Sanity check me as I get up to speed

[dgunthert]

My eternal thanks for this resource and the amazing knowledge available. ;x(

I'm standing on the shoulders of giants here and hoping I can catch my balance before I fall on my face. I've learned quite a bit over the last week or so here and elsewhere, but still struggling a bit. I'm hoping for a sanity check/bit of advice to make sure I'm heading down the right path. Since I'm a DIY kind of person, I'm putting it here.

Basic info:
Planning on converting an existing room to HT. Room layout is a bit goofy, but looks like this:


So basic viewing area is 13' 2" x 11'. Ceiling height is 8'. The light blue line is the outline for a riser in the alcove that will be the home for my electronic drum kit. I may extend that almost to the door to provide an option for a rear love seat or chair and a half. I plan on a non-permanent cover for the window on the left hand wall. That will allow me to use that entire wall but still leave a future home owner the option of taking the room back to a bedroom. The existing closet will be for equipment/storage.

First sanity check needed. For a build process to optimize acoustics, I'm thinking this: Get the room to a rough finished state, particularly riser and carpet installed. Build the speakers and test. Eliminate as many acoustic issues as possible at primary listening location via speaker placement. Install speakers/wiring/etc. Use room treatments to address remaining acoustical issues, where possible. Use EQ to finalize acoustics. I haven't come across how to approach this process yet, so input on this best guess of mine would be welcome. That's not the main point of this thread, though.

The main point I want the sanity check on is the speaker set up I'm considering. I don't want to overbuild (unpossible, right?) for that small space, but of course I want amazing sound. So here goes:

Sub: 2 Fi 18" IB3 speakers using adjacent 10,000 liter crawl space. Mounted in manifold so I don't have to worry about wall movement. That space could also handle 4 15", but can't see the benefit for the extra $440. I'm wondering if even this set up is a bit much, but the idea is just sexy.
LCR: Natalie Ps. Okay for wall mounting? Same as Modula MTM with a cheaper crossover, right? Depending on budget, I may upgrade to the Modulas.
Surrounds: Modula MT. Again, okay for wall mounting?
Rear surrounds: May not do them. That alcove makes placement of a right rear almost impossible, unless I did a ceiling mount for it. Rears would also be pretty much useless for a second row seat, if I do it.

I was originally drooling over the Khan lineup, but really felt like they would be wasted in a room this small.

[BobEllis]

I'm glad you said IB sub. That was the first thing I thought when I saw crawl space. The 2 18" setup should work well in this space.

I haven't heard the Modulas but I did build a set of NatPs and they were great. (Built for a friend). I remember Jon saying that he preferred them to the Modula fairly recently (Was it the update to NatP thread?). NatP needs a bit of room from the back wall. Not as much as the Statements, but some. I don't remember if there is a reduced baffle step version or the MT, but if so that's what you need for wall mounting. Although you may not need to go on wall. You want to avoid sitting midway between front and rear walls to avoid maximum room modes. That puts you back far enough that your seat back will be about even with the entrance way. Give the back of the NatP cabinets a foot or so from the front wall and you're good to go. A second row of seating is probably trying to cram in too much if you also want the best sound when just your main row is in use.

You may want to take a look at CJDs surrounds designed for mounting at the wall/ceiling junction. It will save a lot of valuable floor space and make placement easier.

[dgunthert]

I'm glad you said IB sub. That was the first thing I thought when I saw crawl space. The 2 18" setup should work well in this space.

Pretty much the reason I included the crawl space in the drawing!

You may want to take a look at CJDs surrounds designed for mounting at the wall/ceiling junction. It will save a lot of valuable floor space and make placement easier.

I don't remember seeing this design in the guide or on CJD's web site. Have a link?

[dgunthert]

I've gone back and rethought this a bit and updated the drawing. The general seating area is the black rectangle in the center. Not sure exactly what shape this will take.

In front I've got the LCR flush mounted in a screen frame, much like seattle_ice did in the NatalieP in-wall thread (maroon rectangles on the left). This room will be almost exclusively for movies, gaming, and even regular TV. I'd be surprised if simply listening to music makes up more than 5% of the room's use. That means I'm at a loss as to whether there'd be any significant difference between the Nat-Ps and the Modula MTMs for these.

Modula MT in-wall design on the sides (also maroon). Based on everything I've read, I'm pretty confident that those, whatever I use for LCRs, and the IB sub, the primary sound for the system will be amazing (let's just assume that I back it with the right electronics h.

Now I could just leave it at that and go with 5.1. But it will be tough to get the L and R surrounds behind the listener, even a little bit, because of alcove for the door on one side and the window on the other.
My other option would be to do 6.1 with a Modula MT flush mounted in the rear wall centered about 4' behind the seating at the same height as the side surrounds.
My last option is 7.1. I could build a 1' tall soffit across the top of the alcove to the far wall (orange line in drawing). That would allow for symmetrical flush mounting of two rear speakers. At first I discounted this idea because the speakers would be about 4 ft above the listening position and they would be less than 6" from the junction of the wall and ceiling. But then I wondered if I was overthinking it a bit. If I learned correctly so far, the issue with such a placement would be first order reflections and increased bass response. But these are rear speakers meant for atmosphere. Should great FR really be a necessity? Couldn't I add some treatments to the ceiling and EQ out the worst of the increased bass response? Would it be slightly better to design something to be mounted at a 45 degree angle (maybe still using some of the interior wall space as the enclosure)?

So basically I'm left wondering if, when talking about rear surrounds, is the difference between okay and great that noticeable and worth stressing over?
But don't forget I'm also wondering which of Jon's great designs to build, given the relatively small space and the primary use case.

[kevinm]

Have you considered using that alcove for a rear subwoofer cabinet/IB? If you filled it in with a wall/drywall, you could use the space for a sub box (so it wouldn't be wasted) and then place the right rear surround on it.

[dgunthert]

I still want that space for my drum kit mentioned in the original post.