Rockford Fosgate caused a stir in January when it unveiled a palm-sized car amplifier that doesn’t need a battery connection for power.
Considered to be one of the first amplifiers of its kind, the model PM100X1 100 watt amplifier is now slated to ship in August at $399/pair.
The amplifier can easily sit behind each front speaker to boost the power from a car radio.
There’s some controversy on just how the PM100X1 is able to work without a connection to the car’s battery so here are some answers from Rockford’s Senior Director of Electrical Engineering, Dave Baker.
The amplifier uses what Rockford calls “freeload” technology. This “converts both the AC and DC output of the source unit’s amplifier into its own DC power supply. Freeload continues to draw power from the source amplifier when power demand of the speaker is below the power output capability of the source amplifier.”
Baker continued, “During times of low power demand, freeload replenishes its power supply reservoir to support speaker power demands that exceed the power output capability of the source amplifier.”
Since the PM100x1 is powered by the source amplifier, it “is referenced to chassis ground,” he said, adding that the amp can therefore be grounded to any ground point in the vehicle, including door frames.
In most cases, when an aftermarket amplifier is added to a car, the source unit amplifier and factory speaker wiring is left unused. “What is needed is an amplifier that can provide higher dynamic output power than the original source amplifier that utilizes the existing vehicle audio system infrastructure. Reusing this infrastructure is less wasteful and simplifies installation. Not having to run a dedicated fused power wire to battery is one example how freeload minimizes installation complexity, lowers cost, and saves time,” said Baker.
The Freeload system was developed by Rockford. It allows the PM100X1 to work with either an aftermarket radio or many premium OEM amplifiers.
Baker said, “Premium OEM amplifiers typically output a dynamic 40 watts RMS into 2 ohm speakers. The premium OEM amplifiers typically use the same output configuration as source unit amplifiers, only with a higher output current capability. Installing PM100x1 between the premium OEM amplifier and the speaker will increase the stock dynamic power of 40 watts RMS to 100 watts RMS.”
The PM100X1 has a water and dust resistance rating of at least IPX6, so it may be used in marine and powersports applications.
Other features include:
High Level Turn On
Limited Current to Protect Head Unit for Both 4 Ohm and 2 Ohm Configuration
Optional B+ Connection for Non-Standard Speaker Outputs
Selectable 4 and 2 Ohm Play
60, 80 and 100 Hz Selectable 12dB/Oct HP Butterworth Crossover
Rockford fosgate must of got their hands on a little green man from outer space……. they must of extorted the information from the said alien….. gear job R.F. lol
Lol 😀 (y)
It seems possible, sounds like it’s using a capacitor to store unused energy from the headunit to boost output to the speakers… but doesn’t seem very efficient. What if it’s doing it for long periods of time? I think I’d just rather use a traditional amp.
I think this is a stepping stone for bigger things to come nice work Rockford fosgate
it does, but rockford isnt any of those scamartists in your spamfolder, so there might be a chance it actually works. but physics doesnt seem logic here.
does this sound like bullshit to anyone else???