Time to address my dissatisfaction

[Hughes, G D]

With my new XMC-1 on the way, I thought this a good time to address some things I haven't been happy with as far as overall enjoyment of music and movies. Once upon a time, I lived in a house with a daughter who shared my love of music and movies. Her mom had moved on and left me with a great listening room about 18' x 22'. I had it all tweaked to utter bliss. 
Then, I remarried and moved to a bigger home with my new bride. Set up my system in the new living area and struggled to get back to the bliss. The problem, like most problems is more than one problem. Some can be improved with money and some can be tweaked for small improvements.
The main issue I can not change is sub placement and getting my head wrapped around how to address a large irregular room. Seems every discussion about sub placement and nulls and voids and such is only referencing small or symmetrical rooms. My room has a cathedral ceiling with 13' peak above the front mains. The peak runs all the way into the kitchen area about 28' away. On the right side is a 18' long 10' high wall with a three panel glass door. The left side is a 8' long 9' high with a pair of book shelves and a 10' opening to the foyer and dinning room. Hard reflective surfaces on one side and open to a cave like room on the other. No, wife ain't putting anything over the glass. There is ONLY one place for subs and that is in the wall unit above the mains. The wall unit is full wall height, 13' and the subs are left and right about 8' high. Is this a bad thing? A terrible thing? A sin beyond remorse? I saw this done in a B&W show room so, I thought it might be OK.

My question is "with my subs placed high in a wooden wall unit in such a large room, what are steps I can take with the new XMC-1 to maximize them." Another consideration is that the subs are different. One is an enclosed 15" James  EMB1500 the other is a 12" 1200wRMS , I forget the model but Not and EMB. so, they will have to be dual mono as opposed to stereo.

[simpleman68]

That is a list of limitations. Only thing I can think to consider are some higher end in wall subs. (The cheap ones sound hollow and are poorly constructed)
I say "subs" because you're very likely to have better results from 2 or more subs.

Just need to figure out how to do the sub crawl for an in wall application.
Scott

[vneal]

pictures we need pictures

[Boomzilla]

Contact the sub manufacturers. Give them photos and measurements of your room. Ask them for placement guidance. They have software that will recommend optimum placements. THEN the processor can pick up the slack.

My experience is that "off the floor" placements can work very well. Also some "out into the room" placements can be surprisingly good. And (despite the persistent naysayers) even vertically stacked subs cam be beneficial.

My audio amigo, garbulky, is a proponent of the "subwoofer crawl" where the sub is placed on the listening couch, and while playing bass heavy music, you crawl around the periphery of the room listening for where the bass sounds best. Every time you find a good spot, drop a playing card. If it sounds REALLY good, then drop two. At the end of the crawl, look at the card locations & pick the one that combines best bass response with WAF.

Happy room setup!

Boomzilla (moniker not indicative of listening preference)

[garbulky]

Most people will hate this advice. But you want tight sounding bass - use lots of room treatment. Even if you don't know what you're doing - simply using it will help your audio enjoyment quite a lot. Granted the aesthetics of this stuff is rather low imo. However if you are okay with spending some $$ there is a website that has stunning looking room treatment. I'm talking about custom paintings that span several treatments so that it looks part of a set etc.
I wish I could remember the name of it.
The really good website skips my memory but here is a good one.

www.acoustimac.com/acousticart/ready-made

[AudioHTIT]

I’ve heard some great bass in theatres who have mounted their subs in the middle of the ceiling, the middle of the wall might work fine, but with subs it’s hard to predict. You could turn the sub crawl into a sub climb and get up on a ladder to put your ears where you’re thinking of placing the subs.

[KeithL]

Even though it might seem counter intuitive, a sub doesn't care if it's located on the ceiling or the floor.... and all corners are equal.
Putting one on the floor in the center of a wall is acoustically equal to putting it on the ceiling in the center of a wall.
Therefore, there should be lots of acceptable locations at various points around the room.

The usual reasons why subs are located on the floor are not specifically related to acoustics:
1) they're usually very heavy, so you wouldn't want them to fall on you
2) they tend to produce a lot of vibration, and floors are normally a lot less sensitive to vibration than walls and ceilings
3) taking 1) and 2) together, mounting something that's really heavy and vibrates over your head seems like a bad idea
4) it's not especially convenient to try multiple ceiling or wall locations when trying to figure out where to place your sub
(remember that the formulas aren't absolute, so some hand tweaking of the best location is often necessary).

As someone noted, the subwoofer crawl is sort of limited to the floor, unless you have a really good ladder... or wings.

However, all that aside, there's no reason why there shouldn't be plenty of acoustically good locations on a wall.

[Hughes, G D]

"1) they're usually very heavy, so you wouldn't want them to fall on you"

The left sub is a James EMB1500 weighing 95 lbs and I put it up there all by my self. This is not something I recommend or would care to repeat.