Center perfection
Join Our Community Subscribe to Paul's PostsOver the years I have noticed a perfect center fill can foretell a perfect soundstage.
And while it might at first seem a simple formula—get the center image right and the soundstage falls into place—it doesn’t always work that way.
The problem with relying upon the center fill as a harbinger of soundstage correctness can be found in the difficulty of getting the phantom center channel perfected.
It’s easy to use extreme speaker toe-in to get a holographic center image. Unfortunately, that’s often at the expense of soundstage width.
Center fill perfection occurs when we have all the center channel elements in place: depth, height, size, palpability, and three-dimensionality.
As I write in The Audiophile’s Guide, the solution to getting the center channel right is found not with toe-in but without. The closer you can get to center channel perfection with the speaker baffles parallel to the left/right horizontal ear-plane, the wider, deeper and more convincing your soundstage.
As I explain in the book, the degree to which you can have your center channel and soundstage cake and eat it too depends on your speaker’s off-axis response character. A relatively flat off-axis response is key to soundstage perfection.
Set your bullseye for the center but don’t ignore everything around it.
Centre fill vs Soundstage vs 3D imaging can be a fluid thang; quiet often dependent on how the CD (song) was recorded (mic’ing)
So again, it can sometimes come down to the source.
However, mostly, once you can place your loudspeakers correctly (a la Paul’s book), you should be able to get YOUR desired centre/stage/imaging ratio the way that YOU want it.
I preformed a test of my setting arrangement to see if I was sitting in the wrong position and as suspected, I was. Moving my chairs pretty much fixed my listening and took my ears to a new level. Of course reading Paul’s book helped in that effort. What I’m also realizing is we are always in search mode when it come to our sound because we are changing more then our equipment 🙂 Paul how close are you to getting the zoom calls setup. I was on one last night with Ron from New Record Day and it was so much fun getting to talk and ask questions even with members in the group. Give a big plug to PSA m700’s for a member looking for some great class D’s that wouldn’t break the bank. We got to turn our cameras so that we could see each others system setups after introductions.. So cool. Might not work with PSA cause of the number of folks but worth a try at least. Keep Listening folks 🙂 Oh, gonna devote my next listening session to all the ladies of music 🙂
Hm…a flat off axis response certainly enables more options of less toe in with the same tonality and therefore as you say a wider soundstage than e.g. with more directional tweeters like ribbons or planars. But unless you have a perfectly optimized listening room, this wider radiation of tweeters with flatter off axis response generates more reflections harming soundstaging behavior.
The statement that speakers with flat off axis response (to my knowledge equaling widely radiating tweeters) are a key to soundstage perfection, contradicts many other observations that exactly speakers with quite directional tweeter radiation (and therefore uneven off axis response) enable soundstage perfection (at least within not perfectly tuned rooms).
That’s why I finally think such a recommendation must be at least depending on speaker selection (due to the different toe in sensibilities probably also for other reasons than off axis response) and room sensibility for side and floor/ceiling reflections.
I read or watch the manufacturer’s instructions. They designed the speakers and know how they work best. Preferably before you buy the speakers. Knowing the dealer has been trained by the manufacturer to set them up was a factor for me in a recent purchase. I’ve just watched the manufacturer’s video and it’s very similar to Robert Harley’s guide. I read Paul’s book but did not try the guide as the test tracks were missing. I will probably look at it when we do the final set-up in 3 or 4 months, post-builders. Most guides seem to fall over when you have a bay window (as I do) as there is no fixed distance to the rear wall. That’s where an expert dealer and REW come in.
I only, unfortunately, only have about 7 feet to the listening area from the speakers. If I don’t have toe in I don’t get convergence. Is that thinking correct?
Bill,
You’ll need to experiment. I’d suggest by starting with the loudspeakers facing straight ahead (no toe in) & just slowly toe them in a bit at a time & see what sounds the best to you.
See if you can get a friend to help you turn/move your loudspeakers by doing the toeing in a few degrees at a time while you sit in the designated ‘sweet-spot’ & listen intently to get the final angles right. You might have to bribe him with a case of beer.
Try to have your loudspeakers at least 80cm (2 & a half feet) from the wall that is behind them; called the front wall because it is the wall in front of you.
Bill this will work for you. I did the exact thing and my toe is extremely slight. Again moving my setting was the final key for me.
Thanks. Still working on that. It is getting better every time so I will get there.
I have speakers 4 feet from my ears. I get very good imaging but the soundstage is going to be limited. The manufacturer recommendation is a slight toe-in, and it works well.
I was looking at the video this morning by Mr Wilson of Wilson Speakers (which I own) and he suggests putting the speakers on furniture gliders instead of the spikes when setting up, at at least put gliders under the spikes. Just makes it a lot easier to move them around and make fine adjustments. You can see them on his video, which is also seems to contain very sensible advice.
https://youtu.be/UOI8py0DAC8
Thanks. It is always great to see different ways from people with obvious credentials all reaching the same goal. Good video.
IMO, depends on your speaker design Bill! I also sit about 87″ away for a near-field holographic experience. My upgraded stand monitors include very wide off axis horizontal dispersion RAAL tweeters. Discovered a “5-degree Toe-Out” not only locks in the proper prospective center image, but also inserts instrumentalist and vocalist in their proper sound-stage placement and size.
Once achieved, the stand monitors completely disappeared and the resulting breath, depth, height and width of the auditory room presentation seems only limited by the quality of the recording and the subsequent recorded venue!
Ted
Thanks for the reply. I have managed to get the speakers about 80 cm from the wall. That only leaves me about 2m to the listening chair with it quite tight to the wall, 20 cm or less. Using Paul’s book as a guide, I have the outside of the cabinets pointing to my respective shoulders. More to play with yet. It would be nice to widen both the soundstage and the sweet spot. I have an amp coming this week that has built in dsp (Anthem Room Correction) to hopefully make this task a little easier.
I had my dealer setup the speakers in my house. I think he got it right, but I do wish it was easier to tweak the position so that I could play with it more. The problem is at 300 lbs a speaker it takes a lot of manpower to tweak the position.
Mine are only 72 and that seems like enough to move.
Really good point. I bought Paul’s book and toe-in was the first change I made with my Magnapans. I settled on less toe-in than I had been using and have a more balanced image. Ta-dah! I haven’t played with the CD tracks yet. Anybody else used the book Get Better Sound? I think the author is Jim Smith. It’s good, too. Like Paul, he has music recommendations that you find streaming, but the CD should come in handy.
“. . the solution to getting the center channel right is found not with toe-in but without. The closer you can get to center channel perfection with the speaker baffles parallel to the left/right horizontal ear-plane, the wider, deeper and more convincing your soundstage.”
I’d been reading/viewing all of Paul’s works on this site for some 3+ months, and I’d play with speaker placement and room conditions. Tweak something, wait a day and try again. Then I’d find a new video, or a user comment in the forum, and I’d be back at square one. Being retired and hiding at home from Covid meant I have lots of “idle” time on my hands, so this was all new and fun learning for me.
Then The Book arrived and in a couple of hours I’d filled my brain to capacity, and was about to give up for the day when I read the above advice—BAM, there it was, perfect center image and soundstage and base coupling too.
One would think that a wise old fart like me would have started at some neutral position. Nah, we like to make things difficult.
Thank Paul, my slide into insanity and nirvana continues, with a huge grin on my face.
Agreed! With my 20# stand studio monitors (14″x8″ front baffles on top swiveling stand plates), adjusting toe is quicker than changing a CD! Never liked any toe-in, as a neutral position (baffles parallel to the listening plane) always gave me a great center image and sound-stage holographic wall of sound.
Out of curiosity, final tried a “5-deg toe-out” and Voila, monitors completely disappeared and the sound-stage really opened up well beyond all listening wall barriers. My <1000cf music room can sound as big as a cathedral or as intimate as a soft jazz nightclub. The single sweet spot now became a duo and to my delight, center image became sharper in focus and more natural in size and space!
Believe the very minute toe-out has created a very refined integration to my small listening room acoustics…definitely creates a big smile and listening pleasure with every genre of music I play!
Ted
There are so many factors. For example, if two people sitting side-by-side will be listening, loudspeaker selection and placement should take that into account to create a wider sweet spot. Though centering of image is more difficult to achieve for two listeners, there can still be a large and holographic soundstage. It just won’t be as “accurate.”
To successfully create a perceived center image stereophonic sound relies on creating a sound field where the same sound from tweo speakers arrives at both ears at the same time and with the same loudness. Perception of directional aspects of sound is highest at higher frequencies. Speakers that beam their sound directly at the listener especially at high frequencies restrict the physical area where this is close to possible. At the same time the stereophonic effect depends on other sounds arriving from different perceived directions at slightly different times and loudnesses. These are a hard thing to do especially simultaneously. This is why conventional stereo speakers perform so poorly and why there is a small sweet spot when a single monopolar tweeter aims all of its sound directly at you. It is only made worse when the tweeter becomes increasingly directional as frequency increases.
Speakers that aim some of their sound indirectly such as bipoles and dipoles mitigate this problem. Of products commercially available Bose 901 when properly installed does this in the extreme, one of the reasons non audiophiles like it. but its poor frequency response in both the lower and upper bass and in the treble are a turnoff for audiophiles because the tonality is wildly inaccurate. Reengineering the system to have perceived flat frequency response following the inventor’s original concepts corrected the audiophiles’ problems with it without compromising its desirable aspects. However it is not an easy thing to do especially in the treble. Not expensive but not easy. It takes a lot of engineering knowledge, experimentation, time and patience, and a little money. Was it worth it? Hell yes. Do I listen to it? No, not in about 3 years. Of all the systems in my house I only listen to my best one these days for some reason unknown to me.
Strange thing is…if we look just at the first of the customer setup pages here, my usual observation is roughly confirmed: people tend to rather have too little or no toe in than too much so that most should come from the other direction to find an optimal position. Maybe this has to do with other (imo misleading) advices to tweak too forward treble with toeing out.
What’s left out of this is the speaker design.
Some designs are made specifically for a particular degree of toe, while others are designed to have as little toe as possible.
This even differs between similar speaker types; for example some planars like toe and others don’t want or need it at all.
If you have your speakers toed in, try a little experiment: move your listening position a tiny bit forward, usually just 3″ to 4″ or so – in my experience that gives you a good general idea of what your system would sound like with less toe-in and you can decide whether you want to bother.
I have often found that a I am getting up from my chair there seems to be a spot just inches ahead and slightly down that improves the sound. So are you suggesting slightly less toe in would achieve the same?
Yes, it sounds as if less toe would help in your situation and perhaps a way to raise the back of your speakers a bit.
Then again less toe alone may ameliorate the height issue.
I am now standing on new ground. Recently, AT&T mandated that I “surrender” my DSL connection and switch to their fiber system. I reluctantly gave in because the hookup socket is located on a bad side of the room in regards to where my PC and desktop are located. I now need to step over the fiber cable in one part of the room. Luckily, fiber is inured to anything placed in close proximity, unlike copper cables.
In the past having had mixed results with fiber with my DAC connection to my computer, left me with doubts. Well… Something unexpected came out of it. Not only did my center channel improve. But, the sound of videos copied to my SSD even began to sound better. Which leads me to wonder how much a modem connected to a PC will effect what we hear, even if one is not streaming. That a Modem connection and interaction within the PC effects the sound in ways not yet understood.
Be that as it may. My center image has improved.
Thank you! One more observation that is congruent with my theory of baffle induced time distortion creating cepstral artifacts that are interpreted by audiophiles as soundstaging. I don’t know of any commercial loudspeakers which are flat off axis. It is better for dipoles and cardioids, but it really takes coaxial drivers where the effective radiating dimensions reduce smoothly with increasing frequency or true point source which increases Doppler distortion; and true infinite baffle (flush wall mounting).
Speakers are also only flat on axis at the distance used for tuning them. At other places on axis, the temporal artifacts of flat rectangular baffles cause bobbles from the secondary radiation of the baffle edges. Symmetrical orientation of the baffle edges wrt to listener (toe-in = target seat angle) increases these artifacts, angling the speakers distributes them. Of course, this is tremendously complicated by room reflections of time distorted wavefronts emitted over all 4 PI steradians.
I have only heard a solid phantom center a few times, and it was in meticulously treated rooms – no bare first reflection points; and extreme analog systems: SoundSmith strain gauge or 30ips RtR and electrostatic or flame tweeters. If you want a good center, put a speaker there. Try mono!
The Gerhardt system is reputed to give the best holographic sound field.
Put the speakers at the foci of an ellipse in the room.
Look it up if you can persuade Mrs to love the new furniture setting.