The other one; HT Basement build with kids area

[asal]

Hey all,

For most of those that haven't met me, I'm Saldog's brother, and had asked for some help choosing some whole house distro system (found here http://www.theaudioannex.com/forum/viewtopic.php?f=28&t=6972&hilit=zone) and now that our addition is done, I'm on to my own basement build :banana-dance:

So a little up front matter, I'm looking for a non-intrusive finished product that mostly looks like a basement living room area, but has a drop down screen for movie nights. It won't be 'invisible' as my goal all along has been to use my Polk LSi speakers, which are definitely not invisible

The image below summarizes the basement floor plan, but the area labeled "Zone 2" is now the media room, with the motorized screen being mounted on the left wall north of the mechanical room.

I'm most of the way through framing, and I'm now down to brass tacks when it comes to running my low voltage cables, and wiring. I'll upload some current pics, and my first follow up question which will be regarding subwoofer placement.

thanks. -adam

 

[AndySTL]

Cool! Is this a walk out basement?

 

[asal]

Hi Andy. Yes, it's a walkout basement, the french doors you see open to our driveway/back yard, but at the bottom of the stairs we're underground about 5 ft.

 

[AndySTL]

Hi Andy. Yes, it's a walkout basement, the french doors you see open to our driveway/back yard, but at the bottom of the stairs we're underground about 5 ft.

Ok, got it. It has a lot of similarities to my basement.

Unfortunately I am not a sub placement guru, so I'll let other comment on that.

I will be following this thread though! Good luck!

 

[PaulyT]

Cool! Just out of curiosity, what's with the diagonal jog in the north wall of the mechanical room? Was that existing structure, or...?

 

[asal]

Pauly,

So that wall was existing, and near the floor is a large air return vent right incorporated into that wall. I did scale that "jog" down a little, and pushed that mechanical room wall adjacent to the screen about 3-4 inches closer to the HVAC, but i couldn't move it further than that since my furnace is right on the other side of that wall.

I'll post some pictures soon to show how it looks.

 

[asal]

OK, here are the promised shots:

Screen wall, upon which I have made 2 "alcoves" for my floor standing speakers. I plan on putting OSB on this front wall, then drywall. The "alcoves" will be a bit over 12" wide once done. My front speakers are about 44" tall, so I think I'll put some bookshelves above that to make those look like built-ins.

Theater room (i'm standing at the screen wall looking back into the room). I apologize for the wardrobe blocking the view of everything, but you can see the stairs in the distance to the right. The mechanical room is out of view, but is to my immediate right off screen. The wall straight ahead is the laundry room.

Play room - The mechanical room is seen on the right, and the orange striped area (test paints) is at the bottom of the stairwell. All my low voltage runs back to under the stairs.

 

[asal]

Re: Sub placement

Going back to the question i alluded to, I'm having trouble selecting an ideal place for a subwoofer. I originally was going to do an in-wall solution, likely the Paradigm RVC12-SQ, (I looked at Triad too), but after going to the local dealer and speaking with him, he suggested I would need 2 in-walls and the beefier amp to support it, so this quickly climbed out of my price range ($3k + for subs)

I then tried to think about where I could use a traditional sealed or ported sub, such as the SVS SB-13 Ultra, keeping in mind I still don't want a black box sitting in the middle of my room, and I identified an area behind where my equipment will go, where I could build an MDF box that would face the play area, and try to isolate the sound from going up the stairs maybe via subdude, sub platform, or isolation clips of some kind. I know it's not an ideal location, but I'm wondering what you all think? From the picture it looks far away from the listening area, but it doesn't feel that far away when standing in the "sweet spot", i'd guess maybe 8 - 10 ft away. I'm leaning this way since it would be cheaper, plus I already have a Polk PSW650 i've barely used that I could utilize immediately.

See below for an illustration...

 

[Botch]

I would think that mechanical room is an ideal opportunity to make an infinite baffle sub, which you surely could do for much less than $3K.

 

[Flint]

I would think that mechanical room is an ideal opportunity to make an infinite baffle sub, which you surely could do for much less than $3K.

This.

 

[asal]

Thanks for the suggestion guys. I'm a little worried about vibration of the Hvac equipment or since the gas line comes into the house there. Plus I'd have to seal up every crevice of that room (as I can see the subfloor above e.g), but I'm not really familiar with what it takes to install a successful IB.

I'm not squashing the idea , just curious about level of effort (and hours of labor ) I'd be lookin g at if I undertook an IB

 

[saldog]

Thanks for starting a thread. It looks a lot different than than the last time i was there. I've always been intrigued by the idea of IB, but haven't researched it enough either to know how much work it takes to pull off. I assume the door to the mechanical room would have to be extremely well sealed? And you need to be careful about limiting the combustion air volume for the furnace, right?

 

[asal]

Thanks for starting a thread. It looks a lot different than than the last time i was there. I've always been intrigued by the idea of IB, but haven't researched it enough either to know how much work it takes to pull off. I assume the door to the mechanical room would have to be extremely well sealed? And you need to be careful about limiting the combustion air volume for the furnace, right?

this is true. I'd really hate for anything I do to the home theater to effect my heating system! It's already 20+ years old lol.

 

[Botch]

I'm pretty sure the air volume on the "far" side of the sub cone does not need to be sealed, in fact the more volume the better; but I'll defer to Flint on that (I don't yet have an IB setup, but I've read his posts with interest as my speakers are against an upstairs internal wall, and there's a big area above the stairwell that would work perfectly for me). WRT the door between the listening area and the "far" side of the sub, there might be some "chuffing" under the door but again Flint would know better than I.
The vibration won't have an effect on your HVAC or gas lines, no worries there. On my furnace system (natural gas) a cold air return upstairs feeds the furnace, and there must be some kind of input from outside air too or the furnace would quit running (and my ears would pop). Hmm, I gotta go look and see how that works. (I have a BS in ME, but because I changed majors from Aerospace Engineering I never had a chance to take an HVAC course)

 

[Flint]

The goal is to isolate the sound coming off the rear of the subwoofer cone from going into the HT area. The more isolated, the closer to the perfect theoretical IB loading you have.

That said, if the volume of the equipment room is more than, say, 20 cubic feet, then it is very likely that a good IB sub could easily be installed and used. In fact, you could avoid cutting holes in the wall by replacing the door with a solid door when two large 18" subwoofers mounted in it and seal the door with lots of foam rubber so that when the door is closed and latched it is tightly sealed and won't vibrate or rattle.

The result would be nothing short of absolutely phenomenal. And, when you decide to remove it, you could simple replace the solid woofer door with the original door and remove the rubber seals.

The cost would be:
$50 1ea - Smooth door: http://www.homedepot.com/p/Masonite-Smo ... /202768983
$25 1ea - Sheet of MDF to make the baffle for mounting the woofers
$600 2ea - 18" subwoofers http://www.parts-express.com/dayton-aud ... l--295-518
$400 1ea - powerful amplifier http://www.parts-express.com/dayton-aud ... e--300-811
$20 estimated cost for cabling (Speaker wire and Subwoofer cable from receiver)
$8 2ea - Closed Cell Weather strip

$1,053 total parts costs.

 

[asal]

thanks for the awesome breakdown Flint! That's really helpful. Doing the drivers in a door is an interesting idea as well.

For the woofer you linked to, the Vas is 7.49 cu ft , so that would mean I'd only need a @ 75 cu ft area per woofer, or @ 150 cu ft for the whole setup? I think my mechanical room is in the area of 500+ cu ft.

 

[Flint]

The concept behind an infinite baffle loading is that the acoustic pressure load on either side of the cone is equal. So, the acoustic volume should be the same on both sides. There should be no added pressure behind the woofers and thus the volume needs to be as huge as possible. In this scenario, the woofer's Vas isn't a value worth considering.

 

[jomari]

The goal is to isolate the sound coming off the rear of the subwoofer cone from going into the HT area. The more isolated, the closer to the perfect theoretical IB loading you have.

That said, if the volume of the equipment room is more than, say, 20 cubic feet, then it is very likely that a good IB sub could easily be installed and used. In fact, you could avoid cutting holes in the wall by replacing the door with a solid door when two large 18" subwoofers mounted in it and seal the door with lots of foam rubber so that when the door is closed and latched it is tightly sealed and won't vibrate or rattle.

The result would be nothing short of absolutely phenomenal. And, when you decide to remove it, you could simple replace the solid woofer door with the original door and remove the rubber seals.

The cost would be:
$50 1ea - Smooth door: http://www.homedepot.com/p/Masonite-Smo ... /202768983
$25 1ea - Sheet of MDF to make the baffle for mounting the woofers
$600 2ea - 18" subwoofers http://www.parts-express.com/dayton-aud ... l--295-518
$400 1ea - powerful amplifier http://www.parts-express.com/dayton-aud ... e--300-811
$20 estimated cost for cabling (Speaker wire and Subwoofer cable from receiver)
$8 2ea - Closed Cell Weather strip

$1,053 total parts costs.

this IS an amazing post. i have to tip my hat off to IG on this one. id love to learn how to do IB's but man, i wish i didnt live in california.

 

[Batman]

I can still see myself implementing one, if for no other reason than its just a matter of time until I get the itch for another project. If Flint attends my GTG, I'll be very eager to hear his thoughts on placement options.

 

[PaulyT]

^--- Now THAT would be an awesome GTG project! Better even than fixing squeaky stairs. :eusa-whistle: