Receivers and speakers

Balanced armature speakers

• Balanced-armature, magnetic technology
• High efficiency, stability, and reliability
• Customizable performance and port locations
• Ideal for premium in-ear designs
• Component and subassembly solutions

Knowles sub-miniature speaker designs are based on balanced armature technology, utilized in a variety of high performance audio and communication products.

Knowles balanced armature speakers are available in several sizes and efficiencies, which can be finely tuned to meet your specific performance requirements.

They can be designed to fit inside ear molds, attach to earpieces, or be sub-assembled by Knowles for premium consumer electronics accessories.

BK series

Knowles balanced-armature, magnetic technology to give high efficiency, stability and reliability.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
BK	BK-21600-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	12S	730	285	No	124	137	Tech specs (181.31 kB) 3D models (1.37 MB)
BK	BK-21604-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	12S	6000	2320	No	124	137	Tech specs (174.80 kB) 3D models (1.37 MB)
BK	BK-21610-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	121	12S	145	60	No	124	137	Tech specs (177.10 kB) 3D models (1.37 MB)
BK	BK-21613-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	1S	1200	450	No	124	137	Tech specs (182.70 kB) 3D models (1.49 MB)
BK	BK-21615-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	12S	1200	450	No	124	137	Tech specs (182.88 kB) 3D models (1.48 MB)
BK	BK-21669-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	12C	49	24	No	124	137	Tech specs (106.04 kB) 3D models (1.42 MB)
BK	BK-23134-000	7.87mm x 5.59mm x 4.04mm (.250in x .170in x .119in)	118	12S	730	285	No	124	137	Tech specs (179.92 kB) 3D models (1.37 MB)

CB series

Features Knowles’ balanced-armature, magnetic technology to give high efficiency, stability and reliability.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
CB	CB-22849-000	25.15mm x 25.40mm x 9.65mm (.990in x 1.000in x .380in)	73	Edge	24	24		77	93	Tech specs (135.66 kB) 3D models (3.83 MB)
CB	CB-22850-000	25.15mm x 25.40mm x 9.65mm (.990in x 1.000in x .380in)	48	Edge	48	48		77	93	Tech specs (139.39 kB) 3D models (4.58 MB)

CI series

Knowles’ largest and most powerful receiver. With its high efficiency and a 143dB SPL maximum output, the CI receiver provides high acoustic power.

Features

• 143dB SPL maximum output
• Undamped response
• Two and Three-terminal electrical connection
• Various port locations
• Wide range of coil impedances

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
CI	CI-22748-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	12C	250	0	No	130	143	Tech specs (128.87 kB) 3D models (632.06 kB)
CI	CI-22762-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	1S	175	0	No	130	143	Tech specs (136.61 kB) 3D models (841.32 kB)
CI	CI-22955-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	12C	68	0	No	130	143	Tech specs (130.81 kB) 3D models (632.06 kB)
CI	CI-22960-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	12C	400	0	No	130	143	Tech specs (128.84 kB) 3D models (632.06 kB)
CI	CI-28487-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	1S	100	0	No	130	143	Tech specs (139.97 kB) 3D models (841.32 kB)
CI	CI-28597-000	9.47mm x 7.18mm x 4.10mm (.373in x .283in x .162in)	125	11S	68	0	No	130	143	Tech specs (133.07 kB) 3D models (809.09 kB)

CM series

Knowles balanced-armature, magnetic technology to give high efficiency, stability and reliability. High acoustic efficiency enables sufficient sound output even when limited power is available.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
CM	CM-23152-000	8.38mm x 16.64mm (.330in x .655in)	103	12C/Face		150		111	116	Tech specs (70.76 kB) 3D models (970.14 kB)
CM	CM-23299-000	8.38mm x 16.64mm (.330in x .655in)	103	Face		150		111	116	Tech specs (69.57 kB)

DTEC series

The DTEC Series combines two TEC receiver elements with a single sound port. Case size is equivalent to BK/EF. DTEC provides increased output and reduced vibration compared to a single receiver.

Features

• Dual elements with single sound port
• Increased output
• Reduced vibration
• Enable hi-fi designs

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
DTEC	DTEC-30008-000	7.87mm x 4.09mm x 5.59mm (.310in x .161in x .220in)	123	12S	39	35	No	128	142	Tech specs (166.94 kB) 3D models (1.98 MB)
DTEC	DTEC-30265-000	7.87mm x 4.09mm x 5.59mm (.310in x .161in x .220in)	123	12S		22	No	128	142	Tech specs (172.82 kB) 3D models (1.91 MB)

EC/FEC series

Knowles’ balanced-armature, magnetic technology to give high efficiency, stability and reliability. Available with Knowles’ FerrofluidTM technology.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
EC/FEC	EC-23097-000	7.59mm x 4.34mm x 3.73mm (.299in x .171in x .147in)	108	12S	400	200	No	116	130	Tech specs (137.65 kB) 3D models (2.65 MB)
EC/FEC	EC-23098-000	7.59mm x 4.34mm x 3.73mm (.299in x .171in x .147in)	108	12S	840	425	No	116	130	Tech specs (139.07 kB) 3D models (2.76 MB)
EC/FEC	EC-26368-000	7.59mm x 4.34mm x 3.73mm (.299in x .171in x .147in)	108	12S	100	54	No	116	130	Tech specs (139.13 kB) 3D models (2.65 MB)

ED/FED series

Knowles’ most versatile and most popular receiver, the ED series powers applications ranging from Standard BTE aids and Mini-BTE aids to Full Concha and Half Concha ITE instruments. The ED is made even more functional by the addition of ferrofluid. Its shock survivability makes it a robust receiver for many applications. FED receivers also damp acoustic peaks and reduce vibration to solve feedback problems and closing issues in ITE hearing instruments.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
ED/FED	ED-21744-000	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	104	12C	3050	1700	No	116	128	Tech specs (130.17 kB) 3D models (4.68 MB)
ED/FED	ED-21913-000	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	104	12C	1450	780	No	116	128	Tech specs (130.58 kB) 3D models (1.39 MB)
ED/FED	ED-23147-000	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	104	12C	87	48	No	116	128	Tech specs (136.16 kB) 3D models (1.48 MB)
ED/FED	ED-23619-000	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	104	12C	10.2	7.1	No	116	128	Tech specs (130.01 kB) 3D models (1.48 MB)
ED/FED	ED-29689-000	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	104	12C	10.2	7.1	No	116	128	Tech specs (132.55 kB) 3D models (1.54 MB)
ED/FED	FED-26792-I02	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	102	12C	100	65	Yes	116	DDL	Tech specs (143.40 kB) 3D models (1.50 MB)
ED/FED	FED-30048-I04	6.32mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	103	12N	29	26	Yes	116	DDL	Tech specs (143.80 kB) 3D models (1.20 MB)

EF/FEF series

The staple receiver for modern BTE hearing instruments, the EF series represents a precise balance of output power and compact size. Its length-width-height ratio provides an optimum fit that helps maximize BTE space and layout considerations while still providing superior acoustic output. A full range of Knowles’ PantographTM, FerrofluidTM, and Vibration IsolationTM technologies help maximize the EF series use for any BTE instrument design. The FEF receiver brings the advantages of Ferrofluid damping, including reduced receiver vibration and improved shock survivability. These advantages are added to the EF receiver’s precise balance of power and compact size. A full range of Knowles’ PantographTM and Vibration IsolationTM technologies help maximize the FEF series optimum fit and superior acoustic output.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
EF/FEF	EF-21942-000	7.87mm x 5.59mm x 4.01mm (.310in x .220in x .158in)	125	12S	641	250	No	121	139	Tech specs (203.09 kB) 3D models (1.37 MB)

EH/FEH series

The standard for in-the-ear receivers, the EH series is the workhorse of numerous ITE and ITC designs. Its broad range of design options featuring various port locations, coil impedances, and damping options – including Knowles’ FerrofluidTM technology – means that there is an EH receiver ideal for your ITE or ITC instrument. Ferrofluid provides a damped acoustic response without the wax-clogging problems associated with damping screens. Ferrofluid’s additional ability to reduce receiver vibration and hearing instrument feedback means that there is an FEH receiver for your ITE or ITC instrument.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
EH/FEH	EH-23030-000	5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	100	12C	1055	625	No	110	128	Tech specs (186.97 kB) 3D models (1.69 MB)
EH/FEH	EH-23149-000	5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	100.5	12C	185	110	No	110	128	Tech specs (102.59 kB) 3D models (1.68 MB)

EP series

Based on Knowles’ versatile and popular ED receiver, the EP series adds the benefits of an internal Class-D amplifier. Its compact size and appreciable output power make the EP receiver suitable for a variety of applications and hearing instruments. An option for FerrofluidTM damping furthers EP receiver versatility for BTE or ITE hearing instruments.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
EP	EP-24075-000	6.33mm x 4.31mm x 2.97mm (.249in x .170in x .117in)	106	12C	50000	50000		116	128	Tech specs (109.83 kB)

ES series

The standard Class-D amplified receiver from Knowles offering a built-in amplifier and broad range of design options, port locations, and damping options – including Knowles’ FerrofluidTM technology.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
ES	ES-23127-000	5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	101	12C	50000	50000		110	128	Tech specs (132.67 kB) 3D models (1.58 MB)
ES	ES-23140-000	5.19mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	101	12C	50000	50000		110	128	Tech specs (133.17 kB) 3D models (4.66 MB)

FC/FFC series

The FC series receiver is an improved output and increased headroom version of the standard EH receiver. Moreover, the FC receiver features rounded corners, resulting in a smaller diagonal cross-section for improved fit rates.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
FC/FFC	FC-26171-000	5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	104	12C	225	170	No	112	124	Tech specs (177.74 kB) 3D models (2.11 MB)
FC/FFC	FC-26887-000	5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	100	12C	550	425	No	112	124	Tech specs (208.49 kB) 3D models (2.09 MB)

FH/FFH series

The FH receiver represents an unprecedented combination of ultra-compact size and high SPL output with efficiencies normally found only in much larger receivers. Available with Knowles’ FerrofluidTM technology for reduced vibration, improved shock performance, and reduced wax-clogging problems means easier manufacturing and greater field dependability for ITC and CIC instruments.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
FH/FFH	FFH-23375-I02	5.09mm x 2.80mm x 2.59mm (.200in x .111in x .102in)	96	12S	500	330	Yes	109	DDL	Tech specs (145.32 kB) 3D models (3.55 MB)
FH/FFH	FH-23377-000	5.09mm x 2.80mm x 2.59mm (.200in x .111in x .102in)	100	12S	1030	685	No	109	124	Tech specs (186.32 kB) 3D models (2.14 MB)
FH/FFH	FH-23821-000	5.09mm x 2.80mm x 2.59mm (.200in x .111in x .102in)	100	12S	260	174	No	109	124	Tech specs (186.40 kB) 3D models (2.14 MB)
FH/FFH	FH-26553-000	5.09mm x 2.80mm x 2.59mm (.200in x .111in x .102in)	100	12S	130	80	No	109	124	Tech specs (186.76 kB) 3D models (2.14 MB)

FK series

The world’s smallest balanced-armature receiver, the FK series is designed for CIC applications where minimum size and maximum fit rate is needed. Only 0.025cc in total volume, the FK receiver can provide over 123dB SPL output for even the tightest fittings and deepest insertions. The wide bandwidth version pushes the boundaries of high-frequency performance. As part of the TWFK receiver, the WBFK offers the widest bandwidth response of any receiver.

Features

• 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.

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
FK	FK-23451-000	5.00mm x 2.73mm x 1.93mm (.197in x .108in x .078in)	95.5	12S	630	450	No	108	123	Tech specs (137.51 kB) 3D models (2.36 MB)
FK	FK-23466-000	5.00mm x 2.73mm x 1.93mm (.197in x .108in x .078in)	95.5	12S	630	450	No	108	123	Tech specs (138.69 kB) 3D models (2.36 MB)
FK	FK-26260-000	5.00mm x 2.73mm x 1.93mm (.197in x .108in x .078in)	96	12S	240	180	No	108	123	Tech specs (139.47 kB) 3D models (5.36 MB)

GQ series

The GQ is a two-way balanced armature system with added low frequency headroom, designed for pro-audio\in-ear application. Enables customized cross-over response to achieve target frequency response.

Features

• 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

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
GQ	GQ-30710-000	6.30 x 4.29 x 4.92 (mm)	106.0	12S	90.0	51.7	na	na	na	Tech specs (159.46 kB)
GQ	GQ-30783-000	6.30 x 4.29 x 4.92 (mm)	109.5	12S	37.0	21.5	na	na	na	Tech specs (163.34 kB)

HC/FHC series

Knowles balanced-armature, magnetic technology to give high efficiency, stability and reliability. HC Series provides increased low frequency dynamic range in a package size equal to FC.

Features

• In-ear size receiver
• Improved low frequency headroom

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
HC/FHC	HC-23761-000	5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	101	12C	14.6	8.4	No	116	123	Tech specs (247.46 kB) 3D models (1.95 MB)
HC/FHC	WBHC-23910-000	5.17mm x 3.55mm x 3.00mm (.204in x .140in x .118in)	95	12C	145	130	No	114	121	Tech specs (518.16 kB) 3D models (2.19 MB)

SR series

At 6.40mm diameter, the SR is the first round balanced armature receiver in the marketplace. SR maximizes bass performance while providing crystal-clear treble for a pleasing, full-range response in a small package easily adapted to dynamic earphone designs.

Features

• Round package
• Drop-in upgrade for moving coil dynamic speakers
• Designed for high volume production

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
SR	SR-31843-000	6.40mm dia x 3.99mm (.252 dia x .157in)	105	Face	46.0	32.5	NA	null	null	Tech specs (139.64 kB) 3D models (167.94 kB)
SR	SR6438NWS-000	6.40mm dia x 3.99mm (.252 dia x .157in)	109.5	Face	55.5	36.5	NA	null	null	Tech specs (139.79 kB) 3D models (585.15 kB)

TEC series

The TEC combines output comparable to the larger BK receiver in an ultra-thin package. TEC is suitable for multi-element earphone designs.

Features

• Ultra-thin
• Wideband output

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
TEC	TEC-30033-000	7.87mm x 4.09mm x 2.79mm (.310in x .161in x .110in)	117	12C	59	31	No	118	138	Tech specs (143.89 kB) 3D models (1.36 MB)

TWFK series

The world’s smallest dual balanced armature receiver, the TWFK is designed for pro-audio in-ear applications. It enables customized cross-over systems to achieve target frequency response in a package size smaller than the ED Series.

Features

• Dual elements with single sound port
• Extreme wideband capability
• Unique woofer/tweeter design
• Mechanical shock resistance

Product Families	Model ID	Dimensions	Sensitivity	Port Location	Imp @ 1kHz	Imp @ 500 Hz	Ferrofluid	MPO 500	MPO Pk	Downloads
TWFK	TWFK-30017-000	5.00mm x 2.73mm x 3.86mm (.197in x .108in x .152in)	95	12S	43	31	No	110.5	123.5	Tech specs (156.26 kB) 3D models (4.05 MB)