The Goal: The client was looking for a loud and accurate performance in his ’96 GMC Suburban. The woofer of choice for this project was the DD3515.

The Design: After some plotting, I arrived at a variation of a rear-loading horn. With the size and the shape of the cabin, this was the optimal candidate for a flat headrest response along with high sensitivity along the entire response bandwidth.

The Build: This particular build illustrates a slightly different approach to folding the horn within the alloted footprint. In this instance the horn is wrapped around it’s own compression chamber:

This limits the bends to 90 deg. (as opposed to a more traditional 180 deg. U-bend, which can have an adverse effect on the velocity profile.) Though it may be kind of hard to tell, the throat baffle is beveled with a 0.375″ radius round-over, while the mouth of the horn flares out along a 1.5″ radius. The client also requested that the enclosure be inset for a flush woofer mount. The face of the enclosure is therefore double-stacked allowing for improved structural integrity as well as more material depth to be cut into.

Once the enclosure is assembled into a solid “block,” it is time to “chisel” away the excess, in a sense sculpting the face. No mistakes can be made here; you can’t put back what you’ve taken off:

With the high speed routers and sanders, whatever comes off is turned into fine dust, so proper safety gear is quite essential. On account of the small difference between the woofer’s outer diameter and the enclosure’s height, I decided to implement a split-baffle approach; preserving the flush-mount look while simultaneously cutting away the insets directly above and below the woofer (which would otherwise have to be very thin and extremely fragile.)

The depth of the inset is just under 0.75″ which allows for a perfect flush mount, at the same time preserving almost a full inch of baffle thickness for the woofer to mount to:

At the time, I didn’t have any DD3515s to use for a test fit. Instead, I brought out one of my 15″ RE Destroyers with a standard 12-spoke basket, the outer diameter of which is almost identical to the outer diameter of DD3515–and it fits like a glove. So there it is:

This is how you flush mount a ~15.375″ woofer along a 16″ tall face.