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Re: maximizer opcode request

Date1998-09-19 11:14
FromRichard Dobson
SubjectRe: maximizer opcode request
I see what you mean; but I worry that the audio quality will be much less than
what would be expected intuitively. If a filter has a gain of 30dB, which is
added or otherwise combined with existing material without normalizing it, that
will have the effect of pushing the previous material down by the same 30dB,
eventually descending below audibility into quantization noise (hence the need
for a maximiser, I suppose!).

In the worst case, the number cannot accomodate the addition, and will go
denormal, truncate, or whatever, which would lead to even greater distortion.

Of course, if the 'user' is a Csound user, they have control of this at every
stage (and the peak values in the header will add much to that control), but if
that user is a non-technical user of a GUI environment, they may have no control
at all, and will simply be surprised by what comes out of the DAC. 

I admit this is mostly theorizing on my part, as I always ensure everything I do
is within range; I suppose I will have to create some huge-ranged non-normalized
sounds and see what happens. It's good to have a tool like Csound which enbles
me to do just that, without hiding anything!

Richard Dobson

Matt J. Ingalls wrote:
> 
> > you will need to normalize the data in order to play it on a real-world sound
> > card - and be limited by that card's resolution;
> 
>         of course-but from a "user" point of view there would be no
> normalization-the playback would just be "right" leaving her file
> untouched
> 

Date1998-09-19 20:38
Fromtolve
SubjectRe: maximizer opcode request
just broke down and picked up the L1, which is billed as a limiter. there
are quite a number of companies that are coming out with these devices,
including digidesign, but word on the street is that Waves L1 (available as
part of Native Power Pack which includes eq, compressor, dithering...) is
still the one.

ok, might not be any faster to use if you manage to set an instrument up in
csound. and this is way over my head anyway. what i meant was that they
require minimum tweaking and still do a great job. and about their alleged
intelligence. a wild guess. they may actually be far more complicated than
even multiband limiters. according to the box, L1 does look ahead. may self
adjust compression ratios in specific bands based on levels of overall
frequency content for their normal usage in boosting levels for mastering
cd's. this came up on the motu list a while back and i don't remember if a
programmer from one of the commercial companies commented. as has been
pointed out, this stuff is proprietary and it probably wouldn't matter if i
did remember. and several searches on the internet have turned up squat on
these things.

having said all this, and yet still said nothing, i will say that a
multiband compressor opcode sounds like a great idea. it would be far more
powerful than dam and useful for sound mangling purposes far beyond the
"simple" utility i had in mind. limiting or compression is not in of itself
evil. if you build it i will use it. it's all i can do.

thank you,
tolve

>I see what you mean; but I worry that the audio quality will be much less than
>what would be expected intuitively. If a filter has a gain of 30dB, which is
>added or otherwise combined with existing material without normalizing it,
>that
>will have the effect of pushing the previous material down by the same 30dB,
>eventually descending below audibility into quantization noise (hence the need
>for a maximiser, I suppose!).
>
>In the worst case, the number cannot accomodate the addition, and will go
>denormal, truncate, or whatever, which would lead to even greater distortion.
>
>Of course, if the 'user' is a Csound user, they have control of this at every
>stage (and the peak values in the header will add much to that control),
>but if
>that user is a non-technical user of a GUI environment, they may have no
>control
>at all, and will simply be surprised by what comes out of the DAC.
>
>I admit this is mostly theorizing on my part, as I always ensure
>everything I do
>is within range; I suppose I will have to create some huge-ranged
>non-normalized
>sounds and see what happens. It's good to have a tool like Csound which enbles
>me to do just that, without hiding anything!
>
>Richard Dobson
>
>Matt J. Ingalls wrote:
>>
>> > you will need to normalize the data in order to play it on a
>>real-world sound
>> > card - and be limited by that card's resolution;
>>
>>         of course-but from a "user" point of view there would be no
>> normalization-the playback would just be "right" leaving her file
>> untouched
>>
>[etc]