This formula doesn't seem to work. The 20 should be 10 as Neven pointed out but I believe a -3db reduction should take 65535 to 32767 but it's not close. Any ideas?
Cheers, Ross.
Nello Sestini wrote:
(db/20)
P1 = P2 e i.e. P1 = P2*exp(db/20)
not sure if this is what you are after
(and hope i haven't made some stupid mistake)
-ns
http://www.roserox.co.th
----- Original Message -----
From: "Ross Levis" <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
Sent: Thursday, March 06, 2003 09:57
Subject: [DUG]: db calculation
> Here's a maths question for you. I've never been that good at maths,
> particularly logarithms
>
> Does anyone know the formula to alter an integer value by a particular
> db value.
>
> I'm working on an audio app and I need to alter the volume by a
> particular db setting. The volume can be anywhere in the range 0
> (silent) to 65535 (maximum).
>
> I know that db = 20 log (P1/P2) though I've also seen the 20 at 10. How
> do I get P1 (or is it P2) to the left of the equation.
>
> Thanks,
> Ross Levis.
>
> ---------------------------------------------------------------------------
> New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
> Website: http://www.delphi.org.nz
> To UnSub, send email to: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
> with body of "unsubscribe delphi"
> Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
>
---------------------------------------------------------------------------
New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED]
Website: http://www.delphi.org.nz
To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi"
Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
