Answering an earlier query about the relationship of
decay and bandwidth in fofilter, here is the expression
that will relate the two (approximately, but well for all
practical purposes)

BW = sr/pi * ( 1  - 10 ^ ( (sin(2pi/cf) - 3) / (d*sr) ) )

BW => bandwidth in Hz
cf => centre frequency
d => decay time (s)



Dr Victor Lazzarini
Music Technology Laboratory
Music Department
National University of Ireland, Maynooth 

it would be nice if we were to add this to the manual.

On May 3, 2006, at 8:52 AM, Victor Lazzarini wrote:

> Answering an earlier query about the relationship of
> decay and bandwidth in fofilter, here is the expression
> that will relate the two (approximately, but well for all
> practical purposes)
>
> BW = sr/pi * ( 1  - 10 ^ ( (sin(2pi/cf) - 3) / (d*sr) ) )
>
> BW => bandwidth in Hz
> cf => centre frequency
> d => decay time (s)
>
>
>
> Dr Victor Lazzarini
> Music Technology Laboratory
> Music Department
> National University of Ireland, Maynooth
> -- 
> Send bugs reports to this list.
> To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk

In fact, there is a typo in the formula below, I just noticed:

The correct one is

BW = sr/pi * ( 1  - 10 ^ ( (sin(2*pi*cf/sr) - 3) / (d*sr) ) )

But I think the other solution is simpler (and I'll add that one
to the manual).

Victor


At 14:34 03/05/2006, you wrote:
>it would be nice if we were to add this to the manual.
>
>On May 3, 2006, at 8:52 AM, Victor Lazzarini wrote:
>
>>Answering an earlier query about the relationship of
>>decay and bandwidth in fofilter, here is the expression
>>that will relate the two (approximately, but well for all
>>practical purposes)
>>
>>BW = sr/pi * ( 1  - 10 ^ ( (sin(2pi/cf) - 3) / (d*sr) ) )
>>
>>BW => bandwidth in Hz
>>cf => centre frequency
>>d => decay time (s)
>>
>>
>>
>>Dr Victor Lazzarini
>>Music Technology Laboratory
>>Music Department
>>National University of Ireland, Maynooth
>>--
>>Send bugs reports to this list.
>>To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk
>
>--
>Send bugs reports to this list.
>To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk

Victor Lazzarini
Music Technology Laboratory
Music Department
National University of Ireland, Maynooth 

Of course we all noticed as well! We were just waiting to see how long 
it took you to spot it!

Rory.

Victor Lazzarini wrote:
> In fact, there is a typo in the formula below, I just noticed:
> 
> The correct one is
> 
> BW = sr/pi * ( 1  - 10 ^ ( (sin(2*pi*cf/sr) - 3) / (d*sr) ) )
> 
> But I think the other solution is simpler (and I'll add that one
> to the manual).
> 
> Victor
> 
> 
> At 14:34 03/05/2006, you wrote:
>> it would be nice if we were to add this to the manual.
>>
>> On May 3, 2006, at 8:52 AM, Victor Lazzarini wrote:
>>
>>> Answering an earlier query about the relationship of
>>> decay and bandwidth in fofilter, here is the expression
>>> that will relate the two (approximately, but well for all
>>> practical purposes)
>>>
>>> BW = sr/pi * ( 1  - 10 ^ ( (sin(2pi/cf) - 3) / (d*sr) ) )
>>>
>>> BW => bandwidth in Hz
>>> cf => centre frequency
>>> d => decay time (s)
>>>
>>>
>>>
>>> Dr Victor Lazzarini
>>> Music Technology Laboratory
>>> Music Department
>>> National University of Ireland, Maynooth
>>> -- 
>>> Send bugs reports to this list.
>>> To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk
>>
>> -- 
>> Send bugs reports to this list.
>> To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk
> 
> Victor Lazzarini
> Music Technology Laboratory
> Music Department
> National University of Ireland, Maynooth