Three way speaker using Dayton DC380-8_Eminemce Alpha 6 and Hi-Vi Research RT 2H-A

This speaker is modeled at the request of Loren42.

The woofer is the Dayton DC380-8.  This driver is available from Parts Xpress.  This has an F3 of 30 Hz in a 5.5 cu.ft cabinet tuned with a single 4? diameter port 9.2 inches long flared at both ends.  Spl is 111 db.  The speaker is slightly limited by xmax between 30 and 55Hz, however overall performance is excellent.  The vent air speed velocity is 18 m/sec so there should be no issues with vent chuffing.

The mid range cabinet should have all walls lined with mineral fiber such as Rockwool.  The cavity should be filled with Polyfill without compression.

The bass enclosure should have 50% of each panel lined with 4? thick Rockwool.  Special attention should be payed to placing Rockwool on the panel behind the driver.

Here is the box alignment.

The Crossover is a three way all-pass Linkwitz Riley second order.  The composite electrical and driver slopes are third order 18db per octave in the low pass/band pass filter and fourth order 24 db per octave in the band pass/high pass filter.

Zobel networks have been provided to equalize the impedances of the LF and band pass drivers.

The woofer has a sharp cone break up peak at 1500Hz which has had to be dealt with in the woofer compensation network.

The mid band response with this network is excellent and unusually smooth for inexpensive drivers with this network.  With the polarity of the band pass driver inverted, the phase response is excellent.  Group delay is very acceptable.  The impedance curve has been equalized and this driver should be a very easy amplifier load, and not cause any problems.

Allowing for insertion loss of the network, the sensitivity of these speakers should be 92 db 1 watt I meter.  This accounts for the high spl.

As is is typical of three ways using a large woofer, the crossover network is complex with a part count of 20 components per crossover.  Because the low pass/band pass crossover has to be at 400Hz,some inductor and capacitor values are high.  This cost of the components for these crossovers will be significant.

The ports and all crossover parts are available from Madisound.

Even though  the drive units are all in the lower price range, with a properly braced  and damped enclosure and this crossover network, this should be a superior speaker.

Here is the alignment for a Peavey 15 black widow in a 6 cuft box.  It requires 4, 4inch diameter vents flared at both ends, 11.4″ long.  Optimal box id 2.2 cuft.

Leave a Reply