The primary purpose of Isobarik bass loading is to achieve deeper bass response in a smaller than ideal cabinet by isolating the radiating woofer from the air "spring" in the box by a second driven woofer mounted in a sealed chamber behind it. This can be effective, but there are a few concerns. First, the woofers must be well matched. Next, the parallel connection requires an amp that can drive a low impedance load, or you must use a pair of higher impedance(16ohm) drivers. Third, you still must use a box size that will not significantly impair the cone movement of the rear driver. The drivers must be wired in-phase. This method has been used to good effect in the Linn Isobarik line of loudspeakers. More info is available on the Speakerasylum web forum.
Info on compound/isobaric woofers for DIYers?
I'm interested in building a new set of speakers using
this design, with two woofers in tandem(one behind the
other with a sealed space between them). Would very much
appreciate sources for articles/books on this subject,
especially your own successes in building this type of
speaker.
this design, with two woofers in tandem(one behind the
other with a sealed space between them). Would very much
appreciate sources for articles/books on this subject,
especially your own successes in building this type of
speaker.