Via Scot Hull on AudioHead’s The Occasional Podcast, I just heard about Greg Roberts’ surprising recommended spacings, on the long wall of the room.
16 feet apart, or 18 feet or more. And less than 6 feet from the listening seat. To get scale and drama. In a near-field layout, the listening chair is placed closer than the distance between them.
The orthodox wisdom is that the speakers should be placed on the shortest wall in an equilateral triangle with the listener, or 60° apart from that perspective. This convention is followed by speaker designers, recording producers, system installers, and acoustic rolm treatment specialists. But how did this configuration become the norm?
Researching this unusual layout, I found a review of Volti Audio speakers that mentions this alternative placement …..
Greg Roberts placed the speakers approximately 60″ from the wall behind them and 84″ apart. He would have liked them even wider, but my listening room wouldn’t easily accommodate much more than that. He told me that the Razz should be toed in so that their axes cross about eight inches in front of your nose at your listening seat. His recommended seating position for my living room was only 68″ from the speakers, a bit closer than an equilateral-triangle arrangement recommended by some manufacturers. This quasi-nearfield arrangement was actually ideal, and I did not perceive the imaging as too wide, nor did the music feel too close, as though I were wearing a huge pair of headphones.
http://www.theaudiobeat.com/equipment/volti_audio_razz.htm
In a 2017 Stereophile review of Volti Audio Rival speakers, he said:
I like to space them 10′ apart center-to-center, and turn them almost 45° toe-in to the listening position. My goal is to replicate the characteristics of live music that make it so engaging to listen to. Not just the dynamic range and power, but I want to fool myself into believing that there really could be a saxophone player in the room with me. So the setup to produce this image of music in front of me is of prime importance. It allows me to visualize the music, while the equipment that is reproducing it disappears.
The reviewer, Ken Micallef added this:
After some trial and error, I lessened their degree of toe-in from 45° to where I could just see each inner side panel. In short, the Rivals ended up 66″ from my listening chair, with the centers of their panels 32″ from the front wall
https://www.stereophile.com/content/volti-audio-rival-loudspeaker
It could be that the design of Volti horn speakers make this effect, although other makers also recommend wide spacing.
In this video, the OCD Hi-Fi Guy set his speakers 15 feet apart and 12 feet from his seat.
https://www.evolutionacoustics.com/support/speaker-placement/long-wall-speaker-placement/
Advantages and disadvantages of long wall set-up:
The wide apart placement is both intriguing and somewhat untested for me. I’ve gone to the Ambiophonic 20° spacing configuration to improve on stereo image presentation. My speakers are just 96 cm apart at 2.7 m from my ears when listening. They are on the long wall, though. I did previously have them beyond 60° apart, but not extremely spaced. I now get a big image, with much more ambiance and presence (the image centre is stronger).
Why is 60° separation considered the norm? I don’t know, but maybe it’s the simplicity and neat symmetry of the equilateral triangle – and the layout fits in most domestic rooms. Local audio engineer Richard Hallum commented in his paper on listening angle that the original specification for stereo does not require 60° spacing between speakers. Indeed, several audio engineering/acoustics researchers have called for much bigger listening angles (70°-90°).
Wikipedia: The sweet spot is a term used by audiophiles and recording engineers to describe the focal point between two speakers, where an individual is fully capable of hearing the stereo audio mix the way it was intended to be heard by the mixer. The sweet spot is the location which creates an equilateral triangle together with the stereo loudspeakers. In the case of surround sound, this is the focal point between four or more speakers, i.e., the location at which all wave fronts arrive simultaneously. In international recommendations the sweet spot is referred to as “reference listening point”.
Siegfried Linkwitz said:
“Traditionally, the loudspeakers and listener should form an equilateral triangle with a base width W of at least 2.4 m (8 feet). In that case the distance D from the listener to each loudspeaker is the same as the distance W between the loudspeakers, taking the tweeters and the center of the head as reference points. A distance D of 0.7*W, i.e. a listening angle of 90 degrees rather than 60 degrees, provides a wider auditory scene and can be desirable on well recorded material.”
So why did 60° separation between speakers become the norm in the 1930s? Confined to 60° in the horizontal plane, “speaker-stereo” (Robin Miller) compromises sound reproduction in spatiality and timbre. There’s no scientific or mathematical basis for such a convention that I can find.
I recall that my initiation into stereo listening from my mono portable record player was at a friend’s house. His affluent parents had a stereogram and a dedicated listening room. We played Moody Blues records endlessly. The speakers were built into the cabinet and were about 1 m apart. We didn’t know about a sweet spot.
The more I discuss this with fellow audiophiles, the more I think this compromise was to make stereo equipment acceptable in the domestic situation. Available in the 1960s, stereo didn’t get established commercially until the 1970s.
Ambiophonics puts the speakers much closer together (~20°) to fix the crosstalk interference of the stereo-speaker configuration.
I asked Ralph Glasgal, founder of the Ambiophonics Institute, about speaker spacing ….
The stereo effect is a sonic illusion like an optical illusion. Just as some viewers have a problem seeing optical illusions so some listeners have a problem with the 60 degree stereophonic sound effect. No two humans are likely to agree which speaker angle is the best or even define what best means….. it makes more technical sense to abandon the 100 year old stereo triangle for a loudspeaker binaural method, which fortunately can reproduce so called stereo recordings with flatter response and much better spatial localization.
Music & Hi-fi Appreciations 