I don't really remember what happened moving out of the sweet spot, maybe it wasn't remarkable enough to remember. But for me that wasn't the goal, the goal was to correct the tonality mismatch that comes when sitting at the point of the stereo triangle. The tonal difference that comes from 2 speaker mono vs 1 speaker mono.
Others who have tried this might be better able to comment. I currently do not have a system for which this works.
Others who have tried this might be better able to comment. I currently do not have a system for which this works.
Trinaural, also as decribed in this part of the thread, seems to be all about tweaking, modding, polishing, angling, delaying, levellingout ... until you find a pleasant compromise that fits your subjective needs. Nota bene, a compromise which you potentially will discard the next day only to find the next, seemingly better one ... certainly to be reverted the other day. This trial-and-error processing indeed opens a vast field of hopefully recreative experimentation, which luckily makes DIY so endless.
While doing so, hopefully happily setting up and improving your trinaural system, you also at the same time may be concious of the fact that there is no clean solution for a trinaural system. Can't be: I never was aware of this, until I read an enlightening post of Uli Brüggemann's about trinaural in another forum. In this very basic post, Uli explains how in a trinaural system, as is, and from a mathematical-theoretical approach, you have to deal with a system of equations and unknowns. There are three unknowns in a trinaural system: TrinauralLeft, TrinauralCenter, TrinauralRight. To solve this mathematically, you would need three independent equations containing these unknowns. But there are no such three independent equations. We only have StereoLeft and StereoRight. This is why, from a matematical approach, there can't be a unique (=perfect) solution. Trinaural will always remain a compromise, no mather which algorithms are used, no mather how fancy/expensive a dedicated trinaural processor box comes along.
Strongly recommended: https://www.aktives-hoeren.de/viewtopic.php?f=40&t=13693
Maybe modding a trinaural system therefore corresponds to a contemporary variant of the Sysiphus story. At least, being aware right from the begin that there is no perfect solution might act as a huge relief, thus potentially preventing mental breakdowns when your pet stone rolls down the slope once again ...
While doing so, hopefully happily setting up and improving your trinaural system, you also at the same time may be concious of the fact that there is no clean solution for a trinaural system. Can't be: I never was aware of this, until I read an enlightening post of Uli Brüggemann's about trinaural in another forum. In this very basic post, Uli explains how in a trinaural system, as is, and from a mathematical-theoretical approach, you have to deal with a system of equations and unknowns. There are three unknowns in a trinaural system: TrinauralLeft, TrinauralCenter, TrinauralRight. To solve this mathematically, you would need three independent equations containing these unknowns. But there are no such three independent equations. We only have StereoLeft and StereoRight. This is why, from a matematical approach, there can't be a unique (=perfect) solution. Trinaural will always remain a compromise, no mather which algorithms are used, no mather how fancy/expensive a dedicated trinaural processor box comes along.
Strongly recommended: https://www.aktives-hoeren.de/viewtopic.php?f=40&t=13693
Maybe modding a trinaural system therefore corresponds to a contemporary variant of the Sysiphus story. At least, being aware right from the begin that there is no perfect solution might act as a huge relief, thus potentially preventing mental breakdowns when your pet stone rolls down the slope once again ...
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Geddes pointed out earlier in the thread that mixing engineer has likely compensated for phantom center coloration already. I think it would depend whether mixing engineer listening situation had the issue or not.
But yeah comb filter seems inevitable problem with two speaker stereo and phantom center sound, same mechanism responsible for both the image and the comb filter. De-correlating with phase is a fix to reduce combfilter, but perhaps not worth it in long run, not sure, depending on what listening situation for mixing engineer was. Something to try at least if stuck on two channels.
But yeah comb filter seems inevitable problem with two speaker stereo and phantom center sound, same mechanism responsible for both the image and the comb filter. De-correlating with phase is a fix to reduce combfilter, but perhaps not worth it in long run, not sure, depending on what listening situation for mixing engineer was. Something to try at least if stuck on two channels.
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He did, but he was leaving out an important point. The mix and master engineers have worked on the overall balance (much of which is center) but rarely the hard left and right panned material. Maybe they should, but my experience, and that of some other people who post here, is that they don't. If the mastering engineers did compensate for the tonal shift, we wouldn't hear it, would we?
Yeah I would guess it depends on if the engineer heard it or not. Or perhaps its common knowledge among engineers and consensus is that no compensation should be done for it as it would make too bright sound on systems that don't have the issue. I guess too little 2kHz sounds better than too much Well, worth try compensating it with the phase shuffle if the problem bothers.
ps. I'm no means proper mixing engineer but have done fair many hours mixing as hobby. Mostly on headphones and some on near field monitors. Never thought about there was an issue until this thread, never heard it or paid attention to it, so perhaps this is something that gets often ignored / unnoticed also in the production chain. Just speculating.
Well, worth try compensating it with the phase shuffle if the problem bothers.ps. I'm no means proper mixing engineer but have done fair many hours mixing as hobby. Mostly on headphones and some on near field monitors. Never thought about there was an issue until this thread, never heard it or paid attention to it, so perhaps this is something that gets often ignored / unnoticed also in the production chain. Just speculating.
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Great post. No doubt there's temptation to try to find a perfect unique solution for trinaural.
I feel lucky to have no such temptation. heck, I'm not even tempted to have one fixed response curve for even basic stereo, or single speaker mono.
I like to adjust each songs tonality on the fly, like a live sound guy.
Anyway, back to topic.
I've been playing with a number of trinaural settings/matrices, that are switchable in real time. And also switchable between 2-ch stereo, 2-ch summed-mono, and any single speaker summed-mono.
Never know what's going to sound best.
My conclusion is that stereo itself varies so much in how it was produced, that it's nuts (for me) to think I'll ever find a one matrix fits all for best sound.
Before trinaural, I'd already come to the conclusion some tracks simply sound best on a single speaker summed to mono. Not many, but enough to matter.
Now with trinaural, same thing, some songs sound better as straight 2-ch stereo than any form of trinaural I've found. Again, not many but enough to matter.
By "matter", I mean I want to maintain system capability to switch to.
All that said, I think I'm finding a pleasing 'leave it alone' trinaural middle ground matrix. The trick so far seems to be balancing between how defined the center is vs, how wide the soundstage remains..
Overdone center shrinks the soundstage width; undone center muddies the sound and bloats the image width. This seems to be true for the big majority of tracks , with occasionally super well done stereo tracks/albums breaking the trend.
I think this center definition vs soundstage width phenom from the trinaural, is one of the big differences between stereo & phase shuffling. It seems phase shuffling doesn't effect the width of the soundstage (in my comparatively limited phase shuffling experience).
With the right center balance, I greatly prefer the trinaural applied to most stereo tracks. It's simply sounds clearer, and it's great to have the center image stay intact over a very wide set of listening positions.
That's the second big diff I've noted between trinaural and phantom improved via shuffling. The positive shuffling effect seems constrained to a very precise listening spot.
The last diff between the tri and phantom shuffling is the degree of tonality and clarity change. The tri picks up where the phantom stops. The tri can even make center have elevated tonality vs single speaker summed mono.
Anyway again. much to play with...glad I just enjoy playing around and not really looking for a final solution
If you have controlled directivity speakers, and I know you do, Mark, then pull them 3-4ft from the sidewall and leave the walls untreated. Getting that sidewall bounce greatly widens the soundstage for me, provides image widening (Toole term), and envelopement. All highly desirable to me. It works best with wide directivity speakers and you can adjust the toe-in to taste. In my room and my system, it makes sounds more clear, not less clear, and simply adds to the enjoyment.
I have this performance. When speaker positioning is optimal, the image is stable and unmoving. It’s one of the tests I use. The image literally fades into place. If there is a central vocalist, they stay there if I move out of the sweet spot. And I’m using Acoustat Monitor 3. The “head in a vice” issue really is overblown when you have perfect symmetry. Once it’s there, it’s the same for every recording and reveals the quality of such accordingly. I tweak it in and out just to confirm it. Just brushing against a speaker will change it. That’s how critical placement is ime. Having said that the change from optimal to not isn’t small. It’s either there or it isn’t and very obvious. This is not just in my head. Perfect symmetry is where the image lives. If a speaker moves out of place just 1/2mm, it’s gone and barely still in the ball park. I have Kef 105.2 and Infinity Kappa 9 and the same behaviour applies. As far as comb filtering is concerned, would toe in/out not effectively deal with it? It’s another issue I don’t seem to be aware of. I’m wondering if the way I set up the speakers simply cancells it out incidentally.
Hi, great example of how we can enjoy different means of audio reproduction.
I do not like sidewall bounce, I think it smears away clarity.
I do like envelopment, but prefer that the soundstage comes entirely from within the left and right speakers...and not from outside them.
My room is pretty large at 34ft long x 17ft wide, so I'm able to put the speakers on the long wall about 18ft apart, and still keep them 7-9ft from sidewalls.
The 18ft width makes for a convincingly wide soundstage, when listening at about a 14ft distance from the axis between them.
The LCR synergies are 90x60. If they are toed in where the outside horn walls are almost parallel with side walls, side wall reflections only occur pretty low in freq.
Plus, with the toe in, sound doesn't change much with distance (if i get closer than 14ft.)
So with the center speaker, sweet spot is about 12ft wide with room to move back and forth within in.
My fav setup so far..
Another room feature that aids clarity at LP, is a 6ft wide pass-through opening going into the kitchen right behind LP....so no close rear reflections.
There's also a hallway and kitchen opening in main room corners.
Anyway, point of all that, is I'm a direct sound junkie !!!
Probably due to the music I listen to...studio or live band recordings. Vocals rank supreme for me. When they are right, everything sounds right ime.
Sometimes I think that might be at the root of folks who like clarity over spaciousness.....how much do vocals count to them?
I'm not a classical fan, but I did listen to a lot of it years ago....can't say i remember much with vocals......hmmm?.... .just spitballing now....
I love that speaker ! Are you running them with the servo amps?
I have a pair of the original X's still running with them.
Not following what you mean about symmetry solving the sweet spot issue with them.
I know the 4 panel Monitor 3's may help that issue vs the 3 panel X's, but the X's are a 'head in a vice' type speaker for sure...not matter how symmetrically setup.
Or rather, I guess I've always thought a big part of the symmetrical setup is having my head located exactly between their symmetry..?
What I'm saying with the "head in a vice" issue is that it goes away if there is perfect symmetry. If it prevails, I would challenge whether you have symmetry. The sweet spot with them is much larger than is apparently realized by consensus ime. 1mm tolerance really is the ball park once you've found it. The challenge is finding it. Once you've found it you'll discover it's actually about 20" wide. The farther away your listening position, the better due to increasing dispersion. I use the inner most panels for set up as if I had just single panels. I treat the middle and outer panels as if they are superfluous. If you use the center panel, the inner will obscure/muddle the image and darken the sound. The 4 panel is the Monitor 4 btw, if used with the servos. Especially important with these to use the innermost panel for set up because if you use the center point of the array, no panel will be facing you directly. Yes I do have two pairs of servos driving each two sets of panels in an isobaric configuration on Monitor 3 frames. I've simply stacked/mounted another set of panels on the outside of the frames with a layer of 1/2" felt filling the cavities to tame resonance.
As far as I am concerned the effect I hear has nothing to do with sweet spot's, imaging, or positioning of speakers particularly. It is a difference in tonality between the centre panned sound and the sound to the sides. This can be more apparent when you move your head because it is the head shadowing causing the tonality shift, but as wesayso points out it can manifest just as a difference in apparent tonality between centre panned and side signals without moving your head regardless of the size of the area where the central image remains locked in place. If there are enough early reflections combining with the direct sound the comb filter effect is smoothed out and spatially averaged. One problem with those early reflections is they cause a timbre modification in themselves so the sound you hear is not the same as on the source. You may prefer one poison over the other, but if you don't hear it the early reflections are there masking it.
As in the mathematical formula above it is not a zero sum game. The mix engineer has the opportunity to change the sound of the panned sounds to compensate if they want with greater freedom, but in making them sound more similar it may not produce the most pleasing result so they leave it in. Once in two channel the EQ then has to be Mid Side based to have the desired effect and it becomes another game of compromise.
I've never tried phase shuffling but the Mid Side EQ I use based on wesayso's is very much like what you describe. You can boost the Mid or Side signal and equalize it differently and get much the same effect, it is easy to go too far in one direction and spoil things overall. I use what I consider to be the best balance I found as I do not want to have to change things between tracks or album's but as a result some tracks benefit more than others.
I find that with the Mid Side EQ settings that produce the most even sound between centre and panned it does slightly deteriorate the quality slightly, in that I prefer the sound dead centre without the EQ but choose to have the EQ on as overall I prefer the sound with it. Perhaps the three channel matrix is a better overall solution but I really don't want three speakers
I understand. I’m just wondering if placement could eliminate the effect incidentally. Just because placement alters FR.As far as I am concerned the effect I hear has nothing to do with sweet spot's, imaging, or positioning of speakers particularly. It is a difference in tonality between the centre panned sound and the sound to the sides. This can be more apparent when you move your head because it is the head shadowing causing the tonality shift, but as wesayso points out it can manifest just as a difference in apparent tonality between centre panned and side signals without moving your head regardless of the size of the area where the central image remains locked in place. If there are enough early reflections combining with the direct sound the comb filter effect is smoothed out and spatially averaged. One problem with those early reflections is they cause a timbre modification in themselves so the sound you hear is not the same as on the source. You may prefer one poison over the other, but if you don't hear it the early reflections are there masking it.
As in the mathematical formula above it is not a zero sum game. The mix engineer has the opportunity to change the sound of the panned sounds to compensate if they want with greater freedom, but in making them sound more similar it may not produce the most pleasing result so they leave it in. Once in two channel the EQ then has to be Mid Side based to have the desired effect and it becomes another game of compromise.
I've never tried phase shuffling but the Mid Side EQ I use based on wesayso's is very much like what you describe. You can boost the Mid or Side signal and equalize it differently and get much the same effect, it is easy to go too far in one direction and spoil things overall. I use what I consider to be the best balance I found as I do not want to have to change things between tracks or album's but as a result some tracks benefit more than others.
I find that with the Mid Side EQ settings that produce the most even sound between centre and panned it does slightly deteriorate the quality slightly, in that I prefer the sound dead centre without the EQ but choose to have the EQ on as overall I prefer the sound with it. Perhaps the three channel matrix is a better overall solution but I really don't want three speakers
Ok, thx for that. And yep, i was confusing the Acoustat models...the X and the Monitor 4 are the two I have experience with.
I also found that using the inside panels for alignment to LP is the way to go...successful in at least a dozen different rooms over the years (owned the X's since 1976).
Also agree that a sweet spot can be found for less than 'head in a vise'. It's been pretty easy to get a foot wide zone without much effort.
Never really tried for anything wider, because I guess over time I've come to consider any sweet spot that accommodates only a single listener to be pragmatically the same as head-in-vise....and is/was the source of my misunderstand your comments. My bad.
The thing is, along with optimizing the sweet spot comes optimization of everything else, ie: imaging, depth, width, etc.. you can’t have one without the other.
I think that is particularly true with electrostats or other type planars or ribbons.
I think they have unique line array like properties in both the vertical and horizontal dimensions, that make either everything or nothing, come together as you say.
That said, my X's share the same tonality shift and overall clarity reduction, left or right only, driven with summed mono, as compared to stereo.
I think it's just how stereo and our ears work, as per this thread.
Hey, for a while i had two pair of X's...wish i had the second pair back...could try LCR trinural with stats !!
It's funny, for about 25 years I would have put imaging and soundstage at the top of my list, in terms of the most desired SQ property.
The I tried some high quality prosound speakers used in theatre & live, to gain dynamics, bass, and SPL. After I heard earing how incredibly clear and detailed they sounded outdoors.....well my top of list priority turned to clarity.
For example, I'd rather hear all vocals and instruments distinctly, even in mono, than have the greatest stereo imaging and soundstage, if the stereo is incapable of revealing the detail. I want to understand the words to songs I've heard all my life and still don't know the words. lol ..at myself
Just my cup of tea, but is why this thread and trinaural, Trifield, etc, of are great interest..
I have a Jefferson Airplane CD with original mono and stereo versions, and others come to think of it, I will now listen to.
Interesting idea. I have the gear to do trinaural but I'd have a veritable "massive wall of sound". If the difference is significant enough I may consider it.
Probably not.
Interesting idea. I have the gear to do trinaural but I'd have a veritable "massive wall of sound". If the difference is significant enough I may consider it.
Probably not.
Honestly, I hear no difference between the mono and stereo versions. Yes it changes moving back and forth across center but that's because I no longer hear the summed outputs of both speakers equally, no? Within the sweetspot nothing changes. The only difference I hear is the mono versions are a bit more dynamic.