Rockford Fosgate bd1000a1
www.rockfordfosgate.com
Raw power and an innovative design delivered in a solid new amplifier class.
Rockford Fosgate bd1000a1 Specs

Price & Contact: Call for pricing; 480-967-3565; www.rockfordfosgate.com
All measurements @ 14 volts unless otherwise specified.
Frequency Response (4-ohm IHF Load, 60 Hz Ref. crossover @ highest setting): +0 dB, –3 dB @ 244 Hz
L/R channel error, max deviation 20 Hz to 20 kHz: N/A
Signal-to-Noise Ratio (Below Rated Output, “A” weighted): –84.6 dB
Distortion at Rated Output @ 60 Hz: 0.35%
@ 500 watts
Output Power (Resistive) (4 ohms @ 60 Hz to 1% THD+N): 710 watts @ 14 volts; 589 watts @ 12.8 volts; 374 watts @ 10.5 volts
Output Power (Resistive) (2 ohms @ 60 Hz to 1% THD+N): 1135 watts @ 14 volts; 919 watts @ 12.8 volts; 594 watts @ 10.5 volts
Output Power (Reactive) (4-ohm IHF Load @ 60 Hz to 1% THD+N): 762 watts
Output Power (Reactive) (2-ohm IHF Load @ 60 Hz to 1% THD+N}: 1164 watts
Crosstalk @ rated output, 20 Hz to 20 kHz: N/A
Damping Factor @ 100 Hz: 73
Voltage for Rated Output: 104 mV to 2.3 volts
Idle Current Draw: 1.4 amps
Current Draw @ 1/3 Maximum Power: 35.6 amps @ 377.6 watts
Efficiency @ 1/3 Maximum Power: 76%
Power-Up Noise: 48.5 dB SPL
Power Down Noise: 53.6 dB SPL
by Brian Smith
Everyone and their mother has been on the class D train for years, while Rockford Fosgate just sat back quiet. Meanwhile, “new” amplifier classes are popping up like green flies at a kennel — swarms of nonsensical consonants and claims that would seem to require the repeal of the laws of physics and the re-invention of the wheel. Let’s face it folks, since 1996, marketing has come up with nearly as many classes of amplifiers as engineering has managed since the dawn of time. Here’s a big hint to help you see through the fog: They name amp classes based on the order in which they were invented. That means that other than a combination of two existing classes (i.e., class A/B etc), the next real thing will be class E.

Therein lies the rub — I never saw the class BD designation. There were just a couple of guys on the phone and Internet that said: “Rockford’s got a new amplifier class or somethin’.” It’s funny how those small but important details slip through the cracks. As it turns out, they didn’t invent a new class, they took a problematic 30-year-old class of amplifier design and made it work in a real world, car audio application. In engineering terms, this is no small undertaking and one worthy of much praise if it turns out to be beneficial in the grand scheme of things.

Performance
I’ve looked over all of the schematics and have a basic understanding of how this thing works, but I’m not going into it. I’m not a circuit design guy and neither is the majority of our readership. If you really dig the nuts and bolts of amp design, I’m sure you can find the info on their Web site. I’m more interested in what goes in and comes out than the how’s and why’s in between.

The big question with this amp is the efficiency issue. A new version of the switching subwoofer amp is all well and good, but if it doesn’t offer an advantage in efficiency, what’s the point? The answer is, yes, Rockford Fosgate found the point, to the tune of about 6 percent over the most efficient switching amp that we’ve seen to date. A six percent increase at 1/3 power may not sound like a lot and if we were talking about the difference between 30 percent and 36 percent on a class A/B amp, it wouldn’t be. However, we’re talking about 70 percent vs. 76 percent, at this end of the scale, an increase of a couple of percentage points would be impressive. In the at-the-limit world of SPL contesting, a cushion of that size over the competition is an awfully attractive proposition.

When it comes to output potential, the bd1000a1 is right in the thick of the pack with around 1.1 kW on tap into 2-ohm loads. This is still quite a bit short of the biggest dog that we’ve tested, but if you really need much more than a kilowatt, then you really need to focus on efficiency.

As for the other performance characteristics, suffice it to say, the bd1000a1 is up to the task. The only things that looks a little bothersome are the relatively high turn on/off noises and the rather limited input sensitivity range. These concerns apply mainly to SQ competitors, but I feel pretty sure that this amp was aimed more towards the louder end of competition.

Connections & Adjustments
Power and speaker connections to the bd1000a1 include captive-style terminal blocks that accept up to 4-guage and 8-guage wires, respectively. Other connections include line level RCA inputs and outputs, telephone-style remote bass boost connector, and a single spade connector for remote turn-on. Adjustments include input sensitivity, crossover cutoff frequency (variable from 44 Hz to 244 Hz), and remote bass boost (variable from 0 to +22 dB at 41 Hz).

Installation
Installing the bd1000a1 shouldn’t cause any undue stress. The amp’s footprint covers about 90 square inches without the end caps, and it’s overall height measures 2.5 inches. The amp also sports a sensible heat sink and all of the connections and adjustments are clearly marked.