Frequency response
Frequency response of a speaker's membrane acceleration (
) is presented at the figure below. It was obtained using Akabak software [2] and the loudspeaker whose characteristics are given in annex 4.
Frequency response is calculated for three different configurations:
- loudspeaker in an infinite screen
- loudspeaker mounted in the enclosure of 30 liters volume
- loudspeaker mounted in the enclosure of 5 liter volume
In the case of loudspeaker mounted in an infinite screen, its response has a high-pass type and it is very damped, which can be explained by the low value of total quality factor
(0,52).
In the case of loudspeaker mounted in 30 liter enclosure, resonance frequency of the assembly is higher than that of the loudspeaker in a screen. Total quality factor is also higher.
Finally, in the case of loudspeaker mounted in 5 liter enclosure, resonance frequency and total quality factor are clearly higher than in the case of the screen-mounted loudspeaker.
For both enclosures, the model takes into account the eigenmodes of the enclosure along its axis of greatest dimension, which translates into visible resonances on the pressure response (1st eigen resonance frequency is at about 550 Hz). Amplitude of these resonances is a priori overestimated by the software which does not take into account all losses inside the enclosure.
