naturerecordists
[Top] [All Lists]

Re: Re: Pitch shifting

Subject: Re: Re: Pitch shifting
From: Tim Gray <>
Date: Sat, 19 Jun 2004 11:31:57 -0400
First of all, I apologize if all of you know this.  You guys have 
vastly more experience and knowledge than me on all of this stuff.

I think the recording industry is usually referring to when one is very 
close to those low frequency waves.  From my understanding, trying to 
localize low frequency is hard when one is a) only a low freq 
wavelength or two away from the source (typical for a sub in a home 
stereo system) or b) the sound making device does not have enough 
surface area for said low freq wavelength.  I think to get directional 
bass out of a stereo system, a linear array of speakers like the ones 
the greatful dead used on one (or many?) of their tours is necessary.  
I'm a little unsure on the b) part.

In practice, something like thunder is certainly far enough away to 
localize.  Another way to think about it is to look at polar plots of 
very nice omni mics (senn, schoeps, dpa).  Notice how they get more 
directional at higher frequencies.  Now, take all this with a grain of 
salt, since I am no professional, but my encounters with the "recording 
industry" and their opinions on the directionality of low end mostly 
have to do with the placement of a sub in a stereo or surround system.  
I think the usual comment is how its not the end of the world to 
separate the low bass from the main speakers since low freqs are less 
directional.  Further more, if the wife doesn't want the large black 
sub box in plain view, its ok to hide it off to the side, since again, 
it is less directional.  Sure, it would sound better if we had sub 
capabilities in the main stereo pair (or the surrounds for that 
matter), but let's face it.  Compare hiding a sub behind your chair as 
opposed to the left channel main speaker.  Again, I think this applies 
when you are around 1 wavelength away from the source, keeping in mind 
40 hz has a wavelength of 28 feet.

Tim


On Jun 19, 2004, at 11:14 AM, Lang Elliott wrote:

> I think a human's ability to determine the direction of low frequency 
> sounds
> is much better than the recording industry leads one to believe. For
> instance, I've never had any trouble locating a drumming Ruffed Grouse 
> at 60
> Hz or thereabouts, nor do I have trouble determining the direction of
> distant thunder, much of which is below 60 Hz.



________________________________________________________________________
________________________________________________________________________

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU