Re: Reverb and Cancellation


Subject: Re: Reverb and Cancellation
From: Jay Smalridge (inadaze@mac.com)
Date: Mon Aug 09 2004 - 13:54:16 EDT


Thanks for your answer,
I was just curious as to what other meaning of phase cancellation, besides destructive interference, there could be? Just want to make sure I am using the term properly.

Thanks
Jay
On Monday, August 09, 2004, at 07:02AM, Philippe-Aubert Gauthier <Philippe-Aubert.Gauthier@USherbrooke.ca> wrote:

>Assuming that by "phase cancellation" you mean destructive interference (like a
>sine wave plus a similar sine wave out of phase gives zero), the answer is yes:
>Some strong delays (like early reflections) will cause some dips in your
>frequency spectrum. Its the same for reverberation, but in this case, the
>reflection arrival are so dense (in time) that the frequency spectrum
>alteration is more smooth. You will get a phase cancellation (partial
>destructive interference) when your delay is corresponding to half a period of
>the killed frequency.
>
>This is rougly speaking. You can also have similar physical explanation if you
>take a modal perspective on room dynamics.
>
>Selon Jay Smalridge <inadaze@mac.com>:
>
>> Hi all,
>> I was wondering if anyone knew if reverberation in a room or a delay in the
>> signal creates phase cancellation? I guess the room would have to be small
>> to make any significant change, but does the principle still exist?
>>
>> Thanks
>> Jay
>>
>>
>
>
>%====================================================================%
>% Philippe-Aubert Gauthier, B.Ing, M.Sc. %
>% Étudiant au doctorat en reproduction de champs acoustiques %
>% %
>% GAUS (Groupe d'Acoustique et de vibrations de l'Université de %
>% [ Sherbrooke) %
>% CIRMMT (Centre for Interdisciplinary research in Music, Media %
>% [ and Technology) %
>% %
>% http://www3.sympatico.ca/philippe_aubert_gauthier/acoustics.html %
>%====================================================================%
>
>



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