Front speaker's distance-how far apart should they be?

Discussion in 'Archived Threads 2001-2004' started by Matthew Anderson, Oct 30, 2001.

1. Matthew Anderson Second Unit

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I have read somewhere before about a formula for how far apart your front speakers should be in relation to the distance from listening position. Thanks for any thoughts.
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2. Guy Kuo Supporting Actor

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They are typically close to an equilateral triangle with the points being the speakers and the listener. The ratio of speaker to speaker: listener to speaker distance is usually somewhere around 0.8:1 to 1:1. That's 60 degrees of separation or a bit less. The wider the separation (so long as you don't get too close to side walls) the wider the sound field. If it gets too wide, the center phantom image gets "thin"
Spend a lot of time on the positioning. More than almost any other factor it will affect the sound quality of your system. A 6 inch move can totally alter the severity of peaks and valleys in a speaker response curve.
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Guy Kuo
www.ovationsw.com
Ovation Software, the Home of AVIA DVD

3. JohnMW Second Unit

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I was told that fronts 8 ft. apart mean a 9' 7in seating distance.

4. Saurav Cinematographer

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5. JohnMW Second Unit

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I never said that was accurate, only what I read here on the HTF. With that in mind, if someone can tell us how to properly determine how far 60* is, please translate that into an approximate distance.

6. jeff lam Screenwriter

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If you use the equalateral triangle method, the listening position should be 6.928 ft for an 8ft speaker distance right? Cut the triangle down the center to give you 2 30/60/90 tiangles and use a2+b2=c2 to calculate the distance of the listener. I think that's correct. Or maybe I was sleeping in my geometry class that day. I don't really remember, it was a while ago.

7. Saurav Cinematographer

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Well, your formula is correct, and I'm too lazy to check if your result is correct or not

8. Matthew Anderson Second Unit

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Thanks to all who contributed on this subject. I have better separation now that I have moved the speakers more apart.
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9. Saurav Cinematographer

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IMO, the distance of the speakers from the side and rear walls has a biggest influence on how they sound, and that should be the primary criteria used for positioning. If you're interested, go to www.audioasulum.com and in the FAQ section, read the article on the 'WASP' speaker placement method. I was pretty darn amazed at the results. There are links to other techniques too, and you might get better results from a different technique, based on your room and other constraints.
Good luck.

10. Phil Iturralde Screenwriter

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11. Jeremy Anderson Screenwriter

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I would imagine the reason Dolby recommends no more than 60 degrees is primarily because the sound from most speakers starts to drop off in level at about 30 degrees off-axis. However, a lot of speakers have wider dispersion than that without the level dropping off, so you have to experiment. If you do have them more than about 45 degrees apart, you will most likely need to toe them in a bit so that your listening position is within 30 degrees from the center axis of the speaker.
But, as with all things, your mileage may vary. My mains are 58 degrees apart and not toed in because I wanted a very wide soundstage and larger sweet spot (due to the seating in my room), but my speakers don't significantly drop off until around 45 degrees off-axis.

12. Brian OK Supporting Actor

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Saurav,
Kudos on the WASP placement method.
When I set up my new basement HT (with the dogged desire to again get into 2-channel after a few years, but constricted by my old living room layout) I went with the Cardas recommendation.
Today, a little tinkering, and viola...
WASP accounted for my parallel , yet asymmetrical long walls (two 45 degree intrusions into the room) (2'exactly @45degree) to hide a water meter, as well as a small 16"x4" partition on one wall, not to mention that the opposing wall/ceiling soffits are different dimmensions).
WASP struck a chord. Lorenna McKennitt's stage just blossomed. Sweet.
Thanks,
BOK
darn typos
[Edited last by Brian OK on October 31, 2001 at 08:11 PM]
[Edited last by Brian OK on October 31, 2001 at 08:13 PM]

13. Saurav Cinematographer

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Glad to be of help. I figured that any technique which involved walking around the room talking loudly surely deserved a try