MM-STE · Wall microphone stethoscope

Professional wall microphone with dual contact probes

MM-STE is a stereo contact microphone for monitoring sound through walls, ceilings, doors, windows and floors. Two piezoceramic probes feed a dedicated amplifier with built-in filters and level controls, supporting live headphone monitoring or connection to an external audio recorder.

Two piezoceramic contact probes in metal housings.
60 dB amplifier dynamic range.
Built-in audio filters and ±10 dB stereo level control.
Break-resistant cables with strain-relief connections.
Four AA 1.5 V batteries or an external 9–12 V DC supply.

Product code: MM-STE

Price on request

Specify the surfaces and audio equipment you plan to use.

Technical consultation, training and support.
+39 080 302 6530

Stereo contact monitoring

Dual piezoceramic sensors

The probes pick up sound-induced vibrations in solid surfaces. Metal housings protect the piezoceramic sensors.

Audio controls and filters

The stereo amplifier combines a 60 dB dynamic range with audio filters and ±10 dB stereo level adjustment.

Battery or external power

Four AA 1.5 V batteries support portable operation. An external 9–12 V DC supply provides an alternative power source.

Full description

Contact probes for structural sound pickup

MM-STE uses two piezoceramic sensors to pick up low-level vibrations transmitted through walls, ceilings, windows, doors and floors. The probes send these signals to a dedicated stereo amplifier for audio monitoring.

Each sensor is enclosed in a metal housing and fitted with a break-resistant cable and strain-relief connection. Pickup quality depends on the material, surface thickness and contact between the probe and the structure.

Stereo amplification and audio output

The amplifier provides a 60 dB dynamic range, built-in filters and adjustable audio controls. Stereo level adjustment is ±10 dB, with 40 dB of interchannel attenuation. These controls allow the operator to adjust the received audio for the monitoring location.

Audio can be monitored through headphones or routed to an external recorder. The unit runs on four AA 1.5 V batteries or an external 9–12 V DC supply. Current draw at a medium volume setting is 25 mA.

Technical specifications

Sensors and audio response
Sensors	2 piezoceramic contact probes
Probe housings	Metal
Cables and connections	Break-resistant cables with strain-relief connections
Amplifier dynamic range	60 dB
Amplitude roll-off at 1 kHz	6 dB
Amplitude roll-off at 300 Hz	15 dB
Interchannel attenuation	40 dB

Controls and power
Stereo level control	±10 dB
Audio filters	Built-in
Current draw at medium volume	25 mA
Internal power supply	4 × AA 1.5 V batteries
External power supply	9–12 V DC
Amplifier dimensions	105 × 25 × 120 mm
Audio monitoring	Headphones or connection to an external recorder

Applications

Investigative audio monitoring

For authorized surveillance in hotels, apartments and offices, the contact probes provide an audio monitoring point on an adjacent surface when direct access to the room is unavailable.

Wall, ceiling and floor monitoring

Position the probes on walls, doors, windows, ceilings or floors to monitor structure-borne sound. Built-in filters and stereo level controls help adapt the audio to the selected contact points.

Sound-based search support

The probes can support searches for sounds associated with people in rooms or concealed spaces within a structure. Useful indications depend on the available vibrations and the construction being examined.

Technical support

Application review

Discuss the surfaces and monitoring requirements to assess whether MM-STE fits the application.

Setup and training

Guidance on probe placement, filter settings and stereo level adjustment.

After-sales assistance

Technical support for operation, headphone and recorder connections, and troubleshooting.

Talk to our team

Specify your contact monitoring setup

Describe the surface and your listening or recording requirements. Our team can review the setup and provide pricing for MM-STE.

Or call us: +39 080 302 6530