How not to localize the Sub

If your sub's in the front left corner, and if it's feasible, move it out of that corner and place it somewhere along the front wall. (Do a sub crawl first to determine the best spot along that wall to move it to.)

I found that the front-left corner of my room offered the most SPL, too, but it also made subs localize-able (even with the crossover set at 60Hz), so I never placed them there.

I found that the next-best spots were...
- between the FR and Center speakers, and
- between the FL and Center speakers,
...so that's where the subs went.

I recalibrated the system and everything was good: Plenty of SPL, no more localization.

The center of the room is the middle of the room itself. When someone suggests that you avoid the center of the room, they're usually referring to the placement of your seating / primary listening position.
Edited by eljaycanuck - 6/6/12 at 9:13am

I got the best SPL when my sub (first an SVS PB10-NSD, and then a PB12-NSD) was in the front-left corner. I also got localization. I chose no localization (by moving the sub out of the corner) over max SPL. It was a good compromise.

(And eventually I upgraded to dual 18" subs. )

Anyway, someone else may know how you can leave your sub in the corner and reduce localization at the same time. I'm afraid I don't have that answer.

Between the 7 subwoofer systems in my home and 5 systems in my office, I have found placement to be further down the list of changes which affect localization. My office subwoofer is several feet behind and to the left of me and it is harder to integrate than my home systems. I start by level matching the subs and mains. However, the most important adjustment I have found to help is to get the subwoofer and mains integration correct at the crossover point by using the distance setting. Sealed subs located in the front might need to be a couple feet further than their actual measured distance, ported subs can need around 5 ft, and horns might need up to 17 ft extra. This is just a generalization based on a lot of subs I have measured. You might actually need to reduce the distance setting for some circumstances and location. I like use use the RTA feature in REW and adjust the distance until I get the smoothest response around the crossover frequency.

I also play with different crossover points and different slopes on the crossover simultaneously with the distance setting. Most can't change slopes with a receiver. I can change the low pass slope on the crossover of the sub between 12, 24, 36, and 48 db/octave and I can also change the high pass on the mains to different slopes. By varying the crossover frequency, crossover slope, and distance setting I am able to best integrate the subwoofer with the mains.

The next thing I do is EQ the sub(s). A peak in the midbass or inductance hump will cause one to localize the sub. A smoother frequency response

Even though I start with the subs and mains level matched, it doesn't have as much impact on localization as the distance setting or EQ. Once the distance setting is dialed in and the frequency response is EQ'd, I then raise the sub level by around 3-6 dB. If the sub and mains are well integrated and the subs are EQ'd you can run the subs hot and still not localize them. There are still situations where room placement will limit the variation in SPL between the sub and mains if you don't want localization.

In summary, the following can be adjusted to help with localization:

• Crossover frequency
• Crossover slope
• Distance Setting (Use phase if distance isn't available)
• Equalization of subwoofer
• SPL difference between mains and sub
• Subwoofer location
• Upgrade your entire system

Using a frequency range of 10Hz - 15000Hz as an example:

- When the crossover is set to 80Hz, your sub gets all the frequencies from 10Hz - 80Hz, and your speakers get all the frequencies from 80Hz - 15,000Hz.
- When the crossover is set to 120Hz, your sub gets all the frequencies from 10Hz - 120Hz, and your speakers get all the frequencies from 120Hz - 15,000Hz.

Raising the crossover point allocates more of the lower frequencies to the subwoofer.

(Note: A crossover isn't a hard "cut", but more of a "transition", as in this pic.)
Edited by eljaycanuck - 6/7/12 at 6:35am

Glad to help...and, thanks!

Awesome info, guys. As someone who is not too familiar with subs and how they work, this has been very helpful. Thanks for taking the time to explain it.

Hi Asere, you might as well set your sub's cross over to 80 or below. Theoretically anything over 80 is localizable, so that is probably what is causing your localization. The problem is your left/right mains don't look like they are up to the task of playing down to 80 hz, so if you turn the sub down to 80, you will have a gap in your frequency response. So you have to choose what offends you the least, localized subwoofer or frequency response gap. You might consider getting better front stage speakers.

Get another sub.

Also, what's so bad about locatable bass. When I go to the movies or a concert the bass is always locatable. At the movies, you know the bass in moving from front to back especially if you sitting in the back of the theater like I usually do.

Maybe deaden the entire corner of the room?

I just put a sub the hatchback of my car about a week ago. And then this week, put significant sound deadening in the hatch area floor, the hatch door, and the rear wheel wells. Before, sometimes I felt like the sub bass was coming from the back of the car because of the way it was resonating. Now, I can't tell at all.

Of course it's not practical to sound deaden the corners/walls of most rooms

If you want to know what you're missing, run some frequency sweeps and test tones in that range. Notice how much quieter the sound is at the gap where your speakers won't play and your sub cuts off, which will be from 80 hz to 120 (a rather important range, to be honest). If you want to be sure, get a SPL meter while you are runngin those tests.Here is one frequency sweep that covers 20 hz to 250 hz. The only two solutions to this problem are either get another sub, and co-locate the subs with your left and right front speakers, or get better left and right fronts. Since your front stage is already lacking in that respect, it will most certainly have shortcomings in other areas as well, I would look at replacing the fronts.

I would look at a greater range than that. I would look 20 to 120 or higher, just to see how everything is, but the range we want to focus on is 80 to 120. Yes, you will want to test both 80 hz crossover and 120 hz crossover to see how they differ.

You will just want to test the left/right fronts since they are the ones having trouble.

Could be because of the corner placement. When I had my sub in the corner, it was localize-able even if the crossover was as low as 60Hz. With the sub between a main speaker and the center channel speaker, I could set the crossover to 80Hz or even a bit higher without localizing the sub.

Localized means you hear the sound as coming from the sub rather than wherever in the sound stage the mixer put it. I can put my sub at the far left of my room, and listen to music with deep bass at the far right, and the bass sounds like it's coming from the far right, not from the sub over on the left. That means the sub is not localizable, Our ears/brains use higher frequencies to define sound direction, so unless you have odd room problems, once you get the crossover low enough, everything will appear to come from it's propre location even though you know in your head that the deepest parts of those low notes are really coming from the sub.

Generally speaking, if you're sitting right next to the sub, it will be more localizible than having the sub farther away. If for no other reason than you'll feel vibrations coming from the sub.

place them both on each side of the couch and get the phase alignment correct and you will not be able tell where the bass is coming from. when you plece the subs at a large of distance then they are not hitting in the same wave legnth, so the sub you sit closest to will be localized.