-A Wayne Wendel design-
-And named by his daughter, Grace...
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Design a very narrow baffle full range speaker for under $250, which should result in very good
imaging, spouse approval, and as the design progressed, would somehow come to resemble a
The design centers around the Hi-Vi B3N. A pretty decent driver really, but like all small drivers,
suffers from low sensitivity. This fact, coupled with their low price, made a multiple driver design a
pretty good option. The PE ND20A was the obvious choice for the high end that the B3 can't quite
reach. For a great bass in a small package, we had to look no further than the Dayton Classic 8"
The enclosure was designed to give some visual appeal without being overly difficult to construct. An eye was also cast to
being able to modify the enclosure shape, in the event that some DIYers may prefer a different look. Therefore, the
enclosure was built out of MDF as separate upper and lower sections that are joined together, and the sides were then
veneered. The front baffles are hardwood, although the woofer section has a 'sub' baffle made of ¾" MDF for extra rigidity.
The woofer was ported after listening to it in a sealed configuration. It was determined that the porting was necessary to
extend the low bass response and attenuate some of the peaks in the mid-bass regions. See Wayne's drawings for
dimensions and a cut list.
The Cinderella's are a 3.5 way design. The B3N's perform well down to 400 Hz, and their relatively flat response made them
an easy cross to the Dayton neo tweeter at 3500Hz. The center to center spacing of the drivers necessitated the outside 2
B3N's perform the baffle step duty, while the inside two carry on up to the tweeter crossover frequency. This insures low
excursions of the B3's even at high SPL, presumably minimizing distortion, and optimizes the vertical off axis performance.
The position of the DC-200 adds about 2-3 dB of additional gain via floor loading and melds well with the B3's, providing a
resultant system sensitivity of about 86 dB. The woofer crossover topology is a conventional 2nd order electrical with zobel.
The midranges share the same topology with a 1st order electrical high pass, and 2nd order low pass sections. The 10 ohm
shunt resistors mitigate the impedance rise at the drivers fs and provide additional attenuation. This enables a relatively flat
on-axis response, and something of a BBC dip.