4x18" subwoofer (Industrial Bass Machine)

Something too big, too heavy and too useless for most applications.

I give you my latest experiment:

the 4x18" Subwoofer conveniently called IBM , which is an abbreviation from "Industrial Bass Machine"

 Why build it then? Because I can!

 and ...

 I don't care if someone will ever buy such a product.

It's a push pull design built around the Celestion CF1840 subwoofer driver. (700W Cast frame with ferrite magnet and 3" voice coil)

each sub uses 4 speakers inside a manifold

the outer dimensions are 1450mm W x 552mm H x 1100mm D (without wheels)

Prototype is being built right now from chipboard to keep costs down in case it is a huge failure.

in the images below the braces are not mounted and the central manifold is not screwed in yet, just placed inside the enclosure to see how well it fits.

the central manifold:

 I am trying to get some mechanical distortion from this.(the slot gives uneven loading between the inner and outer speakers so there will be more distortion because of the difference in movement) I find push pull subs too clean sounding... The brain loves some distortion in the low end and the perceived SPL will be much higher than with a regular clean push pull design.

Cool project. The 'designing in some distortion' to give the sound you want is like designing from the point of view of of luthier or musician rather than an engineer. I hope it brings the smiles. Props for showing the build.

Because it is similar to bandpass. Although this driver seems very fast in that box.

How does the kick sound?

Where did you get those grills?