PWK Designs sub box

        Here is a build log for my PWK Designs sub stage for my car. I specifically requested an operating response of 25Hz to 80Hz, primary purpose is to maximize SQ so that it can easily blend with the front stage and not overpowering but with some authority on the bottom end since I also occasionally listen to rap and RnB and for the times when I like to turn it up.

This was the resulting design.

And the Predicted in-car response at the headrest.

I asked the help of Blueprint Mobile Concept Audio for help in building the box to ensure the box is built accurately according to the drawings. Here are the wood panels cut up to size.

Box built, sealing the corners.

The corners are sealed and sanded to ensure smooth airflow.

The visible parts of the vent are painted black:.

The plastic terminal cups aren't good enough especially the fact that the box design doesn't allow the terminals to be hidden from view so custom heavy duty gold binding posts and brushed aluminum panels are made.


The box finished by adding small roundovers on all corners and wrapped in carpet.

Installed in the car as soon as the box was completed.

Closeup of the speaker terminals.

The woofers doing what they do best.

A few more daytime pics installed in the back of my car.



Listening impressions? The sub does what it was predicted to do. Give tons of low end but still sounding pretty good; Tight and defined not boomy and muddy. The 8's have enough output to flex the tailgate and rear side windows, rattle all the plastic trim and spare tire cover of the tailgate and move some serious air. Everyone who has listened to the pair are surprised of the output and low end this combination brings. Especially the fact that the Polk Audio MM840dvc subs are designed for SQ and not for ground pounding output.


13 Nov 2011: I joined dbDrag (Street stock A) just for kicks and had this box metered even though it was designed for music and audible performance. It landed a 136.3db at 48Hz on TermLab, dbDrag rules, sensor on the windshield. I guess it isn't too bad for a pair of 8 inch SQ subs and just under a kW of available power.


        Sorry, but no requests of the box measurements will be granted as this a vehicle and application specific design. You'll have to use the exact speakers, same vehicle, same amp, same install arrangement and same listening preference for this to work on your side. If you want your own custom PWK Designed Box, go to PWK Designs and submit a Project assessment form for your needs.

Page updated and copyright R.Quan © 09 Nov 2011.