Kicker ZX350.4 - Clarity With Agressive Looks

by CAE, Apr 16, 2007

ListeningThe ZX350.4 was installed in the trunk of my Buick and initially connected to the front separates and the rear 6 x 9s. The crossovers were set for fullrange and the subwoofer was not hooked up.

I started out as always with Donald Fagen's Kamakiriad, which is a very well-mastered recording. There is a lot going on in all of these tracks, so it can really reveal any shortcomings with the amps and speakers. Track 1, "Trans-Island Skyway" starts out with a guitar riff, adding bass, keys and percussion as the intro builds. The bass line is pretty busy and can sound muddy, but the Kicker came through. Not only was the bass clean and clear, but everything else sounded distinct and well-balanced. The center image was a little fuzzy and quite low. I checked out "Tomorrow's Girls" for the highs. The cymbals in the intro were clear and smooth. "Snowbound" revealed good low-end clarity on the Fender Rhodes keyboard and bass guitar.

Tracks from Dada's Puzzle and Mary Chapin Carpenter's Come On, Come On reinforced my initial impressions that the response and clarity were excellent, but the image remained low and somewhat indistinct.

I returned to the trunk and changed the configuration. I kept the front separates connected but set the highpass to 100Hz. The other 2-channels were bridged and connected to the subwoofer with the lowpass set to the 100Hz. I repeated some earlier tracks with good results, and then went to "Posters" on the Dada CD. This one starts out with a great drum solo, adding electric guitar along the way. It sounded great, but didn't get as loud as I really like it. No foul here, it's just a smaller amplifier than I have permanently installed. In this configuration it should put out 60 watts each to the front speakers, and 175 watts to the subwoofer, where I normally have 100 watts to each corner and over 300 on the subwoofer.

PerformanceThe amp performed well on the bench, meeting or exceeding every specification as listed in the owner's manual. The S/N ratio was a very respectable >94dB and the frequency response measured 13Hz to an astonishing 66kHz. The crossovers drifted ever so slightly from the published spec, but the difference was small and the curves were textbook. While filters are spec'd at 50Hz to 200Hz, the lowpass range was measured 54Hz to 203Hz, and the highpass was 45Hz to 180Hz. The bass boost was right on with the published 18dB boost, but centered at 41Hz rather than 40Hz. Trust me, you're not going to hear the difference on any of this.

The protection circuits worked well, both short-circuit and thermal. I like that they're self-resetting so you don't have to turn the system off and back on. On the bench the amp fired up smoothly and there was no turn-on or turn-off noise in the car at all.

ConclusionI like this amplifier a lot because it did what it said it would do. The Kicker ZX350.4 is a very straightforward unit that is usable in several configurations. When auditioning the amp in my car I didn't feel the imaging and staging were as good as my reference amps, but I realize that it's not an issue for most people. However, clarity and frequency response were very impressive and that's something every consumer should be concerned with.

The ZX350.4 is stylish, somewhat aggressively so. At a retail price of $349, and a max power of 387 watts, it comes in at 90 cents per watt. As a general rule, anything with a retail price under a dollar per watt is not bad (for an amp below 500 watts). Overall it's a good amp at a reasonable price.

ManualThe owner's manual really cuts to the chase. On page 2 there's a place to write down the purchase details; then it tells you how to mount the amp. Wiring is next, still on page 2, and then it slows down a little to cover different system configurations and the setting of controls. Page 5 covers troubleshooting and specifications, while pages 6 and 7 are the warranty covered in four different languages. Speaking of warranty, Kicker provides a 2-year deal when purchased from an authorized dealer. As always, keep your receipt.

Starting with the power supply, power and ground is accepted through two large brass blocks. These two blocks will accept up to 4-gauge cable, although the manual recommends 8-gauge for this one as it is the smallest 4-channel in the series. B+ runs through a pair of 20-amp fuses and a small inductor. It then goes past three 2,200F capacitors for primary filtering and on to two pairs of high-speed, 49-amp switching Mosfets. A TL494 pwm controller drives the switching through the toroidal transformer at about 36kHz, achieving rails of + and - 30VDC. Secondary filtering consists of four 3,300F capacitors to stabilize the rails.