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.

Well crap- I plan on getting a 600 and was going to put it in the front right corner- then put my 500 in the back left corner behind the love seat...

Now if I decide it sounds best with both up front my subs won't match! maybe I should get a 500 instead... otherwise I may end up doing a 'trade up' to get dual 600's!

That sounds like an upshot, not a problem.

Yes an upshot first class problem.

Yes, that's an interesting article that's been referenced here in past years, for example here in discussing forward vs down-firing subs. The author's points about the advantages of corner placement of a single sub seem very solid, but his suggestion about placing two subs along the front wall is a bit shakier. Although he correctly points out that the room mode in that one horizontal direction would be cancelled, other positions aren't discussed which involve placement at nulls and opposite phase points, e.g. the midwall front and back, or mid side walls, or diagonally opposite corners, which are among the best positions measured in the Harman paper.

The Harman paper did take the concept further. Nevertheless, multiple subs up front has alot going for it. Anytime I have heard subs with upfront placement it sounded very good, though the visual impact may have been a factor. I like his idea that "reflections from the side walls will continue, creating a line source of infinite length". It helps explain why that placement always sounded good.

With duals in the corners, its more hit and miss than suggested in Ohman's article. It can contribute to boomy bass from reinforced peaks, especially in smaller or square rooms.

I agree completely with this. Since corner placement increases SPL for the room modes, and is not uniform accross the full frequency range for the sub. You get more SPL at the expense of flatness, generally- but each room and sub combo is different so you just have to experiment. Randy will vouch for this

My 600 sounded too boomy in every corner I tried. 1/3 of the way down the wall worked best for my room.

I'm terrified about what the EP350 is going to sound like. I can only put it in a corner...

Then it might not be for you. You should send it to me as I have no fear of this animal and can raise it up to be a fine young sub that you will be free to visit any time you like.

Uh hunh. I don't think so.

I have 2 EP500s firing from the front and it sounds good to me too. And it looks good too.

Actually, judging by the FR posted by Randy in another thread, it would sound pretty good in a corner. If you take a look at the 350v3 FR curve it resembles the FR of a typical sealed sub with FR rolling off by some 12db/octave below 30hz. It represent the kind of profile that could benefit from corner loading to get higher output from the room transfer function. In other words by placing the 350v3 in the corner you would boost the response at frequencies less than 30hz from close boundary reinforcemt.

Corner placement would be less ideal with the EP subs because of their high output down low. In fact output would need to be trimmed in most cases with that placement.

Agreed.

Guess I get to find out soon. Just got the magic email!

Congrats... *drool jealously*

My ep500 sounds better in the the front corner then just on the front alone

Ken, I think your going to like the 350...

You'll like your 350. Your neighbors won't though.

I'm not worried about the neighbors. They don't worry about me with their goddamn car subs. I'm worried about my wife!

Axiom does have a trade-up program .

For wives?

That's important however...

Cograts on the soon to arrive sub.

Nah, I'm not really concerned. It'll just be a challenge to get it calibrated. I suspect it will be sitting turned off until the weekend. After I get it on Monday. Sigh. But The Boy needs his sleep.

I'm looking forward to your thoughts on the new sub Ken. Congrats. And I agree with John and Mojo, that corner placement may be just fine in your situation. Just try and see. If it is too boomy, then you can try moving it even just a foot or two in either direction.