Dr. Hsu is brilliant, and this unique design is extremely intriguing.
Specifications from Hsu
Woofer: Cast frame 8˝ polypropylene cone woofer with treated cloth surround, flat polycotton spider and high temperature 2˝ edge wound copper clad aluminum voice coil.
Tweeter: Concentrically mounted using the woofer pole piece and cone as constant directivity horn. Neodymium magnet, ferrofluid cooled. Aluminum diaphragm.
Crossover: Computer aided time aligned design, final voicing by Dr. Hsu.
Grille: Magnetically attached nicely shaped metal grille. Can be rotated as needed.
Frequency Response: 50 - 20 kHz +/- 2 dB,
flattest at 15 degrees off axis(designed for listening at 15 degrees offaxis, speaker axes to cross in front of listener)
Sensitivity: 94 dB/1m/2.83V rms, half space
Nominal Impedance: 6 ohms Minimum Impedance: 4 ohms
Enclosure Type: Vented Enclosure Material: 3/4˝ MDF Dimensions: 15˝ H x 10.5˝ W x 12˝ D Net Weight: 22 lbs
Recommended Amplifier Power: 10 - 400 W rms
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My concerns:
1. use as recommended, 15 degrees off axis; toed in properly, see specs. I suspect that has to do with the ’horn’ portion of the woofer cone’s angle of dispersion of the tweeter’s frequencies (not as wide as ’true horns’). The 8" woofer should be wide disbursement of bass frequencies.
2. high efficiency, I always like that to allow moderately low power amps, including tube amps;
3. but moderately low impedence, so check your amp’s taps and power reserves for instantaneous peak needs.
4. NOT BOOKSHELF! 12" deep with rear ports, angled positioning.
a. rear ports. 12" deep enclosure: more depth is needed unless you stuff the ports closed.
b. they call for angled direction, also needing further depth shelves, ports still an issue.
c. they illustrate them on a stand in free space on the web page and in the manual.
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Option: Stuff the ports, then add a self-powered sub, perhaps one of HSU’s, any decent one with adjustable crossover, and, go from pre-amp to sub crossover, then to amp, then to CCB-8, to take the bass requirements away from the amp and away from the CCB-8’s. Some systems allow remote volume of sub, which, except for cost, would be a handy feature to have.