Having been quite impressed with the output from my small battery powered speakers which used PAM8403 class D amplifier chip rated at a maximum of 3w, so after finding the pair of 10″ woofers I salvaged from the 1989 Sirocco a friend and I took to Africa I decided to see how the tiny amplifier chip would react to a 16 fold increase in cone area, also I was listening to a lot of Eric.B and Rakim and wanted to hear them through an appropriate system.

The prototype is made of light pallet wood and birch ply, but heavily braced with softwood struts. The result is a very stiff reasonably light box, a good thing as 10″ woofers aren’t exactly the lightest speakers in the world – The whole thing is still pretty heavy though, I need to sort out a sturdy handle or strap for it if its going to be moved anywhere.

I’m not quite happy with the look yet but the sound is pretty good when the tweeters output is balanced with the woofers (I only had 4 ohm tweeters around and the woofers are 8 ohm hence the one tweeter / two woofers).

It seems to be able to match the mini rustics 90dB output, and with bass extending an octave or two lower which is pretty good, it can average 96dB on some tracks, but its definitely running out of headroom at that point. So far power drain seems comparable to the smaller speakers, more testing is needed to see if it can play for days on 4 AA batteries, but it seems likely.

Next step is to clean up the design and build a more polished prototype, possibly scaled down to a more sane (?) 1×10″ arrangement – something closer to the classic JVC RC-550 maybe. . . probably should add more dials- maybe some sliders.

The other option is to scale up and see how far 3w can go with horn loaded 12″ or 15″ speakers, I’m pretty confident it should be possible to get a clean full range 100dB+