New year wish: a surround version of AAR

[teacue]

As a happy new user of Arts Acoustic Reverb I nevertherles wish a surround version.

Bonne année

[HunterKiller]

Great idea - like Wizoo W5 - it'd make AAR, a great reverb, even greater!
I certainly think its the way forward for AA!
But not only 5.1, more like up to 10.2

[nick at artsacoustic]

there are no plans to do so for the near future, unfortunateley, sorry.

[egbert]

Does AA have plans for new products in 2007?

[nick at artsacoustic]

yes

[egbert]

Coy is not a good look in a lead developer

Any hints?

[teacue]

there are no plans to do so for the near future, unfortunateley, sorry.

Wie schade, wo Surround so schön ist

Could you maybe explain this:
I often have read that using one instance of a Reverb plug for L+R and an other for SL+SR instead of a surround plug, can lead to problems.
I am not talking about routing or CPU-use problems but about acoustic things like "modulations differences" or "correlation issues" or what ever ...
When I do this, I cant say I would really notice something, but I am more musician and composer than engineer.
I would be glad if you could explain something on this and also say if there are possibly any tricks using AAR for surround to avoid these problems.

Best regards

[nick at artsacoustic]

well, we have users that sucessfully use the artsacoustic reverb like that. i'll try to contact them to get involved to this topic.
of course i can't guarantee that they will contribute, but it would be nice indeed.

[Cinemascore]

Could you maybe explain this:
I often have read that using one instance of a Reverb plug for L+R and an other for SL+SR instead of a surround plug, can lead to problems.
I am not talking about routing or CPU-use problems but about acoustic things like "modulations differences" or "correlation issues" or what ever ...
When I do this, I cant say I would really notice something, but I am more musician and composer than engineer.
I would be glad if you could explain something on this and also say if there are possibly any tricks using AAR for surround to avoid these problems.

teacue -

I've been using AARs in surround since it was first released. And I do use them in the way that you described: a basic quad setup of one for L/R and one for surround L/R. The main key is to use a slightly darker and longer tailed version with added predeley to the rear AAR, so that the front and rear instances do not correlate. Call up your favorite preset in the front AAR first, then copy it to the rear copy, then adjust by ear so that the ambience provides a bit of motion from the front to rear automatically when, say, striking a percussion or staccato instrument (similar to how a real concert hall would behave). You may have correlation issues when/if you are folding or mixing down to stereo (I've had this problem as AAR [or any other stereo-only reverb] isn't truly 5.1 linked, of course) in which I remedy it quickly by disabling the rear AAR and cranking up the front AAR to compensate.

Hope that helps!

[nick at artsacoustic]

Does AA have plans for new products in 2007?

sorry, we cant't talk about it at this stage.
we'll tease you at the right time, don't worry

[teacue]

teacue -

I've been using AARs in surround since it was first released. And I do use them in the way that you described: a basic quad setup of one for L/R and one for surround L/R. The main key is to use a slightly darker and longer tailed version with added predeley to the rear AAR, so that the front and rear instances do not correlate. Call up your favorite preset in the front AAR first, then copy it to the rear copy, then adjust by ear so that the ambience provides a bit of motion from the front to rear automatically when, say, striking a percussion or staccato instrument (similar to how a real concert hall would behave). You may have correlation issues when/if you are folding or mixing down to stereo (I've had this problem as AAR [or any other stereo-only reverb] isn't truly 5.1 linked, of course) in which I remedy it quickly by disabling the rear AAR and cranking up the front AAR to compensate.

Hope that helps!

Thanks Nick for your answer and thanks a lot Cinemascope for your usefull informations

I made some research and found some interesting papers.
One of them is:
"Recommendations For Surround Sound Production"
from The Recording Academy's Producers & Engineers Wing
Written by the Producers & Engineers Wing Surround Sound Recommendations Committee

Among others you can find such name as: Bob Clearmountain, Bob Ludwig, George Massenburg, Phil Ramone

You can find the complete document here
http://www.grammy.com/Recording_Academy ... uidelines/

As I believe that these informations could be usefull for this special question I add two extracts from this paper.

First extract(from chapter 4.3):

"One potential problem that can arise from routing a signal into two or more speakers is the danger of increased, and increasingly complex, comb filtering.
This problem multiplies as more speakers are engaged and can become critical if downmixing is ever employed by the playback system. Therefore, many
experienced surround mixers selectively turn off channels when bringing a sound "inside" the surround bubble or when dynamically panning a sound from one area in the surround space to another. It is recommended that whenever signal is placed into three, four, or five speakers, it be decorrelated"


Second extract:

"4.7 Creating Realistic Ambience
Unless one is working with material that was recorded with multiple ambient microphones (or a multichannel microphone array), the surround mixer often has to deal with single channel sources that need to be clearly positioned within an open, defined space. There is often also a need to move the sound around freely in that space - and at the same time have the acoustics work correctly.
For such precision panning to work realistically, the accompanying ambience needs to change as well.
The key to accomplishing this is the use of decorrelated effects, where the output of each channel is similar, but not exactly the same (if they were exactly the same, they would be correlated). Decorrelation is achieved when one or more basic parameters - typically filter settings, delay times, and/or pitch - are very slightly offset in each channel. In any two-channel pair, the sound of a left-right decorrelated pair is distributed evenly across the field; in contrast, an exactly correlated pair sounds monophonic. The sum of any two correlated signals is 6dB higher in their center, while the sum of any two perfectly decorrelated signals is only 3dB higher in the center. More importantly, decorrelated signals yield a sense of realistic ambience, because real spaces are decorrelated. In the case of a decorrelated surround sound reverb, instead of yielding a sense of a different reverb in the back, the listener gets the sense of a real space.
While dedicated multichannel reverberation algorithms and hardware devices provide an easy means for decorrelation, it can also be accomplished with stereo, or even mono reverbs. In the case of stereo reverbs, which often are programmed with identical parameters in the left and right channels, care must
be taken to alter one or more basic parameters in one side only. Some engineers prefer to use multiple mono reverbs instead, routing each to a different speaker and creating decorrelation by calling up the same preset in each, then slightly altering selected settings.
As with most mixing techniques, the best way to approach the creation of realistic multichannel ambience is to listen carefully and experiment. Take the time to listen to a sound in a live acoustic space, then go back into the studio and try to duplicate what you are hearing."

I hope this can help others too
Best regards