Class J Stereo amplifier


Earthquake XJ-300ST Class J Stereo amplifier

The new XJ-300ST amplifier packs more power and flexibility than any other amplifier. No amplification task is beyond its capability. With an unimposing miniature size and almost unreal amounts of cool running power, this advanced Class J amplifier is the installers go to dream.

The XJ-300ST is also exciting news for the tactile transducer/bass-shaker crowd as it sports all the features of the 300R while adding a whopping 20 percent more power.

The special XJ technology allows for a novel 2.1 configuration. With the XJ-300ST it is possible to connect a third speaker between the two main channels. This matrix, mono channel plays the combined content of both channels. This is extremely useful for powering 2 satellites and a subwoofer.


More details about the XJ-300ST and the technology behind it

Sammenling produkt

3.211,25 DKK

Sælges enkeltvis

EAN: 0068975901388 Excluding VAT 2569 DKK

2.1 Speaker Setup


Adding to this flexibility comes the new patented EQ Interlock design - two amplifiers can be clicked together resulting in a 4 channel amplifier using only 1 rack U of space. The XJ-300ST can also be mounted on the wall or inside the cabinet by fastening the short mounting ears to the pre-assigned holes on the side of the amplifier.


With endless configuration scenarios, the XJ-300ST amplifiers can be used as mono (bridged) amplifiers, 2.1 channel amplifiers, 2-channel amplifiers, 4/8/12 and 16 channel amplification with industry leading power density and efficiency.

All the installer or avid user needs to begin any size installation is a given number of XJ-300ST amplifiers. No need to buy a cumbersome mix of different amplifiers to achieve a certain number of channels or power level. Besides the simplicity this is an inventory dream for any installer.

Need a subwoofer amp? Grab 1 x XJ-300ST.

Need a 4 channel amp? Grab 2 x  XJ-300ST.

Need to wire a complete 7.1 system with very large front speakers? Grab 5 x XJ-300ST.

Bridge one for each LCR and use the remaining two for the 4 rear channels. All this using only 3U of rack space!

Approaching 99 percent efficiency, the XJ amp never gets hot and can be placed in a tight rack with components on all sides. At only 1U rack high and half a rack in width, this is an amazing achievement.

The XJ-300ST produces continuous rock solid power - 110 Watts RMS at 8 ohms pr channel and 320 Watts RMS bridged into 8 ohm.

This massive power capability is possible due to the advanced nature of the patented Class J output stage. The switching frequency of the output and the amplitude of the power supply is modulated in real time based on the frequency and amplitude content of the input. No other amp can match the efficiency and power of Class J.

rm-300fr_06b_largeOptional Long Ears extension bracket for the XJ-300ST

In the box:

  • (1) Amplifier
  • (1) Power Cable
  • (4) Detachable Rack Ears
  • (1) Connector Bracket
  • (1) Connector plug for 12V trigger (Green)
  • (10) Countersunk Screws for detachable Rack Ears (Black)
  • (4) Pan head Screws for Connector Bracket (Black)
  • (2) Special connecting screws (Silver)
  • (16) Long pan head screws for wood (Black)
  • (4) Rubber feet
  • (1) User Manual (ENG)
  • 10 minutes of no signal puts the amp into sleep mode. (It takes 0.05 volt of signal to wake up up from sleep mode. With gain to max it takes 0.270 volt to clip the amp at 1 percent). The amp now has a square wave detector built in to its protection circuits. This means it can tell if a signal feed to it is already clipped. IF this happens the amp will shut off. It has to be powered on and off for it to reset after this happens. This new protection system will help prevent damaged tweeters due to line signal clipping. Caution should still be exercised to run all system components within their design limits.



Box dimensions
10 × 31 × 28 cm
2.3 kg


50Hz – 160Hz
Damping Factor
> 1400
Frequency Response
20Hz – 20kHz
High Pass Filter
15 Hz
Load Impedance
2 Ohms or greater
MAX Power
320 W-IHF (dynamic power) @ 230 volt AC (4-Ohm Mono Bridged)
Power Line Voltage
110-220 ~ AC50/60Hz
RMS Power
170 WRMS @ 110 volt AC (8-Ohm Mono Bridged)
2 X 110 WRMS (8-Ohm Stereo)
2 x 170 WRMS (4-Ohm Stereo)
210 WRMS @ 230 volt AC (8-Ohm Mono Bridged)
Signal to Noise Ratio
101 dB

Produkt Dimensioner

48 mm (52.3 mm w/feet)
216 mm
203 mm
Net Weight
1.7 kg
  • 12V trigger
  • Class “J” Stereo Modular design
  • Comes with 4 detachable rack ears + 1 connector bracket (for connecting multiple amplifiers)
  • Compact size
  • Finish: Flat Black
  • OPTIONAL Long Ears extension brackets available
  • Phase infinitely variable: 0 to 180 degr
  • RCA Inputs
  • Volume control
  • Wall or rack mountable



Product release



XJ-300FR Speaker Selection Guide

XJ-300FR Cable Setup Manual