Loudspeaker Designs and Articles for the DIY Enthusiast
|MTM and MT designs offered
in various configurations for
Music and Home Theater
Driver Selection Process:
Shortly before this design was envisioned, Parts Express had come out with several new drivers. Among them
was the RS28F-4. This tweeter is the soft dome version of the popular RS28A aluminum dome. This is a very
impressive tweeter at any price, (Let alone the entry price of a paltry C-note for a pair.) The RS28F-4 offers
near class leading performance, and some of the lowest crossover capabilities of any tweeter. This low
frequency performance significantly improves the center channel horizontal off axis response compared to a
typical commercial design.
The ND140-8 proves the old axiom “You can’t tell a book by its cover.” The stamped steel frame of this
aluminum coned neodymium motored driver belies its abilities as a fine sounding and very capable midwoofer.
Its relatively high Qt can be used to good effect in both the sealed and transmission line designs, and provides
more bass extension than would otherwise be expected from a 5.25" midwoofer. The lack of a dust cap
provides a smooth and elegant look. Another useful attribute is its claimed Xlim of 20 mm, which is about 3 to 4
times more than most 5.25" drivers. I did no independent testing of the Xlim, but the driver appears to be more
than capable of providing quite high SPL's with no audible or mechanical issues.