Knowles Corporation
Itasca, Illinois, United States · founded 1946
Knowles is the company that invented the miniature balanced armature receiver (for hearing aids in the 1950s) and remains the dominant supplier of the BA drivers used throughout the IEM industry — making it a foundational, largely invisible link in the supply chain behind many boutique multi-BA in-ear monitors.
Knowles Corporation (NYSE: KN) is a US-based, publicly traded supplier of high-performance micro-acoustic components, founded in 1946 by acoustical engineer Hugh S. Knowles and headquartered in Itasca, Illinois. It is the dominant maker of miniature balanced armature (BA) receivers/speakers — a technology it pioneered for hearing aids in the 1950s — that are now used as drivers throughout the in-ear monitor (IEM) and true-wireless earbud industry, alongside MedTech microphones, precision capacitors, and RF filtering products. Knowles became an independent public company in 2014 after spinning off from Dover Corporation, and in December 2024 completed the sale of its Consumer MEMS Microphone business to Syntiant, retaining its balanced armature and precision-devices businesses. The company sells components B2B to other manufacturers rather than finished consumer products.
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At a glance
- Type
- Supplier
- Founder
- Hugh S. Knowles
- Founded
- 1946
- Headquarters
- Itasca, Illinois, United States
- Price range
- Budget → flagship
- Makes / sells
- balanced armature receivers/speakers (drivers), hearing aid receivers and microphones, MedTech / hearing health microphones, SiSonic MEMS microphones (historically; consumer MEMS mic line divested to Syntiant Dec 2024), precision capacitors, RF/microwave filters and components
- Known for
- miniature balanced armature drivers, multi-BA driver configurations for IEMs, hearing health acoustics, micro-acoustic component engineering, OEM/B2B audio component supply
- Website
- www.knowles.com
Notable products
- Balanced Armature (BA) receivers/drivers — Knowles pioneered the miniature balanced armature receiver for hearing aids in the 1950s; these are the BA drivers used across a large share of the IEM industry.
- SiSonic MEMS microphones — Silicon MEMS microphone line for consumer/wearable devices; the Consumer MEMS Microphone business was sold to Syntiant, closing December 2024.
- Custom collaborative BA drivers — Knowles co-develops custom BA drivers with IEM makers, e.g. the EJ-33877 driver developed with FiiO for the FA9.
Supplies
Notable brands that use their components:
Sources: Knowles Corporation official website (company/products/HQ) · Knowles Corporation Debuts as Independent, Public Company Following Spin-Off from Dover Corporation (Business Wire, 2014) · Hugh S. Knowles - Wikipedia (founder biography, patents) · Knowles Celebrates 75 Years of Industry Firsts and Leadership in the Audio Industry (Forbes, 2022) · Knowles Corporation Completes the Sale of Its Consumer MEMS Microphone Business to Syntiant (Business Wire, Dec 2024) · FiiO FA9 Knowles 6 Balanced Armature Driver IEM (retailer product listing, custom EJ-33877 driver) · Darko.Audio — Campfire Audio Clara IEM (uses Knowles BA drivers)