NOTE: SPECS AT END OF THIS POST
On Sunday the 25th of April (2010), I attended a gathering of bass players (mostly from the TalkBass forum) in Seattle, Washington. There I displayed a prototype bass cabinet, which was quite well-received [edit: The cab will be going into production as the AudioKinesis "Thunder Child"]:
Photo courtesy of Tony Lloyd.
The production version will be painted black. I used white because I wanted it to stand out and be noticed and remembered.
At first glance the most obvious difference in comparison with other bass cabs is the big horn. The reason is, I want my horn to go down much lower than normal. When done right, the result is good clarity without coloration over a fairly wide arc.
One of the people there was experienced soundman, bass player, and DIY guru Charlie Escher. Charlie has been the soundman at over a thousand shows, and no longer uses measurements to set the EQ at a show because he can do it just as well and much more quickly by ear. I asked Charlie to tell me of anything he heard that wasn't right, of any areas where there could be improvement, as I learn far more from my critics than from my fans. After playing through my cab a couple of times, he told me that it would work just fine for any of the gigs he does, and that he didn't hear anything wrong with it. He went on to say that that's not something he says lightly, as the focus of his day job is finding something wrong and pointing it out. So I take Charlie's compliment as unusually highly qualified. Charlie's personal cabs are based on TalkBasser greenboy's fEarfuls, but with Charlies' custom crossovers and a few hotrod components. He has owned some very highly regarded cabs but built his own because no manufacturer was making cabs that would do what he wants... well, maybe not up until now.
My little cabinet uses a custom long-throw 12" woofer and a PA-style compression driver, crossed over at about 1.8 kHz. While the pattern-matching in the crossover region is not quite as ideal as a lower crossover point would provide, in this application the compression driver's power handling figures into the juggling of tradeoffs. The frequency response of the cab is exceptionally smooth, as doing a good job with the crossover is where I earn my nickel. I would rather hear the sound of the bass player's instrument without a cabinet's characteristic signature super-imposed on top. In particular, my high frequency section doesn't have horn honk or edginess or any of the other negative attributes that have made many bass players hate horns. Just as my home high-end audio speakers have won over people who traditionally don't like horns, I expect to do the same thing among bass players.
Now the Thunderchild does give up some bass fatness compared to some of the competition; that's a result of the inevitable tradeoff between bass extension, box size, and efficiency. The good news is, the woofer can take a fair amount of bass boost. So if you need to crank in a couple of decibels of bass boost you can do so, and you'll still come out slightly ahead as far as total power requirement to meet a certain broadband SPL as compared to a lower-efficiency cab that didn't need any bass boost.
Features include a padded recessed handle on top so that it's comfortable to one-hand carry and you can still set a microhead on top; a switch on the back that toggles between extension to 18 kHz or a gentle rolloff at 3.5 kHz; and two flared 3" ports that can be plugged with expanding plumber's test plugs to transform the cab into a sealed box. Note that for a high-power application, either leaving both ports open or plugging both ports works best. The production version will have a second switch that will kill the compression driver completely.
The woofer I'm using is a custom 4-ohm unit that has the same excursion and thermal limits as the Eminence Kappalite 3012LF, but slightly higher efficiency. Inevitably some bottom end is traded off in exchange for the increased efficiency, but bass amps are highly adjustable so it's easy to dial in a couple dB of bass boost if needed.
My target market is bass players who have to take the subway or bus, or who otherwise would like a very good sounding lightweight cabinet that can take full advantage of a high-end microhead. I expect to find a small secondary market among luthiers who wish to hear clearly what their bass really sounds like.
Towards the end of the show I asked one of the bass players, Tim, to give my cab a workout, and told him that if he could break anything he'd be doing me a favor because then I'd know what was going to fail first. Driven by an amp that puts out one kilowatt into 4 ohms, he had the little cab rattling the rafters and turning heads but it didn't fartout and nothing broke. The switch on the back was set for "flat" (no top end rolloff), and of course both ports were open.
Here's a shot of Tim in action:
Photo courtesy of Tony Lloyd.
Needless to say, I came away from Seattle quite encouraged.
The cabs will be built to order, with typical delivery time projected at about ten to fourteen weeks, variable with my workload. I'll give you an estimate when you place the order.
The price is $800 plus shipping, with a $400.00 deposit required to place the order and the balance due before shipment. The "acoustic friendly" version is $120 more.
HERE ARE THE SPECS:
Type: Two-way vented bass guitar cabinet
Impedance: 4 ohms, fairly smooth aside from the bass impedance peaks
Efficiency: 95 dB/1 watt, based on Thiele/Small parameters
Thermal Power Handling: 450 watts RMS, 900 watts music program
Displacement (cone area x one-way linear excursion): 496 cubic centimeters (more than most 15's)
Bandwidth: 56 Hz to 15 kHz plus or minus 3 dB (with normal port tuning), -10 dB at 41 Hz, no upper bass bump. Top end extension switchable to a gentle rolloff starting at 3.5 kHz.
Crossover: About 2 kHz, no audible peak or dip in crossover region
Radiation pattern: 90 degree constant directivity in the horizontal plane from the crossover region on up
Port tuning options: 50 Hz normal (both ports open, -3 dB at 56 Hz, fairly steep rolloff); 37 Hz (one port plugged, -3 dB at 80 Hz, gentle rolloff down to tuning frequency and steep rolloff thereafter, slightly reduced fartout resistance); and Qtc = .53 box with both ports pluged (-3 dB at 100 Hz, gentle rolloff, significantly reduced fartout resistance)
Dimensions: 22" tall by 14" wide by 14" deep; net internal volume 1.7 cubic feet
Weight: 31 pounds (33 pounds for "acoustic friendly" version)
Current Price: $800 plus shipping, direct sales only ($920 for "
acoustic friendly" version)
Options: rear-firing tweeter for "
acoustic friendly" version, $120; pair of strap-type handles on the sides for two-hand carry, $25.00
Return policy: Fourteen days, you eat the shipping, full refund if in like-new condition, otherwise there will be a restocking fee based on condition
Contact: Duke LeJeune, audiokinesis at yahoo dot com; 208-852-2610
