Axiom Home Page Forums General Discussion Home Theater Major sub issues

I am afraid a different sub wouldn't help much other than it might feel louder for the same volume level, this was what I experienced moving up to the PB13 from the PB12. I would still try the sub in various locations to see if you can achieve the sound/feel you are looking for, the sub crawl is more for even/loud sound, you may find a spot that works better for your tastes.

I have tried it all around, if I put the sub in my seating area (moving the couch), where it is I have the most feel and the most db. Crawling up front by screen there is literally nothing there, it's super weird to feel in person, it's almost like turning the sub off other than the pressure difference.

I'm glad you responded though because this just has to be the issue, I can't see how it could be anything else. I must have a hole in the 50 - 80 hz range. It also makes sense why Audyssey set my W22's to 60hz crossover when I had the sub in a different spot which didn't output as much. According to Axiom the W22's will do 60 hz without more than 3db loss, so perhaps they should be set there.

Perhaps I will go to Best Buy and buy a small sub to test with, see if it can fill that hole. My only concern is if I just split the signal and feed both subs, the smaller one may get overdriven at high levels, unless there is a way to send the small one a certain frequency range.

I would place the sub right behind the couch, a couple of feet away from the wall, and see if that helps. The AVS post indicated you had the sub in the back left corner; that seems problematic since the couch appears to be roughly centered in the room (front to back).

If your seating position is on the left seat of the couch (furthest from the wall), putting the sub against the wall will leave you in a null, but putting the sub too far from the wall will result in a frequency dip as well. I'm thinking maybe 2 feet from the wall would be best.

Note that with your room size and construction even a foot or two will make a big difference, so your sub crawl will have to be much more precise than normal, ie you can't stick your head close to the wall (a foot or two away so you don't bang it), hear bass, and then stick the sub right against the wall and get good results.

Good luck. You will get it worked out. You'll need multiple subs to get decent bass in all the listening positions but most of us only care about getting good bass in one seat anyways

Spud, I haven't read the AVS thread, but I can tell you that people frequently underestimate the room itself in seeking good bass.

I have a square room and get get 20dB swings by moving the meter a foot and a half because I have nasty nulls (places where the bass waves cancel each other out).

So relax, You don't need a new sub. Only a new house!!

Well, start by trying the sub crawl first....

^ Well, here is how it is now:

I like to sit in the right side of the couch, which is basically right against the wall, which is where I placed the sub to do the sub crawls (about 18" from the wall, firing toward the screen. My head is only about 18" from the QS8 but with level adjustment sounds the same as the other one. I currently have the sub on the other side of the loveseat than what is shown in the pics, closer to the A/V equipment. The back half of the room sounds not too bad especially close to the walls, the front half is severely lacking, but like you said I do not care about up there.

Now, I do not mind moving the couch into the center of the room at all, but I just do not seem to be getting as much bass there. Maybe what I should do tonight is put the sub right in the middle of the room about four or five feet from the back wall, and do the crawl again. I think I am getting the most response in that back corner because the ceiling is lower there as well. Maybe I should place it somewhere with a little less db, but then turn the gain up a bit to compensate.

I guess it's back to experimenting tonight... Darn work strikes again.

EDIT :

Mark, thank you for that. It's good to know I'm not alone in this, there are definate db swings in my room as well. It seems this is totally normal, I just want to find the best solution. Without boards like this... Man, I couldn't imagine.

One thing you do not want to do is sit in the middle of the room, you will have bass nulls for sure.

Have you tried the sub in a front corner?

Corner placement helped my square room a good deal. Unfortunately, the sub crawl resulted in my best placement options as being roughly 1/3 in the middle of the room between the couch and the TV wall. Not something that would sit well with my wife for too long.

Bad assumption on my part - I guessed that you sat in the left seat of the couch (closest to centerline of the screen) which would be roughly centered in the room L-R. As others have said, being in the center of the room is a Bad Thing if the sub is by the wall. Being in the center of the room if your sub is also centered is fine - you just don't get bass by the walls

Just checking - when you did the sub crawl did you actually have the sub sitting up in your preferred spot on the couch ? It doesn't need a beer but it should be sitting *exactly* where you do.

IMO having the couch by the wall like you do now is best, but I think you'll want the sub very close to the couch for best results. If you sit by the wall then I would try the sub by the wall, either right behind the couch or right in front of it with a cushion for your feet

I did the sub crawl with it on the ground. I could place it on the couch I guess, I'll try that tonight.

There is room in the back corner directly behind where I sit. I do get decent response there but not quite as good as the other corner by the A/V equipment, again I assume because the ceiling is higher. I would actually prefer it here because it's out of the way and behind the door when it's open. I also don't know if it makes any difference at all but having my equipment 12" from the sub doesn't exactly appeal to me either.

Hmm, five more hours and I can start experimenting again.

The very first place I put it was about 1/3 of the way back from the front wall, on the side wall as it makes a great end table for my loveseat. I wasn't getting much impact which is what made me start this whole process in the first place. I figured this thing was overkill and I could place it anywhere and get good results, which I am clearly finding out, is not the case.

When I did the sub crawl, there is no impact near the front wall in either corner, at all.