[PD] Compressor in Pd

[Roman Haefeli]

On Tue, 2010-05-18 at 07:28 -0400, chris clepper wrote:
> On Tue, May 18, 2010 at 5:54 AM, Roman Haefeli <reduzierer at yahoo.de>
> wrote:
>         
>         P.S.: @pdmtl guys
>         It's plain wrong to have a wet/dry parameter for dynamic
>         processing fx.
>         It just doesn't make sense at all to have the compressor
>         output mixed
>         with the input signal (It not only doesn't make sense, it even
>         adds
>         strange phasing effects, if the the dynamic processor uses a
>         look-ahead
>         delay).
>         Can we agree on that? And if not, can we discuss this, so that
>         we
>         finally can agree on that?
>         
>         
> 
> That sounds like parallel (or New York) compression, which is far from
> being wrong.  It allows for an increase in RMS without affecting the
> source's transient response, and in many cases this technique is far
> superior to series compression.  A fair majority of rock/pop records
> of the past quarter century have had parallel compression applied to
> the drum bus.
> 
> In the box, latency has to be compensated for though, so you will have
> to delay the source to properly mix with the compressed output.  You
> can simply send the 'dry' signal through the same compression with a
> 1:1 ratio and high threshold to achieve this.

I don't fully understand that last sentence: why sending the dry signal
through a compression (which makes it not dry anymore) and how does
threshold matter, when the ratio is 1:1 (which is basically the same as
sending the signal not through a compressor at all) ?

> http://en.wikipedia.org/wiki/Parallel_compression


Ok. I stand corrected. Thanks for the link. I was definitely wrong by
saying, that it doesn't make sense to mix the dry signal with the
compressed signal. Indeed, the effect is different from just
'destroying' the effect of the compressor (which is - simply said -
lowering the output gain the higher the input gain is). With parallel
compression the ratio between input and output gain above threshold is
not linear anymore, but tends towards 1:1 the louder the input signal
is. Or in other words: the ratio is dependent on the input gain.

Roman