2 opposing thoughts on subwoofer placement (1 Viewer)

[Eddie L]

To start I have 2 Yamaha YST-SW 305's (yea I know, not the best, but.....)
So I'm reading 2 different ideas from folks
1) put both together
2) put one a 1/4 width against back wall and the other about 1/2 length along one of the side walls
I have a dedicated room 15' by 14'
the reason I'm asking is about having to put in another outlet or 2.
I've a feeling most are going to say "experiment"
Thanks,
Ed

 

[Chu Gai]

Well if you want to experiment, that's up to you. Tom Nousaine, some time ago in S&V (I think?) did some work along these lines. To summarize, two subs in one corner is better than 4 all around or 2 subs in the two corners. The specific reasons had to do with one corner gave the best low frequency extension, SPL, and most even frequency response in the room.

A quote from Nousaine, where he was addressing the positionin of 4 drivers follows:

At subwoofer frequencies and wavelengths of 10 - 50 feet and longer room modes are the dominant feature. Modes occur at all frequencies between any two parallel surfaces. Play a sine wave @ 1000 Hz (wavelength @ 1 foot) and you'll hear the sound change as you move your head due to modal effects. However because the wavelength is fairly short you'll get exactly the same effect no matter where you are in the room. In other words the modes have a high statistical density.

At lower frequencies with longer wavelengths the result is hot/cold spots in sound pressure dependent on listener positioning. Below 100 Hz most rooms have only 5 axial and secondary modes. IOW low density. So the problem at low frequencies is a relative lack of modes.

A corner is the only location that will produce maximal modal excitation. Any other location will fail to excite one or more modes exacerbating the cold spots in SPL. Response will still uneven but it will be as good as it can be in that room.

If you put them all in the same corner they will combine coherently and give approximately a 12-dB reinforcement. Putting two in each corner will deliver roughly 6-9 dB.

Is here where I'm supposed to put YMMV?

 

[Kevin C Brown]

Chu- Awesome.

I have also come across the 1/2, 1/4 suggestion. I question this, because then you end up in room null (valley, minimums, etc.) positions, that effectively robs the sub of output.

If you put them in *odd* nodes, 1/3 and 2/5's are the recommended positions that I've read about, then you reinforce the sound.

But... the best approach that I've heard for 2 subs, is stacked in a corner. Then, you don't have to worry about nasty interference effects between them. And, you get the loudest output. You still will get some room nodes, but that's easily rectified with an EQ like the a BFD, Art, Rane, etc. Or, even stacked in the 1/3 or 2/5 position might work out too. Supposed to be the best compromise between output and flat freq response. Or, chuck the two subs you have, and just get one bigger, better, deeper extension, lower distortion sub.

 

[Chu Gai]

All depends sometimes on what the significant other has to say about matters too

 

[Brett DiMichele]

You could always chuck the S.O for a bigger and better S.O

 

[Eddie L]

"....the thumpin's comin' thru Blind Baby..."

Thanks for repsonses
I see many references on this board about SO who won't.....
Must be tough

 

[Chu Gai]

depends on what they won't i think.

 

[Eddie L]

"depends on what they won't i think."

like them not letting you do your HT the way it should be done..."I want it more of a family room, I want gaudy colors, I don't want the lights down that low, I want couches and recliners, I don't want those big speakers, I don't want it that loud, I don't want a stage, I don't want those posters all over the place....Blah, blah, blah

 

[Chu Gai]

your time's coming

 

[PaulT]

There are a couple of interesting White Papers published by the folks at Harman Kardon, one of which specifically deals with this question:

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

In my room with huge peaks at 75 and 36 Hz I found that placement along opposite walls helped make a 'null' to tame the room mode peaks.

I also played with some software available here:
http://www.pvconsultants.com/audio/reflection/rrc.htm

Check out a bunch more useful programs on the FRD Consortium Site.

 

[Eddie L]

Oh, it's come around, again and again, and again...
".....I don't trust anything that bleeds for a week and doesn't die!"

 

[Kevin C Brown]

Paul- Awesome article! Lots of good references too.

I guess now I'll have to question, "the best placement of 2 subs is stacked in a corner" recommendation. One problem? One side of my room opens into the kitchen, and the TV is right smack in the middle of one of the walls, so for me, I'd probably still just do 2 in a corner.

Interesting in that they seem to dubunk the recommendation that I've always heard, "1/3 or 2/5 along the longest wall for best compromise between output and freq response." But that is with only one sub too.

And, maybe a little different, but right in my speaker's manual is the suggestion to place the speakers on odd nodes. (1/3, 1/5, etc.) Maybe high freqs vs low.

(And the other best rule of thumb I've seen is speakers at 1/3, 2/3; 1/3 from the front wall, and then the seating position centered, 2/3 back from the front wall.)

I love when I get a little bit o' science behind all this. Thanks. Man, I got to do some more reading... (Ref 4 as a summary looks to be a good place to start.) There's also the other links from the Harmon site too...

 

[Chu Gai]

Well Nousaine did say 'most rooms' and if you're going to measure FR then it'd seem that the corner is a good place to start to figure out what your sub/room interactions actually are. Definitely a good read over at Harmon.

 

[Kevin C Brown]

Yeah, I just printed out the Part 3 one, haven't read it yet, but even in the linked one, the corner isn't too bad compared to all the other plots.

I gots to look into that J A E S...