What's the quality difference between convution reverbs?

[dburgan]

BTW that is a nice site indeed! Thanks for the link.

[aMUSEd]

And possibly

3. They offer additional features.

WizooVerb has two reverb engines, a convolution reverb (HDIR) and an algorithmic reverb (AIR) that can be combined. Prosoniq´s RayVerb uses inverse raytracing to recreate a room from an impulse response file and offers the possibility to move the sound source within the room, change the material of the walls and even the proportions of the room.

/Yoss

The Waves one also has a hybrid engine but rather than using them as alternatives as in the Wizoo one it uses both to create a convolution based but synthesis completed space. I'm a bit surprised that people think it sounds so good because it has a limit on tail length and seems to take a few shortcuts compared to the fully convolution based reverbs. The other difference with the Wizzooverb is it uses higher resolution impluses than the others.

Rayverb looks nice on paper but from what I've heard it's not that great sounding.

Imho the convolution module that comes with Kontakt 2 sounds better than any I've tried and you can use zero latency with it (though I tend to compromise a little to reduce CPU) - it's a pity you can't use Kontakt as an effect like with most other NI plugins.

[FEV]

c.) they are using an optimized FFT algorithm that does things like precompute lookup table values for sin/cos, etc. to support fast-but-approximate trig functions

Yep. One can do that. But 1. creating an accurate and fast sin/cos approximation is quite easy and 2. in FFT's the use of sin/cos is substantialy reduced (compared to straightforward DFT). What I want to say, is that even if the developers used that kind of optimizations, I have big doubts if those changes cause any audiable ( < -120 dBFS ) distortions.

d.) they are using a different internal resolution (e.g. long double v. float) which results in different rounding error behavior

Well float vs. double can make an audiable difference in some cases (recursive IIR filters are a good example), but for convolution, doubles are not really necessary (the differences between outputs of a routine processing floats and the equivalent using doubles is way below audiable threshold (-120 dBFS)).

e.) they are using a different FFT block size to process the audio stream

f.) they are using a different windowing function to deal with the fact the audio stream is chunked up into a number of discrete blocks

FFT block size and windowing function won't matter if you do a proper window overlaping. That's why these kind of settings are not exposed to the end user in convolution plugins. Well I'm still after .b

cheers,
Bart

[sidrat]

But sidrat, isn't the point of this thread to see how the same impulse response, fed into different convo reverbs, would sound? We all know the IR1 impulses are great - but then IR1 costs crazy money.

the convolution algo is a smaller factor of how they sound, imo. i'd say the impulses make a -much- bigger difference than the algo. what i wanted to do was compare the sound of each reverb's ir library with the plugins being equal.

besides, when you buy one of the expensive reverbs, you're really buying into the library that comes with it... especially if it uses a proprietary format like ir1/altiverb/spacedesigner.

[defjamm]

I'm a bit surprised that people think it sounds so good because it has a limit on tail length and seems to take a few shortcuts compared to the fully convolution based reverbs.

i think they like the included ir's.

[aMUSEd]

I'm a bit surprised that people think it sounds so good because it has a limit on tail length and seems to take a few shortcuts compared to the fully convolution based reverbs.

i think they like the included ir's.

Not so good though if you can't use them in other plugins.

[helium]

You are correct of course concerning most IR reverb type filters, where the IR will be quite long. But in the case of simple filtering, for real-time processing, linear convolution may actually be preferred.

Just wanted to point out that it is definately not cut & dry. And that CPUs today have no problem with simple linear convolution.

My speaker-simulation uses simple linear convolution and works pretty fine.

[DevonB]

Imho the convolution module that comes with Kontakt 2 sounds better than any I've tried and you can use zero latency with it (though I tend to compromise a little to reduce CPU) - it's a pity you can't use Kontakt as an effect like with most other NI plugins.

Really? I like K2, but I wasn't impressed with the convo at all. GigaPulse has more features and sounded much better to me.

Devon

[AKJ]

right, it's all about the quality of the IRs. For a long time I igored Voxengo Impulse Modeler. But now I gave it a test drive and I must say: the quality of the IRs which it models/creates is 1st rate. And it gives you the freedom to model spaces according to your imagination. That's ultra cool. Everybody should give it a try, even if only loading the presets it's well worth while (and even the demo allows the creation of IRs!!!).

best, AKJ

[aMUSEd]

Imho the convolution module that comes with Kontakt 2 sounds better than any I've tried and you can use zero latency with it (though I tend to compromise a little to reduce CPU) - it's a pity you can't use Kontakt as an effect like with most other NI plugins.

Really? I like K2, but I wasn't impressed with the convo at all. GigaPulse has more features and sounded much better to me.

Devon

I'm sure Gigapulse does have more features but I just thought the K2 convo sounded really natural and spacious and meshes well with the rest of the sampler.

[defjamm]

I'm a bit surprised that people think it sounds so good because it has a limit on tail length and seems to take a few shortcuts compared to the fully convolution based reverbs.

i think they like the included ir's.

Not so good though if you can't use them in other plugins.

that's why it comes with one.

[kevvvvv]

I took the convolution wavs from Kontakt 2 and tried feeding them into Convo Boy.

I don't think they sounded as good.

In K2 the convolution reverb sounds quite good, especially with the VSL strings.

But when the wavs are moved across something gets lost.

Maybe I should buy Pristine Space Lite (or at least try the demo) and try the K2 wavs that way.

Would anyone recommend the Pristine Space Lite route?

At $59 ... well

[AKJ]

well, yes. just chekc the demo of PS Light. I find it quite good. but why are you so eager to use the K2 IRs? Make sure to also check the free IRs at noisevault and Voxengo Impulse Modeler.

AKJ

[Rajah]

Altiverb5 took first place due to its features,its flexibility and sheer beauty of sound.

Too bad it's just for Macs.. But it is a beauty in design also (GUI).

[Foxglove]

fwiw, i just did an informal listening test of ir's from altiverb, space designer, ir1 and tl space.

Wow, you must be very very rich