Will this proposed sub placement yield good results? (pix)

Unfortunately there is no way to tell best placement than to try it/take measurements in room. Trying to predict best placement is even harder in an abnormally shaped room like yours. Are you looking for more output or smoother seat to seat frequency response? It really depends on your wanting to do.

Many here use REW with mic and sound card to measure room response. I use a dayton omnimic from parts express. I plan on adding another sub in the back of the room for smoothing purposes as I get over 110db peak output (hit 114 in my seat the other day with TRON) from sub as is and it is enough for me. I will probably give it a go with both up front for a week or two with my favorite bass movies for fun though!

In general colocating same sub will give you 6db increase, and spreading subs out will give ~3db increase but will smooth room response. Chances are though if you get a nice ID subwoofer, it is going to have more output and extension than your KLH 10" so results will differ.

Edit: don't run cable in wall until you have found best placement for sub through testing.

I have an alternate location for you. In the corner of the "L" created by the two couches. Typically a sub "in the corner", then along the wall, in the middle, can add, and smooth out, your bass response.

Setting the one between the couches at a 45 degree angle from the wall can help with bass cancellation as well.

Although the 45 degree angle is assuming both subs are front firing. If one, or both, is down firing then the 45 degrees is moot.

Also, just in case...

Both subs HAVE TO BE pushing the same basic direction. If for "esthetics", they need to "face each other"...make sure one is set 180 degrees. Facing each other in unison will cancel each other.

So, the one, if placed in the corner of the couches, still needs to face the back of the room. But that position, like your other 3, is just a suggestion. More than likely...there is no "perfect" spot...there is simply the one place it "seems to work the best".

I wouldn't move the first sub, if you already like what it is doing.

I'm sorry, but all of this is just wrong. Phase doesn't work based on the direction the driver is facing. It works based on when the waves generated by the drivers arrive at the listening position. Setting one sub at 180 degrees can potentially cause cancellation. It depends on the room and where in the room the combined response is measured. Your assesement would only be correct at *exactly* half way between the drivers. Anywhere else in the room, the arrival times will vary, and that will impact the cancellation/reinforcement.

OP, placing your 2nd sub in the rear corner is probably a good placement. Welti's research showed it to be the 2nd best possibility and only slightly not as good as the "best" possibility, which was dual, mid-wall placements.:
http://www.harman.com/EN-US/OurCompa...s/multsubs.pdf


Just be sure you crossover to the speakers at 80 Hz or lower to ensure you don't have localization of the rear sub. Also, be sure to "gain-match" the subs.

Craig

My assessment of phase isn't "completely wrong". I just didn't completely explain it(which he can google further for information).

Two subs can cancel each other out. One way to minimize that is the phase switch, the other is to move them about the room till you find where they won't cancel each other. Canting one so that they aren't "exactly aligned" is a tried and true way to keep them from canceling each other.

There is a very old M&K paper about multiple sub placement. The paper is mainly intended for sub arrays, but what you read in it still applies to 2 subwoofers. Been awhile since I read it, but it is out there on the net.

I thought these would be good links for OP and schan.

Audioholics has some easy to follow articles that can be very helpfull.

http://www.audioholics.com/tweaks/get-good-bass

The Harman White Papers are very good reads. Subwoofers: Optimum Number and Locations, and Part Three: Getting the Bass Right will both be of help.

http://www.avsforum.com/avs-vb/newre...e=1&p=20373031

To OP: If currect location is good, stay with it. Do a sub crawl to find a few good places. I would just get a long sub cable, and give it a go with the other one in the other places, adjusting phase of the new sub to get phase good. Once find the best placement, run your cable to it. I agree with Craig that opposite corners will probably be best. You will still get corner loading with good LFE output, and will get room smoothing. Give it a go, and let us know how it turns out! Do you have a rat shack meter or anything, or is this all by ear?

Might want to download some bass sweeps and test tones. Can listen to sweeps to see if smooth, and if not change phase on sub you are adding. Once find best placement and have subs in phase. Check phase between mains and subs, lets say you use 80hz crossover. Run an 80hz test tone and adjust subwoofer distance setting in avr until you have most output. When have most output at crossover, this lets you know they are working in phase together. Good luck and happy reading!

Subwoofer arrays? They are used in professional applications, (concert venues, etc.), for bass directionality. However, that is completely unrelated to how subwoofers interact in a room.

BTW, I searched for the M&K paper and couldn't find it. Can you post a link? I would like to read it.

Craig

Glad its working out! No better way to find out than to give it a try in some different spots. Let us know how the measurements and tweaking work turns out.