Listen conversations from a distance without anyone to notice you
with surveillance directional microphone X64ACS

X64ACS is a handheld long range highly directional microphone surveillance system. This type directional microphone is based on a fixed phased array technology or also called acoustic radar, specially designed for the execution of a single task - collecting of human voice audio information in real time for complex situations. 64 channel fixed phased array is used to create an acoustic antenna with a more desirable form factor than the conventional parabolic reflector or cassegrain reflector. Same principle of beamforming and amplification is today used in radar systems. This technology allows receiving conversation to 150 meters. Range exceeds 200 meters if there is no strong presence of ambient noise.


X64ACS is ordinary everyday laptop case ... with a surveillance directional microphone inside

Key element of every surveillance action is its target to remain unsuspecting. Implementating this task in audio surveillance situation outdoor in urban areas needs proper camouflage. Using typical everyday object such as simple laptop case gives you the power to eavesdrop everywhere at any time.


The name of the microphone – X64ACS itself represents the basic principle of work. Incoming audio signals are processed or multiplied [X] with [64] acoustical [A] channels [C] which are separated [S].
Microphone based on a fixed phased array has inherently directional nature, because the amount of audio signal seen by the aperture varies with the direction of the arrival. The term phased refers to the time of arriving of the signal to the acoustic channel, and array is actually multiple elements sharing one and the same flat linear surface. The array used for X64ACS is constructed by 64 independent acoustic channels which are interconnected by phase channels providing sound processing.
If the front wave of the incoming sound signals is unidirectional, they arrive at one and the same time to all 64 channels of the directional microphone array. Arriving of signal at one and the same time means that all of the received components of the sound are in phase and will be summed and thus amplified. When sound waves come from direction which is not perpendicular to the face of the directional microphone array the time of the received signals is different in all 64 channels. That means signals are out of phase and they will cancel each other out – phase cancellation or destructive interference. The biggest the angle is, the lower the signal is.


Transition from flat to complex surface

To achieve even better performance with bigger Signal to Noise Ratio [SNR] the construction of X64ACS array is flat only for the absolutely perpendicular wavefront of the incoming audio signal. This is achieved by mechanical realisation of a so called acoustic tiered-retardant series.

Eliminated noise from mechanical vibrations

The case in which the microphone is situated is designed to serve as a shock absorber, and prevents any vibration generated noise to be transferred to the active surface of the directional microphone.

Dynamic camouflage that works

The attachment of the front part of the phased array is flat elastic system, ensuring both firmly fixed directional microphone to the bag and no impact to the front of the incoming sound wave. The rear panel of the laptop bag is sound-conductive fabric indistinguishable from standard unmodified one.

enhanced directional response of the microphone array

Basic features of the X64ACS audio amplifier

Fast adaptive Class A headphone amplifier designed and built to meet the requirements of changing tactical situations and varying environmental noises.

Using directional microphone for audio surveillance in urban areas usually requires extremely short response time for the operator. Achieve your objective using AGC system with momentary response and no distortion. System that cannot be fooled by surrounding noises. Simple to use control panel operated in a seconds gives you tactical advantage in a places crowded with people.

Directional microphone amplifier with ultra low noise performance

directional microphone amplifier with ultra low noise performance

Huge amount of headphone power delivered by Class A amplifier

Headphone power amplifier built to hear even the subtlest nuances from the targeted area. Designed to amplify every detail crystal clear, using precision FET operational amplifier with new level of performance - Burr Brown OPA627.
Precision High-SpeedDifet® Operational amplifier that offers lower noise, lower offset voltage and higher speed. Amplifier that extracts more detail from complex mixed sounds, where human voices sound realistic and had their own space around them.

Automatic Gain Control

Performing audio surveillance outdoor using directional microphone as a primary tool takes you in a very complicated acoustic scene.
The primary use of Automatic Gain Control (AGC) is to tame the substantial variations in signal levels encountered with speech or other useful source of sound. The goal of the AGC is to provide comfortable listening while moving the signal level closer to the ideal target level without eliminating the natural dynamics of the signal.
The X64ACS AGC system is free for the operator - you can set your own threshold level, and while you set it your ears will always be protected from dangerous sound levels.

Human speech bandpass filter

Active second order bandpass filter that rejects all noises which are not in the human voice frequency band.
The frequency spectrum that goes through this filter is from 300Hz to 4500Hz. Additional option to switch On or Off the filter gives you more flexibility of the device.
For example - switch off the filter if you want to record wild animals from far away. Switch it on if you use the directional microphone in urban area with lots of background noises and simply want to hear someone's conversation.

Covert surveillance microphone that can spy even on a moving target

Stay invisible and listen everywhere

Entire directional microphone is placed in a specially modified laptop case, indistinguishable from the original one.

Hear most distant conversations

Using 64 channel acoustical phased grid gives you all the amplification you need for detailed audio surveillance. No need to worry about hiding parabolic reflector anymore.

Pickup talk while carrying it along

Carrying a laptop bag over your shoulder, you can hear the conversation of interest without raising the slightest suspicion in nearby passers.

Undisturbed listening in case of sudden noises

The perfect combination of soft compressor, human voice bandpass filter, AMPFLAB smart automatic gain control system gives you comfort and protects your ears without loosing dynamics of the sound.

Visually fully standard laptop case

Mass fabricated widely available 15.6 inch laptop case which is fully identical to the original one from the outside.

Listen with audiophile quality

Directional microphone with powerfull Class A Di-Fet headphone amplifier powered by 18 volts. The amplifier is based on OPA627, that many consider to be one of the best audio chips available.

Be everywhere and do not miss an important moment

23 volts battery pack.
Go operational for 36 hours continuous work without worrying about charging or replacing batteries. Power pack that turns your directional microphone in a stand-alone surveillance system. Same operational time with the lighest 9V version

Simple to use hidden control panel

Management of the amplifier, headphone output and output for recording device are located in the outer pocket of the bag, again camouflaged and indistinguishable to the observer.

Remove with one click unnecessary sounds

Second order active bandpass filter designed to amplify human voice frequency range. Eliminate with just one switch all unwanted ambient sounds. Enjoy hearing amplified from a long range conversation without disturbing sounds.