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Discussion Starter #1
I've got the beginnings of a shared-use basement HT and am looking for some advice on acoustic treatment, room correction, etc. that takes into consideration some frustrating limitations. Per the rough sketch below, the HT area occupies the left half of the room and my wife's office / reading area takes up the right half.

Some basic room dims:

Total room size is about 430 sq. ft. / 3,440 cu. ft.

The room has 8' ceilings, tile floors, drywalled walls/ceiling. Very little in the way of wall hangings, throw rugs, etc. and no acoustic treatments (yet), so it's very "live" acoustically, to say the least.

The left wall contains an 8' 9" floor-to-ceiling (more or less) window that takes up virtually all of the space between the MLP and the left front speaker. It also has a door just behind the MLP. With the exception of a 2' 4" wall space between the door and window, and about 8" of wall between the top of the window and the ceiling, there's virtually no space for any type of acoustic panel on left side of the room. (The window and door have blackout shades, and I'll be adding additional treatments around the window to close off the remaining light gaps.)

I've got a projector (Epson 2030) directly above the MLP, aimed at at 120" diagonal/112" wide screen. The screen is 13' from the MLP/projector. The MLP is about 6' in front of the back wall.

Total size of the HT area of the basement is about 11' x 18', with another 12.5' x 15' of mostly empty space (my wife's office area) to the right. There's also a 3' x 5' hallway extending back from the right rear "corner" of the HT area.


Equipment setup is as follows:

L/R mains are NHT VT-3s (oldies but goodies). They're about 11' 2" from the MLP and about 10" from the wall (to accommodate the rear-firing drivers). Both are very slightly toed in - just a few degrees.

The left main is only 1' from the left wall - which is an issue because the VT3s have two 10" powered subs per tower, so the left ones are aimed directly at the wall that's a foot away. Not good, I know, but I don't see any way around it. The mains are positioned as close to the screen as I can get them without obstructing visibility. (About 9' 6" apart, relative to the 9' 4" wide screen, so they can't really get any closer.)

Center is an NHT VC-3, mounted just below the screen and about 11' from the MLP. No real issues there.

Rears are NHT VR-3s mounted on the rear wall, slightly above and about 5' 8" from the MLP. Again, the left rear is only about 1' 6" from the left wall - though it's slightly less of an issue because there's no sub involved. The rears are spaced slightly closer to each other than the mains - about 7' 4".


Issues and questions

First and foremost, I'm concerned about the acoustic "imbalance" created by having the left front and rear speakers (unavoidably) located so close to the outer wall - especially since the large window and door pretty much preclude hanging any type of acoustic treatment. Contrast that with the wide open space to the right of the room, in which the right wall is a good 12' away. This makes for a lot of left/right disparity, to say the least.

Question 1: How much of a problem is it going to be to have the subs in the left main positioned so close to the left wall? Obviously, having only 12" of room is less than ideal, but is it a fatal flaw?

Question 2: Keeping in mind WAF concerns (given that this room also serves as my wife's office area) and the likelihood that I'll be limited in how many acoustic panels, bass traps, etc. I'll be able to hang, where should I focus on applying acoustic treatments? (Again, the left wall is probably not an option due to the window and door location.) The ~7' between the rears might be doable, as well as the narrow spaces on either side of the screen. Ceiling too, thought that may be a long shot WAF-wise.

Question 3: How much does the empty space on the right side of the room factor in acoustically? Should I be looking at doing anything to the far right wall, even though it's 12'+ from the right speakers? How about the empty wall space to the right of the screen?

Question 4: I'm planning on upgrading to an Emotiva XMC-1 with the Dirac room correction. How much can I expect the Dirac to compensate for a room with such extensive limitations?


Those are the main concerns. I'm sure others have had to deal with similar room layouts and limitations, so any guidance on how to offset these kinds of issues - or on setting realistic expectations for how much I will or won't be able to overcome - would be appreciated.

Thanks!
 

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Take a look at my thread (in my signature). It seems you have a lot of the same issues I was dealing with and I've been thrilled with the results I've gotten.
 

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Nice write-up, Thrillcat. Looks like a great environment for kicking back and enjoying a game. It's always a pleasure and an inspiration to watch as setups evolve over time. (And it's reassuring to see other people who are always on the lookout for the next improvement.)

Am I right in my read that you haven't done much (and maybe not needed to do much) in terms of acoustic treatments and room correction, aside from the Linacoustic behind your screen? I'm just starting to read up on Linacoustic and would be very interested in figuring out whether a sheet behind my non-AT screen would be beneficial. Helpful and invisible would definitely be a great combination...

Also glad to hear that the Emotiva gear is working out for you. I actually live just up the road from Emotiva here in Nashville, and one of my colleagues/buddies used to do engineering for them, so I've gotten a bit of a behind-the-scenes look at their operations. Quite the unique and interesting company. Once I knock out some other projects, I'm looking forward to making a few Emotiva purchases and seeing how much Dirac will help offset some of my room's limitations.
 

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Correct, I had full intentions of working on some acoustic treatments as I had a chance to listen to the room and see what might be necessary, but quite frankly, I think some of the quirks of my room have made them largely unnecessary. For example, under my riser there is no real foundation to speak of. Under the front of the room is a small old patio (the entrance to my room used to be a walkout lower level door). So, when the previous owner built the room, he didn't rip out the patio, he framed over it. Under the other end he actually dug out a pit, I'm guessing to keep any water from touching the bottom of the framing in heavy rains/thaw. After discussing it with some friends, I think we've come to a decision that that pit under there has actually acted as a bass trap that prevents any major bass buildup. Strange, but true.

If you're using a non-AT screen, I don't think Linacoustic would do much if anything behind it. It basically keeps the LCRs/sound from interacting with the front wall, but if your screen isn't AT, the speakers will interact with the screen itself, not the wall behind it. Not to say there aren't other places it could prove effective in your room, but I think you'd be wasting money putting it behind a non-AT screen.

I'm planning to do some soundproofing stuff this summer. I'm going to tear out the ceiling and do green glue & drywall between the joists, and then putting a ceiling back in, probably drywall and framing like the walls. I've also considered pulling out the riser, trying to place a bottom layer under the floor joists over the pit with a vapor barrier and then placing insulation between the joists, then buttoning it all back up, just to try and warm it up in there during the winter. It can get pretty chilly. But, of course, if it's acting as a bass trap, I don't want to kill that, either. :/

The Emotiva stuff has been great. I bought it at seemingly the height of the XMC-1 controversy. I had never heard anything of theirs before. There were people all over the internet bashing them as being bumbling fools that couldn't deliver a product. But I was interested in diving into separates on a budget, and their product was just more appealing to me than the Outlaw stuff, so I took a flyer and ordered it. It's not been without its quirks, but I've been very happy with its performance. I don't regret the purchase one bit. I feel sorry for the company, quite frankly, as they seem to be a good bunch of guys who tried to give their customer base what they wanted (more information) and ended up digging themselves into a hole where hundreds of internet trolls who were never interested in purchasing an Emotiva product decided to pile on and try to bury them. The XMC-1 seems to have proven itself as a pretty good shovel to get them out of that hole. I doubt we get as many 'updates' on future products from Emotiva, which of course the trolls will jump all over and say they're shady because they're hiding information. They've made their share of mistakes, I think they had the best of intentions, but they'll forever be damned if they do and damned if they don't. Too bad, too. They make a fantastic gesture for their customers and fans and it gets all bent and twisted by the trolls. In what world does a company give a month of advance notice about a price increase and get raked over the coals for it? Most companies would just quietly raise it.

Anyway, good luck with your room, I'll be following along and will be happy to help however I can.

Remember, if it ain't broke, you can probably still fix it. ;)
 

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Discussion Starter #5
A built-in bass trap - love it! I bet the previous owner had no idea that they were installing a custom acoustic treatment. Talk about making lemonade...

As is often the case here on the forums, I'm getting a lot of different perspectives on the Linacoustic and non-AT screen question. I can see the logic in the scenario that you describe. On the other hand, I've seen other posts suggesting that the screen basically functions like a drum head - while the sound doesn't pass through, it still causes the screen to vibrate, set up sound waves that bounce off the wall, re-hit the screen, etc., etc. In theory, the Linacoustic might still absorb some of those transmitted vibrations; though I agree that the benefit would be less than it might be with an AT screen. Guess I'll be doing some more digging before I make a final decision. What's clear in any case is that the Linacoustic would only help with mid- to high frequency issues, so I'll need to figure out a way to manage the low end first and foremost. Probably best to collect some hard measurements via REW and get a clear understanding of exactly what my room needs. Otherwise, I'd probably just put up treatments blindly and end up making things worse. As much of a learning curve as there is with all of this, I'm at least having fun throwing myself in and figuring it all out!

From what I've seen of Emotiva as a company, I get the impression that they're a pretty typical small- to mid-sized operation that's experiencing some growing pains. Big enough to put out good, quality products, but still small enough to struggle with the business side of things insofar as hitting release dates, etc. I work for a company in a similar position and I feel their pain. Bottom line, they seem to put out some very, very good products for the price, and one could do a lot worse in terms of getting good performance-per-dollar value. And given that they're pretty much in my back yard, I'm a little less worried about getting support should something go wrong. So yeah, I'm pretty excited about making that step up in the not-too-distant future. As far as all of the criticism goes, I tend to take that with a grain of salt. The A/V community seems to attract more than its share of very demanding, hyper-perfectionist types that don't hesitate to call down fire and brimstone on any company that doesn't cater to their most exacting idiosyncrasies. I try not to get too caught up in that mindset. "Perfect is the enemy of the good" and all that...

Anyway, thanks for all the feedback, and best of luck on your continued improvements. I'll be sure to post updates as I figure all of this out.
 
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