Directed Electronics' 1100D
Directed's latest addition offers class D quality
and tons of power.
DEI 1100d Specs

Price & Contact: $720; 760-598-6200;
All measurements @ 14 volts unless otherwise specified.
Frequency Response (2-ohm IHF load, 30 Hz Ref. crossover at highest setting): +.65 dB, -3 dB @ 350 Hz
L/R channel error max deviation 20 Hz to 20 kHz: N/A
Signal-to-Noise Ratio (Below Rated Output, "A" weighted): -97 dB
Distortion at Rated Output @ 60 Hz: 1.4% THD @ 1100 watts
Output Power (Resistive) (2 ohms @ 60 Hz to 1% THD+N): 768 watts @ 14 volts; 634 watts @ 12.8 volts; 427 watts @ 10.5 volts
Output Power (Resistive) (1 ohm @ 60 Hz to 1% THD+N): 1072 watts @14 volts; 895 watts @ 12.8 volts; 603 watts @ 10.5 volts
Output Power (Reactive) (2-ohm IHF Load @ 60 Hz to 1% THD+N): 808 watts
Crosstalk @ rated output, 20 Hz to 20 kHz: N/A
Damping Factor @ 100 Hz: 42
Voltage for Rated Output: 153mV to 7.8V
Idle Current Draw: 2.6 amps
Current Draw @ 1/3 Maximum Power: 35 amps @ 357 watts
Efficiency @ 1/3 Maximum Power: 73%
Power-Up Noise: 40.3 dB SPL

by Brian Smith
Class D subwoofer amps are popping up everywhere. This issue's amp du jour is the 1100D from Directed, a division of DEI. Features include a subsonic filter, bass boost with wired remote, polarity invert, variable crossover frequency adjustment, and the ability to bridge two units into a single load.

The 1100D performed quite well during its ride on our test bench. Maximum output measured 1072 watts driving a 1-ohm resistive load. Output into a 2-ohm reactive load measured 808 watts. Efficiency is the major benefit of a class D design, and the 1100D is among the best that we've tested. We observed 73 percent efficiency at 1/3 maximum power into 1 ohm. This is especially impressive considering that the 1100D doesn't double its output when the load impedance is decreased from 2 ohms to 1 ohm. This would indicate that efficiency into 2 ohms might be even better.

Connections and Adjustments
Connections to the 1100D include RCA inputs that are internally summed, RCA invert in and out (for use in slave mode), a remote connector, and hefty gold-plated screw terminals for all power and ground connections. Adjustments include input sensitivity, subsonic filter enable and frequency adjustment, crossover cutoff frequency, bass boost enable, master/slave switch, and a polarity reversal switch.

Like most other class D designs, the 1100D runs relatively cool and provides a lot of output for its size. Unlike most of the others, its front end provides a fair amount of flexibility, namely the ability to bridge two amps on one load. This should allow installations that range anywhere from mild to wild. One word of warning - in a bridged configuration, two of these puppies will develop upwards of 80 Volts. That's more than enough to make you wet your pants if you get across the outputs when the amps are near full boogie.

The manual for this unit covers only two amps, the 1100D and its little brother the 600D. However, it's nearly a novel. Its 16 pages provide you with lots of usable information. My favorite part is the complete lack of a troubleshooting guide. Most of these guides are so inane that it's practically a crime to waste the paper printing them. When an amp won't turn on, does anyone really need a manual to point out that you may have a bad connection or fuse? If the thoroughness of an owners manual had any correlation with amp quality, the 600D and 1100D would probably be the best car audio amplifiers ever made.