Axiom Home Page Forums General Discussion Technical Questions Another look at multiple subwoofer placement

I recently read this article "The placement of one or several subwoofers" by Ingvar Öhman first published in "Musik och Ljudteknik", no.1, 1997, Sweden (don't fret its in English)

It was written before the Harman paper on the same subject. The writer favours corner loading duals and front loading multiple subs to minimize phase errors and interference. I tried this setup once and thought it sounded pretty good. It also looks very cool having all that gear up front in an HT. I never tried his suggestion of two subs near the ceiling and two on the floor but his rational makes sense acoustically.

http://www.sonicdesign.se/subplace.html

Do you think that Axiom will make ceiling mount brackets for the ep 600????

You never know. I recall Amie posting not too long ago that Ian was toying with the idea of something to mount his 600s higher up the wall.

With 4 subs, the bigger issue would be to keep from bringing the ceiling down.

Yup. You sure would need to know where the ceiling joice are located. I found this part very interesting.


"By using two subwoofers instead of one, and placing them in opposite corners on the same distance from the listener, (it is best done in each corner behind the main speakers) there will be an obvious reduction of the room resonances, while the directly radiated sound pressure will increase. This is because two corners in a room will have opposite phase effects of the fundamental (half wavelength) room resonances acting in this direction.

If we have two subwoofers placed on the floor against the front wall the horizontal standing wave will disappear. If we have two subwoofers in the same horizontal direction instead, but one placed on the floor and one up against the ceiling, the vertical standing wave will disappear.

If we have four subwoofers (down left, up left, down right, up right) then we avoid both the horizontal and the vertical standing waves in those two directions (I then assume mono connected subwoofers). If you want to lessen the action of even higher order multiple standing waves, i.e. full wave resonance, 1.5 wave resonance and others, even more subwoofers may be added to the system. One example of an excellent placement of four subwoofers is an even distribution horizontally behind the main speakers. When the four real subwoofers come to an end, the reflections from the side walls will continue, creating a line source of infinite length.

I never could explain it technically, but I have prefferred the sound of the two EP500s at the front of the room. I tried one each at the mid front and back of the room, but didn't like it as much. Phase and calibration was also easier with them both up front, and as you said John- it looks good too.

Brotherbob should be along any minute now telling you that you can hang an ep600 straight in the drywall with an EZ anchor!

Good one!

So now I guess Randy is going to have try the EP350s up front and the EP600 up high to see if it can make his setup show a flatter response. I guess he could use the aforementioned EZ anchor to hold it up

I hear you Dave. Having duals or more up front does sound nice. I was always torn between the Harman sidewall recommendation and just leaving them paired up front where they looked better anyway.