haven't ran into any yet but they are in the area...if I feel the need to get up close and personal with a Grizzly what the locals affectionately call the bear jail
is 8 miles away
not on site...the lot is flat as a pancake but I can see a few a couple miles away
yes!!! there will be one; this part is true
eventually, but if left to my devices expect glacial pace
In continuing the tradition of intellectually deep naming traditions practiced by most of us on AVS, the Bear Canyon Bunker Build gets it's name via geography...we are building this house a few miles away from what is probably one of many Bear Canyons in South Central Montana. The bunker aspect comes from the space having solid concrete for all surfaces and is a roughly 34' x 20' x 11' room under the garage. Spancrete was the original plan but with no dealers within 400 miles I was convinced to go with a locally fabricated option consisting of poured concrete sitting on Vulcraft metal decking that is bolted to 16" steel beams. To end up with 11' walls the foundation needed to be excavated an additional 3' deeper than the house basement at 13'; the house basement is a 10' dig and will end up with a 9' finished ceiling. The fact that this isn't a walkout made excavation a bit more interesting (and expensive) but the resulting sound isolation and climate control from being so deep in the ground should make this an incredible space to hole up in and enjoy movies and music.
All is not perfect in bunker-land though and there are some challenges. Solid concrete rooms can be a b!tch to tame and generate many more room modes as the bass can't dissipate like it would with typical lossy walls. Being that there is a very good chance I may die in this house, I decided to enlist Nyal Mellor at Acoustic Frontiers to come up with a sound plan (both literally and figuratively). I've been on AVS for many years and have been hoping to do a decent scope theater build for over 10 years, but I figured Nyal is probably about a billion times better than me at coming up with an acoustic plan and it was worth it to spend the money on a pro...a sound investment (did it again). I'm viewing the project as a one-time chance to get it right from the start and not an ongoing science project. He is working behind the scenes scheming and crunching numbers as this is being typed even though I don't anticipate starting construction until sometime next spring...the hole was just dug last week and the foundation will be done sometime next week. We aren't expecting to move in until early spring.
Another downside about the room is the concrete floor...tough to excite the concrete enough to provide the wonderful tactile feel that a wood joist floor provides. Okay, it's basically impossible. If I do experience tactility in the concrete, that's a problem for me (and possibly the rest of the world) as the house will be about 55 straight-line miles from this thing
-- the world's largest active volcano at 34 x 45 miles in area. If that sucker blows I'll be one of the first to go!
I know I'm not supposed to fixate on equipment in the opening post, but what the hell! I believe my desire to use Yorkville U15 Unity as LCR may not be Nyal's first choice (or 2nd, 3rd, 4th, etc. for that matter), but that was the original thought. Six JBL Control 322C 12" pro coax (with compression drivers)for two rows of side surrounds and rear surround and four or six Control 328C 8" for Atmos would round out the speakers. The U15's and 322's are cousins perhaps and do have some sound synergy with the Unities using a BMS 4550 compression driver and the 322C a JBL 2407h / BMS 4540nd. Also have some Tannoy 12" Dual-Concentrics (same drivers as used in their Definition DC12i custom install speaker) that are in the running for LCR (perhaps augmented by pairs of JBL 2226J 15" as midbass?). I own exactly nine of the Tannoys and could use them for side/rear as well and go with 8" Duals for Atmos. There will be stout full-width baffle wall in either scenario.
Bass will be 'ample' -- twelve FI IB318 18's and eight SI HT18's are standing by to deliver the goods. I have been fixated on a mass quantity of IB drivers for quite some time now; this stems back to plans for my current house's bonus room space which would have been perfect for IB save for the deal-breaker unfortunate reality that containing all of the bass energy would have been extremely difficult for numerous reasons; due to this and the room's uninspiring 12' width the project was kicked around but never completed. Not sure Nyal is completely sold on the IB idea as it does eat up a fair amount of real estate from the room...right now the screen wall is drawn at 5' in from the foundation wall to accommodate the 1080 cu.ft. needed to attain 10x VAS of eight of the FI drivers, but I'm considering going with a 3' depth to allow for a slightly bigger screen (there is an additional 1000 cu.ft. storage area that connects to the area behind the screen wall that would more than make up the difference). The SI drivers will be implemented out into the room to balance response...perhaps even nearfield into the 2nd/3rd row riser.
Amplification and DSP are from QSC with a stack of DCA amplifiers and a couple Basis DSP. Both the processor and projector are undecided but hopefully will compliment the rest of the gear.
The room's finished interior dimensions after treatment should end up between 27'8" and 29'8" deep, 18'7" wide, and have an 11' high ceiling in the 1st (and primary) row and 9'6" high in the 2nd & 3rd rows. The 3rd row will employ the obligatory counter with elevated bar-type seating and the room will be entered at riser-height in the back right corner through a 9'x12' foyer that will also serve as an equipment room (this is also under the garage). Seating is undecided as of yet but I am strongly leaning towards a couple of long 120" leather couches right now (actually sectionals with their corner connector pieces kicked to the curb). My wife is pretty sure I am going to want proper home theater recliners as soon as the room is nearing completion...we'll see.
With Nyal spec'ing the acoustic treatments the room should stand half a chance of sounding pretty damn good.
(will add more room details and do this better when I know more)
Looking for advice in a few areas:
The house will have a zoned forced air system with three zones (basement, main floor, upstairs)...the theater could be a 4th zone but I am leaning towards installing a mini-split for a few reasons. The complete isolation from the home's ductwork would mitigate any possibility of sound leakage/intrusion. I really don't anticipate needing to cool the room due to having 13' of solid earth on three sides of the room and being in a mountainous Northern climate. I believe I read that Rms8 hasn't needed to cool his rustic bunker room nor has Mcasio with the Cinemar (not technically a bunker but basement with dirt on three sides). Not really anticipating much heat needed either thanks to the mid-50's ground temps and me liking it cool. Cost will almost certainly be less than an additional zone as well (planning a self install). Would appreciate opinions!
Trying to figure out how to induce a little tactile feel into the 1st row seats *without installing tactile transducers*. I know rms8 and a few others swear by them, and I admit to having no experience with them, but I still don't want to use them.
I'm planning some sort of floating floor but haven't worked out the details yet; perhaps something as simple as 2x4's sitting on rubber strips with a plywood deck. I don't want to have to step up onto a dedicated seating platform for row 1 and would prefer to just do the whole lower level at the same height. The 2nd row riser (20" or so?) will work well for tactility. Anybody have any great ideas for the 1st row? *Found a nice resource for this issue*
No nifty renders or anything but here are pictures of the Acoustic Frontier layout concept for a better visual and one of the hole in the ground.
Here's the hole: