95Honda

Check out the specs on these drivers, lol... http://www.ari-web.com/aurasound/pdf/nrt18-8.pdf

As all have pretty much said. Most drivers intended for pro-sound require large enclosures to make their efficiency shine. Also, this isn't a new idea. There have been a few pro-sound drivers on the block for decades,, that would fit this application. I have used both of them. In the early 90's I did a few pro-audio installs with the McCauley 6174 18" driver. I was highly efficient, had a low Fs and almost 3/4" of one way linear excursion. I also have used the Aura 1808 (and the newer NRT-18) several times over the last few decades. It also was very efficient, had a low Fs and plenty of excursion... Both very low distortion high output drivers... The drawbacks? They were $1000 each, even back in the day, and they needed relatively large enclosures... BUT, if you were in some type of class that limited you to say a single driver of any size and low power, say 500 watts, and you had no enclosure limitations, then these two drivers would be every car audio driver, hands down... But that really doesn't really fit into any classes that I am aware of... Here are the boxes I made for (4) of the Aura 18's almost 10 years ago... They are like 20ft3 each, lol... Also, that is $4k for (4) subs...

If you guys are talking vented enclosures, the primary purpose of dampening material is too attenuate mechanical noise and upper harmonics. It does NOT cause the driver to act as if it is in a larger enclosure nearly as effectively as it does in sealed alignment. There are diminishing returns with applying dampening material in a vented alignment and you will drastically start lowering efficiency if you over stuff the box. Polyfill really has no place in vented alignments unless you are lining the walls with it... Even so, It does NOT work as good as fiberglass at attenuating the garbage you are trying to get rid of in a vented alignment...

You guys are kind of missing a bunch of basic laws here. 1. Any upgrades in getting current to your amplifier (and decreasing voltage drop across that path) is going to lower the voltage level at the main battery up front due to the lower resistance between it and your amplifier. This will in turn cause increased voltage drop at your headlights as they are fed off of your front battery. 2. To decrease the voltage drop at your front battery (where your headlights are fed) you need to get the amplifier sourcing it's current from somewhere else, like another battery closer to it. 3. If you lower your ground resistance between the amplifier and the front of the car you again lower total overall resistance and enable the amplifier to draw more current from the front battery and in turn have more voltage drop to your headlights. 4. Honestly, who cares if the headlights dim anyways?

I would stick with something and see it ALL the way through to the end.

Before you decide on anything, you should probably see how those subs will behave in your planned alignment. If you have the time, pick up the Loudspeaker Design Cookbook. First few chapters will get you squared away.

I still think your missing our point, you have enough power for both. If you are going to do 2 of them, do it from the start and don't waste your money.

Yeah, make it internal... Seriously, you don't need to make it stick out. It doesn't make designing any easier...

Listen to lithium, you don't have to have a certain amount of power. For a pair of BTL 15s a pair of 8" PVC pipes would be enough cross sectional area to more than likely give you low compression, only require you to cut a pair of 8" holes and be impervious to weather between your cab and bed. Only a suggestion, of course... 2 BTL 15s wil be louder and have lower distortion on as little as 100 watts versus a single one... You need to model to see what your options are. Make sure those subs don't have any weird response variations in a 4th order bandpass also, I have no idea what their T/S parameters are...

Yes^^ Or just have them inside the box and calculate accordingly. You'll have to adjust your volume accordingly, but that, and your efficiency are only going to go up with the higher tuning (shorter) port. Use easy round numbers like 7.25 cubic feet tuned to 32Hz. Nobody builds a box that is 7.2466756 cubic feet tuned to 32.564729487Hz. That is what I call mental masturbation, and gets you nowhere. Just think it through and keep it simple.

This has nothing to do with your woofer. I would try and fix whatever in your signal chain is bad before you break something.

That is damn loud out of a trunk...

I wouldn't run a driver with a Qts that high in a ported enclosure. They don't have the ability to self dampen enough to get flat response. If you must go ported, I would sell it and get another driver.

How do you know you need more than 5Kw? Unless you have modeled for excursion you have no idea. That (5Kw), as a minimum, is almost more than the drivers are rated for thermally. Depending on the amp, you could be applying well over the continuous rating of the drivers and cause thermal failure. Again, until you model for excursion, in your chosen alignment, you have no idea how much power you will need to get full, non-distorted, output from your subwoofers. Nothing wrong at all with having all that power, you just need to be careful when using it.

Or just do it right the first time...

Any review you get on a car audio forum will be mostly subjective. Look at the parameters and decide if the driver will fit your needs.

^^ Sort of. A Q of around .7 will be flattest. A Q lower than that can give you some more low end extension but with a perceived "flatness" to the sound. A Q of around 1+ gives you a bump in upper bass, this is what most manufacturers suggest in their recommended alignments. You'll see Q's as high as 1.5+ in some suggested alignments, lol... I would go between .7-.8 personally... There is nothing wrong with bracing a small box. I think we forget what bracing does on here sometime. The whole reason we brace is to raise the resonant point of the braced panel to a level above the range of the enclosure. If we raise it high enough it will be dampened by the enclosure material itself or additional dampening added by the builder. You could get resonant modes in a small box that will cause distortion, if you brace, you just move those modes higher out of your usable spectrum. A combination of good bracing and the application of effective dampening compound will ensure a solid, non-resonant enclosure...

Wasn't sure. I just remember all the Adire/Chad drama back in 05'-06'...

Is Chad still the owner?

And good job, Quentin.

^^ Not really.

Yes^^ And remember, Re is just the DC resistance of the wire the coil is made of. It has little to do with what load the amplifier sees. In reality, an amplifier will never under any circumstances even see a load as low as Re due to losses in the interconnect cabling... It may be close, but it will always see just above Re and higher... The only way to see the actual load (excluding interconnect cabling) is to model the driver in your enclosure, as the enclosure is the #1 contributor to a majority of the load your amplifier sees...

I think I also thread jacked, sorry Quentin!

The frequency response of a high quality tube amp is flat beyond the audible range, this is a product of good design and quality output transformers. Even order harmonics contribute to a warmer sound. Tubes run into clipping much more gracefully without all the nasty odd order harmonics solid state gets a bad rap for. Dampening factor isn't everything, but it has it's place. Tubes aren't the only designs with high output impedance/low dampening. I built a set of Nelson Pass Son of Zen, single ended, MOSFET amplifiers back in the late 90s. They had worse dampening than almost any tube amp, but sounded very good. A passive crossover that keeps the drivers from playing out of their bands will work, but normally doesn't sound so good. Getting a passive crossover to give flat response and decent impedance is the hard part. Most of this CANNOT be modeled exactly due to way too many driver response variations. Driver measurements need to be imported into the modeling software or measurements of the overall system need to be made. Your ears are good at telling you something doesn't sound right, measuring is good at telling you where it doesn't sound right...

And that is why I prefer tubes my friend... No odd-order garbage...