the
> >> sound waves must vary that strongly. Anyway, I LIKE the effect, and
was
> >> wondering if anyone else has experienced this, and if so, 1.) what
causes
> >> it, and 2.) have you ever heard it in a song?
> >> re there any other things I should look out for when doing this?
> >
> >
> > There's not by chance a ceiling fan in the room is there? Just
checking.
> >
> > I've also gotten tremolo effects from strings that were too old. If
this
> > is the case, it will be more pornounced on single note playing than on
> > strumming, and won't affect all strings equally.
> >
>
> OR.....you're using an expander or gate and some structure borne
vibration is
> causing the circuit to shimmy.
>
> I had that once with an attic fan that was two floors above my recording
> space. Turn the fan off and the shimmy went away.

I missed the beginning of this thread, so pardon me if I'm repeating
something someone's already said... but has anyone mentioned the
possibility of the guitar body moving around as the guy is playing it as
being the casue of this? That'll certainly cause some amplitude shifts if
it's single-mic'ed and sometimes phasing between two mics depending on
where they're positioned/how close they are etc.
--

Neil Henderson
Saqqara Records
http://www.saqqararecords.com