I was looking at the comments on the JBL 1200.1 (which I just ordered ), and there were a couple comments mentioning a subsonic filter and the 1200.1 not having one. What does the subsonic filter do and is it really that important?

 

It's basically a high pass filter, but usually is set at 30Hz.

It's made to keep your subs safe from destruction, primarily in ported enclosures.

 

sub-sonic = below frequency we can hear... it basically filters out the sound that we wouldnt hear anyway that would just cause distortion... I dont think anything below 18-20 Hz can be heard by a human... Not to say you couldnt "feel" it.

 

this becomes a very important thing when subs are in a ported box. most subs cant handle the very low notes and can be damaged by them. by having a subsonic filter, less effort is being made by the sub (and amp) to produce those notes. less hard work on the lower notes allows the sub and amp to concentrate on the other ones.

 

A subsonic filter is to be use in conjuction with a ported box. The filter is a highpass filter used in the lower frequency range (50 hertz and down) The purpose is to keep the sub from unloading in the encloser which is just like playing the sub freeair which can very quickly damage a sub. Usually the filter is set 5-10 hertz below the tuning of the box.

 

So...if I use a sealed box instead of a ported box the subsonic filter doesnt really matter?

 

No...to answer your question....although I would not want to use a subsonic filter in a sealed box setup.