BASSBOSS Questions
I'm looking at buying one or the other. Why would I want the ZV18 vs. the SSP118?
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BASSBOSS - David Lee
You may have noticed that the SSP118 is -3dB at 30Hz and the ZV18 is -3dB at 24Hz. That doesn't sound like much of a difference but the difference in the amount of energy required to produce the same SPL at 30 Hz and 24Hz is quite considerable. All things being equal, every octave you go down in frequency requires 4x the energy.

That means if the driver diameter is the same, the driver efficiency is the same and the enclosure efficiency is the same, the cone has to move 4x further in excursion to produce the same SPL at 1 octave below a given frequency. To produce the same SPL at 24Hz that is produced at 30Hz, given efficiencies remain the same, demands almost double the energy.  

If you increase efficiency in the motor or enclosure then you can deliver the same SPL at lower frequencies using less than 2x the power and less than 2x the excursion. This requires higher-strength motors and a more efficient enclosure design. Both those requirements add to the cost because the ZV18 has a driver with longer excursion, higher power handling, a bigger voice coil and a larger magnet structure than the SSP118.

The enclosure is also bigger, more thoroughly braced and with larger ports to allow low-frequency performance to be maintained at high levels. More complicated processing is also involved to keep everything working while the woofer is performing at the very limits of its low-frequency capabilities.

So, the ZV18 costs that much more because it costs us that much more to build it. The SSP118 is a great single 18" subwoofer, capable of putting out 12dB more than a QSC KW181 from 30 to 45Hz. That's the output of four KW181s! The ZV18 doesn't go louder than the SSP118, it goes lower. You only need the ZV18 if you need/want extremely deep bass. And I mean so deep that you've probably never heard stuff down there...

––David Lee
BASSBOSS
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