attack simulation problem

Mattebass's icon
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Hello to everyone, I had a problem that I can't understand. I was following sone examples on a book and I've done this patch

As written, I can't understand the difference between the two processes : how a gain could "limit" the feedback?

thanks

brendan mccloskey's icon

Hi
I'm not 100% sure I understand the question, but if you are asking about a reciprocating delayline, with control over the feedback amount, then this is how to do it (using your [tapin~]/[tapout~] pair):

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If the feedback signal is summed with the input, then that signal must be scaled to < 1. Otherwise the system will reverberate infinitely, and even explode if you exceed a scalar of 1.

Brendan

Peter McCulloch's icon
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And here is a patch that is almost certainly not the correct pedagogical answer...but it's fun. It also has the nice property of being (almost?) impossible to blow up.

Roman Thilenius's icon

it can "limit" the number of noticeable delays, because there is a limit where the
human ear - especially under the condition that the original of the delayed audio
(or other audio) still plays - wont no longer hear them.

if gain in a feedback loop is set to * 0.5, the gain of the second loop is at * 0.25
and the 8th is already at * 0.0078125, which is no longer hearable even when
nothing else plays and your stereo is at full power.

so using * 0.5 will ... feel like ... 4-5 taps.

if gain is set to * 0.1, the second delay is at * 0.1 and the third one is already
at 0.01 - which means -40 db/A compared to the current full power.
you wont be able to hear that. you will hear only one tap.

otoh, using a gain of 0.99999 or less will make 100% sure that your feedback
loop will never ever become continioulsy raising.

-110