I decided not to do ported configs to the 3K for the simple reason that any port that would make sense from a SQ stand point would not make sense. The port area would have to be at least 25" inches for a TC-3000 and that is a minimum because of the amount of air it moves.
OK variable two: because the motor is powerful and the Q is very low, a larger box yields no benefits over a smaller box even for a ported configuration. Most drivers are not lucky enough to reek that benefit. This is actually very ideal for car audio. You guys are lucky because you can build these things into tiny boxes with enormous output.
The porting length required to get any sort of benefits from a port from a sound quality standpoint would force the length of the ports to nearly 40" even 80" in some cases. You can't build any kind of box if you need a 40" port in there for your car. Of course you can just choose a higher port frequency, but you'll have a huge peak in your frequency response and it will sound bad. WELL it may be desirable, but I firmly believe in linear sound because I come from a home audio background. Trust me, linear bass is a REALLY good thing.
Ok, so does that mean you can't port it? Not at all, TC-3000 will generate huge output benefits from a ported box, as long as you can do it right, I felt that PR’s were a much more effect method of gaining these output benefits and ultimately they should be the method used for this driver and our larger ones too simply because you really don’t want to see what kind of box it would have to do in, it just means when you port it, you either comprise quality, or your end up with this:
http://www.tcsounds.com/forums/index.php?showtopic=172
That will work for HT, and I’m certain that would rival every HT subwoofer every developed, however, it’s HUGE! This beast is an HT sub designed for dual 15TC-3000 ported and to accommodate the long port required for the 75 square inches of port area, the box had to be 14 cubic feet. That will not fit in your car, or truck, trust me. We could make this same subwoofer with PR’s less than one third the size of that with almost no loss in output. So now you see the advantage of the PR’s
PR's are actually better than ports in many respects. On average, they are about 1dB less efficient access the frequency bandwidth, but that’s almost inaudible. The PR's don't require the long port and they can eliminate many problems that ports have such as air noise. Most car audio subs that are ported are not flared, secondly the ports are rarely long enough to lend towards linear output. The PR's only need to be weighted to lower the tuning frequency.
We'll have the PR's up for sale shortly.
Now, next topic. If SPL is your fancy and you do either dB drag or what not, the TC-3000’s are actually pretty good for this because they don’t require a large box you can just use a small port at the resonance frequency of your car (80hz, 50hz 60hz.. whatever) and the box really doest have to be that large to get maximum output. So if size is a constraint for your contest, the TC-3000’s are versatile in that regard. But if you do this, and port it for maximum output at once frequency.
So to sum it up:
Good daily driers: So sealed with 2000 watts / driver
If you want a loud daily driver, go passive with 2000 watts / driver
If you do competition, port it at a high frequency like the resonance of your car and use the size of the box recommend for a passive config. IE: if the passives call for 3.5 cubic feet, make your ported design 3.5 cubic feet + the port volume. DO NOT DO THAT unless this is for dB drag.
thanks