Audio glossary
A compact English reference for the terms used across the project pages and calculators.
Enclosure tuning frequency of a bass-reflex or passive-radiator system.
Frequency where response is 3 dB below the chosen reference level.
Free-air resonance frequency of a loudspeaker driver.
Total Q of the driver at resonance, combining electrical and mechanical damping.
Equivalent compliance volume of the driver suspension.
Manufacturer-defined linear excursion limit; definitions can differ.
Sound pressure produced for a defined electrical input and distance.
Sound-pressure level, expressed in decibels relative to 20 µPa.
Vented alignment using a tuned air mass in a port.
Unpowered diaphragm used as the tuning mass instead of a port.
Mounting where front and rear radiation are effectively separated by a very large boundary/back volume.
Digital signal processing for filters, EQ, delay, protection and routing.
Crossover family designed for flat acoustic summation when implemented with the intended slopes and phase relationship.
Low-frequency resonance caused by room dimensions and boundaries.
Available margin before clipping, excursion, thermal or other limits are reached.
Reduction in acoustic output as voice-coil heating raises resistance and changes driver behaviour.
Usable internal air volume after subtracting driver, bracing, ports and other internal displacement.
Air speed in a bass-reflex vent; excessive velocity may cause turbulence and noise.
Small-signal parameter set used to model low-frequency loudspeaker behaviour.
Centre-to-centre spacing between acoustic sources/drivers.
A vented loudspeaker alignment in which a tuned port contributes acoustic output around the enclosure tuning frequency.
Usable internal air volume after subtracting drivers, ports, bracing and other internal displacement.
The target resonance frequency of a bass-reflex or passive-radiator system; often written as Fb.
Geometric internal enclosure volume before subtracting drivers, ports, bracing and other displacements.
The electro-acoustic transducer itself, such as a woofer, midrange or compression driver.
Internal structural reinforcement used to reduce panel flex and enclosure resonance.
Logarithmic unit used for ratios such as sound-pressure level and gain.
Audible turbulence or chuffing caused by excessive air speed or unfavourable geometry in a vent.
Highest useful acoustic output before a defined excursion, thermal, distortion or amplifier limit is reached.
Acoustic output level as a function of frequency under defined measurement conditions.
Electrical and thermal power a component can tolerate under specified conditions; it is not by itself a maximum-SPL rating.
Volume of air moved per unit time, relevant to cone motion and port airflow.
Tuned duct or opening whose air mass forms the resonant element of a vented loudspeaker system.
Magnitude of a signal or sound-pressure quantity, commonly expressed in decibels.
Internal enclosure volume occupied by drivers, ports, bracing or other components and therefore unavailable as net acoustic volume.
Model-based prediction from stated assumptions and parameters; it must be distinguished from a real measurement.
Porous or fibrous material used inside an enclosure to attenuate internal resonances and modify acoustic losses.