Cab Lab – Acoustic Image Flex Bass Cabinet

This Article Was Originally Published On: February 3rd, 2015 #Issue 15.

The steel grill is held in place by four small bolts, which thread into small “towers.” Each “tower” gets its own rubber “cap” to keep vibration down to a minimum. These bolts are far smaller than what we normally see holding grills in place, but the unique construction of the Flex Cab allows for very precise tolerances, and this grill attachment method is very secure. The 2.5″ tweeter is mounted directly to the grill, and the wire leads from the tweeter attach to small terminals (using push-on connectors) which, in turn, connect to the 50-watt amplifier. In addition to the rubber “tower caps,” two additional pieces of cushioning are strategically positioned to eliminate unwanted vibration from the grill.

The front-firing woofer is held in place using eight Allen-head bolts, fed into threaded inserts. This is the best, most secure, driver attachment method I have seen. Well done, AI! The threaded inserts are a part of the injection-molded enclosure, and as such, they cannot come loose or move out of position (as some T-nuts are prone to do). The downward-firing woofer is held in place using eight screws with embedded nuts. These screws also hold the grill for the downward-firing woofer in place. Both drivers have a gasket beneath the lip of the frame, allowing for an air-tight seal with the enclosure.

Inside the enclosure, we find the two ICEpower amp modules, the active crossover (with the tweeter power amp), the necessary wiring, and absolutely no acoustic batting. However, given the mostly cylindrical design of the enclosure and the lack of ports, it may be a non-factor. The inside walls of the enclosure do have vertical ridges, which may help to break up any waves moving along the interior surface of the enclosure (though my suspicion is that they primarily serve a structural stiffening purpose).

The bottom of the enclosure has four good-sized rubber feet, and two smaller feet are also positioned on the spring-loaded tilt-back stand. The injection-molded structural foam used to construct the Flex Cab is given a coat of flat, dark grey paint, and looks great. There are two handles built into the top/side edges of the enclosure, and they easily facilitate either a two-handed or one-handed carry. A magnetic attachment system built into the top of the enclosure allows for secure placement of the Flex Pre on top of the Flex Cab.

When used in conjunction with the Flex Pre, connection between the two units is made via a Cat5 (“Ethernet”) cable using the RJ-45 jacks on both units. This cable supplies the Flex Pre with power (and ground) from the Flex Cab, as well as sending the (balanced) signal from the Flex Pre to the Flex Cab. For use with another preamp, the Flex Cab is equipped with a standard 1/4″ input (10 kOhm impedance, unbalanced). If you desire to power an additional Flex Cab, or to send the signal on to any other destination, the 1/4″ Through jack (10 kOhm impedance, unbalanced) will pass signal from either the 1/4″ or RJ-45 inputs. In this fashion, you could line up and use as many Flex Cabs as you like. Nice!

In addition to a Master Level control (for overall volume), the Flex Cab provides control over the downward-firing woofer’s cutoff frequency (30Hz to 150Hz), a -6dB pad for the downward-firing woofer, and an adjustment for the Tweeter Level (which has a range of -10dB to +6dB; set straight up, the tweeter output is in balance with the other drivers). The back panel also hosts LEDs for power on and thermal overload indicators. The Flex Cab is designed to operate with AC voltages between 100V and 240V. An internal switch automatically selects the appropriate mode of operation.

1-5 (unacceptable to impeccable)

On-bench

Sonic Profile:

Lows: Deep, but controlled; room-filling, but not overpowering
Mids: Very clear, with minimal coloration
Highs: Smooth, yet clear