Rockford Fosgate RFD2210 - Manual (Page 8)

8
B
UILDING AN
E
NCLOSURE
To work properly, the walls of the enclosure must be rigid and not flex when subjected to the high
pressures generated by the speaker's operation. For optimum performance, we recommend using
3/4" MDF (Medium Density Fiberboard) and internal bracing. The enclosure should be glued
together and secured with nails or screws. MDF is porous; therefore, it is suggested to also seal the
outside walls with polyurethane.
CALCULATING VOLUME
Calculating volume is merely a matter of measuring the dimensions in inches and using the formula:
S
UBWOOFER
C
ROSSOVERS
There are two operational types of crossovers, passive and active. Passive crossovers (coils or
inductors) are placed on the speaker leads between the amplifier and speaker. An active crossover is
an electronic filter which separates the audio signal fed to different amplifiers. For optimum
subwoofer performance, we recommend using an active 80-100Hz low-pass crossover at
12dB/octave.
Box Volume = Height “ x Width” x Depth”
(cubic feet) 1728 cu. in./cu. ft.
If two facing sides are of uneven length, add them together and divide by two to take the average.
Using this number will give you the volume without the necessity of calculating the box in sections
and adding the sections together. The thickness of the baffle material reduces the internal volume so
this must be subtracted from the outside dimensions to determine the internal volume. The speaker
itself also reduces the internal volume. The amount of air displaced by each model is listed on the
specification sheet and should also be subtracted from the gross volume calculation.