Acoustically Treating a Bomb Shelter


Seriously.  My house came with a 1960s era bomb shelter.  It's a total of 2,200 square feet of Cold War Era awesomeness, basically divided into two 51X21 long rectangular rooms.

It's under a pool and pool house, easily 15 feet down. Hard concrete walls. Huge metal out swing doors that could keep out Bob Dylan looking for a string bean. 

We turned one big room into a giant pantry, wine cellar, and storage room.

The other I softened with hardwood floors, sheet rock (with foam insulation) on walls and ceiling, in that it could make an excellent apartment, being 1000 sf by itself, not counting the kitchen and bath.  And has two entrances, one at each end.  Very airy with good ventilation (and expensive filters).

It's this (now) 50 X 20 room iswhere my listening area is.  Ceilings are 14 foot sloping down (the short way on the rectangle) to 12 feet.

I've divided it into three areas of roughly equal area.  One end has a power rack and tons of free weights and whatnot.  On top of the hardwood is a protective layer, hardwood, and then rubber horse stall mats.  Kitchen and bath beyond that.

The other end is an emergency bedroom, with flip down Murphy beds, etc.  Area rug where the wife does yoga.  At its end are double metal doors, then stairs, then another metal door.

The middle third is my listening area.  Speakers and subs on the higher-ceiling side, although I could flip it.  Set up in the classic 60 degree triangle with a leather couch facing the speakers.  Chairs to the side, and a table I use as a desk behind the couch.  Area rug.  Decor: think Andy Warhol meets Austin Powers.

My thought is I don't get a lot of reflection from either the right or left side, due to the width of the room, and the stuff in each room.  I suspect I mainly get reverb off the back wall.  And perhaps the ceiling, although it is sloped up to the speakers.

I'm thinking all I need is some absorption on the back wall, immediately behind the couch/table (so facing the speakers), as I sit closer to the back wall than the speakers.   Perhaps something on the ceiling about 2/3 of the way across the room.

Thoughts?  I'd like to be informed a tad before I get involved with GIK or one of those groups.

davetheoilguy

@lou_setriodes 

1.  Am Israel Chi!  Go do whatever is necessary, please!  Ignore the media.

2.  For clarity, I live in West Texas.  This house was built by an extremely wealthy oil man back in the 1960s during the height of the Cold War.  Very rural.  If I ever have to shelter from bombs it’s because China Russia and the USA have decided to have a massive nuclear exchange.  All in, the shelter is as large as most people’s houses.

3.  Yes, we have plenty of food.  And about 2000 bottles of French, Californian, and even Israeli wine.  All set for the apocalypse.  Also a rather large library.

4.  We are fortunate enough here to not be preparing for said apocalypse, but rather finding something useful to do with a massive room with wonderful filtered electricity and completely silent, if oddly shaped.

 

 

Totally joking.  Pretty cool to have that unique story with the space. Living through the cold war with nuclear missiles pointed at each other was frightful. 

Good luck on your room acoustics.

Place absorption panels at first reflection points front wall (the wall you're looking at behind the speakers), side walls, ceiling, and rear wall (the wall behind you).

My dedicated room is treated just that way. Sounds wonderful. Yours will too.

@tomcarr 

Thanks for the advice.  As noted, the side walls are too far away to be of concern, but I do have a pretty pronounced standing wave.  I’ve bought multiple 4 inch thick panels for the back wall and behind the speakers/subs..  Also a bit just behind the turntable (dead center).

Moving the subs inside the primary speakers also helped immediately, as did widening the distance between the primary speakers from the classic 60/60/60 triangle by about 4 feet.  The Bowers 800s have plenty of “umph” with the big subs and Classe amps to handle being offset.  Really helped with separation.

Because of the canted ceiling, I’ve got 3 hanging baffles (pretty thick) staggered behind the listening position that I’m going to hang this week.

The back panels placed in the center back also incorporate some dispersion elements.