Definition:
Acoustic suspension refers to a loudspeaker enclosure design in which the air inside a sealed cabinet acts as a spring to control the motion of the speaker driver's cone, particularly at low frequencies.
Overview:
Acoustic suspension is a method of loudspeaker design that enhances the low-frequency response and improves the accuracy of bass reproduction. This design was developed as an alternative to bass reflex or ported enclosures, which use a port or vent to enhance bass output. Acoustic suspension systems are known for their tight, controlled bass and improved transient response, making them suitable for high-fidelity audio applications.
Etymology/Origin:
The term "acoustic suspension" originates from the functional analogy between the compressible air inside a sealed speaker cabinet and a mechanical suspension system. The concept was first successfully commercialized in the late 1950s by Edgar Villchur and Henry Kloss through the founding of Acoustic Research, Inc. Their AR-1 and AR-2 speaker models popularized the design, which utilized a sealed (airtight) enclosure to provide a restoring force for the woofer cone, replacing the stiffer mechanical suspensions used in earlier speakers.
Characteristics:
- Sealed cabinet design that prevents air leakage.
- Relies on the elasticity of trapped air to provide a linear restoring force on the driver.
- Typically results in lower distortion and better transient response compared to ported designs.
- Requires drivers with specific compliance and motor strength to function optimally.
- Generally less efficient than bass reflex designs, requiring more amplifier power for equivalent low-frequency output.
- Roll-off in bass response is typically at a 12 dB per octave rate.
Related Topics:
- Loudspeaker enclosure types (e.g., bass reflex, transmission line, infinite baffle)
- Thiele/Small parameters (used to model and design loudspeaker systems)
- High-fidelity audio equipment
- Speaker driver design and compliance
- Audio engineering and room acoustics