KU40

Where is your low pass filter set? But yes, midbass would be your better friend for rock music. Maybe think about putting some 8's (midbasses, not subs), in your doors.

No the sub volume for the preouts were all the way up. The radio was 3/4 full volume when I set my gain. Oh ok. I must have glanced over the sub in sub volume in your first post. Try turning the bass boost down. Even though it's "only" 4db, that can add a lot of power. You said you set the gain with no EQ or anything, so that furthers the argument that the bass boost is messing it up. Was the sub volume on the head unit maxed when you set the gain?

98 Explorer XLT, 193,000 miles. I've owned it for 3 years and put on about 40k miles.

If it is really tuned to 40 hz I'd change that first. To me that will cause a response that's way too peaky in the 45-55 hz range and not have anything in the 25-35. But I guess that could also depend on what kind of music you listen to. If you just listen to rock, maybe that would be fine since the kick drum is above your tuning frequency.

You say you turned the head unit volume up all the way, which on 99% of decks will cause clipping from the deck. I also doubt you set the gain with the volume on max. If you did, that was wrong. Either way, you're clipping the hell out of it.

If you have a warranty on the amp, do not open it up. Send it in for repair. However, if your warranty has run out or you bought it used, go ahead and open it up. I've had three Crossfire amps blow on me for no apparent reason so this wouldn't really surprise me.

The issue is that a movable port wall would not be ideal unless you can seal it after each time you move it. You don't want air leaking from the internal box into the middle of the port. Your idea of attaching some plugs that take up some internal volume would likely work better. Or else make a totally removable port and have two port areas and lengths attached to their own baffle that you can then just attach into an opening in the box. Orrrrr make the port external so that you can just detach the whole thing and attach another one (this probably works best with aero ports)

The vibrations through the sub from playing will loosen and widen the crack and eventually make things worse and more out of alignment.

My guess is that your percieved tuning frequency on either the new boxes or the old one was off from the reality, hence the different responses.

Could it have been just a hairline crack at the time that maybe you just missed? I'm just saying, there's no way for this to happen without them being dropped.

You are overpowering the sub. Just because you set the gains with an oscope doesn't mean you aren't still sending the sub too much power. You're sending a 1000 watt RMS sub between 1500 and 1800 watts. A ported box will have the most control of the cone from probably 2hz below tuning to about 10 hz above tuning. If you download winISD and take a look at an excursion plot you'll see what I mean. Excursion dips around tuning then raises quite a bit above there.

It was dropped. Sucks that you didn't inspect it upon purchase, sounds like you got ripped off.

2-12's have more cone area so yes they will be louder. thats not always the case...take 2 12" Sony explodes in a couple prefab boxes and then build a nice box for 1 12" Btl or equivalent and tell me which one is louder. its all in the install. that being said i have heard great things about both subwoofers and i would personally go with 1 xcon. With the cone area argument it is assumed that the same or at least similar model drivers will be used. Obviously it's way different between different drivers and if they can handle the available power. If you want to give up the extra space, the Icons will probably be louder.

Max of the wire. 80-100 amps should be fine.

I would definitely get a dual 2 ohm sub, that way you can wire it down to 1 ohm. Reason being that the class is based on amplifier power at 4 ohms, and with an unregulated power supply amp it will put out approximately twice as much power at 1 ohm than 2. That way instead of only having an amp that can do 1200 x 1 @ 2 ohms (or 600 x 1 at 4 ohms), you can get down to 1 ohm and that amp will then do 2400 watts at 1 ohm (same 600 @ 4 ohm power rating). If you can turn it into a dual 2 depends largely on the motor. You'll just have to ask the reconer. You'll just have to ask about the 15 to 12 size change also. This can be done on many subs, but it obviously also includes changing the basket as well as just the soft parts like a normal recone so it may have an extra charge, not sure.

I guess the check engine light was just a dirty MAF sensor. I sprayed MAF cleaner on it but I guess that wasn't enough. Though granted I just sprayed it while it was still in the intake because one of the bolts holding the housing has goup all over one of the screw heads. So I'm not really sure how they got it off and out, if they did. I haven't checked their work yet. But it's nice having a bill of only 25 bucks for once.

I don't care how many girls would be there, no way I'd ever be within 1000 feet of that place. i have to work the event Even worse, that means you actually have to hear the music.

That's half of 50, right? um, 45. But I can't tell if you're being serious or not.

I don't care how many girls would be there, no way I'd ever be within 1000 feet of that place.

Looks like something between the red and blue lines might be what you want. Average their volumes and see what that gives you. Also, there is no way I'd ever adhere to a "rule" like a 15 needs 1.5 cubes sealed and an 18 needs 2 and the ratios and all that. Every driver is different and every driver will perform differently with both different volumes and ratios, even with the same cone area.

Um, you realize that whether you have 4000 watts with one amplifier or 4000 watts combined with two 2,000 amplifiers that they will draw relatively the same current?

You just need more port area. At LEAST two flared (aero) 4" ports, or probably at least three 4" regular ports, if not four. But you won't be able to make them each 13" long, you'll have to redo the equation to figure out the needed port lengths. The internal net volume of the enclosure will also be lowered. Sucks that JBL published such a horrible design recommendation. If you tell us if that 3.45 cube figure is net after sub and port displacements or gross we can help you with a new design. Dimensions also help, as well as system goals.

It would help if you told us what graphs we're looking at, and it would also help if you would change the settings on the graphs so that the vertical scale includes all of the curve.

impedance.

Oh the humanity