Radio communications

  • High efficiency, stability, and reliability
  • Ideal for critical communications applications
  • Realistic, high fidelity environmental sound pass-through
  • Customizable performance and port locations
  • Component and subassembly solutions

Knowles sub-miniature drivers are based on balanced armature technology. Their small size allows for smaller, lightweight radio communications earpieces suitable for all-day wear. Accurate sound reproduction provides both increased vocal intelligibility and accurate reproduction of environmental sounds passed through to the earpiece – important in critical applications such as military communications and ear protection devices.

Knowles balanced armature drivers are available in a number of sizes and efficiencies, which can be finely tuned to meet your specific performance requirements. They can be designed to fit inside ear molds, assembled into earpieces, or be sub-assembled by Knowles into your communications device.

Select a product category to view features, benefits, documents and performance details

Image Series Dimensions Features
Balanced armature speakers BK series BK series balanced armature speakers 7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)
  • High sensitivity
  • Responses include standard and broader band
  • Low distortion
  • Self-shielded for low magnetic radiation
  • Wide range of port locations and impedances
  • 2 and 3 terminal versions
Balanced armature speakers CB series CB series balanced armature speakers 25.15mm x 25.40mm x 9.65mm (.990in x 1.000in x .380in)
  • Excellent sound quality
  • High speech intelligibility
  • Suitable for PCB mounting
  • Can function as a microphone or beeper
  • Various impedances
  • Face and edge port locations available
Balanced armature speakers CI series CI series balanced armature speakers 9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)
  • 143dB SPL maximum output
  • Undamped response
  • Two and Three-terminal electrical connection
  • Various port locations
  • Wide range of coil impedances
Balanced armature speakers CM series CM series balanced armature speakers 8.38mm x 16.64mm (.330in x .655in)
  • Built-in static protection
  • Lightweight, matt-black, plastic housing
  • Ergonomically designed with rounded edge to fit the concha
  • High-quality sound output
  • Tailored bandwidth for superb speech intelligibility
  • Rugged construction
  • Various impedances
  • Flexi-circuit or wire lead-out options
  • Can be modified to function as a microphone
Balanced armature speakers DTEC series DTEC series balanced armature speakers 7.87mm x 4.09mm x 5.23mm (.310in x .161in x .206in)
  • Dual elements with single sound port
  • Increased output
  • Reduced vibration
  • Enable hi-fi designs
Balanced armature speakers EC/FEC series EC/FEC series balanced armature speakers 7.59mm x 4.34mm x 3.73mm (.299in x .171in x .147in)
  • High sensitivity
  • Ferrofluid available for screenless damping and improved shock performance
  • Low distortion
  • Self-shielded for low magnetic radiation
  • Wide range of impedances
  • 2 and 3 terminal versions
Balanced armature speakers ED/FED series ED/FED series balanced armature speakers 6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)
  • Compact size - 0.081cc
  • Appreciable output power - 112dB nominal, 129dB maximum
  • Two-terminal zero-bias and three-terminal center-tapped configurations
  • Undamped, screen damped, internally damped, and FerrofluidTM damped responses with 2dB, 4dB, or 6dB peak amplitude
  • Numerous port locations
  • Wide range of coil impedances
  • Available with FerrofluidTM technology for screenless damping and improved shock performance
Balanced armature speakers EF/FEF series EF/FEF series balanced armature speakers 7.87mm x 5.59mm x 4.01mm (.310in x .220in x .158in)
  • For all ranges of BTE applications
  • 139dB SPL maximum output
  • Two-terminal zero-bias and three-terminal center-tapped configurations
  • Broad bandwidth for improved sound quality
  • Undamped, screen damped and FerrofluidTM damped responses with 2dB, 4dB, or 6dB peak amplitude
  • Numerous port locations
  • Wide range of coil impedances
  • Available with PantographTM, FerrofluidTM, and Vibration IsolationTM technologies
Balanced armature speakers EH/FEH series EH/FEH series balanced armature speakers 5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)
  • 128dB SPL maximum output
  • Two-terminal zero-bias and three-terminal center-tapped configurations
  • Undamped, screen damped, internally damped, and FerrofluidTM damped responses with 2dB, 4dB, or 6dB peak amplitude
  • Numerous port locations
  • Wide range of coil impedances
  • Available in Class-D amplified version as ES or FES receiver
Balanced armature speakers EP series EP series balanced armature speakers 6.33mm x 4.31mm x 2.97mm (.249in x .170in x .117in)
  • 125dB SPL maximum output
  • Five power levels - 96dB, 100dB, 102dB, 106dB, and 108dB nominal SPL output at 1kHz
  • Three-terminal electrical connection
  • Undamped, screen damped, internally damped, and FerrofluidTM damped responses
  • Numerous port locations
  • Available in four-terminal clock sync version
Balanced armature speakers ES series ES series balanced armature speakers 5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)
  • EH micro speaker, but with internal, highly-efficient, class D amplifier
  •  Lower current drain prolongs battery life
  •  Lower distortion
  •  Available in a range of SPL ratings
Balanced armature speakers FC/FFC series FC/FFC series balanced armature speakers 5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in) with rounded corners.
  • 127dB SPL maximum output
  • Available in High-Output HC receiver version - even more MPO
  • Two-terminal zero-bias and three-terminal center-tapped configurations
  • Undamped, screen damped, internally damped, and FerrofluidTM damped responses with 2dB or 4dB peak amplitude
  • Numerous port locations
  • Wide range of coil impedances
  • Available with FerrofluidTM technology offering screenless damping and improved shock performance
  • Available in Class-D amplified version as FD and FFD receiver
Balanced armature speakers FH/FFH series FH/FFH series balanced armature speakers 5.09mm x 2.80mm x 2.59mm (.200in x .111in x .102in)
  • 124dB SPL maximum output
  • Two-terminal zero-bias and three-terminal configurations
  • Undamped, screen damped, internally damped, and FerrofluidTM damped responses with 2dB, 4dB, or 6dB peak amplitude
  • Numerous port locations
  • Wide range of coil impedances
  • Available with FerrofluidTM technology offering screenless damping for superior shock performance and reduced receiver vibration
Balanced armature speakers FK series FK series balanced armature speakers 5.00mm x 2.73mm x 1.93mm (.197in x .108in x .078in)
  • 123dB SPL maximum output
  • Two-terminal zero-bias configuration
  • Undamped, screen damped, and internally damped responses
  • Numerous port locations
  • Wide range of coil impedances
  • Wide bandwidth version available - ideal for patients with mild to moderate high-frequency hearing loss.
Balanced armature speakers GQ series GQ series balanced armature speakers 6.30 x 4.29 x 4.92 (mm)
  • Dual element with enhanced bass capabilities and wideband response
  •  Unique, subminiature woofer/tweeter combination for in-ear applications
  • Integral RFI suppression
  • Single port for simplified earphone design
Balanced armature speakers HC/FHC series HC/FHC series balanced armature speakers 5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in) with rounded corners.
  • In-ear size receiver
  • Improved low frequency headroom
Balanced armature speakers RAB series RAB series balanced armature speakers 5.15mm x 2.96mm x 2.58mm (.203in x .117in x .101in)
  • Small size
  • Wideband output with 3 sound profiles
  • Model 32063 also suitable as midrange-tweeter in hybrid earphones
Balanced armature speakers SR series SR series balanced armature speakers 6.40 dia x 3.99mm (.252 dia x .157in)
  • Round package
  • Drop-in upgrade for moving coil dynamic speakers
  • Designed for high volume production
Balanced armature speakers TEC series TEC series balanced armature speakers 7.87mm x 4.09mm x 2.79mm (.310in x .161in x .110in)
  • Ultra-thin
  • Wideband output
Balanced armature speakers TWFK series TWFK series balanced armature speakers 5.00mm x 2.73mm x 3.86mm (.197in x .108in x .152in)
  • Dual elements with single sound port
  • Extreme wideband capability
  • Unique woofer/tweeter design
  • Mechanical shock resistance