Kole Audio Reviews!

Not sure that I entirely agree.  what ur saying is to run a subsonic filter below port tuning requency, right?  As long as you filter below port tuning frequency, right?  yipes!  Did I not read these were 8" L7's?  if so, the port tuning frequency will be quite high (prolly in the high 40's or low 50's).  Assuming this is the case, the customer will be missing the bottom two octaves of the subbase region  (not that 8's have appreciable output in that range anyway, but still...its missing!!!!!)

The subsonic filter is a safety for a vented box, and not much more.  We know that as the sub plays closer to tuning freq, the drivers movement becomes less and less.  Theoretically, the driver will almost not move at tuning freq.  BUT...as we dip below port tuning, the sub begins to move wildly, unloading and behaving as if its not in a box at all.....I would suggest that if you can put big power on them, a medium sealed box (which is quite small for that driver) would be much better. 

0.02

good for you. they make spl and farenheit. you want a cookie? or a medal for that? whos your wholesale dealer? the wholesale house?

This is a good point to bring up, and thank you for that. And I do not disagree with what you are saying, but I think it's important to discuss what exactly will be missing, as I think assuming high 40's to low 50's is a little extreme.

Kicker indicates in the owner's manual for the 8" L7 that a 25 Hz subsonic filter will give a ported box the same RMS power handling as the sealed box would. This filter would only cut off the lowest part of the lowest audible octave (the bottom 5 Hz, assuming a 20 to 20k frequency spread), which in the vast majority of cases will not be missed at all. The Fs of the speaker is 38 Hz; I would actually have filtered it at 30 or 32 in a vented box and still you would have all but some very low harmonic information (now missing only the the last 10 to 12 Hz), but Kicker indicates different, so I'd say go with that. My point is just that using the numbers, it looks like a vented box would perform just as well as a sealed box except at the lowest (30 Hz and down appx.) frequencies, which in my experience you will not miss at all.

The subsonic filter is just a safety, you are absolutely right, and it does cut out some information. These ideas always are just that - ideas. Ultimately you have to look at the program material that the listener intends to use, and how abusive they will be. If you listen to a lot of synthesized bass, or electronica/ techno, you may find that you are hanging around below the tuned frequency of the box, and yes you might miss the tones in that case. But as long as I have been designing and building boxes, I have only run in to that a couple of times.

I stand by my idea to port those subs as long as you can properly control them (All hail the mighty subsonic filter!!!). But more importantly, go listen to the difference between ported and sealed before you make the final decision which to make. You have to use the box, after all, all we can do is advise you based on our own experience. I just have my opinions and a few meager facts to back them up.