Better to put two subwoofers close to each other?

[superedge88]

I am wondering if it is more likely to get odd cancellation issues with a two subwoofer set up if the subs are set far apart. Am I better off placing the subs close to each other? I am pondering placing two Klipsch SUB-12 subs right next to each other, if that is not recommended then I only have one other place to put the second SUB-12 which is about 14 feet away. I am exploring these options before I purchase the second SUB-12. Thanks for any input!

[wuzzzer]

There are benefits of co-locating subwoofers. I have my Ultras literally touching each other and they sound incredible. Some have either stacked one sub on top of the other or set them side-by-side.

Here's just one thread about it at AVSForum:

http://www.avsforum.com/avs-vb/showthread.php?p=16097883#post16097883

[russ69]

Go to the Hsu Research forum, tons of info on sub placement.

Thanx, Russ

[JohnA]

I am wondering if it is more likely to get odd cancellation issues with a two subwoofer set up if the subs are set far apart. Am I better off placing the subs close to each other? ......... Thanks for any input!

This is very room dependent and all rooms have nodes aka resonances. You are more likely to increase room resonances and reinforce them with co-located subwoofers. Placing them far apart is more likely (but not guaranteed, since nodes are based on the room's geometry) to excite a series of different resonances based on the different distances from the subs to the walls that would smooth the overall response.

[superedge88]

OK, so from what I am reading...

I should possibly try the other spot across the room with the other SUB-12 and see if it flattens the bass tones. And then see if switching the phase of one of the woofers makes it louder. It shouldn't make a difference which sub I switch the phase of should it? Of course this is assuming that switching the phase would increase gain.

[Edgar]

Search for a paper named "Subwoofers: Optimum Number and Locations", by Todd Welti, Research Acoustician, Harman International. It used to be available on the Harman site, but I couldn't find it there today. Anyway, the short answer is that the best configuration for two subwoofers is: one in the middle of the front wall, and the other in the middle of the back wall.

Greg

[superedge88]

I will look for that paper, of course niether of those locations are available for either subwoofer, but I will read that paper you suggested and see what else I can figure out. Thanks!

[BusaDude]

I will look for that paper, of course niether of those locations are available for either subwoofer, but I will read that paper you suggested and see what else I can figure out. Thanks!

Here is the file... saved it from the Harman Website several years ago. Not sure if there have been any updates, but it's still good reading.

Mulitiple Subs - Number and Locations.pdf

[nola]

No doubt all rooms are different. In my bedroom I have my RSW-15 in corner. The driver is aimed away from the bed down the hallway to the kitchen. Yet, it works great. In the main room, I prefer distinct L and R subs, I have 4 now. Give that a try. "They" will tell you that low freq sound is uni/omni directional.

B U L L ! ! ! !

Maybe due to harmonics, etc., I can definitely tell where the sub is. Bedroom sub takes everything below 80 Hz; main room - I think below 60 Hz. I wish subsonic sound was directionally recorded, for those of with multiple subs. If you simply take your main spkrs, Khorns in my case, (eg set your rcvr to stereo mode or whatever works for the purpose) and allow full range to your spkrs and subs, you will never willingly go back to "point .1". Mind you not every room is big enough to handle my 6 18" drivers. In fact, my bedroom single 15" rumbles with Led Zep. A buddy has a self made 15" driver, 24" wide, about 3.5 ft tall cylinder sub - totally awesome - but I think he needs paired subs too.

Stacking: they will reinforce each other, esp when combined with corner placement. Do a search on AVS forums for craigsub's stuff of over a yr ago. However, there is some physics here. That 300 yr old organ in Europe sounds awesome for reasons, including sheer size of the pipes and the overall cathedral space. Sorry mon cheri, our 1500 cu ft HT rooms will never be able to approach that. Similar areas of air moved (driver size): single 18", dual 15", quad 12", etc. Why not get the biggest driver and largest box you can afford if you only want point .1?

My 2 cents.