## Impulses reverb

Device/Module Wishlist

Original topic on PlanetZ: https://forums.scopeusers.com/viewtopic.php?t=23576

#### Impulses reverb

Posted: Thu Nov 08, 2007 12:15 pm
by RecS
Hi
Thank you for your work! it is good! Very well!
Is it possible to make a device of reverb for the use of impulses of WAV???
As it for VST:

Attachments
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#### Re: Impulses reverb

Posted: Fri Nov 09, 2007 5:52 pm
by RecS
Do you think it does not make sense?
Impulsive reverb badly it?

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Posted: Fri Nov 09, 2007 11:43 pm
by Lima
Hi RecS!
The idea is really good, indeed, but I suppose (I'm not a developer) that there aren't enough tools to make it with the sdk.
Maybe a developer could conferm it.
Anyway If you would to recreate a realistic room/hall reverb I could suggest to take a look at the masterverb PRO wich has a lot of parameter to control room size and early reflection with ease
This is the manual:
ftp://ftp.cwaudio.de/Manuals/SCOPE/Manu ... %20Pro.pdf

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Posted: Sat Nov 10, 2007 7:33 am
by petal
The problem with impulse reverbs on the Scope platform is that the reverb unit uses long wav-files to create the reverb effect. The long wav-file will have to be loaded into memory which the Scope cards does not have a lot of.
I believe this is why we havn't seen an impulse reverb on the Scope platform, because the platform simply doesn't support the technology behind impluse reverbs well enough to do it properly.

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Posted: Sat Nov 10, 2007 10:10 am
by RecS
This idea borned when I worked with STS 4000!
STS 4000 uses wav-files not longer than impulses!
In any case - THANK YOU!

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Posted: Mon Nov 12, 2007 12:42 pm
by astroman
an impulse reverb on a single individual source sounds great, usually
in a mix it tends to blur the sound - for a 'natural' emulation of the scenery you'd need a dedicated impulse for each track/instrument
and the response of the environment also contains unwanted room resonance
for this reason many engineers (are said to) prefer high-quality algorithmic reverbs, which make it easier to set parameters properly.
Petal is right about the resources. The DSPs have very limited Ram so both the source and the impulse response would have to be fed through the PCI bus to the card.
The actual calculation is a very simple thing and does not take particular advantage of DSP chips.
There's no point in not doing it in native code on the main CPU, even more as recent multi-cores are affordable and have huge caches.
cheers, Tom

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Posted: Mon Nov 12, 2007 1:49 pm
by hifiboom
I`m very sceptical about impulse response reverbs too.
not only that they are inflexible in the setup, I also think they have an decrease in soundquality if you compare a real algorithmic reverb preset with an impulse reponse record generated from this preset patch....
so imo the impulse response technology is nice and in todays world also cheap, but I think its not the end-of-line-technology to replace well designed algo reverbs ....

#### Re:

Posted: Sun Nov 23, 2008 4:28 am
by RecS

> hifiboom wrote:I`m very sceptical about impulse response reverbs too/

Ok!
SHORT impulses - from guitar cabinets?
(I already have all of the guitar modules for S|C)
All works perfectly, but sometimes (for a play on a guitar in real time) exactly a cabinet is determined by a sound.
Will a short impulse be arranged by the size of memory of platform?
P.S. - well, but can be BETTER! -

#### Re: Impulses reverb

Posted: Thu Nov 27, 2008 11:51 am
by dawman
I look forward to the GPU based IR's becoming more editable and capable of doing cabinet ambiences, etc.
GigaPulse sounds pretty good doing those as a member here has demonstrated, but it takes away resources from the CPU.
Most of us have these video cards w/ at least 128/256 MB's of RAM. That RAM is also of a higher speed and quality of the RAM that we use on our CPU's if I'm correct. This is perfect for the task.
Having a few quality DSP verbs on the AUX's and your channels providing different IR's from a GPU seems perfect, and I welcome further developement. The idea of using resources that go unused is quite appealing to all of us.
Developers of Romplers all have verbs on the instruments, but they tend to have an undesirable sound, probably due to the developer not wanting to kill the customers CPU. I understand that, and thankfully they can be disabled.
These IR's for the GPU will surely get further developements and when they become available, those of us using the CPU and DSP based reverbs can enjoy the benefits.

#### Re: Impulses reverb

Posted: Fri Nov 28, 2008 2:35 pm
by Warp69

> stardust wrote:The main disadvantage is that they are not so tweakable - yet.

What would you like to tweak, besides filter and RT?
If you like to tweak modulation, size, shape (envelope) etc. - then there's no point in Convolution reverbs, no? You should then use an algorithmic reverb. When you try to scale the IR for emulating the size parameter, then it sounds like crap - same problem with pitch shifting of samples - the reason why we all use multisamples.
I just tried Altiverb and their AMS RMX16 IR's - There's someting wrong with those IR's - they doesn't sound like my AMS RXM16 - I picked a 2s Hall IR and tried that on different things, then I loaded a little longer IR (3.2s Hall) from the same AMS library - Those sounds were totally different - I had no idea what happened.
The plates were very good however.

#### Re: Impulses reverb

Posted: Fri Nov 28, 2008 8:15 pm
by dawman
Those products sound great to people who do not use, nor have ever had hardware effects before.
A friend of mine here in Nevada that has used all in the box methods for years decided to have his project mastered @ a well known mastering house and was so excited he ran out and bought a few different hardware effects. I tend to believe it was a combination of the analog summing and effects, but he hasn't used his Altiverb since.
I tried the GPU based IR's out and actually cannot find a single use for them, as they sound confined and colored.
I have had success w/ GigaPulse as a mic modeler/placement IR, and for Early RFlec's, but these are used to reproduce the harmonics insdie of an acoustic Piano w/ the pedal down, and the resonant body of a Guitar, Cello, etc.
The best sound I have ever used was combing 2 x hardware reverbs having early reflections, and larger spaces on the other. Most dual engine hardware verbs do a fine job of this.
I am really hoping to find a really good sounding DSP verb for early reflections to be applied per channel on my mixers, while having a couple of larger spaces on 2 x AUX's and a top shelf hardware verb on the 3rd AUX.
I do this now on our groups live project, but use a mix of DSP and GigaPulse on the channels, and hardware on the AUX.
I am not quite satisfied to record like this but live it sounds pretty sweet as we can make it seem as though we are in a much larger venue than the current 150 seat max. room.
The Horn Sections, keyboards and drums sound very natural since I control those, but sadly the people I work with enjoy bathing their vocals in reverb/delay/chorus, etc.
I trick them somewhat by giving them want they want in their wireless ear monitors and keeping the mains as dry as possible.
I can't wait for the A100/P100 and other new DSP verbs w/ an XITE-1.
That w/ a top shelf hardware verb should sound very good live and recorded.

#### Re: Impulses reverb

Posted: Sat Nov 29, 2008 4:28 am
by dawman
Martin your gonna howl at this one.
I found another set of IR's for my 8800GT and thought I would try again as they night have a chance. They are wav.'s of short lengths and ambient spaces, and yeah they also suck.
But there were a couple that were amusing as they had the name Mod L 7, and PCM906.
Great entertainment though.
I need my XITE-1 very soon before I start taking meds and watching Jerry Springer re runs.

#### Re: Impulses reverb

Posted: Sat Nov 29, 2008 12:39 pm
by Warp69

> stardust wrote:exactly.
> size and color would be nice.
> nd having a hybrid would not be so unusual.
> A wavetable for the responses should not be so starnge. Even if I see we are not yet there.

But those parameters are inherited in the actual IR - you can't change those parameters afterwards without sounding unnatural. It's just like sampling a minimoog with lowpass filter and then want the sound 2 octaves up and without filter - it would never sound like the real thing.
By a hybrid you mean an early reflection engine with a real hall IR and the an algorithmic reverb - well those exists already.

#### Re: Impulses reverb

Posted: Sat Nov 29, 2008 12:54 pm
by Warp69
It's not possible to sample the Concertgebouw Hall (or any other room) with different sizes or frequency responses, because they dont exists.
Multilayered IR of what?
You'll be able to emulate the modulation if you had 64 IR of the exact same room/hall and interpolate between them for each sample - but that would need some processing power.

#### Re: Impulses reverb

Posted: Sat Nov 29, 2008 2:28 pm
by Warp69

> stardust wrote:But a acoustic room can be modified or It is possible to use 'standardized' real room IRs to represent support points in the IR mod.
> And yes. processing power is key.

That would not work - the future will be something like this : Odeon (www.odeon.dk) or Catt (www.catt.se) - but it would take years before this can be done in realtime.