Sealed or Closed Subwoofer Box Design Calculator
Car Audio - Home Theater Sound System

AJ Sealed Designer calculates the required sealed/closed enclosure parameters for woofers and subwoofers.

Equations

		if
		if

Where

Inputs
Vas	=	air volume equal equal to compliance of driver suspension
Qts	=	total driver Q at fs
fs	=	driver resonance frequency
Qtc	=	total system Q at fc
Calculated
Vb	=	net enclosure volume(internal)
f3	=	frequency where the 3 decibel power drop occurs
fb	=	box resonance frequency
dbpeak	=	system response maximum dip or peak

Input Parameters

Notes:

1) Theile Small parameters are required for input. These values can be found in the speaker's manual or on the manufacture's web site.

2) For Qtc, choose a value between 0.1 and 2.0. A value between 0.5 and 1.2 gives the best results. Try varying this parameter to see how the size of the box and the frequency response can be changed.

Calculated Values

Notes:

1) f3 is the most meaningful parameter. The lower the f3 parameter the deeper the bass will sound. An f3 below 50 Hz is suitable for a sealed enclosure. An value below of 40 hz gives the best results.

2) Vb is the net size (volume) of the enclosure to be built. Generally, the lower the bass the larger the box.

3) In the frequency response plot, the output SPL, sound pressure level, is based at 1 watt/meter