non convolution analogue warmth

In general, various degrees of low-pass filtering, small amounts of
randomness ('noise' in audio signals and control data), and (for
emulating vintage opto-compressor circuits) a bit of delay in the
side-chain (control) circuit are all going to get you a bit closer to
an analog compressor than the purely digital starting point. Season
to taste - your mileage may vary...

On Mar 30, 2007, at 9:10 AM, Michael Gounelas wrote:

> I was wondering if there are any general algorithm techniques in
> order to achieve an analogue sound result. I know this question is
> a bit general and has been discussed before, but the only sources i
> found in this forum are about building 'analogue' synths rather
> than 'analogue' compressors.
> So I would be grateful if someone could give some advices for doing
> my compressor patch sound a bit more 'analogue'. I could post my
> patch but what I'm looking for is some general advices that can be
> implied in many cases and not only on this specific patch.
>

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Steven M. Miller

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hi Steven and thanks for the reply.
Could you please be a bit more specific by saying ''various degrees of low-pass filtering''? Where should i apply the filters and what are they supposed to do inside a compressor?

thanks,
m

The low-pass filtering should be applied to the audio signal on
input. The specific setting of the Fc would really depend on which
unit you're trying to emulate, and/or what sort of general "analog"
sound you're interested in. The slope would generally be a simple
first-order 6 dB per octave. Doing a comparison on a scope of input-
vs.-output frequency response (and phase, if you want to go there)
might be a good 'objective' guide, but your ears are probably fine
for most work (assuming you're going for the general sound, and not a
specific emulation).

For that matter, some filtering (or 'smoothing') of the side-chain
(control) signal would also be a good idea.

The idea here is merely to reflect the reduced frequency response of
a lot analog equipment (particularly vintage gear). It's not
necessarily part of the original analog designs, but an attempt to
emulate their characteristics in the digital domain.

Hope this helps!

On Mar 30, 2007, at 10:05 AM, Michael Gounelas wrote:

> Could you please be a bit more specific by saying ''various degrees
> of low-pass filtering''? Where should i apply the filters and what
> are they supposed to do inside a compressor?
>

----
Steven M. Miller

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hi smill,

yeas, great info. i didn't really know that you can use a lp in compreossors to be honest. I'll give a try when i go back home.

PS. i'm still interesting to hear advices and techniquesabout this :)

thnaks,
mike

> The low-pass filtering should be applied to the audio
> signal on
> input. The specific setting of the Fc would really depend
> on which
> unit you're trying to emulate,

should i assume that the Fc is below the audible frequency bandwidth or not? If not what would be the higher value for Fc? It sounds a bit confusing to me cause if the Fc is at 80Hz (say) how can you compress a bass guitar without loosing the bottom end? or the answer is to eq it after the compression?

thanks,
mike

sorry about the last post. i confused LP with Hp :) but my question remains the same.
replace 'bass guitar' with hihats and '80Hz' with 10Khz... does this make sense?

thanks,
m

The Fc of the low-pass filter would be on the upper end, to reduce
the high-frequency content of the overall signal - say somewhere
between 12kHz - 18kHz or so, depending on the sound you're going for.
I'd recommend doing the filtering before compressing, to make for
smoother compression, all else being equal.

On Mar 30, 2007, at 11:15 AM, Michael Gounelas wrote:

>
> should i assume that the Fc is below the audible frequency
> bandwidth or not? If not what would be the higher value for Fc? It
> sounds a bit confusing to me cause if the Fc is at 80Hz (say) how
> can you compress a bass guitar without loosing the bottom end? or
> the answer is to eq it after the compression?

----
Steven M. Miller

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ok, i get you, thanks

m

You're welcome - good luck & have fun!

On Mar 30, 2007, at 11:50 AM, Michael Gounelas wrote:

>
> ok, i get you, thanks
>
> m

----
Steven M. Miller

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