Simulating guitar feedback

[ilmai]

I have been wondering for quite a while how to simulate guitar feedback sound with a synth. I have tried various feedback methods using both plugins and mics, but nothing seemed to work. Finally I realized that the point of the guitar feedback effect is resonation and not the feedback itself, so I created an effects bus with a resonating filter with keyboard tracking, and a reverb to make the sound more pleasing. Then I mapped a controller knob to FX send amount so I could easily control. That seemed to have nailed it! Here's a test clip:

https://clyp.it/4cemkj0e

First set of sounds is with configuration described above, while the second set adds guitar amp + cab simulation between the filter and the reverb. I'm sure the effect chain could be futher tweaked to make it sound even better. Any suggestions are welcome.

[an-electric-heart]

Interesting. I was Googling how to do this just a couple of days ago... I didn't find an answer, I changed the song so I didn't need to do it, I normally find a solution pretty quickly.

But, now that I think about it: I probably could have done it by cross-fading between the guitar (Kontakt samples, Strawberry, I think) and a high sustained synth note, both going to the same channel/amp/effects chain.

[Jace-BeOS]

Interesting indeed. Would you be willing to share more details? Which DAW tools/plugins did you use for filter/resonance, delay, settings...?

It would be interesting if someone could build a multi-string physical model in Reaktor where there was a knob to feed the output of the instrument back into the string model so that "plucking" one string would result in stimulating the other, unplucked, strings. I'm not remotely skilled enough with Reaktor to do this myself.

[ilmai]

Sure. I'm using Bitwig with the setup below:

Feedback Bus.png

The Note Receiver device is used to get keytracking notes from the synth (Repro-5) I'm using for the test. For the filter, I'm using Bitwig's Resonator Bank with one band enabled at 1000Hz, Q=10, Gain +18dB, and 100% key tracking. The Chain is used purely to conveniently automate the Thermionik Psycho A amp sim and Recabinet 5 cab sim on and off for the demo. At the end of the chain, there's a VintageVerb with the Ambience Plate preset. For delay, I'm using the Guitar Solo preset of Replika XT.

Things I want to try to tweak the sound:
- Feed both the dry synth sound and the feedback sound into the same rerverb and delay chain, maybe also a compressor?
- Play more with resonator frequency and key tracking amount.
- The version with the amp sim fades in too quickly, maybe automate filter gain instead of / in addition to FX send amount?

[ilmai]

It would be interesting if someone could build a multi-string physical model in Reaktor where there was a knob to feed the output of the instrument back into the string model so that "plucking" one string would result in stimulating the other, unplucked, strings. I'm not remotely skilled enough with Reaktor to do this myself.

Maybe use additional resonating filters without keytracking to simulate unplucked (and unmuted) strings? I might try this. Of course a string will resonate at multiple harmonic frequencies and (as far as my understanding goes) the actual frequency that ends up resonating in the feedback chain is based on the setup and situation.

[ilmai]

But, now that I think about it: I probably could have done it by cross-fading between the guitar (Kontakt samples, Strawberry, I think) and a high sustained synth note, both going to the same channel/amp/effects chain.

Yeah I actually tried the cross-fading trick already. The problem there is that it's really difficult to make the crossfade sound natural, i.e. that it's coming from the same instrument. I'm sure it can be done, but at least to me, the filter method I found sounds a lot more natural. Of course it still needs tuning to make it actually usable in a track.

[ShawnG]

Reaktor prism has a pretty banging feedback model, and quite a few of the presets are loaded with it. Sounds pretty good to me.

Of course if you are trying to "simulate" feedback while playing a real guitar through an amp sim, you can just crank your monitors to 11 and get the real thing...

[cturner]

Don't forget Tritik's Moodal and the INA-GRM Tools Resonator.

[Jace-BeOS]

Sure. I'm using Bitwig with the setup below:

Feedback Bus.png

The Note Receiver device is used to get keytracking notes from the synth (Repro-5) I'm using for the test. For the filter, I'm using Bitwig's Resonator Bank with one band enabled at 1000Hz, Q=10, Gain +18dB, and 100% key tracking. The Chain is used purely to conveniently automate the Thermionik Psycho A amp sim and Recabinet 5 cab sim on and off for the demo. At the end of the chain, there's a VintageVerb with the Ambience Plate preset. For delay, I'm using the Guitar Solo preset of Replika XT.

Things I want to try to tweak the sound:
- Feed both the dry synth sound and the feedback sound into the same rerverb and delay chain, maybe also a compressor?
- Play more with resonator frequency and key tracking amount.
- The version with the amp sim fades in too quickly, maybe automate filter gain instead of / in addition to FX send amount?

Thanks for the details on your signal chain I don't have Bitwig, but it's interesting to get an idea (and a visual) of what's going on.

[Jace-BeOS]

Don't forget Tritik's Moodal and the INA-GRM Tools Resonator.

Moodal looks neat but it seems to mostly do metallic tones(?). I'd play with the demo to be sure, of course, but that's my impression from the video. How would you use this to simulate guitar feedback? [Edit: feed the resonator output into a delay and amp sim?]

There was one moment in the demo where they turned a snare into the metallic "KlimBim" sample found in old 4-channel tracker MODs. I now have some idea of what that sample actually is! The notion of recreating that sample in 16-bit was a briefly exciting one... but I'm no longer buying things just to reproduce one or two very short samples from them (i.e., my V-Synth XT with its D50 emulator, to reproduce ST-0x sample sets ).

[Jace-BeOS]

Reaktor prism has a pretty banging feedback model, and quite a few of the presets are loaded with it. Sounds pretty good to me.

Thanks for the mention. I'll have to go give the presets another look.

Of course if you are trying to "simulate" feedback while playing a real guitar through an amp sim, you can just crank your monitors to 11 and get the real thing...

Wear earplugs! Also, be careful not to blow out your studio monitors!

[ShawnG]

Reaktor prism has a pretty banging feedback model, and quite a few of the presets are loaded with it. Sounds pretty good to me.

Thanks for the mention. I'll have to go give the presets another look.

Of course if you are trying to "simulate" feedback while playing a real guitar through an amp sim, you can just crank your monitors to 11 and get the real thing...

Wear earplugs! Also, be careful not to blow out your studio monitors!

try "orange glow" and "strato drive" in the leads category. Reaktor being reaktor, I'm sure you can pillage prism for component parts and add to something else, but that's usually beyond what I feel like doing.

and yes, don't blow out your eardrums and/or monitors, but there does need to be a fair bit of volume to get the feedback going. I am a feedback junkie, lol. have spent non productive hours at times with my guitar just letting it wail in different ways. Its a wonder I'm still married.