You are here: Products Acoustics Microphones Specialty transducers

audio banner


Knowles Specialty Transducers

stmKnowles Specialty Transducer (ST) product line consists of miniature microphones and assemblies.

Hundreds of design possibilities can be applied to your product challenge with our high-performance microphone designs.
Ideal for new product ideas that require premium audio and very small form factors, solutions include noise canceling, omni-directional and unidirectional performance.
Other variables include size, shape, amplification, sensitivity, low noise, and resistance to vibration and mechanical shock.
Knowles ST components and assemblies are unique in fit, form and function.

Knowles Specialty Transducer microphones are designed into high value applications in markets such as the following:

    • Sensor
    • Radio communication
    • Pro audio
    • Outdoor
    • Medical and more

Knowles Specialty Transducer microphones include:

    • Subminiature performance microphones (GA, FG, DFG, EM, EK, EL and NR Series)
    • Magnetic microphones(BJ Serie)
    • Piezo Ceramic microphones (BL Serie)
    • and Waterproof/Submersible subminiature microphones (WPand MR Series)

Knowles' magnetic microphones (BJ serie) are based on balanced armature technology and are self-shielded against external magnetic fields. The microphones offer high efficiency, stability, and reliability and are small in size.

The piezo ceramic microphones (BL serie) are rugged, stable, and versatile.
This serie features high vibration sensitivity & high resistance to mechanical shock. They may be used as accelerometers.

Knowles' waterproof/submersible subminiature microphones are designed to survive complete immersion in water:

    • WP serie can be immersed in water to a depth of 1 meter
    • MR serie can be immersed in water to a depth of 15 meters

Serie Picture Microphone type Dimensions (mm) Directivity Comments
GA GA Subminiature 2.00 x 2.00 x 4.00 Omni
FG/DFG FGDFG Subminiature Ø2.56 x 2.56 Omni (FG)
Uni (DFG)
Low noise, high shock resistance. DFG is improved FK with enhanced PFA performance
EM EM Subminiature 3.63 x 3.63 x 2.28 Omni EM is EK reduced package size with comparable benefits
WP wp Waterproof
3.99 x 5.56 x 2.21 Omni
Noise canceling
WP is a waterproof EK. Immersion up to 1m depth
EK/EL EK Subminiature 4.00 x 5.59 x 2.28 Omni (EL)
Uni (EL)
EK offers highest SNR and dyn. Range
NR NR Subminiature
Noise canceling
4.00 x 5.59 x 2.28 Noise canceling NR is a noise cancelling EK. Stable directional pattern through 10kHz
BJ BJ Magnetic 7.87 x 5.59 x 4.01 Omni, Noise canceling
BL BL Piezo Ceramic 7.87 x 5.54 x 4.06
7.87 x 5.54 x 2.24
MR MR Waterproof
Ø22.12 x 7.6
Ø22.12 x 9.3
Ø22.12 x 11.43
Omni MR models integrate BJ and WP. Immersion up to 15m depth

To best choose the Specialty Transducer microphone for your application, please do not hesitate to contact us. Our team will be pleased to support you.


questionmark 53We are a specialized international distributor on the professional market.


shopping cart_53 Discover our products: Audio, RF tuners, Capacitive sensors, Antennas...
Check out!


phone on_information_53Seltech is here to help you in all your projects. Do not hesitate!
Contact us...