Inches matter

January 23, 2023
 by Paul McGowan

Loudspeaker setup is a funny thing. Inches matter for the speaker’s position, yet those minuscule changes affect a much larger area in the seating position. Why would that be?

With a well-designed loudspeaker pair with flat off-axis response, the sweet spot for listening is rather broad. For example, Music Room Three with the aspen FR30s has a full three-seat-wide area. And, in any one of those seats, you can clearly hear small incremental differences in speaker positioning.

There are a couple of things going on here. First, think of the speakers as you might a flashlight pointing at your listening position. The farther you are from the source of light, the more spread you get from the beam. Small incremental changes at the source change brightness levels in a broad area at the listening position. Secondly, we cannot think about speaker positioning as affecting only the focus on the listening position. We are also impacting the speaker/room interaction.

Combine the impacts of audio “spread” and room interaction, and it should be a bit more obvious why inches matter.

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35 comments on “Inches matter”

  1. I believe that what Paul is alluding to here, without actually saying it, is 3D soundstaging & pinpoint imaging.
    Loudspeaker pair matching is a very helpful ‘ingredient’ as well, & how
    the studio or live recording was ‘assembled’ can also help or hinder the
    resulting 3D illusion that is presented to the listener sitting in the sweet-spot.

  2. When you imagine that the room is actually a musical instrument you sit inside. And when you remember how a guitar string sounds different every time you pick a string in different places. Thus, the sound in the room initiated in different places sounds different. You can play flageolets on the guitar (or any string)?
    I just tried it out – I have a new “stereo” room and it’s not finished yet and I have this sharp echo when clapping my hands. When I was tuning the place for the speakers, I could hear nicely how the speaker echoes strongly in some places and less so in others. A difference of two inches. So now I have the speakers in a not so optimal place, but where it does not strongly resonate.

    1. My large living room had clap echo until I put an area rug, window shades and furniture in it. A combination of absorptive and diffusive surfaces will do the trick.

  3. Although initially reluctant I found it very beneficial when I experimented with my speakers, primarily reducing toe in which really opened up the soundstage and helped with imaging. Small movements of the subs also helped with the bass response. To be honest I was quite surprised. It was like a free upgrade that you might have paid big bucks for. I’d urge anyone thinking about it to give it a go. It’s all about degrees.

    1. Agreed.
      For the first time ever I actually have my current floor-
      standers toed-out by about 4 degrees & it’s opened
      the soundstage right up in a small/medium room.

    2. Richtea,

      I, like you, thought of the things you talk about as a free upgrade. Then I thought less than initially an optimal set-up.
      Either way a sonic improvement was can be had without having to outlay any cash.
      I still play around with room acoustics and very small amounts of speakers / subs placement. Many times it takes months to see if the change made was the right one (mainly because of focus on one aspect at the expense of another?).

  4. A “full three-seat-wide sweet spot” is absolutely impossible unless you have loudspeakers whose drivers aren’t phase-aligned at all resulting in an overall muddled sound. Every pair of loudspeakers I ever had the chance to listen to created a center image which always shifted with lateral movements of my head. Thus the “sweet spot” normally is very tiny! Thus here is another miracle of Paul McGowan – similar to the miracle of the mysterious synergy of unknown audio components.

    1. I would also say, no matter what speaker, if you place 3 people in the sweet spot, their demand regarding imaging focus shouldn’t be too high.

      What would also need a bit more depth, is the connection and impact of flatness of off-axis response, dispersion extent of off-axis response, sweet spot extent in terms of tonality vs. imaging, untreated room reflection sensitivity and focus & imaging accuracy.

      I’d say a speaker design for a bigger sweet spot mostly means other compromises, which are often not mentioned in the same breath.

    2. Thanks, Paul. To be clear, the “sweetest” spot is still in the center. The left and right side seats still have a wonderful center image but it’s kind of like looking at the 3d image from a different angle.

        1. If only this would be possible (without the BACCH processor catching your head movements 😉 ).

          Just try it, it doesn’t work at all. It’s not always as extreme as in my case of speaker positioning. A voice in my case is ripped apart from a centered 3D imaging with only 2-4 inches head movement to the side, not to speak of someone sitting more than 2ft aside of me.

          But the important thing is what happens regardless of the head distance sideways. Not at all „looking from a different angle“. The voice by trend (in certain positioning more in others less) is widened or even ripped to the sides, focus, enveloping character and 3D disappears.

          1. Have to agree with Paul, Joe and FR. I have a love seat with the sweetest spot right in the middle sitting position, where center images can be very deep, offer tremendous spacial air and render natural 3D dimensional musicians and singers in their recorded acoustical space. Sitting in either the full left or full right positions (15 inches off center), I still hear the center image placement (albeit, with less depth), but audibly perceive sitting left or right of the center image, with clear sonic recognition of any musician ques that are to the opposite side of the channel I am sitting in front of.

            Believe my synergistic system/room setup and wide horizontal dispersion ribbon tweeters (monitors are also set to 5 degrees toe-out) contribute to the larger holographic sweet spot 2-channel listening window!!

          2. Full blown 3D holographic means that the illusion is maintained everywhere you move in the listening space – you know, just like the real thing … 🙂 . Blew me away, first time I heard it; it becomes impossible to locate the speakers, if, say, blindfolded, and you move around “to try and find them”. Has nothing to do with inches sideways of head and body movement – in that sense there is *no* sweet spot.

            The unfortunate aspect of the deal is that the integrity of the replay has to be so close to 100% to get this, that it occurs very rarely. 99.5% doesn’t cut it – the illusion just evaporates.

            Only the most motivated people will get this, with current audio gear – the amount of careful tweaking to achieve it will probably drive most audio types nuts, 😀 … but it does exist, as a goal, for those who care enough …

            1. Except for omnidirectional or very widely radiating speakers (with other disadvantages of a less defined imaging among others), this seems like a fairytale to me, as the precondition for focused holographic imaging is, that sound waves left/right arrive at the ear simultaneously (which isn’t the case anywhere in the room). It’s as if you claim you can see 3D with one eye shut…it’s plain physics in my understanding.

              Just as … the wider the sweet spot, the more people still hear a roughly correct imaging , but the less focused it is.

              But even in an extreme nearfield setup, the soundstage from anywhere in the room behind the sweet spot still sounds very airy and spacious, with 3D positioning of instruments behind the speakers …but not that well focused anymore.

              1. That’s the conventional thinking … but what that fails to take into account is for the ear/brain’s ability to compensate for “anomalies”, when it “knows” what it’s listening to. Now, this might sound “fairytale” stuff to many – but for someone who has played with a rig, as I did decades ago, which could be in a state good enough to pull this off this one time, but not, say, an hour later – it’s a ‘rock solid fact’.

                Note, this is not some incredible “pin sharp” imaging, which some apparently delight in; but how live acoustic music, played by real musicians, comes across – if after the former, then, yes, what you say will be required.

                1. I think your last paragraph is where we meet. I know this from quite widely radiating or omnidirectional speakers…sounds lifelike with similar imaging from everywhere, but no way as focused and holographic as other options…still very fascinating…different, still 3D in its way.

              2. Plain physics doesn’t count where the brain is concerned – a good example is upside down focusing glasses; put them on, and at some point the brain understands what’s going on – and perfectly compensates, 🙂 .

                With audio, you are exploiting the very same ability, of the human senses to make, er, sense of things …

  5. Clean your preamps input and volume control as well as other switches and pots and you will experience a dramatic improvement in sound. So many manufactures hype the latest stuff as being dramatically better than what you have. It might very well be if you’re comparing something new to something that needs a good cleaning, but once are both the old is operating as it should the new state of the art is not better sounding. At least not dramatically better.

    1. Joe,
      Some science buffs, one in particular with a PhD, recommend
      not to disconnect gold plated on gold plated connections, as
      the two gold surfaces will bond better if left undisturbed.

      1. IME, normal quality gold plating on audio gear isn’t good enough – I spent months experimenting on this, decades ago; the contact surfaces *always* degrade over time; and contact enhancers are even worse … confirmed by pulling things apart, carefully cleaning surfaces, and reattaching; the SQ was then restored, to what it should be.

        Only solutions that *did* work, long term, were hardwiring, ie, a good solder joint, or very carefully applied silver pastes and greases.

        1. fas42,
          Not every connection can be hardwired, it’s just not practical.
          I didn’t have to spend hours & a lot of painstaking effort creating a synergistic home-audio system.
          For me it was just dumb-luck that my components at the time worked extremely well together & I just happened to place the loudspeakers in the exact right position to create a 3D holographic soundstage that simply amazed everyone who sat down in front of it & listened…this was thirty years ago.

          1. Unfortunately, “dumb luck” is generally what is needed in the audio game, especially at lower cost levels, to get best sound.

            It was *luck* in my case also – but I had to work at it! By trial and error I determined that hard wiring *was* necessary for that rig, 35 years ago; the SQ degraded too much otherwise. This all added up, and the system finally had enough integrity to bowl me over, one day, because it delivered peak quality, at a completely new level of presentation. And it couldn’t sustain – it lost “the magic”, quite predictably, after a certain period – but could always be restored.

            This told me a lot of things: that SQ was absolutely dependent on playback chain integrity; that “cheap and nasty” speakers could easily do it, and that only “luck” and/or careful effort could make it happen.

            Which motivated me, over the years, to understand better – work with a whole range of audio gear told me that it had nothing to do with the brand, price, technology – all the usual stuff that audiophiles obsess about, 🙂 .

            These days, you can now buy gear, at extreme prices, to do the job; the alternative is to tweak your way to quality presentation, by understanding where the weakness that matter are, and eliminating them, one by one. For most rigs, poor contact quality somewhere in the path is enough to do the damage, and it will be impossible to get optimum sound, no matter how much money is spent elsewhere.

  6. In response to todays post… I believe the radiation pattern of a speaker has as much to do with what is described as does placement. (Point source radiating pattern versus a cylindrical radiating pattern as an example)

    In the end inches matter in placement and in some cases when dealing with tilt and toe in/out 10ths of a degree can matter.

    Or more simply put – it all matters – how much it matters is an individual call based on many factors.

    1. Agreed Mike! Even fractions of a degree in toeing/tilting differences has not only solidified an amazing holographic soundstage in my setup, but also a wonderful 2-seater listening window. Though like Paul said, the center sweet spot is still the Best!

  7. Paul, my speaker set up procedure includes measuring frequencies for smoothest response from 200 down to 40 Hz as I move the speakers out from the front wall in 2″ increments. As I move the speakers away from the wall this begins to flatten out, up to a point. After that, greater distance begins increasing the frequency variation. Then I go back to the best distance and measure again, moving 1″ forward and backward from that point. This has been successful in obtaining the smoothest bass response, although not necessarily the lowest Hz produced.

    It becomes surprising sometimes how much a few inches matter.

  8. A few weeks ago I got to experience a Vandersteen 7 setup and it’s final tweaking. All the usual stuff was done as well as adjusting the enclosure vertically and horizontally. Aligning the driver edges as well. I’ve seen this process last year with big Wilson’s. The final stages were cabinet movement in inches , toe in by 1/4 inches and also tilting each individual driver so that they all aligned. In both incidents PHASE was being addressed as best they could. The final effect was not subtle. What started out as good, very good, …. YES!! And room reflection points altered phase due to deep diffusers too close to both speakers and listener.

    The sweet spot was there and the zone of listening was broader than some. Not as broad and MBL.

    It’s all an illusion as the song tells us.

  9. Inches clearly matter, however, how much do they matter?

    In 2017 I spent about 9 months trying to decide whether I wanted to buy Wilson Audio Alexia ( 2 ) or Magico S7 speakers. Two things help me make my choice since both are extremely good speakers.

    The first thing for me is I thought the S7 had better bass.

    The second thing was a matter of inches. With the Alexia the position of the tweeter and midrange drivers can be fine tuned so that the sweet spot can be adjusted to your room arrangement. This should be a good thing, but it is not necessarily so. My speakers are in the main room of our house and I do not always sit in the sweet spot. I want the speakers to sound good in the rest of the room, not just in the sweet spot. The S7 did that very well and the Alexia was not as good sounding outside of the sweet spot.

  10. “With a well-designed loudspeaker pair with flat off-axis response…”

    If this were true, based on the proper understanding of Directivity Index, this speaker would be unbearably bright on axis.

    Paul confuses smooth response with flat response. The “ideal” off-axis response, while smooth (not flat), has a slow decline with increasing frequency.

  11. I like the flashlight analogy. With my Von Schweikert floorstanding speakers, I too have a wide sweet area because of the speaker design, the large room, the distance between the speakers and the listening area and side walls. The image is still holographic and focused, but at the same time natural.

    In additon to speaker driver spreads, there are other reasons the sound from our stereo speakers changes as we move our heads from side to side. Let me illustrate with my digital pipe organ audio system. I sit on the organ bench, only six feet from the Harbeths, which are performing as mid-field monitors. Even so close, the soundstage is huge, the Harbeths virtually disappearing. When I play stops, the individual virtual pipes sound far away, as in the actual space, unless the recording was done close to the pipes. When playing, my head is not frozen, but moves laterally. Just a few millimeters changes the high frequencies of individual notes. But that has nothing to do with the speaker driver spreads. That is because the stereo sound field is a virtual reproduction of the actual sound field created by the organ in its acoustic space. In the actual space when you move your head from side to side certain frequencies of individual pipes change due to differences in what the left ear and right ear are hearing in space, and also wave interactions between pipes. The sound of some high frequencies can even disappear and reappear as you move your head incrementally.

    Because live sound changes with small lateral movements of the head, why shouldn’t we expect the sound of recorded instruments on our stereo systems to also change when we shift our head positions? There is no designated sweet spot seat in a concert hall. Why should we expect a pinpoint sweet spot in our home audio systems? It they are recreating a concert hall, in a good system moving your head a few inches in any direction should not make a big difference to the enjoyment of the music. I know some speakers are sweet-spot-fussy. I would avoid them and go for those that have a more natural, broader spread, unless you are into transcendental meditation and like to listen motionless from a frozen position.

  12. Funny thing about sweet spots. Many say the Maggies have a narrow sweet spot. And that was somewhat true back in the dark ages when the tweeter was planar magnetic (I remember my MG1s). But I find now, with both quasi and true ribbons (I’ve had both), what I experience if i move around the room is exactly what I’d experience if I got up and moved around a concert hall (horizontally). It’s really quite a remarkable experience. I’m not sure I’ve ever had boxes do this.

    1. Boxes can do it, but it requires more attention to detail on improving the quality of the electrical path – panel speakers have some natural advantages, and so the illusion is easier to manifest on this type of speaker …

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