Odd but simple subwoofer

[skootsi]

Some years ago, I ran across an Internet article about a subwoofer that consisted of a square tube about a foot on a side and four feet long. Mounted at the halfway point (inside, of course) was a 10" woofer. Essentially it was a 4'X4' open baffle rolled up. What apparently made it work was its intended location, which was at the juncture of floor and wall, which gives considerable bass boost. I don't remember if there was any equalization involved. I think there was some connection to the Linkwitz site, but I'm not sure. Anyway, does that ring a bell with anyone?

 

[bjorno]

Some years ago, I ran across an Internet article about a subwoofer that consisted of a square tube about a foot on a side and four feet long. Mounted at the halfway point (inside, of course) was a 10" woofer. Essentially it was a 4'X4' open baffle rolled up. What apparently made it work was its intended location, which was at the juncture of floor and wall, which gives considerable bass boost. I don't remember if there was any equalization involved. I think there was some connection to the Linkwitz site, but I'm not sure. Anyway, does that ring a bell with anyone?

Hi skootsi,

See the picture of what happens if you place the H-Frame at the juncture of floor and rear wall, which gives considerable bass attenuation compared to a side wall that are boosting the level only moderately,IMO still a mid-bass.


b

 

[skootsi]

Bjorno...

Thanks immensely. Of course I had forgotten all the terminology, so I couldn't search effectively. Your attachment gives me things to study, as well as what I need to find other references. I already know a lot more than I did (couldn't know less).

Is there a reason why the vast majority of subwoofers are sealed or vented boxes, rather than U frame or H frame dipole types? Power handling/SPL? Neither is a consideration in my case, as I can't play music too loudly. I just want efficient, solid (boom-free) bass extension from a package I can build myself for a reasonable amount.

 

[BP1Fanatic]

Simplicity & costs. Anybody can build a 6 board sealed box. However, add a 7th board & you can have a tapped horn that can out perform a sealed, vented, BP1, BP2, FLH, & RLH of the same size.
http://www.avsforum.com/avs-vb/showthread.php?t=1212465

http://www.diyaudio.com/forums/subwoofers/135879-evolution-tapped-horn.html?referrerid=92501