eliya wrote:Yeah, the whole point of the feedback is that it's an infinite loop. I guess technically it's not if we let that resonance decay. Anyway, I don't know how algorithmically they can handle that kind of a loop because the program could easily throw itself into an infinite loop.It can be done by modeling the analog circuit including the feedback or calculating all the effects and rendering it (FFT).

eliya wrote:FWIW, most if not all DAWs have delay compensation, so there's no delay if you're not running the signal out of the computer and back in there should be no delay.Yeah, that works if you just run the signal through an equalizer. Here you're feeding the equalizer as a parallel channel, then feeding that return back through the equalizer. There's no avoiding the processing time for the equalizer algorithm when the signal cycles through it multiple times as feedback.Say the latency of the equalizer at a certain setting is N samples. If you apply the equalizer to a channel, that channel will be offset N samples to compensate for the latency. If you're feeding it from a bus, then you can't offset the channel feeding the bus because it isn't a through-put, and that would put the channel out of sync with the rest of the session by N samples. So the return has a delay of N samples.You then feed that return back through the same bus, so the feedback has an additional N samples of delay, and additional delay on the feedback of that signal coming back into the parallel channel and so forth, regenerating the delay more and more with more feedback.If there were a way to offset the entire session to compensate for the latency of the equalizer, allowing you to offset the send by N samples, the feedback would still incorporate the processing delay, because it can't be offset -- you can't move forward in time a signal that hasn't yet been generated -- so the parallel equalized channel could conceivably be latency compensated, but the feedback cannot.Yes, I have thought about this a lot.

eliya wrote:I believe you're right here.Well la-de-fuckin' da.

tmoneygetpaid wrote:Worth noting that HD Pro Tools has plugins that have zero samples delay, so you could use a TDM/ AAX DSP plugin for this purpose.This is of course impossible, so the language "zero samples delay" means they are compensating for the algorithmic processing time on the effected signals or the session as a whole.Which is what I was talking about.

Stinky Pete wrote:The Q of most parametric EQ is set largely through an internal feedback loop.Exactly. If you regenerate the audio through the EQ you increase this effect beyond the design of the hardware unit, tightening the Q to be precisely tuneable and verging on oscillation, and that's the auxiliary signal you mix with the "normal" bass drum. The reason you do it in parallel is to leave the original bass drum track intact, while adding a small amount of the ringing resonance. If the audio is run through the equalizer with high feedback near the point of oscillation, the effect will be much more drastic than the same signal being mixed with the unmolested bass drum to taste.

tmoneygetpaid wrote:All audio is delayed by the buffer amount.Plugins access the audio stored in the buffer and manipulate it before it is "queued" in the digital audio stream.And then the audio, after being queued into the digital audio stream, is partially fed back through the bus and into the buffer.

andteater wrote:steve wrote:I'm happy to demonstrate the effect sometime, just pop in during any mix session.is this an invite for all of us, because i've been specifically told i'm not allowed near the studio for a while.I believe the court order says 150 feet. I'll turn it up so you can hear it from the corner.

tmoneygetpaid wrote:So are you acknowledging now that a plugin that doesn't create latency is possible?Bussing does not cause latency/ delay either, so where would this delay be coming from?When you put the audio into a buffer (delay) in order to process a signal through the plug-in, then take the processed audio (delayed) and feed it back through the buffer (delay) in order to re-process it (the feedback path), you will reiterate the delay.That is why I suggested several times that you might be able to do it with an analog filter model that incorporates resonance (like a moog filter), but not using any old eq plug-in.I mean, please don't believe me. What do I know. Try it yourself.

projectMalamute wrote:nvolves the signal going from the output and back to the input a theoretically infinite number of times instantly. Exactly. In an analog circuit, the voltage appears instantly at the input of the circuit when fed back from the output because the voltage appears across the conductive path all at once (okay there are skin effects etc but practically it's instantaneous). The filter network has a time constant, but that is on the order of a phase change rather than an audible delay.

eliya wrote:Yeah, the whole point of the feedback is that it's an infinite loop. I guess technically it's not if we let that resonance decay. Anyway, I don't know how algorithmically they can handle that kind of a loop because the program could easily throw itself into an infinite loop.It can be done by modeling the analog circuit including the feedback or calculating all the effects and rendering it (FFT).