Subwoofer placement


There are so many different ideas and opinions on this. Corner, center between the mains, side walls.

What have some of you found works best? Sit the sub where you sit and crawl around the room looking for the spot where it sounds best? Or just stuff it in a corner?

Finally, do subs with automatic room equalization functions render placement a relative non-issue?

Revamping my room, looking for some thoughts. Thanks!
afc
What have some of you found works best?
There are as many answers to this as there are people who use subs.What's "best" for me might not work for YOU at all.YOU have to experiment and put it where it sounds best to YOU. YOU are the one that is hearing it.YOU are the one that has to live with it.Notice the emphasis on YOU?Start out using placements suggested in the manual and work from there.Good luck.

Finally, do subs with automatic room equalization functions render placement a relative non-issue?
IMHO,no.
You may want to look at this thread by the same name. There are some good ideas.
http://forum.audiogon.com/cgi-bin/fr.pl?bhome&1256518815
For my room I have my sub in the corner. If I put it between my speakers (which I thought would be best) it was the worst place. Little bass in the sweet spot but everywhere else was great. I'll be the first to admit I have a terrible room for bass. The corner is the best compromise again for MY room.
Here's a good primer on setup from ACI, no longer in business:

5) System setup

Getting the optimum performance from your sub(s) is going to require some careful listening. Keep in mind the sound you want. Using test instruments, test CDS, etc., can be helpful but also be fairly confusing. Low frequency room response testing is a complicated subject. Suffice it to say that inexpensive test equipment used without a lot of experience and understanding may give very misleading results. We suggest making your final judgment based on how music/film sounds to you.

Read your subwoofer owner's manual. It may give you all the information you need to optimize your system. The tips below may or may not be in your owner's manual.

-Placing the sub (s) near your main speakers is the easiest way to get a good match. The ideal placement is often somewhere between the main speakers. Placements outside of the main speakers can also work well. If you are crossing over below 80-100Hz, try a corner placement behind your main speakers. A corner placement is usually the optimum placement for maximum, undistorted output with the most accuracy.

-Instead of moving a heavy subwoofer around the room to find the best response try this simple trick. Place the sub where you normally sit to listen. While playing either test tones or music with a steady bass, walk around the room and listen for the deepest, tightest and smoothest bass response. Move the sub to the place where you heard the best bass.

-Placing the sub(s) close to a wall will increase bass output but may also make the bass less even. Moving the sub(s) into a corner will increase bass output even further. Use the placement to fine tune the bass your system produces.

-Placement of the sub(s) will often be determined by your room's configuration and furniture layout. Experienced audiophiles know that "fine-tuning" room placement can yield important gains in sound quality. Most listeners will be more than happy with the results they get from the most "convenient" placement. Very serious listeners will want to experiment with various placements to really optimize the match to the main speakers.

-Correct phase of the subwoofer is dependent on the frequency response of the main speakers, the crossover filters and the placement of the subwoofer relative to the main speakers. If you have a phase or polarity switch on your sub try both positions. The correct position yields the greatest amount of bass. If you have infinitely adjustable phase, dial it in until you have the greatest bass level. If you don't have adjustable phase, start with all speaker connections positive-to-positive and negative-to-negative. If there seems to be a gap in the response between the sub(s) and main speakers, try reversing the leads to either the subwoofer(s) or the main speakers. You will then probably have to re-adjust the crossover frequency and output level. The correct phase is the one with the most bass.

-Use (line-level) connections if you have line-outputs in your system. If you don't you will need to use the speaker-level inputs or adapters. The high input impedance of most powered sub(s) will not use any power from your receiver or amp.

-The low-frequency response of your main speakers must be considered. Crossover frequency should be set as low as possible. Lower crossovers will allow the subwoofer to audibly "disappear" and placement is less critical. The deeper your main speakers go, the easier it will be to get a seamless match. If your main speakers are a ported (vented) design, you will often get the best results with the vent plugged. A cloth or towel will work fine. Just stuff it so that you no longer get air pressure coming from the vent when the speaker is playing.
Although no one can tell you where to put your sub, and Lord knows how many times I have moved my sub here and there and back again, I like these white paper studies from Harman. They make for some interesting reading about acoustics, reproduction, speaker and sub placement.

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Pages/WhitePapers.aspx?CategoryID=White%20papers

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/multsubs.pdf

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/LoudspeakersandRoomsPt3.pdf
Be careful with the "automatic" part of automatic room EQ. My Velodyne SMS-1 does a completely half-ass job on auto room EQ (paramteric controls are NOT employed in the "auto set-up"), but allows astonishingly good results if you're willing to take the (whole lot of) time required to manually tweak the parametrics for optimal results.

Marty
BTW,

I'm surprised by the ACI comment re: "near wall placement" as so kindly posted by Jax2. It's true that this placement increases output, but -IME- it also provides much smoother bass response. In fact, it's not even close, as measured by either StudioWizzard or the RTA function internal to my Velodyne SMS.

Marty
Cant beat center placement. I dont care what anyone says. I know better. HUGE difference!
I tried most of whats been offered and if you have a room that you can place the sub "anywhere".... I would try putting it in the listening position firing into the room and then place it where the bass is best sounding in the room.
I agree with with Tom as that is where YOU sit.
If you move from that spot(even a foot)you will hear a big change in the bass.
Two subs even out the layer of bass,so if you move,it sounds more consistent.I'd never go back to one sub.
try putting her where you sit as Tom suggests(as that's your
sweet spot),happy subbing.
with single sub have it in your listening chair then crawl around on hands and knees to find best spot while playing rolling bass line.

corners or walls work well.

Also, if you crossover at fairly high level (60Hz or higher) then try to keep sub within 3 feet of mains to reduce group delay. Or else, use digital correction to delay mains and keep group time with sub.

Once you have placement, play accoustically recorded cello to integrate with volume and phase. Don't integrate using same bass line you used to place, you need to get upper bass working with bass.
Thanks all. Went through the "put the sub in the listening spot" trick, and it's a corner placement that's best. That's where it is now, and it's quite a big difference from the former center placement.