# True stereo convolution



## Pier (Oct 14, 2021)

I was introduced to the notion of TS convolution in another thread and was wondering if any of you can recommend plugins and libraries that support it.

For others like me that do not know what TS is, the general idea is that TS IRs come with 4 channels (two stereo IRs) that help simulating the "cross feed" in real acoustic spaces (the stuff from L going into R, and R going into L). Or something like that...

This is probably a better explanation:



> The left input channel is convolved with the left and right impulse response file channels from IR1-A and the right input channel is convolved with the left and right impulse response file channel from IR1-B. The two output convolutions’ respective left and right components are then summed into a single stereo output. This configuration is necessary to take full advantage of true stereo impulse responses. True stereo impulse responses are required to be provided as two separate stereo files and loaded into IR1-A and IR1-B (or IR2-A and IR2-B). This configuration is typically found in high-end algorithmic reverbs.



https://www.liquidsonics.com/knowledge-base/reverb-processing-topologies/ 


I found this free plugin that support TS:






Convology XT Plugin | Impulse Record







impulserecord.com





Does anyone know if Waves IR1 support TS? Does it include TS IRs? It's on sale now at $29.


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## doctoremmet (Oct 14, 2021)

Pier said:


> Does anyone know if Waves IR1 support TS? Does it include TS IRs? It's on sale now at $29.


It is always $29.


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## doctoremmet (Oct 14, 2021)

Meldaproduction MConvolutionMB has True Stereo support.


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## Dietz (Oct 14, 2021)

Waves IR-1 "Full" is always true stereo as long as the IRs support it. The information is displayed directly in the plug-in's GUI:
​




​


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## Dietz (Oct 14, 2021)

PS: Vienna Suite's "Convolution Reverb", "Hybrid Reverb" and "Hybrid Reverb Pro" support multi-channel IRs too, of course. 8-)


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## musicalweather (Oct 14, 2021)

The SIR3 convolution plugin does this as well.


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## Beat Kaufmann (Oct 14, 2021)

I don't quite see the value of recorded algo reverbs - even if they are classics. Especially in the context of orchestral music, I wouldn't know how best to use them.
In addition, those IRs only represent one moment, even if the original of the reverb represented uses a modeled algorithm. So I would therefore rather invest in good IRs of natural rooms, such as those offered by VSL or other manufacturers.

Beat


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## Obi-Wan Spaghetti (Oct 14, 2021)

Dietz said:


> PS: Vienna Suite's "Convolution Reverb", "Hybrid Reverb" and "Hybrid Reverb Pro" support multi-channel IRs too, of course. 8-)


What about mirX? Is it TS? Thanks.


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## obey (Oct 14, 2021)

I believe AudioThing Fog Convolver supports true stereo IRs. I came from the same thread on the Kilohearts Convolver so I'm interested in the subject because I have some quadraphonic and left-right IR pairs I'd like to hear properly spaced.


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## Dietz (Oct 14, 2021)

Obi-Wan Spaghetti said:


> What about mirX? Is it TS? Thanks.


Yes, of course. Derived from MIR Pro, the source's stereo width settings have triggered the selection of the respective positional IRs of the chosen MIR Venue.


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## Pier (Oct 14, 2021)

obey said:


> I believe AudioThing Fog Convolver supports true stereo IRs. I came from the same thread on the Kilohearts Convolver so I'm interested in the subject because I have some quadraphonic and left-right IR pairs I'd like to hear properly spaced.


Yeah it does:









Fog Convolver - Creative Convolution Reverb Plugin (VST, AU, AAX)


Fog Convolver is a convolution reverb plugin. Convolution works by applying the sonic character of an impulse response to another sound in real time.




www.audiothing.net


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## CGR (Oct 14, 2021)

Pier said:


> Yeah it does:
> 
> 
> 
> ...


A top product - I use it often. I read it is going to be updated at some stage soonish.


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## emasters (Oct 14, 2021)

East West Spaces II also has the ability to do true stereo convolution reverb. Some of their supplied convolution files support true stereo.


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## mscp (Oct 14, 2021)

Beat Kaufmann said:


> I don't quite see the value of recorded algo reverbs - even if they are classics. Especially in the context of orchestral music, I wouldn't know how best to use them.
> In addition, those IRs only represent one moment, even if the original of the reverb represented uses a modeled algorithm. So I would therefore rather invest in good IRs of natural rooms, such as those offered by VSL or other manufacturers.
> 
> Beat


THIS ^


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## Trash Panda (Oct 14, 2021)

East West Spaces 2 and Reverberate 3 for sure. I think Seventh Heaven might be true stereo, but haven’t delved deep enough to find out for sure.


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## timbit2006 (Oct 14, 2021)

doctoremmet said:


> Meldaproduction MConvolutionMB has True Stereo support.


Do you know if any of the stock IRs are true stereo? I'm going to look next time I startup the DAW


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## cedricm (Oct 15, 2021)

Here is the answer of Kilohearts:
Regarding 'True Stereo Convolution', you can set it up yourself in Snap Heap if you like. We don't have any direct plans to add support for it within Convolver itself. I've attached a screenshot of what it can look like when properly set up to work with 2 stereo IRs (with gain compensation and a global mix macro for good measure). You can use the same principle to set up a 4 lane version if you want to work with 4 mono IRs.
I don't think I'll purchase Convolver. I've already have other TS compatible plugins, and I assume in most cases I can add them behind the Kilohearts plugins.


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## Rob (Oct 15, 2021)

Pier said:


> I was introduced to the notion of TS convolution in another thread and was wondering if any of you can recommend plugins and libraries that support it.
> 
> For others like me that do not know what TS is, the general idea is that TS IRs come with 4 channels (two stereo IRs) that help simulating the "cross feed" in real acoustic spaces (the stuff from L going into R, and R going into L). Or something like that...
> 
> ...


Buy it, still using it today, after many years... the Irs library provided is really good


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## Pier (Dec 6, 2021)

So I bought Audio Thing Fog Convolver but... it doesn't come with any true stereo impulses.

Can anyone recommend a library (free or commercial) of true stereo impulses?

Edit:

It seems the vast majority of TS libraries are locked behind a plugin like Waves, SIR, Reverberate, AltiVerb, etc.

Convology XT has some TS IRs but from hardware reverbs...

Waves offers a huge library of IRs but it only works with their plugins. There's an open source tool to extract the wav files from the wir file but it produces garbage.

It seems the easiest way to get into TS is to just get Waves IR1.

Edit 2:

I ended up buying these Bricasti M7 TS impulses. They are very nice, but unfortunately not the real thing.

I will probably end up buying IR1 😂


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## CGR (Dec 6, 2021)

Pier said:


> So I bought Audio Thing Fog Convolver but... it doesn't come with any true stereo impulses.
> 
> Can anyone recommend a library (free or commercial) of true stereo impulses?
> 
> ...


Try these:



balancemastering.com



I'll try and dig up some others.


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## CGR (Dec 6, 2021)

Website no longer exists



There are other true stereo impulses available:



Website no longer exists


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## CGR (Dec 6, 2021)

It seems the Free Teufelsberg NSA listening tower impulse responses are only 2 channel stereo, not 4 channel True Stereo impulses. Apologies for the misinformation.

The Open Air collection definitely has some True Stereo impulses within their collection. Here's the description of the St Albans Cathedral impulses, taken from the website:

_"This data consists of 2 sets of impulse responses measured in the Lady Chapel at St Albans Cathedral. Measurements were taken at two different source and receiver positions, A and B. The positions of the sources and receivers for the two configurations, A and B, can be are described in the attached diagram. Each set consists of a *4 channel B-format response*, a 2-channel ORTF stereo response, a 2-channel binaural stereo response and a 5-channel discrete microphone response (5.0) based on the Williams MMA microphone technique. Construction of the cathedral was started by the Normans in 1077 and hundreds of years of construction have resulted in a mixture of different architectural styles. The Lady Chapel is an example of architecture from the Decorated Gothic Period and was completed in 1327."_


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## Obi-Wan Spaghetti (Dec 6, 2021)

Pier said:


> So I bought Audio Thing Fog Convolver but... it doesn't come with any true stereo impulses.
> 
> Can anyone recommend a library (free or commercial) of true stereo impulses?
> 
> ...


Have a look here:






Samplicity's Bricasti M7 Impulse Response Library v1.1 - Samplicity


Samplicity has created a new and FREE Impulse Response Library, based on the immensely popular and highly acclaimed Bricasti M7 reverb unit.



web.archive.org


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## Pier (Dec 7, 2021)

CGR said:


> Website no longer exists
> 
> 
> 
> ...


Thanks!

This is exactly what I was looking for!


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## Pier (Dec 7, 2021)

CGR said:


> Each set consists of a *4 channel B-format response*, a 2-channel ORTF stereo response, a 2-channel binaural stereo response and a 5-channel discrete microphone response (5.0) based on the Williams MMA microphone technique.


I wonder if these need some special convolution technique?

I will try those out later today and see how it goes.


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## Tralen (Dec 7, 2021)

Pier said:


> So I bought Audio Thing Fog Convolver but... it doesn't come with any true stereo impulses.
> 
> Can anyone recommend a library (free or commercial) of true stereo impulses?
> 
> ...


Even without TS impulses, Fog still allows you to load a different IR on each channel. It is fun and creates interesting effects.


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## Pier (Dec 7, 2021)

CGR said:


> Website no longer exists
> 
> 
> 
> ...


So I downloaded about a dozen of the OpenAir locations but couldn't find any TS (as in 2 stereo files).

A couple of the locations were in mono.

Others had multiple stereo files, of different mics and positions, but no real quad stereo capture.

I also found a couple of folders labelled "B format" which according https://illatooscurodellafase.wordpress.com/2020/06/28/comparison-of-b-format-room-impulse-response-ambisonics-recordings-in-smaart-v8-beta/ (to this page) are some binaural format files. I imagine this requires a special convolver or maybe some decoder to transform those to TS?

And some locations had 5.1 surround files with 6 discrete channels of audio which Fog Convolver didn't know what to do with. And I suspect these are not TS either since it would need crossfeed information.


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## rhizomusicosmos (Dec 7, 2021)

Pier said:


> So I downloaded about a dozen of the OpenAir locations but couldn't find any TS (as in 2 stereo files).
> 
> A couple of the locations were in mono.
> 
> ...


"B format" is ambisonics surround based on 3D coordinates rather than speaker placement. It can be decoded to speaker- or headphone-based surround formats such as stereo, binaural, 5.1, etc. Melda MConvolutionMB can work with up to 7th order Ambisonic files (64-channel spatial resolution).


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## Robo Rivard (Dec 7, 2021)

musicalweather said:


> The SIR3 convolution plugin does this as well.


Haha, I didn't know there was a SIR 3... I thought the company died a long time ago... Since I already own SIR 2 plus the HDIR that came with it, I wonder what I would gain upgrading to version 3?... I also have EW Space II and Breeze 2 along with Precedence.


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## Pier (Dec 7, 2021)

rhizomusicosmos said:


> Melda MConvolutionMB can work with up to 7th order Ambisonic files (64-channel spatial resolution).


I'm torn between getting MConvolutionMB or Waves IR1 which cost about the same.

IR1 is less flexible but has a huge library of TS impulses.


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## Zanshin (Dec 7, 2021)

Pier said:


> I'm torn between getting MConvolutionMB or Waves IR1 which cost about the same.
> 
> IR1 is less flexible but has a huge library of TS impulses.


I think the Waves IRs are a free download if that helps:








IR Convolution Reverb Library (4.8 GB) | Downloads | Waves


Download for free this massive library of high-definition impulse responses for the Waves IR-series reverb plugins, for optimal sonic depth and dimension.




www.waves.com





You already have Reverberate?


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## Pier (Dec 7, 2021)

Zanshin said:


> think the Waves IRs are a free download if that helps:


Yeah. On a previous comment I explained that they come in a custom format that only Waves IR plugins can use.


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## Zanshin (Dec 7, 2021)

Pier said:


> Yeah. On a previous comment I explained that they come in a custom format that only Waves IR plugins can use.


Whoops, sorry.


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## Pier (Dec 7, 2021)

Zanshin said:


> Whoops, sorry.


No worries!


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## Zanshin (Dec 7, 2021)

Reverberate 3 can load the waves wir files apparently, I was wondering why I had them if they were not useful...


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## rhizomusicosmos (Dec 7, 2021)

Pier said:


> I'm torn between getting MConvolutionMB or Waves IR1 which cost about the same.
> 
> IR1 is less flexible but has a huge library of TS impulses.



It think ambisonics is a whole other (fascinating) rabbit hole, but if you are more focused on stereo, then I agree that the IR1 seems to offer a lot. Is it the case that if you buy the IR360 you get the IR-1 and IR-L as well?


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## Pier (Dec 7, 2021)

liquidlino said:


> But not as great as R4 that's on sale at JRR right now for a tenner, ridiculous.


Woah thanks for the tip! I actually paid $8.50 😂


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## tc9000 (Dec 20, 2021)

Zanshin said:


> Reverberate 3 can load the waves wir files apparently, I was wondering why I had them if they were not useful...


Nice! I have a lot of reverbs but reverberate3 just keeps on giving!


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## nickhmusic (Dec 20, 2021)

I think my friend Peter Roos' Bricasti impulses are True Stereo, they are 4-channel 32bit float 48k files, and highly recommend them. Although as of today, the site seems to no longer exist. He is a lovely guy though and might chime in on here as he knows what he's talking about.


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## MartinH. (Dec 20, 2021)

nickhmusic said:


> I think my friend Peter Roos' Bricasti impulses are True Stereo, they are 4-channel 32bit float 48k files, and highly recommend them. Although as of today, the site seems to no longer exist. He is a lovely guy though and might chime in on here as he knows what he's talking about.



I remember these, they are fantastic! I always wondered if he took them down because other people started hosting and selling them, which as far as I remember was both against his own terms of use and his agreement with Bricasti Design.


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## nickhmusic (Dec 20, 2021)

MartinH. said:


> I remember these, they are fantastic! I always wondered if he took them down because other people started hosting and selling them, which as far as I remember was both against his own terms of use and his agreement with Bricasti Design.


They are indeed spectacular, although I'm still interested in renting a Bricasti unit to compare with the real thing, I use the "6 Spaces 06 Scoring Stage Quad" and it helped immensely with LASS and putting things in a room before further tail reverb.


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