BK-21669-000

Overview

The Knowles BK-21669-000 is a balanced armature receiver speaker designed for high-efficiency audio applications. It features a magnetic technology construction with a top port configuration and rectangular form factor. The component operates within a frequency range of 200 Hz to 3.8 kHz, providing clear sound reproduction for voice and mid-range frequencies. Key electrical specifications include an impedance of 59 Ohms and a high efficiency rating of 127 dBA. This model utilizes solder pad termination for secure circuit board integration.

Feature Summary

• Balanced armature driver technology for precise acoustic output
• High sensitivity design achieving 127 dBA efficiency
• Top port orientation for directed sound projection
• Rectangular package geometry optimized for space-constrained layouts

Applications

• Medical diagnostic equipment requiring clear audio feedback
• Industrial control panels and user interfaces
• Portable communication devices and headsets
• Consumer electronics with limited internal volume

Procurement Notes

Verify the specific datasheet revision when ordering, as outline drawings may vary between manufacturing batches. Confirm that the 59 Ohm impedance matches your amplifier or driver circuit requirements to ensure optimal power transfer. Ensure PCB layout accommodates the rectangular footprint and solder pad termination style specified in the official mechanical drawing. Cross-reference the part number with authorized distributors to confirm authenticity and traceability.

Selection Notes

Select this component when high efficiency is critical for battery-operated systems due to its 127 dBA rating. The 59 Ohm impedance offers a specific load characteristic suitable for certain driver configurations. Consider the 200 Hz to 3.8 kHz frequency response to ensure it aligns with the target audio bandwidth. The top port design influences acoustic coupling and must be accounted for in the enclosure design relative to other available orientations.

Part Context

Knowles specializes in micro-acoustic components for demanding environments. The BK series represents their balanced armature lineup, engineered for reliability in medical and industrial sectors. This specific model integrates into broader audio subsystems where size and performance are prioritized. The manufacturer provides detailed mechanical and electrical documentation to support integration into complex electronic assemblies.

Replacement Considerations

No public confirmed substitute part numbers are available for this specific component. Direct replacement requires matching the 59 Ohm impedance, 127 dBA efficiency, and rectangular top-port physical dimensions. Verify compatibility with existing acoustic chambers and PCB footprints before considering alternative balanced armature speakers from other manufacturers.