95Honda

If you added a spider, raise the Fs and drop the Vas a little if you model... Like 5%-10%... 40in3 isn't a small amount of cross-sectional vent area, for any 15" driver with almost any power input... It is actually a lot...

Looks good. I would Line-X it, stain just will never look great once you bung up some of the veneer... Here is a single 15 I Line-X'd...

It is more about overall driver Q. Lower Q drivers need more augmentation because they self dampen, that is why vented works better for them... Higher Q drivers need less augmentation due to the fact that they are under-dampened... Sealed and 4th order band-pass lend well to this. Also, a 6th order vented bandpass has a lot of variables to screw up...

Model both designs and post plots on here and we can help you decide what will better suite your needs...

SSF is a high pass filter and like said ^^ is set according to your enclosure resonance. For your lpf question, the answer is an unequivocal "NO"...

3" more inductance? Than what?

I find this funny. Do you know how many of these subs David built at RE? He probably knows as much about this woofer as anyone...

There isn't much, on earth, that can keep up with 4 18s and 12Kw in a vehicle... My only advice would be to spend as much effort, time and money on the front stage as possible...

This is why I model. I built some 6th order series tuned in the early 90's, modeling saved my butt... I think I was using Macspeakers by Clear Image Audio back then... Anyway, I knew nothing about dual vented bandpass designs (I was actually using a passive radiator on one side) and modeling really helped me understand how everything effects all aspects... The same is true today...

I have been using Noalox for about 20 years. If I know it won't be serviced for years, I will use Noalox and then clean off the exterior very good and put several coats of good quality paint on to seal everything... http://www.idealindustries.ca/products/wire_installation/accessories/noalox.php

They will all plot impedance, but remember, impedance varies (drastically) with frequency...

What does high power handling have to do with anything? Are you looking for output? If so, the RMS rating of the subwoofer has nothing to do with this...

The voltage doesn't cut in half when you use RCA splitters.

The T/S parameters change (sometimes a lot) after the soft parts fully break in. This will change the the impedance curve and thus your load presented to the amplifier will be different.

My guess is, anywhere in the realm you are thinking, if you build the box CORRECTLY it is going to be very loud. The vents won't really affect the sound if they are still behaving like vents... If they are too small, they will increase compression as output is increased...

It just kills me. Everyone's lives matters. But this weekend 100% innocent children were shot... That is who we should be protesting about first, criminals are way further down on the list... I lived in DC from 98'-00'... It seemed like Baltimore was constantly in the news... First month I was there, there was a gang initiation shooting at the Baltimore Zoo, they killed random people...

9 more people were shot and killed over the weekend in Baltimore... Where are the riots now???

The bigger the box, the more efficient, too a point.... A normal ported box is a 4th or 6th order depending on the filtering used. If you mean a 6th order bandpass, then that could be complicated to get right. If you want a low tuned box, tune low. I would go with whatever Fi suggests, they are the ones who designed the driver after all...

I really like the Zed Leviathan... I have no idea if you can still get them... I have installed 2 of them. They are a really flexible and good sounding amp...

Like I said, it is a phase issue. It is more than just driver spacing... **Edit** And don't forget, just like any acoustic/electrical phasing/coupling as you increase efficiency by decreasing radiated pattern/beamwidth, it does just that... So phasing can become a serious issue and is why you'll never really see those huge gains. I'm not saying you wrong, I am just saying there is so much more to this than simple driver spacing.

Kind of a misleading statement... The drivers could be completely dis-coupled (as you state it) and loose zero net output if there are no phase differentials... It is simply about phase issues between drivers, that is rarely an issue if the box is somewhat symmetrical... In a properly build enclosure, there is never any output gained by common airspace, the only exception being minimum vent dimensions...

Looks like you toasted the voicecoil. Just plain too much power... And no, it isn't specifically because you were clipping your amp. That amp can produce a 3200 watt sine wave and almost double that under certain conditions with certain signals. That amp has enough power to blow ANY subwoofer. You need to see if AC voltage is coming out of the amp at the speaker terminals while music is playing. It should be between 5-40V and varying constantly...

Mostly before the internet. Engineering classes. When you look into all the parameters of the loudspeaker system as a whole, there is much more than the voicecoil.

It is much more Re and Xl. You are confining your definition to the actual voice coil inductance. You are forgetting about all the other properties that effect the overall impedance. But I am not going to argue with you. *Edit. Quote fail...