LNGR / Glossary

Audio glossary

A compact English reference for the terms used across the project pages and calculators.

Fb

Enclosure tuning frequency of a bass-reflex or passive-radiator system.

F3

Frequency where response is 3 dB below the chosen reference level.

Fs

Free-air resonance frequency of a loudspeaker driver.

Qts

Total Q of the driver at resonance, combining electrical and mechanical damping.

Vas

Equivalent compliance volume of the driver suspension.

Xmax

Manufacturer-defined linear excursion limit; definitions can differ.

Sensitivity

Sound pressure produced for a defined electrical input and distance.

SPL

Sound-pressure level, expressed in decibels relative to 20 µPa.

Bass reflex

Vented alignment using a tuned air mass in a port.

Passive radiator

Unpowered diaphragm used as the tuning mass instead of a port.

Infinite baffle

Mounting where front and rear radiation are effectively separated by a very large boundary/back volume.

DSP

Digital signal processing for filters, EQ, delay, protection and routing.

Linkwitz-Riley

Crossover family designed for flat acoustic summation when implemented with the intended slopes and phase relationship.

Room mode

Low-frequency resonance caused by room dimensions and boundaries.

Headroom

Available margin before clipping, excursion, thermal or other limits are reached.

Power compression

Reduction in acoustic output as voice-coil heating raises resistance and changes driver behaviour.

Net volume

Usable internal air volume after subtracting driver, bracing, ports and other internal displacement.

Port velocity

Air speed in a bass-reflex vent; excessive velocity may cause turbulence and noise.

Thiele/Small

Small-signal parameter set used to model low-frequency loudspeaker behaviour.

CTC

Centre-to-centre spacing between acoustic sources/drivers.