Additional box solutions for the PB412S4 are shown immediately below.  For actual in-box curves, scroll down to the end of this page, or, click here.

All images below are clickable to see the full size image.

The PB412S4 can of course be used in sealed boxes under 1.0 cubic feet internal volume.  Below is a projection in a 0.83 cu. ft. box.  Heat buildup becomes an issue in smaller boxes, so, this projection was run at 700 watts amplifier power.  At this level, excursion is almost identical to Xmax, meaning that distortion stays very low, and nowhere near peak mechanical capacity.  Put another way, mechanically, the speaker is almost “coasting”.   If your amplifier has an infrasonic filter, we suggest setting it to around 15 Hz, for this and the 1.0 cu. ft. sealed boxes.

Here is a projection showing the PB412S4 in the 1.0 cu. ft. box, at it’s maximum power rating of 800 watts. 

Below is an interesting option for either home theater, or for car systems with very strong, extended low bass.  We recommend a port = 4″ I.D. /  16.1″ long, or, if you have room for it, 5″ I.D. / 26″ long .  (Be sure to allow for the volume occupied by the port in your enclosure volume calculation, unless the port is external to the cabinet.)  To obtain maximum power handling, you will need a steep infrasonic filter cutting in at 24-25 Hz.

For the real bass-heads, the PB412S4 is excellent in a 2.0 cu. ft. cabinet, tuned to 42 Hz.  This will result in extremely powerful output 40-60 Hz output.  Additionally, excursion is reduced in the 35-50 Hz range, with a minimum at 42 Hz.  This is an excellent match-up for amps or eq’s with a bass boost around 40-45 Hz, as the boost is right at the frequencies where the system enhances the mechanical power handling of the woofer the most.  We recommend use of a  port = 5″ I.D. / 11.5″ long”.  If you don’t have room for that, the port can be 4″ I.D. / 6.75″ long.  If using a 400 watt amplifier, a 24 Hz infrasonic filter is needed to prevent overexcursion below the port tuning frequency.

If using an 800 watt amplifier with the 2.0 cu. ft. 42 Hz ported box, then use a steep slope 30-32 Hz infrasonic filter.  (Basically, you sacrifice a little response under 30 Hz, for maximum output above 35 Hz, especially the 40-60 Hz range.)  The port is the same:  5″ I.D. / 11.5″ long”.  If you don’t have room for that, the port can be 4″ I.D. / 6.75″ long.  This system will really rattle your head on it’s shoulders!

Last but not least, here are some actual measured curves:

The yellow curve is with the PB412S4 in the large dual-chamber quasi-aperodic box / baffle we use for response testing of various drivers - the intent being more to examine mid/high response smoothness in a nearly 2 pi free field, than to obtain the “best bass”.  (The bass is not bad, however.)  The blue curve was done in a box with approx. 0.65 cu. ft. internal volume, after allowance for the displacement of the woofer.  That is probably on the “small side” of what most users would want to use with this woofer, as it results in a bumped up, punchy mid-bass, but a little loss of deep bass.  The mic’d curves include upper frequency rolloff due to the very close microphone position used to eliminate room effects at low frequencies, and the driver’s own inductance.  It is possible to get useful response to around 800 Hz, but this woofer is primarily recommended for subwoofer usage to 100 or perhaps 150 Hz.