Concrete line arrays

Afflicted

Member
2019-11-03 12:16 pm
Well after 4 months of hard work, hard lessons and lots of skinned knuckles there finished. 650 lb monster line arrays
 

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Afflicted

Member
2019-11-03 12:16 pm
Well, they sound fantastic IMO.

There are 9 Peerless 830869 x 8” wired 3x3 to hold 8 ohms. The ribbons are Newform Research. Bryston 10Bsub sends everything 80hz and below to a twin 15”’ sub. The line arrays are passive x-overs at 1200 hz achieving an acoustic x-over at about 2000 hz. The x-sexction of the speaker is a half ellipse 18” x12” (major/minor). The concrete is 2” thick with 7 vertical post tensioned tie rods to 150 ft lb. Some more pictures to follow. Inner baffle is 3/4” Baltic birch with 1/2” thick 6061 aluminum on outer baffle. Packed with sheep’s wool. Concrete was polished but then I ended up coating in black epoxy.
 

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adason

Member
Paid Member
2004-11-10 8:31 pm
Maryland
All jokes aside, i once made a subwoofer out of concrete. Actually, it was two subwoofers together in one box, each side had two 10" isobaric arranged woofers. Total of four woofers per sub. It took two people to move it. Its still in use, for some 20+ years, by my brother.
 

Afflicted

Member
2019-11-03 12:16 pm
All jokes aside, i once made a subwoofer out of concrete. Actually, it was two subwoofers together in one box, each side had two 10" isobaric arranged woofers. Total of four woofers per sub. It took two people to move it. Its still in use, for some 20+ years, by my brother.

He who laughs first laughs last. The boxes can not resonate. The sound is incredible. And yes, twin concrete subs are on the drawing board.
 

Afflicted

Member
2019-11-03 12:16 pm
Wow, hope there is enough support under the floorboards! These sound like they would warp the base boards with that much weight in one point.

Not really, they sit on 2” swivel feet on composite flooring on top of concrete slab. Yes they have low WAF but some does everything down in my man cave, key word MY.

Also if you look around at some of the bigger wooden speakers out there such as Montanas or Monitor PI 500 they don’t weigh a whole lot more.

All I can say is after all this work I’m glad they sound fabulous