Multiple Sub Placement???????

[spasticpitbull]

What would be the best place to place my subs in my livingroom?
Room is 28'x11' with 10ft Ceilings. Right now i have a sub on each side of my fronts. Sounds good but could probably sound better. Would stacking them be better in one corner? Also i have them hooked up to my amp with a monster splitter from the back wsplit to each sub. Is this the best?

Onkyo TSXR500
PSW350
PSW202
Fronts RT50
Center CSi30
Rears Kenwood somethins?

All help is much appreciated.

[GuitarheadCA]

The best and ONLY way to find the optimal placement is to try a few. I've unplugged and hauled subs across my room many times to find the optimal location. So go move 'em.

A few notes though- Stacking subs will increase the volume the most- but it doesnt' really take care of null spots like you can by having them separtated. Also, if it's plenty loud and you want it to sound cleaner, you can take them away from corners and perhaps put them on the inside of your speakers. I would however keep them on the same wall, as this helps to blend with the mains and keeps phase problems to a minimum. So just play around with it - there's really no wrong way :-)

Oh, and splitting the signal cable will work just fine.

[Tour2ma]

Slight disagreement with ya GCA...

spasticpb (nice handle),

First off, welcome to the Forum. Nice little place here, I think you'll enjoy yourself...

Big room you have there at ~3000 cu ft. Those two Polks may even have trouble filling it, but worth a shot.

In addition to getting the spl boost GCA mentioned, co-locating sub's (stacking) is a good way to minimize the bass peaks and valleys that the parallel surfaces of any standard construction room are sure to produce. Multiple sources of bass distributed throughout a room increase the chances of wave cancellation and reinforcement with each other as well as reflections from their separated outputs.

As for the best spot to stack 'em in a given room... start in a corner and work away from it. Check the room's listening positions by ear, or better yet with a SPL meter, for hot and cold spots. Sweep a range of frequencies from just above your cross over point to the subs' lower limits.

If you have to keep the subs up front, in proximity to your mains to achieve a blend, you may be crossing over at too high a frequency. At 80 Hz and below localization of the bass source becomes more difficult.

Good luck...

[GuitarheadCA]

Tour,

Thanks for cleaning up my post a little, I also want to clarify a something: Will co-locating subs reduce peaks and nulls as much as separating them will? I figued it WOULD help, but not as MUCH as moving them apart.

And I still stand by having the sub on the same wall as speakers (probably just because I noticed a sig. difference in my system crossed over @ 80) :-)

[spasticpitbull]

I am new to this game and excuse me for such a dumb question but you mention 80 db. How do i know it is at the setting. I know on my amp TSXR 500 Onkyo its has crossover settings but i havent really played with them. IS this what you are reffering to?

[Dr. Spec]

Originally posted by GuitarheadCA
Tour,

Thanks for cleaning up my post a little, I also want to clarify a something: Will co-locating subs reduce peaks and nulls as much as separating them will? I figued it WOULD help, but not as MUCH as moving them apart.

And I still stand by having the sub on the same wall as speakers (probably just because I noticed a sig. difference in my system crossed over @ 80) :-)

Lots of very interesting stuff on this subject lately.

IF you have the time and energy and equipment, you can experiment with dual subs in different locations and "theoretically" cancel more nulls at more listening locations.

Conversely, you could also screw it all up and make it much worse than co-located subs. It all depends on what you are willing to put into it, and your particular room acoustics.

Subs and real estate have three things in common: location, location, location.

Here are some articles on the subject. High tech and heady but understandable if you want to take your time.

Bottom line - if you are unwilling to put forth the effort, stack 'em.

Doc

http://www.harman.com/wp/pdf/Loudspeakers&RoomsPt3.pdf

http://www.harman.com/wp/index.jsp?articleId=1003

[GuitarheadCA]

Spastic,
To steer away from placement for a second and adress your last question: Yes, your Onkyo has a variable crossover, and you can select between 80, 100, and 120 hz. I believe this can be done by hitting the "speaker adjust" button below the display. for your setup, you'll most likely want to use 80, but like I said earlier- always go with what sounds best. Play with it :-)

[Tour2ma]

Originally posted by Dr. Spec
Lots of very interesting stuff on this subject lately.
IF you have the time and energy and equipment, you can experiment with dual subs in different locations and "theoretically" cancel more nulls at more listening locations.
Doc Interesting reads (or at least skims)... looks like 5000 subs in a room pretty well take the guesswork out of the whole thing... :lol:

[spasticpitbull]

I went down to the local R.S. to check out a spl meter and was talking to one of the older gents and he was saying its not worth it as I have old hard wood floors with carpet on top and would probably end up with more nulls moving them in seperate parts of the room (eg. one up front and the other in the middle) and went into some lingo about low single this and that. so i think i'll stack for now and go from there. :)

[Tour2ma]

spb,
With all respect to the "old gent"... go back and get the meter. For $35 the RS analog SPL is an essential tool for proper HT set-up.

More than locating the subs optimally, which the stacked pair will need tweaking, it is used to balance your speakers for your prime listening position.

[RuSsMaN]

Originally posted by Tour2ma
prime listening position

Often referred to as the 'Sweet Spot'. ;)

[spasticpitbull]

I started bidding on ebay for one....thanks for the help.

[Tour2ma]

Never would have thought to look there, but there is one.

Good Luck...