View Full Version : Are Sealed boxes tuned?

06-15-2008, 08:52 PM
Hey. Been doing some reading around here lately as opposed to just browsing classifieds and I've come up with a couple of questions.

When designing a sealed enclosure, do you tune the box to a frequency? Or is that simply a ported enclosure requirement?

Reason I ask, is I have four jbl p1022s in a sealed enclosure. I am waiting for a new amp, and i believe it has a subsonic filter. After doing some reading, it seems i could damage or ruin my subs if i have the subsonic filter incorrectly according the what my box is tuned for. Is this something I have to worry about with a sealed enclosure? The shop that built the box told me no, because sealed enclosures aren't tuned; therefore I will have no idea what to do with the subsonic filter when the time comes (hopefully a couple of weeks)

06-15-2008, 08:56 PM
subsonics are typically used for a ported application, so you dont run the risk of smoking the sub if it plays below its Fs too much or the tuning of the box or whatever... someone will chime in with a better answer I bet.

06-15-2008, 09:01 PM
subsonic filters are for ported boxes so you should not need to worry about it with a sealed box.

I just read the specs on those subs...and the freq response goes down to 25.

( http://manuals.harman.com/JBL/CAR/Boxes%20and%20Parameters/Power%201022.pdf )

So if the filter goes any lower than 25, set it at 25, and you'll be fine.

06-15-2008, 09:09 PM
Oh okay, thanks for explaining that for me. It is much appreciated.