Ultimate ACW1200
Ultimate Sound has been in the mobile audio business for 26 years. During that time the company claims to have built over 25 million speakers, so they must be doing something right (visit the company's site at ultimate-sound.com). The product submitted for this review is the Ultimate ACW1200 from the company's new Cupric line of products. This recently introduced subwoofer represents the top-of-the-line for Ultimate and has its share of bells and whistles.
The ACW1200 is built on a very attractive gray painted cast aluminum frame designed specifically for this new woofer. Depth below the spider on this frame is about 27 mm (1.06") and allows for substantial rear spider travel. This area also includes a series of four vents for additional voice coil cooling. Providing the motive power for this woofer are twin stacked ferrite magnets sandwiched between a single piece T-yoke back plate/pole piece and the front plate. Both plates have milled edges and are finished in black coating that enhances heat dissipation (black objects radiate heat more effectively than other colors). Other features for the motor system includes a 5 mm extended pole piece, a 40 mm diameter pole vent (with debris screen) and 1.5mm undercut back plate. The extended pole piece is near optimal at roughly 1/2 the thickness of the front plate. This optimizes the forward direction magnetic fringe field just outside the gap without causing increased losses in Bl (Bl is like horsepower to a car engine and describes the power available) and also provides increased voice coil alignment on extreme forward excursions.
The ACW1200 is a dual voice coil woofer and has two 2-layer voice coils wound on a 65 mm (2.5") Kapton former (this is a high temperature plastic type material that is frequently used for loudspeaker voice coils). The voice coil tinsel lead wires are connected to a pair of gold plated five-way binding post located on opposite sides of the frame that will handle up to 12 gauge wire.
"Cupric" is both the name Ultimate uses for the line of woofers and amplifiers and the name they use for the alloy of copper, aluminum and magnesium that is used for the metal cone. The cone assembly uses a single piece cone with no dustcap and is connected to the voice coil with a conventional 6" diameter paper cone that not only adds depth for long excursion, but adds further stiffness to the all ready stiff metal cone. Cone stiffness is also enhanced by having the outside edge of the cone turned down, a fairly common trick used by any manufacturer that employ metal cones. Cosmetically, this Cupric cone has a copper/bronze appearance with an embossed Ultimate logo to add the finishing touch. The suspension system combines a black butyl rubber surround with a single 7" diameter black Conex (a cotton blend material that has good resistance to sagging over time) linear spider mounted on a 10mm height metal standoff. The surround is a moderate 27mm(1.06") wide (16mm height), at least moderate when compared to this batch of woofers. For rear mounting the ACW1200 has foam capped fiber (paper) mounting gasket.
MA Audio | 
Audiobahn | 
Earthquake |
Ultimate | | |
While we have two distinct pairs of woofers in this group that have similar characteristics, the Earthquake and Ultimate and the Audiobahn and MA Audio, the group as a whole has some interesting performance attributes in common. If you examine the numbers in the Data Chart, all four woofer's produce about the same -3dB frequency (low-frequency roll off), around 30Hz, in a 1.5ft3 vented box. The main difference is that the lower Vas for the Audiobahn and MA Audio subs means they are somewhat less damped in this size enclosure. Maximum undistorted SPL numbers are also similar and the spread between all four products is less than 3dB and this at levels that, if you are smart, you won't ever be listening at for any period of time. You then have to ask yourself why you would pay more for the larger more expensive woofs? The answer is really power handling.
The Audiobahn and MA Audio woofers are both rated at very high power levels, have substantially more motor mass for heat dissipation and also have larger 3" voice coils (not to mention more chrome than a '57 Buick!). Bang for the buck, the Earthquake sub would be hard to beat, and I suspect the street price of the Ultimate AWC1200 makes it a close second. If you are looking for maximum high SPL performance, dB Drags sort of thing, then the Audiobahn or MA Audio subs are definitely the ticket. But, this conclusion is only from the objective measured and simulated data. How they sound musically is an entirely different story. This month we have industry veteran Tim Kelly tuning up his "golden ears" to see what's what and who's who in this group of high excursion subwoofers.