Hi all,

Learning the attached file "DeepNote.csd" i found in Dr tutos, i try to
enhance the output volume via the ampdb opcode, which is set in the example
file at 68 (db). If i make that (to 72 or more), i get in the console a lot
of "out of limits samples". In the fact, this message had no real bad
effect, the file is played as well, with the output sound enhanced as
attempted. But in all cases i'm interested to understand why this message,
and how to modify the tinstrument to have a perfect console output with any
ampdb parameter, not only 68 db or less. If someone can take a quick look
and explain me that... 

http://csound.1045644.n5.nabble.com/file/n5445967/DeepNote.csd DeepNote.csd 


Cheers,

Sergio


 

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Out-of-range samples means you have too high a volume when rendering your piece.

On 1/31/12, COCHEDELAFERTE  wrote:
> Hi all,
>
> Learning the attached file "DeepNote.csd" i found in Dr tutos, i try to
> enhance the output volume via the ampdb opcode, which is set in the example
> file at 68 (db). If i make that (to 72 or more), i get in the console a lot
> of "out of limits samples". In the fact, this message had no real bad
> effect, the file is played as well, with the output sound enhanced as
> attempted. But in all cases i'm interested to understand why this message,
> and how to modify the tinstrument to have a perfect console output with any
> ampdb parameter, not only 68 db or less. If someone can take a quick look
> and explain me that...
>
> http://csound.1045644.n5.nabble.com/file/n5445967/DeepNote.csd DeepNote.csd
>
>
> Cheers,
>
> Sergio
>
>
>
>
> --
> View this message in context:
> http://csound.1045644.n5.nabble.com/ampdb-tp5445967p5445967.html
> Sent from the Csound - General mailing list archive at Nabble.com.
>
>
> Send bugs reports to the Sourceforge bug tracker
>             https://sourceforge.net/tracker/?group_id=81968&atid=564599
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> csound"
>
>

On 31/01/2012 22:57, COCHEDELAFERTE wrote:
> Hi all,
>
> Learning the attached file "DeepNote.csd" i found in Dr tutos, i try to
> enhance the output volume via the ampdb opcode, which is set in the example
> file at 68 (db). If i make that (to 72 or more), i get in the console a lot
> of "out of limits samples". In the fact, this message had no real bad
> effect, the file is played as well, with the output sound enhanced as
> attempted. But in all cases i'm interested to understand why this message,
> and how to modify the tinstrument to have a perfect console output with any
> ampdb parameter, not only 68 db or less. If someone can take a quick look
> and explain me that...
>
> http://csound.1045644.n5.nabble.com/file/n5445967/DeepNote.csd DeepNote.csd
>
>

It is adding 30 tones, which mathematically (not allowing for possible 
cancellations between components) gives a level of approx +30dBFS, or 
"way over" digital peak. So, it has to be scaled downwards accordingly 
to bring it within range, which the code duly does, in a particular way. 
It is living a bit dangerously, indeed; for  the usual 16bit range 
maximum is in ampdb terms 96dB, so the target should really be 66 (or 
even 60) not 68. The output is in practice reported as  some -1.7dB 
below digital peak, which is really borderline but just about OK. Thus, 
rasising the value given to ampdb even just a little will take you into 
overload. The output is really already as loud as it can be. If you want 
more "impact" etc, you have to resort to the usual artifice of 
compression, further synthetic enhancement, et al.

These days the recommended approach is to use ampdbfs with a value such 
as -30, as dBs only really make sense relative to a maximum, which by 
convention is 0dB. You can also to set 0dbfs = 1, to obviate any wrong 
impression that the raw amplitude numbers relate in any literal way to 
the output sample format.

Richard Dobson

I suspect that it is out of limit for only some small periods. In that 
case it may still sound ok, but most people prefer not to do that. The 
listener can always turn up the volume of his computer or hifi 
installation :-)

Mark

Op 31/01/2012 23:57, COCHEDELAFERTE schreef:
> Hi all,
>
> Learning the attached file "DeepNote.csd" i found in Dr tutos, i try to
> enhance the output volume via the ampdb opcode, which is set in the example
> file at 68 (db). If i make that (to 72 or more), i get in the console a lot
> of "out of limits samples". In the fact, this message had no real bad
> effect, the file is played as well, with the output sound enhanced as
> attempted. But in all cases i'm interested to understand why this message,
> and how to modify the tinstrument to have a perfect console output with any
> ampdb parameter, not only 68 db or less. If someone can take a quick look
> and explain me that...
>
> http://csound.1045644.n5.nabble.com/file/n5445967/DeepNote.csd DeepNote.csd
>
>
> Cheers,
>
> Sergio
>
>
>

Hi all tree 


Thank's greatly for your replies. Now i'll try several things as possible
with Odb (last part of Richard's explanations) or also, just to see what
happens, completely without amdb, i mean with usual amplitude notation
instead. In the fact i found that the sound isn't particularly strong in
this piece, ewen with 30 tons, comparatively anothers usual examples or
things i yet composed.


Cheers,

Sergio

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Hi again,


1) Thank's, Peiman, for the acoustical explanations you added this day.

2) I tried to use the common amplitude declaration (just a p-field) instead
the ampdb opcode : same problem if i enhance too, i'm becoming again out of
limits. The question is really in the 30 tones.

3) Richard, if you read me again, can you please give a bit more details (or
just a link) about what you mean with "the usual artifice of compression,
further synthetic enhancement", maybe that can help me other hand.


Cheers,

Sergio


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