Sub firing direction plan

[Blazin_Jason]

Ok I have 2 JL12w6v2s that I am building sealed boxes for, material is already cut. I wanted them to be down firing. After researching a bit the only real issue I would have is the lack of spacing and the carpet they sit on. So to get around that I was thinking of taking the sonotube design ideas and use that. Make a piece out of mdf 1.5" thick spaced 4" down from the box. Any reason why I can't do this and try it out?

[marchel]

I;ve read somewhere that the minimum space btwwen the sub and floor should be 3", So you should be fine.

One concern I have with down firing is that ,that JL sub have heavy cone which might disalign the motor by a few mm in the long run.

[Blazin_Jason]

Yea I read up a little about sag. They have been sitting in the boxes face up for about 3 years now. I'm only using these for now since I have them. I plan to eventually change them out with something else in the future.

[Blazin_Jason]

Going to go put the second one together now.

[chris661]

the space between the floor and the box should be equal, or greater than, the area of the speaker cone divided by the length of the egdes of the box around the driver.

This way the air sitting between the box and the floor will only move as far as the driver moves - shortening the distance will make the box (if it was sealed) like a 4th order bandpass thing, without tuning.

[GM]

Close, you ideally need to factor in peak excursion........ FWIW, since Xsus usually isn't known, I use 1.5x Xmax as a close enough approximation except for XBL^2 motors. My limited experience with these is to slot load them if there's enough power on tap to drive them beyond Xmax.

Anyway, 4" is plenty for two of these drivers and based on published specs there's no problem with sag either.

GM