Positioning and Listening distance


As run-off from another thread ( Legacy speakers ), we ended up talking about speaker positioning, listening distance and minimizing room interaction. While we are all aware of the various formulas for speaker placement and listening position, none of these take into account the size or design of the speaker. As such, i've found that speakers with a lot of drivers or drivers that are spaced out quite a bit typically require a greater listening distance than a physically small speaker or speaker that uses just a few drivers. On top of this, the greater listening distance also tends to highlight problems that may be present in the speaker / room interface. While we can theorize on why this might be so, i was wondering if anybody else has run into this situation and what their experience / results were. Any / All comments appreciated and welcome. Sean
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sean
Interesting, Sean. I have found dynamic dipoles to be the most difficult to position following speaker placement fundamentals. Dipoles subscribe to the multiplicity of drivers (and bigger physical size) you refer to.
The lower register is an example. For one, the direct waveform @, say, 20hz is quite long (hence, room size??); also, up to a certain listening level, our ears are comparatively more sensitive to the 300-3000hz range. Conventional wisdom leads us to play with distance from the back wall in order to find the best sounding spot vs. our listening position. This would be either, the distance where the waveform is complete (vocab?) or, the best sounding compromise between direct & reflected sound. If the room is small, as in doclb & dds' cases, achieving this is very tricky affair.

With a dipole, the waveform is dynamically reproduced (albeit, in X degrees phase inversion, depending upon speaker design) from behind too -- adding to the waveform length through the back wall reflection... and, I think, to complexity and the need for a larger room!

Which brings me back to the original question. My experiential conclusions (pls note, I can't provide scientific explanation) regarding larger speakers w/ multiple drivers is that these need comparatively *more* energy in order to perform optimally i.e., reproducing signals as they were designed and tuned. In turn, such speakers *produce* more energy at optimal operating level, exacerbating room-induced anomalies. Indeed, in my experience, the worst anomaly has been that such speakers *drown*, rather than "are drowned" in, a small listening room.
I have found this happening regardless of speaker sensitivity...
Numerically speaking: my present speakers have 8 drivers each. Assume I *am* providing enough energy (amp current) to get the drivers operating well together. How do I fit the sound *quantity* into a less than text-book room? By compromising in reproduction spectrum: controlling the lower register, damping highs... whatever.

BTW, Sean I too have found that the further away the listening position, the more room acoustics enter the musical equation -- but I get that lower register OK... Difficult to win on all accounts.

Sorry for the lengthy diatribe!
I was considering starting a thread asking simply how far apart people's speakers are...
While doing some math for my ~12 foot wide room, I found that the Cardas method puts the speakers only five feet apart. I set them there anyway just to try it and confirmed that that's just too narrow. The soundstage was all cluttered, for my taste anyway. So I decided to keep them six feet apart as a constant and tweak everything else as best as possible. I have sound proofing I can place for the side walls that gives me some flexability, at least with the reflection. My room is so crammed with furnishing and crap that I have yet to experienced any obvious trouble with resonances.
I set the listening position in an equilateral triangle as a starting point, but with slight toe-in it sounds really good there, so that's where it's staying.
I'm just wondering how far apart people keep their speakers, and how many people can score a room wider that 12' for this.
Grungle, we must have posted ¬simultaneously. My speakers are 7ft apart, with slight toe-in, against manufacturer's instructions (closer & no toe-in).
My room is 14x18x8, with a 5' doorway behind my chair on the back wall leading into a smaller room.
I sit in a 7.5' triangle, 8-9' out from the front wall
(grand piano behind the speaker plane), and can assure you that I have an incredibly DEEP soundstage that also is wider than the speaker spread. Sidewall reflections are tamed by
stuffed sofa and chair against sidewall reflection points,m sometimes with a throw-pillow propped on top. Flipping the piano's music desk downward significantly eliminates imaging vagueness. This nearfield arrangement works superbly to eliminate room-induced problems, but only with speakers that cohere nicely in the nearfield. I was VERY unhappy with the N803 in this regard...surprisingly incoherent! I blew all my $$ on Parsifal Encores. Their superb midrange is crossed extremely (150/5500hz), so lobing issues are minimized. The (front-firing-arranged) woofers are quick and potent enough to be flat in-room to 30Hz! Toe-in to reduce sidewall splatter and widen sweet-spot a bit results in a little 6-8k heat, so many CDs sound too edgy, but I live with it.
Other speakers demoed included Aeriel 8 (way too bass-heavy), Aeriel 7b (not bad), Thiel 2.3 (too lean), Fidelio (rear-firing woofer anemic when way out from front wall), and Revel F30 (SUPERB midrange, esp for the $, but poor WAF in New England Arts & Crafts decor, and lumpier bass).
To repeat: although I sit only about 6 ft from the speaker plane, I "see" images routinely way back to the front wall
(16'), and sometimes outside into the front yard bushes!
It's clear that near-field listening ENABLES, not PRECLUDES
huge soundstage depth, while minimizing room reflection problems and POSSIBLY lumpy bass nodes. But ya gotta find speakers that cohere in a short distance. Good Luck.
Ernie
I too am a small room,near field listener (how does 9'8"x13',8'ceiling sound?)I really had to do some speaker auditioning before I found one that capably worked.I was also not willing to totally limit myself with one that wouldn't work in a more "normal" size once I finally get myself a more fitting location.After living with ML Aerius i's(I had Maggie IIIA's in previous house and couldn't give up the big spkr.sound right away),I auditioned Aerial 7B's and 6's (both of which were very engaging and musical, but far too ripe for such a small space... also lacked that top end air I was used to with the ML's).I tried both the Joseph Audios (RM22 and 25si's)but neither liked me sitting too near-field(I agree with the "multi-driver theory" of needing X distance, previously discussed, before they "Gel").Tried some beautiful Pro-Ac's which were very promising but ultimately ended up with Audio Physics (Tempo III's),a speaker wholly capable/actually designed for near-field listening.After A LOT of experimentig...both through listening and through the Stereophile test CD #2 (tracks 16,17,notably) w/ my RS SPL meter and measuring tape,note pad and graph paper, I finally found "my spot".I ended up with spkrs. just over 5' apart (that's center to center) and 3'from front wall,listening seat just a little more (about 5'8" or so)and just a bit over 3'from back wall.RPG diffusors on all 4 walls work well for me.Patience works.