Making a feedback delay
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- KVRer
- Topic Starter
- 7 posts since 19 Feb, 2008
So I've been using sonic birth for a few months now and I'm starting to get the hang of it, but one thing still puzzles me. How do you make a delay that has feedback and actually delays at a constant time?
The feedback device has a fixed delay time of 10 usec and in order to make any kind of feedback you have to use it, but each time the fedback signal hits it, it gets delayed an additional 10 usecs which causes the timing of the signal to spread out over time. I've been working on a tempo synced delay and this has been driving me nuts...is there a way around this? I want to have access to the feedback signal path (to do filtering etc) so I don't think using the combfilter module would work...any tips?
The feedback device has a fixed delay time of 10 usec and in order to make any kind of feedback you have to use it, but each time the fedback signal hits it, it gets delayed an additional 10 usecs which causes the timing of the signal to spread out over time. I've been working on a tempo synced delay and this has been driving me nuts...is there a way around this? I want to have access to the feedback signal path (to do filtering etc) so I don't think using the combfilter module would work...any tips?
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- KVRist
- 238 posts since 17 Aug, 2005
.
Here are two solutions:
ONE: Subtract 10µs from the calculated delay and add the same amount in series with the output - after the fedback loop, either splitting the signal after the feedback element or by using a second fixed delay to compensate.
TWO: Use the allpass filter for it's delay capabilities and use it's internal feedback capability (input "b" controls feedback).
EDIT: The feedback element adds 10ms NOt 10 µs of delay!!
Here are two solutions:
ONE: Subtract 10µs from the calculated delay and add the same amount in series with the output - after the fedback loop, either splitting the signal after the feedback element or by using a second fixed delay to compensate.
TWO: Use the allpass filter for it's delay capabilities and use it's internal feedback capability (input "b" controls feedback).
EDIT: The feedback element adds 10ms NOt 10 µs of delay!!
Last edited by zmix on Fri Apr 11, 2008 3:09 pm, edited 1 time in total.
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- KVRer
- Topic Starter
- 7 posts since 19 Feb, 2008
it is entirely possible that I'm being stupid, but it seems that if I create a pulse and want it to essentially loop in the delay say be repeated every 400 mS, i can make a delay object that has a delay time of 390 ms so it hits the delay, , delays 390 ms the output of this module is sent to the output and into a feedback module, then hits the feedback module, delays 390 + 10 ms, then hits delay again....it seems that the timing of either the first delay is off or the timing of the subsequent repeats is off by the amount of the feedback module (10ms)...and it seems additive, falls out of sync over time...maybe I need to just move where the output comes from?
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- KVRer
- Topic Starter
- 7 posts since 19 Feb, 2008
ahhh thanks!zmix wrote:.
Here are two solutions:
ONE: Subtract 10µs from the calculated delay and add the same amount in series with the output - after the fedback loop, either splitting the signal after the feedback element or by using a second fixed delay to compensate.
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- KVRer
- 18 posts since 19 Feb, 2008
i tried setting up a second delay to compensate, but it added to the overall delay time, so my "Delay Time" slider was no longer accurate...and when it was pulled down to "0", there was still a quick delay. am i doing something wrong? is there an easier way to add constant feedback to a delay?
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- KVRer
- 18 posts since 19 Feb, 2008
oh! method TWO, the allpass...that's a piece of cake. i should have read that more carefully. thanks, zmix.
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- KVRist
- 238 posts since 17 Aug, 2005
ghetto3jon wrote:oh! method TWO, the allpass...that's a piece of cake. i should have read that more carefully. thanks, zmix.
If you do use the first method, dont for get to report the additional latency!