detail about Isobaric 6th Order Bandpass Subwoofer

Dan McGrath (from Great Britain) sent an email with a link to his recent DIY Subwoofer project. For the subwoofer project, Dan decided to use an Isobaric Sixth Order Series-Tuned Bandpass enclosure. The basic layout of a 6th order isobaric bandpass enclosure is shown in the figure below.


The enclosure was constructed using Medium-Density Fiberboard (MDF) which is inexpensive and easy to work with. To make the enclosure rigid, Dan doubled up the MDF as shown below (click photo to enlarge).


For the subwoofer project Dan used two Eminence Beta 10 drivers. The Eminence Beta 10 is an 8 ohm, 10 inch bass driver with a power rating of 250W and a sensitivity 97 dB. With the very high efficiency of these drivers, the subwoofer will be able to produce high SPL with only modest power. The Eminence Beta 10 is readily available (often locally) and it is relatively inexpensive. The photo below (click to enlarge) shows the two drivers in the baffle.


The finished subwoofer enclosure is shown in the photo below (click to enlarge). Dan has been using the subwoofer for a few months now and is very pleased with the results. That should not come as a surprise considering the level of effort he put in to this build. Very nice work Dan.