There are two models of EMP 2.5K Power Pack. The EMP 2.5K Master and the EMP 2.5K Slave.

The EMP 2.5K master is a 2-way asymmetric Hi – Lo single channel power pack designed to drive Electromotive Laboratories Infrasound Series loudspeakers. The Master has on-board system processing for two loudspeaker systems using our custom engineered DSP filters and system alignment algorithms. The EMP 2.5K Master has a network based control bus, additional system bus link output, and analogue outputs to drive a second EMP 2.5K Slave pack.

The EMP 2.5K Slave is exactly the same as the EMP 2.5K master pack without the internal DSP system processor.

The EMP 2.5K is a no compromise power pack designed specially to drive our larger series of studio monitor loudspeakers. A lack of suitable commercially available power units led us to develop our own range of high quality no compromise modern power units based on some of the most modern circuits available. Each section of the EMP 2.5K is a completely isolated dedicated power unit that drives each loudspeaker driver totally independently of the other stage, there can be no power supply degradation of one band in relation to the content of the other, and the single channel nature of the power pack prevents any left, right crosstalk or power supply issues.


Along with our theory of minimising the effect of loudspeaker diaphragm free air resonance upon the performance of the tuned system, the stiff and solid connection of the low frequency driver to a low impedance source is a crucial factor in the low frequency extension and time response of our Model 5 and 10 systems. The EMP 2.5K also utilises the extension of the amplifiers feedback circuit right to the loudspeaker driver terminals resulting in excellent control of the drive unit and assures that the signal that drives the loudspeaker is as true as is practically possible.

In conjunction with our theories of solid low impedance drive the EMP series of amplifiers have been designed to be located as close to the loudspeaker as possible. Not only does this reduce loudspeaker cable losses but it will minimise any EMI radiation or reception by the loudspeaker cabling systems.

The EMP 2.5K is designed to drive the Electromotive Laboratories Model 5 and Model 10 systems in large rooms. The EMP 2.5K has adequate power to drive all components to their maximum performance without any stresses, either thermal or signal related, upon the power pack.


The EMP 2.5K has a frequency response from DC to 50,000 Hz, well in excess of human hearing ability, and well in excess of loudspeaker driver technology in most sensible professional drive units. We deliberately have chosen to use components that specifically do not exceed 50,000Hz high frequency bandwidth for sensible technical reasons, principle among them potential problems with radio frequency signal reception, amplification, and emission. In a modern studio environment, many switched mode power supplies can operate in the 100kHz range and have significant harmonics below this, significant amounts of these signals can be filtered onto audio grounds and power line grounds. Poor power line grounds can have very substantial amounts of VHF energy that can be passed into audio equipment that is not adequately filtered, if this energy is subsequently amplified to the level of hundreds of watts by unprotected unfiltered amplification equipment, or other unfiltered audio systems it can result in loudspeaker cables acting as high power longwave transmitter antennae.

Excessive amounts of inaudible VHF (Longwave) signal, often highly distorted passing anywhere in an audio system can result in severe signal degradation, overload, and overheating events that can be seemingly inexplicable. Additionally, harmonics of distorted VHF signals can manifest themselves in audible bands.


For all these reasons we deem that 50,000Hz is way more than adequate for a high quality high-resolution power amplification system and the best compromise between clearly passing the highest audible signals and blocking unwanted inaudible signals. At the low frequency limit, we have chosen to direct couple our amplifiers for optimum infrasonic performance when used with infrasonic capable monitoring systems. All amplifiers carry output DC monitoring circuits and are DC protected to prevent loudspeaker damage. This means the user must take care to avoid DC offset in poor D to A converters or the EMP 2.5K can enter protect mode without warning.


The EMP 2.5K was designed as a no-compromise wide bandwidth high power high resolution critical monitoring system power amplifier for use in the most critical of situations.


The EMP 2.5K is designed for use with an external control panel that is normally mounted in the front baffle of Model 5 and Model 10 series loudspeakers.


Optionally this remote panel may be located elsewhere when specified as part of a custom system, examples are mounted in front monitor walls, desktop enclosures, or in custom mixing console panels.

The remote panel features separate low and high amplifier enable switches, power indicators for both channels, and clip and fault indicators.

Baseline technical parameters




Input Voltage

AC power requirements

Amplifier type

Power output

Frequency response






600 x 270 x 160 mm


220 – 240 V AC or 110 to 120 V AC internally pre-set

2.5KW Max

2 x high quality studio grade PWM power converters

Adequate to drive all Electromotive Laboratories loudspeakers

DC to 50,000 Hz (power section)

(EMP Master only)  24-bit 96K high resolution high quality DAC DSP

Custom algorithm.

Powercon AC power, XLR Audio, Neutrik NL8 Speaker and control link.

The Electromotive Laboratories EMP is a part of the Electromotive Infrasound range of infrasonic loudspeakers

When used in the correct acoustic environment program material in the infrasonic range is clearly reproduced.

Electromotive Laboratories

A Division of Newell Acoustic Engineering

Funchalinho, Caparica, Portugal