Armageddon Audio Transducers
- Tweeters: Vifa D25AG-35-06 1" aluminum dome (upgraded to
Focal TC90Tdx 1" Ti oxide dome)
- Midranges: Vifa P13WH 5" polypropylene cone
- Woofers: Audio Concepts AC10 10" polypropylene cone
- HF enclosure: Approximately 1/4 cubic foot volume with
2" port tuned to around 70Hz. 3/4" MDF walls,
no internal bracing (unnecessary).
- Woofer enclosures: Approximately 2.5 cubic foot volume
with 4" port tuned to around 31Hz. 1.5" MDF
walls, no internal bracing (not really necessary, but
mainly because it would have been too much of a hassle).
- Electrical bulkheads: 1/4" aluminum plate with banana
jacks, sealed with silicone caulk.
- Active 4th order Linkwitz-Riley, at 280Hz and 2800Hz.
- 2nd order high pass in the woofer section designed as part
of a 6th-order sub-Chebyshev tuning for the woofer
response. Theoretical acoustic cutoff frequency f3 = 34 Hz.
- Option to change jumpers, thus changing the normal 280Hz
high-pass filter on the midranges to a "booster"
filter designed as part of a 6th order Chebyshev
tuning. This allows stand-alone operation of the HF
enclosures, theoretically down to 50 Hz. I doubt I'm
currently getting that partly due to the 1.5"
port, partly because the port hasn't been tuned
- Burr Brown OPA-2604 dual BiFET audio op-amps (upgraded to
OPA-2134), 1% metal film resistors, 2% polypropylene
- 12V split-rail regulated linear power supply, can be
upgraded to 18V if higher voltages are required.
- Theoretical frequency response curves for the 6th-order midrange and
woofer tunings available on request, in gnuplot or PostScript
John Stimson /
Art Rock Cafe, New Armageddon /