Are there any preprocessors on the market or coming to market soon that compensate for irregular speaker positioning?

Let's say instead of having the "recommended" ~110 degree angles on the back speakers you have 125 degrees, or instead of 30 degrees in the front you have 40 degrees. Are there any preprocessors or add-ons that can digitally alter the signal to compensate for these kinds of setups? This is one of the questions I asked about the Krell Evo 707.

I know the new DTS and DD lossless algorithms will have some forms of compensation built in for alternate speaker layouts, but nothing that is this precise from what I had read about a year ago. You either use their alternate speaker layouts, or it won't compensate for your speaker layout correctly.

What options are out there if your room doesn't allow the best speaker positioning?

It can't be too difficult to put some kind of algorithm into a device that allows you to specify speaker angles along with the other variables we already program in, such as distance and phase. Systems that do things like Logic 7 are basically using the same type of thinking to split up a 5.1 stream into 7.1 already. All that is needed is the extra processing power to compensate for the worst case scenario. I do realize there is a point of no return where a setup can not be fixed due to speaker positions being too far apart, but going 10-20 degrees off target should be workable, right?

Thanks.

I don't know that anyone does that with PLII as that is Dolby's thing. However, it would be a cool thing, rather than that 'center width' thing they have. You're right, all you'd be doing is altering the algorithm slightly and it's a good idea for someone though i don't know if Dolby would allow anyone to mess with their algorithm, so it might have to be a from scratch kind of thing. PLIIIx anyone?

That being said, I don't think a few degrees would make for a drastic change in the overall experience if you have nice, wide dispersion speakers.

I think that's getting into the area of room correction, isn't it? I mean, I guess one doesn't necessarily need to do frequency response or impulse response correction in order to (simply) correct for arrival times or (more complex) re-matrix the soundfield to account for the different arrival angles. But for irregular placement it might be worthwhile to let the processor figure out how to compensate automatically. I know those Trinnov folks that Noah was talking about claim to compensate for irregular positioning.

I know those Trinnov folks that Noah was talking about claim to compensate for irregular positioning.

I'm going to have to check that Trinnov out. I quickly read their description of "Optimization of Loudspeaker Positions in 3D (http://www.trinnov.com/product_Optimizer.php)." This is exactly the kind of thing I was asking about.

I'm finding the MSRP to be around $13K unless you get it included in another product. Does anyone know what preprocessors use or plan on using their technology?

Thanks.

Trying to simulate a difference angle of incidence is very difficult. The Trinnov system sounds interesting, but I'm not sure it can reconstruct a good enough soundfield using normal speakers since normal speakers have very low order radiation patterns (basically omni and pseudo-cardioid) that may not provide sufficient basis (in the orthogonal, cross-product is 0 kind of sense) to reconstruct the kind of soundfield that's necessary to simulate different angles of incidence.

Wide dispersion speakers are no help as well, and this is due to the perceptual issues. A speaker at 90 degrees to the side is perceived very differently than one in front, or to the rear, for example. The HRTF will filter different angles differently for each ear, and the energy moving across both ears will be different in both intensity and timing.

The best thing is either to get the angles right or put enough speakers in your system so that you can cover all the angles.

An analogy is to think about a lightbulb (which is basically omni in the horizontal plane) being moved around your head. Depending on what angle the bulb is to your head, different parts of your head are illuminated differently. You can't really do too much about the shadowed areas without getting another light source.

Logic 7 is trying to solve a different problem. Side speakers at 90 degrees are best for creating envelopment, while rear speakers at 150 degrees give you that sense of things moving from front to back. With a 5-channel system, you have to choose one or the other or neither if you use the IEC-recommened 110-degree setup. With a properly designed 7-channel system, you get to have both.

--Andre

i think you could compensate when you're doing a steering thing, but largely only with the channels that are actually being created and steered.

Trying to simulate a difference angle of incidence is very difficult. The Trinnov system sounds interesting, but I'm not sure it can reconstruct a good enough soundfield using normal speakers since normal speakers have very low order radiation patterns (basically omni and pseudo-cardioid) that may not provide sufficient basis (in the orthogonal, cross-product is 0 kind of sense) to reconstruct the kind of soundfield that's necessary to simulate different angles of incidence.

Wide dispersion speakers are no help as well, and this is due to the perceptual issues. A speaker at 90 degrees to the side is perceived very differently than one in front, or to the rear, for example. The HRTF will filter different angles differently for each ear, and the energy moving across both ears will be different in both intensity and timing.

The best thing is either to get the angles right or put enough speakers in your system so that you can cover all the angles.

An analogy is to think about a lightbulb (which is basically omni in the horizontal plane) being moved around your head. Depending on what angle the bulb is to your head, different parts of your head are illuminated differently. You can't really do too much about the shadowed areas without getting another light source.

Logic 7 is trying to solve a different problem. Side speakers at 90 degrees are best for creating envelopment, while rear speakers at 150 degrees give you that sense of things moving from front to back. With a 5-channel system, you have to choose one or the other or neither if you use the IEC-recommened 110-degree setup. With a properly designed 7-channel system, you get to have both.

--Andre

I like your analogy to a light bulb. Gives proper perspective to the problem. Unless the off-axis speaker response is so poor to begin with, you should be able to get a decent result from most speakers until they were about 15-20 degrees max- off from the best position....no?

I'm going to have to check that Trinnov out. I quickly read their description of "Optimization of Loudspeaker Positions in 3D (http://www.trinnov.com/product_Optimizer.php)." This is exactly the kind of thing I was asking about.

I'm finding the MSRP to be around $13K unless you get it included in another product. Does anyone know what preprocessors use or plan on using their technology?

Thanks.The Trinnov works, at least in the brief demos that I have heard. Sherwood is bringing out an AVR with the Trinnov processing for a fraction of Trinnov's price. There's a thread here on AVS about it.

Logic 7 is trying to solve a different problem. Side speakers at 90 degrees are best for creating envelopment, while rear speakers at 150 degrees give you that sense of things moving from front to back. With a 5-channel system, you have to choose one or the other or neither if you use the IEC-recommened 110-degree setup. With a properly designed 7-channel system, you get to have both.

No one said they were the same problem...

Trying to simulate a difference angle of incidence is very difficult. The Trinnov system sounds interesting, but I'm not sure it can reconstruct a good enough soundfield using normal speakers since normal speakers have very low order radiation patterns (basically omni and pseudo-cardioid) that may not provide sufficient basis (in the orthogonal, cross-product is 0 kind of sense) to reconstruct the kind of soundfield that's necessary to simulate different angles of incidence.

If you don't know much about the piece of equipment, why speculate that it doesn't work? It casts bad light on something you don't know about.

The Trinnov works, at least in the brief demos that I have heard. Sherwood is bringing out an AVR with the Trinnov processing for a fraction of Trinnov's price. There's a thread here on AVS about it.

I saw that piece of equipment online. It appears to be a receiver though. Are there any preprocessors in the works without built in amps?

Wide dispersion speakers are no help as well, and this is due to the perceptual issues. A speaker at 90 degrees to the side is perceived very differently than one in front, or to the rear, for example.

Depends. I certainly wouldn't say 'no help' as a wide dispersion speaker's spaciousness allows it to disappear a little more into the sound field than a more directional speaker. That doesn't directly help being off, but indirectly helps the speaker merge into the soundfield better.

As far as processing, the ear is very easily fooled by DSP, so as long as you could map things pretty well with the appropriate algorithms, you could fake the ear out to an extent, within a relatively small listening area, at least, for the front/center speakers. As far as rears which are being created and steered from the sides, that would be pretty easy, so now that it comes up, i'm a bit surprised that's not in the PLIIx algorithm.

i came up with a scheme for converting 6.1 DTS to 7.1 once and pitched it to Fosgate Audionics, the only bummer being that 6.1 DTS really didn't become popular enough to even make it worth the effort.

From what I read, they don't attempt to change any angles of incidence, to me it seems that they shift the stereophonic imaging (or as they call it remap the radiation matrix). In other words, they are just shifting parts of the field so they are moved/stretched/etc to the correct places to reproduce the originally intended surround field. This isn't anything unordinary in terms of stereo; it is the nature of stereo. They are moving the overall stereo illusion around between the speakers (changing speaker weighting to strengthen positioning) so they are in the correct places to recreate the intended surround field.

Of course it won't work if you stack all five speakers right on top of each other. I didn't start this thread because I plan on stacking five speakers right on top of each other (or anything else silly) so I can implement a device like the one mentioned with the expectation that it will sound like a 5.1 surround system when I am done...

You know, a *real* man would just buy the pro unit ;)

I saw that piece of equipment online. It appears to be a receiver though. Are there any preprocessors in the works without built in amps?Yup. Sherwood promises a pre/pro eventually.

Yup. Sherwood promises a pre/pro eventually.

Excellent!

You know, a *real* man would just buy the pro unit ;)

LOL. I've already had an e-mail exchange earlier today with the USA distribution representative. I was hoping they would have a pro-dealer local to me, but they don't. I doubt I'll get any kind of discount from a distributor though. :(

My setup is fairly close to the recommended 5.1. I think my surround speakers are somewhere around 115 to 120 degrees, my fronts are likely on the money. I do get excellent surround as is with the speakers only being a little bit off the recommended angles, but I want to squeeze out the extra immersion in the central seating position.

Are there any preprocessors on the market or coming to market soon that compensate for irregular speaker positioning?

What options are out there if your room doesn't allow the best speaker positioning?


Mcintosh is developing a processor. I would assume it's release is not too far off as references to how to connect it to Mcintosh's video processor are in the current owner's manual. "The AP1000 will feature the new Trinoff room correction system that employs proprietary processing to electronically "move" speakers around the room to correct for compromises in speaker placement. Find it necessary to place your center channel speaker a foot below your screen while your surround speakers are mounted in the ceiling? No problem - a twist of a dial here, a turn of a knob there and all of your speakers will now sound like they're on the same horizontal plane for a more seamless surround sound stage."
http://www.soundandvisionmag.com/newproducts/2133/new-product-mcintosh-vp1000-video-processor-and-ap1000-audio-control-center.html

Mcintosh is developing a processor. I would assume it's release is not too far off as references to how to connect it to Mcintosh's video processor are in the current owner's manual. "The AP1000 will feature the new Trinoff room correction system that employs proprietary processing to electronically "move" speakers around the room to correct for compromises in speaker placement. Find it necessary to place your center channel speaker a foot below your screen while your surround speakers are mounted in the ceiling? No problem - a twist of a dial here, a turn of a knob there and all of your speakers will now sound like they're on the same horizontal plane for a more seamless surround sound stage."
http://www.soundandvisionmag.com/newproducts/2133/new-product-mcintosh-vp1000-video-processor-and-ap1000-audio-control-center.html

Excellent, thanks! I like McIntosh, they are NY based! ;)

This one looks like a good choice, as long as they aren't serious about turning knobs to adjust the Trinnov, except perhaps to turn it on and run measurements. I assume they will use the same mic setup that the dedicated unit uses. I trust McIntosh will have great quality control. I don't mind paying for quality assurance.

Something like this will make a good next step in my upgrade path after I install a second screen with 2.35:1 ratio plus an anamorphic lens.

The new Denon pre/pro includes Audyssey Pro. It's more of a room correction tool, but if the measurements were taken in a tight area around listening position, it should compensate somewhat for poor speaker placement.

Find it necessary to place your center channel speaker a foot below your screen while your surround speakers are mounted in the ceiling? No problem - a twist of a dial here, a turn of a knob there and all of your speakers will now sound like they're on the same horizontal plane for a more seamless surround sound stage."

Aside from misspelling Trinnov, it's not quite so easy to electronically reposition speakers in the vertical domain. You could address small issues that might help the channel blend, but S&V is kinda clueless there.

The new Denon pre/pro includes Audyssey Pro. It's more of a room correction tool, but if the measurements were taken in a tight area around listening position, it should compensate somewhat for poor speaker placement.

Yes, but the stock implementation in the Denons also compensates for having that terribly good bass and non-fatiguing highs ;)

Aside from misspelling Trinnov, it's not quite so easy to electronically reposition speakers in the vertical domain. Ah, but a little known feature of the Trinnov system is a synthesized voice that comes up during the correction process and says, "move yer damn speakers!"

HAH. Reminds me of Zork. 'Placing your speakers in this position is a sign of impending mental collapse'. "Are you sure you want to do that?"

THAT would be a useful feature, finally!

The new Denon pre/pro includes Audyssey Pro. It's more of a room correction tool, but if the measurements were taken in a tight area around listening position, it should compensate somewhat for poor speaker placement.Compensation for poor placement is not the same thing as moving the virtual source.

Ah, but a little known feature of the Trinnov system is a synthesized voice that comes up during the correction process and says, "move yer damn speakers!"

Hmm, sounds familiar... Now if only the Trinnov could cook as well; it would make a better wife than my current one. :D

Of course, her room correction is not geared toward optimization... So perhaps even without the cooking I would be better served with a Trinnov.

Speaking of being served, what was that punchline from the joke about the magic frog - "If I can teach this frog how to cook, you're outta here!"

"it's not quite so easy to electronically reposition speakers in the vertical domain. You could address small issues that might help the channel blend, but S&V is kinda clueless there."

I'd think it easier than surround w/o rear speakers, which I believe has been done with some success.

Some JVC receivers had/have (haven't been following them) the center channel height adjustment and at least one review said it was rather effective.

Another neat trick the Trinnov can do is rotate the entire soundstage.

This is fantastic for my intended setup of audio and video on adjacent walls; now I won't have to wire the complex switchbox for rerouting all the signals.

Aside from misspelling Trinnov, it's not quite so easy to electronically reposition speakers in the vertical domain. You could address small issues that might help the channel blend, but S&V is kinda clueless there.

Blame the magazine from which I copy and pasted the quote. Have you ever tried a processor capable of doing this? Rather I should ask which as you already know the answer?

What are the inputs on the Trinnov? Preamp level 7.1?

Excellent, thanks! I like McIntosh, they are NY based! ;)

This one looks like a good choice, as long as they aren't serious about turning knobs to adjust the Trinnov, except perhaps to turn it on and run measurements. I assume they will use the same mic setup that the dedicated unit uses. I trust McIntosh will have great quality control. I don't mind paying for quality assurance.

Something like this will make a good next step in my upgrade path after I install a second screen with 2.35:1 ratio plus an anamorphic lens.
Don't be so exited with the Mc .I called many times Ron Cornelius ( Mcproduct manager)
AP1000 is not ready .....and may be never !!!!!!!!!!!!!!!

Blame the magazine from which I copy and pasted the quote. Have you ever tried a processor capable of doing this? Rather I should ask which as you already know the answer?

i was, no worries. i'm say in general, you can't just 'move' a speaker vertically, though you could horizontally based on what you feed to other speakers and monkeying with phase/time as you have other speakers to use. Well, maybe we'll just have to see what it can do, i'm just saying that it wouldn't be easy to do and would have to be something of a 'hat trick'. So I won't say impossible just yet.

What are the inputs on the Trinnov? Preamp level 7.1?Here's the link to the stand-alone unit: http://www.trinnov.com/product_Optimizer.php

The built-in varieties will be determined by the devices in which they reside.

Don't be so exited with the Mc .I called many times Ron Cornelius ( Mcproduct manager)
AP1000 is not ready .....and may be never !!!!!!!!!!!!!!!

Ack! :(