Right. I meant another woofer shrouded by the side panels on standoffs facing the same direction as the one on the baffle. Standoffs/ side panels' length tuned to suit.Hi Pete,
Bert Doppenberg from The Netherlands once had a pretty clever design with a Feastrex 5-inch on the narrow front part and 2 bass drivers on the wider wings of the baffle, but I can´t find it anymore in the net. Of course this had nothing in commen with an isobaric design.
Some time ago, I planned to adapt his design for another 5-inch on front and 2 10-inch on the sidewings, the 2 bass drivers of course wired in phase, but I never built it so far. All in all, a pretty clever design which requires a little bit of woodwork skills.
Another thing is a construction with 2 or more bass drivers situated behind each other (Kronos Gaia, Legacy and others). This configuration acoustically simulates a larger baffle than physically available, works only in the bass region, and takes away a little stress of the woofers, but does not halve it. Of course, in parallel you´re halving impedance and thus have better efficiency at 2,8 volts (not with 1 watt...).
Hope that might have helped... if not, I didn´t understand the TO´s question well. A sketch might help.
All the best
Yes, that can be applied also to smaller woofers. I think that it's the very reason of why isobaric was born, to extend a little the bass from older units, as it's not a new idea. The woofers were a little stiffer, so Cms and Vas would benefit from such arrangement. Indeed, I did try it with old woofers and it worked, putting new ( rubber surround and 4 mm excursion one way ) resulted in a broken/rubbing former in a woofer, probably suffering from the elasticity of air in the chamber between them.Some of the big woofers only move 2mm max, two of 'em could do it only moving a mm. The isobaric would still move the full 2mm, but there must be some other advantage I dont understand...