What makes a wave a wave?

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meatballfulton
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Re: What makes a wave a wave?

Post by meatballfulton » Fri Apr 22, 2016 12:28 pm

madtheory wrote: I doubt the filters are running in parallel.
There's six buttons and you can switch between filters in real time while playing without a glitch. From the horse's mouth:
The research part is, we have implemented the same pretty extreme model of the CEM3320 Curtis filter chip in our vintage Pro-One using 5 different numerical methods, each costing a very different amount of CPU. We wish for you to spot the "most analogue" sounding method. By that we wish to see if it is worth spending a lot of CPU or if we could get away with something cheaper. Furthermore we wish to discuss the following questions:

what differences do you spot between the models?
when do these differences become audible, i.e. which settings promote these differences?

We are sorry if some of you can not run this plug-in due to CPU consumption. This isn't an indicator to the final version being CPU hungry as well, it is just a necessity for the trial - several filter algorithms are always run in parallel so that one can not spot the most accurate one by CPU hunger.

Enjoy,

- Urs
Yes, each filter variation sounds a little different. Cool idea, getting end users to help fine tune the software design.
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Re: What makes a wave a wave?

Post by madtheory » Fri Apr 22, 2016 1:55 pm

I stand corrected :) But my point about CPU still stands.
briandc wrote:
madtheory wrote: I doubt the filters are running in parallel. That would actually be kind of hard to do in software, and anyway there is no reason to do it that way.
Why is it so hard to do? I have seen several VST synths offer filters running in parallel..


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I said it's "kind of" hard to do. Like, why would you deliberately have a filter filtering when there's no audio going through? Answer: if you are Cubase VST c. 1997 LOL! So it can be done obvs.

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Re: What makes a wave a wave?

Post by commodorejohn » Fri Apr 22, 2016 3:32 pm

briandc wrote:Is the high CPU usage due to a higher bit-depth? (similar to resolution quality in digital photos?)
If so, perhaps trying to emulate an analog digitally is kind of useless. (Like buying a sampler synth just to play a sampled piano, it kind of defeats the purpose of it.)
Bitdepth is a factor, but not by as much as you'd think - CPUs these days handle 32-bit numbers or higher without even blinking. Sample rate is a much bigger factor, since going from (f'rexample) 44.1KHz to 96KHz more than doubles the workload. But I think the big factor in the specific example being discussed is that he's using a much more complex algorithm to avoid aliasing; based on the description, I think he's basically doing additive synthesis to construct the waveforms while innately band-limiting them, which is a whole h**l of a lot more complicated than the phase-accumulator approach.
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Re: What makes a wave a wave?

Post by madtheory » Fri Apr 22, 2016 7:54 pm

piRoN wrote:using some complicated integration of pulse trains or something, from what I can recall.
Probably in relation to the Juno emulation? Because that's how the real thing does it.

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Re: What makes a wave a wave?

Post by briandc » Fri Apr 22, 2016 8:19 pm

commodorejohn wrote:
briandc wrote:Is the high CPU usage due to a higher bit-depth? (similar to resolution quality in digital photos?)
If so, perhaps trying to emulate an analog digitally is kind of useless. (Like buying a sampler synth just to play a sampled piano, it kind of defeats the purpose of it.)
Bitdepth is a factor, but not by as much as you'd think - CPUs these days handle 32-bit numbers or higher without even blinking. Sample rate is a much bigger factor, since going from (f'rexample) 44.1KHz to 96KHz more than doubles the workload. But I think the big factor in the specific example being discussed is that he's using a much more complex algorithm to avoid aliasing; based on the description, I think he's basically doing additive synthesis to construct the waveforms while innately band-limiting them, which is a whole h**l of a lot more complicated than the phase-accumulator approach.
Ok. So is that (the sample rate) the reason for the high CPU usage in the Pro-One that Meatballfulton mentioned?


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Re: What makes a wave a wave?

Post by commodorejohn » Fri Apr 22, 2016 9:50 pm

briandc wrote:Ok. So is that (the sample rate) the reason for the high CPU usage in the Pro-One that Meatballfulton mentioned?
From what meatball said it sounds like it's mostly because it's running six different filter algorithms in parallel. So it's kind of a different version of the same bottleneck - it's still having to generate many times more samples per second, just for a different reason.
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