OMG, thanks for the massive feedback. I just google all of the interesting keywords right now. Groupdiy.com crowd does not disappoint!
Perhaps if you could figure out a way to mechanically change the spring tension?
This also came to my mind first, but does the spring tension really change the reverb time?
Or simply by damping the spring with a felt pad.
I am not sure if this can be reproducibly realized. The mechanical damping of the springs definitely has potential, the sound of the "room" response is drastically changed. Very interesting.
Conversely a dynamic expander would shorten the tails.
Now it isn't as satisfying as using diverse tanks. Damping springs is a very delicate affair that requires fluffy materials that are not stable enough for repeatability.
I'm also always a little wary of fiddling with the springs directly because the suspensions of the springs are so fragile.
The Micmix DynaFex - a downward expander and sliding filter - was originally developed to shorten spring reverb decay tails.
Thats interesting, I have to do some google work on this topic.
Back at Peavey (80-90s) I designed a combination downward expander with sliding LPF as an AMR rack mount studio piece. I used two VCAs, one for each filter effect. IIRC I did a subtractive trick to attenuate the low level HF noise, so there was no attack time issue for HF transients to overcome.
I have surely discussed this design here before (I love all my children).
Whoa, heavy stuff! I am grateful for any further info.
Maybe you can try to use two same type tank in parallel with (out of phase) blend at input and sum at output. (have this in mind since long time but never try)
Initial time and freq response tolerance between tank will be the unknown factor, the clever AKG solution being to use one spring.
The issue I see with active dynamic is that the threshold signal modulate the tail length, continuous and stable signal will keep gate/expand change inactive until your level change, still this can be fun for FX.
What about an envelope comparator ? it should change the tail only based on fixed (selectable) timing difference and not on absolute level.
I have also thought about a back to back constalation, the rest is beyond my horizon.
Sorry Zam-man!
I once did a mechanical damper on a tank with two felt pads damping the outer springs. It did not really have the desired effect on reverb time but it does change the density of the reverb. There is a clip with a picture on my soundcloud cozmikproduktionz . I'm on my Phone Linking the file is a bit of a hassle now as my Phone keeps changing eveything to Dutch....
Thanks for feedback. This corresponds to my first experience.
I also know the "autocorrection funktion in a foreign language" problem very well on my phone. I hate it and it costs an incredible amount of time. I am interested in your material, I will google for it.
A powerful combination!
Indeed, adding echo is a good way of lengthening reverb, but the challenge is shortening it.
Very true. In fact, my idea is to dampen the longest possible decay tank somehow to achieve shorter times.
an old studio trick was adding delay in series with the input of a reverb...
Indeed, the results are incredible. I have tested it last weekend and the outcome was very promising!!
You can add only some predelay up to the creation of "real" rooms via first reflections. Very powerful.
I wonder if negative/positive feedback mixed with the input signal would accomplish anything? Does anyone have a link to the AKG patent that was mentioned above?
I am still searching, I will post my results here.
That's not what I read; apparently he wants to "change the length of the reverb tail of a spring reverb"
You are right.
Feedback doesn't work with uncorrelated signals, unfortunately.
I have also thought about this, what really happens here?
The service manuals for the various BX types have a lot of information, but don't describe the motional control that's the basis of active damping.
It takes a lot of time to understand all the interconnections, then it becomes clearer.
Okay, I will check them.
I modded up a tank with a perspex top , I cut a slot so the sponge damper could slide over either or both springs , I agree with Permo its more a tonal change than lenght of reverb it effects . Something like a Drawmer DS201 dual gate is a good way to chop the reverb tail off ,but of course you'd still need to boost the output of the spring before feeding it into the gate .
Regeneration with a controlled amount of positive feedback from output back to input is an effective way of making the decay longer , of course if you over do it with the levels it will break into oscillation quite readily .
Thanks, I have to think about this.
