Agreed.

Its got the TS credentials too though, definitely no all show no go driver. Motor strength looks hefty with a BL product of 25 and moving mass is low.

It isn't intended to be an absolutely depth charge, but will reach happily into the upper teens. The main goal was a tight and very nimble sub that gets around the problem of drivers with a low resonance frequency.

This design is the results of a collaborative effort between me and Scott - a bright audio enthusiast from the US.

Here are the primary goals that Scott quotes:

And when asked why we'd choose a driver with an Fs of 42hz to build a sub:

Here's some pics of the enclosure design that I drew up:

Plan view from the front:

Side view:

They're exactly the same height as the mains I built with just a little less depth and very slender(about the same as the mains) when viewed front on. They'll be two of these BTW, one for each loudspeaker.

I started on the cabinets yesterday so haven't done much but here a shot of the driver bracing:

And that's all the MDF needed to build just a single sub