creyc

I think you would be alright with 2000 rms CLEAN unclipped power. I've got 1500 rms to my Havocs (fully loaded Q's) and they take it like a champ, the BL is designed for a bit more power, better cooling, so I would feel pretty confident giving it 2k rms.

What about a sealed clamshell wall? Lots of guys run this configuration with many drivers in a relatively small space and get excellent results. The subs would still be facing each other but you'd have more distance between them.

Yes this is a daily driver, and I don't really feel like putting in an isolator. It's working quite well setup like this, my voltage never dips below 14.2v while driving.

Good info Boon. The point of a fuse is to cut off power if things go awry. You can shut your car off and your alternator stops putting out power, but it is impossible to turn "off" a battery. If it shorts out, it will give the wire/car everything its got, which is PLENTY of energy to start a fire/weld sheet metal/burn all the wires insulation instantly. The way to avoid such a situation is to protect every source of "unlimited" current (battery) by fusing EVERY wire coming off a positive battery terminal. Exceptions would be a short jumper to another battery within 18". As far as what size fuse to run, it's quite simple. The largest fuse you can use would be the one matched to the size of your power cable, which is what you're actually protecting. (1/0 - 350A, 2 awg - 225A, 4 awg - 150A) You can ALWAYS use a smaller fuse, but it may let go if it's smaller than your amp load. Finally you have a fuse between the second battery and the amp. This fuse serves two purposes, and is crucial for your setup. 1. it protects the amp from pulling too much current and frying itself. 2. this wire goes DIRECTLY to a positive battery terminal, i.e. a source of "unlimited" current, and should this wire come out from the amp's terminal it would weld itself to any grounded surface with no protection.

Also you mentioned running the wire through the firewall, did you be sure to use a grommet there around the wire? If not, vibrations from the car combined with the sharp edges of the sheet metal will cut through the power wires insulation and ground your power wire to your chassis for you. At which time, the fuse would open and save your car from a potential meltdown. 1. make sure you put the fuse in 2. always use a grommet when passing through the firewall or any compartment with sharp edges And welcome!

I believe what you're getting at is using two amplifiers to drive the same load, which is known as a paralleled amplifier. Yes it can be done, but it requires a bit of knowledge and some extra thought. The premise of a paralleled amplifier is to increase the current handling capabilities, as it has NO effect on maximum voltage output. In a way it's somewhat the opposite of bridging an amplifier. When you bridge a multi channel amp you double the maximum voltage swing, keeping current handling the same, but also doubling your minimum impedance for the setup. A paralleled amplifier maintains the same voltage swing, but doubles the current capability and cuts the minimum impedance handling in half. (i.e. if it were 1 ohm stable, it would now be 0.5 stable) If you just throw two amplifiers outputs together however they will try to drive current into each other, fight each other, and then overheat. To prevent this you need output resistors in series with each amplifiers output, of much lower impedance than the load you're driving and sized based on the amount of power the amplifiers provide. You'll have to hunt down the formulas to find out exactly what resistor you'll need. Finally, will all this make it "louder"? Maybe, maybe not. If you're current-limited by your amplifier then adding a second amp in parallel can help you put more power to the speaker. But if you're tapped out on the voltage side of things, this will be of no benefit whatsoever. Good luck!

That does sound like a low voltage issue, particularly because it's fine with the bass amp off. If this setup has been working in the past my first suspicion would be of a big 3 wire came lose, or the charge wire has a bad connection on the alt, or the alt has one bad leg. Because there are three diodes, you may not realize it at first when your alt is going out...

Looks pretty cool, but nothing remarkable? I like the curved profile however.

What are your current box and sub specs by the way? If you're running that IB3 ported that could account for part of your unloading issues above 30Hz. I plotted it out in WinISD and see what you're talking about when you say you have to watch cone excursion in the 30-40Hz range. I have never tried a 15Hz port in my box (interchangeable ports) but I think I might try one tomorrow if I can fit it. I would be surprised if it unloads too bad at 30-40Hz

If you get a battery like the ones used on newer cadillacs and many GM cars which are kept in the trunk, these batteries have a built in venting tube which can be extended and run outside of the vehicle. I was looking at this on my sisters car the other day and thought it was a pretty simple, cheap way to put a lead-acid batt in a cabin.

From what I can understand of your post it sounds like you're looking for a design that sounds "good" on 99% of the music out there, but then completely destroys the lows as well. I think you may be able to better tune your desired output with a 6th order bandpass box since you're looking for something fairly specific. Just remember you have to make sacrifices somewhere. There is no such thing as a "perfect" enclosure, because it's all relative to your preferences. If you NEED to peak at 20-30Hz, you're gonna have to accept that most music will play at a lower level.

The voltage drop part is obvious. That explains why the lights are dimming, why the electronics and gauges are resetting themselves and why the amps sometimes shut off completely. The reason could be something as simple as the amps are pulling more current than the trucks stock electrical can provide, or there may be a broken part of the electrical system as ISO suggested. I'm almost 100% certain the front battery, if its a standard lead acid type, is just about done for. They do not like being deeply discharged and then slowly (if at all) recharged when driving with the system off or playing low. I would get a good battery in there, and definitely add a large second battery for the amp. If the alternator is bad this wont solve anything, as the second battery will discharge and you'll be back to dimming lights. If that's the case I would pay close attention to the alternator, and consider getting it tested or simply replaced with a HO model.

Regarding two runs of wire to a sub, perfectly fine and wont affect quality. Especially not at the frequencies we're talking about for bass, hell a stick covered in aluminum foil would probably work. Secondly, strand count is a very poor method for comparing a wire's current carrying capacity, since again, at the frequencies we're dealing with power conducts THROUGH the conductor not on the outer skin as is the case for HF. Not to mention the size of the strand is NOT defined in either circumstance, it's a guess at best. So the proper way to compare the ampacity of two cables is to look at the conductors cross sectional area, in circular mils or kcmils. A 14g conductor is 4106 cmils. Two 14g conductors in parallel is 8212 cmils. An 8g conductor is 16507 cmils. To equal the same current carrying capacity in a 14g cable you would need 4 parallel conductors. Two 14g conductors is between a 12g and 10g conductor, perfectly fine for most subwoofer wiring tasks.

My optima, and previous wal-mart special have all had the GM bolt-on terminals, so it's always been a pretty simple matter of ring terminals on a bolt. This new optima yellow top says to use the side bolts only for starting purposes, so I think I'll pick up the KnuKonceptz terminals which allow 3 sets of 1/0 to be used. I'll need to move the big-3 on these posts so I'll need at least 2 receptacles for 1/0 on the ground, and $18 a terminal isn't TOO bad.

If they are in fact W7's (somehow really doubt it now) then it's not a bad deal if the subs are in good shape. (again, somehow really doubt it) If they're W1's or W3's forget it...you can do better.

Got the 'yella top. I'll be adding another "big" battery in the back as funds surface, maybe a D3100, HC2400 or something similar to join the HC 1800.

I will be running my SAZ-3000D in my blazer and am trying to work out the battery situation. I've got an HC1800 in the back, which I tried to move to the front but can't make it fit nicely. So I'm considering putting a yellow top up front ($162) and keeping my HC1800 in the back by the amp. I've also got a MechMan 250A Rhino alt with external voltage regulation at 14.9V and the big-3 in 1/0 Kicker Hyper Flex, as well as 1/0 to the amp. Will this be enough to run one SAZ-3000D? 250A Alt @ 14.9v (1) yellow top (1) Kinetik HC1800 I kind of need to know quick cause I was going to buy the yellow top today if that's a wise move.

And how about a chambered t-line?

Not to mention MT's are crazy efficient subs, but still the difference in cone area will put you at such a disadvantage against the 15's that the decision should be fairly simple. As far as the reference to Alans setup, that's like comparing apples to oranges. You can't compare a system designed to transduce electrical power into one specific frequency as efficiently as possible to something used to play music. There are more differences than similarities between a setup like Alans and a music oriented system. What Alan does is certainly impressive and respectable, I don't really see any ties to "car audio" with his setup, except that his enclosure is on wheels. To me that doesn't belong in car audio, but we all have our opinions.

Amp model? Subs model? Not enough info..

Yea Neil Barber can pull hair tricks all day long on almost any song. I stuck my head in that thing at SBN last year and the bass nearly knocks you back. I think his is a sealed clamshell too? 24 Kicker L7 10's and 6 Powerbass XA-4000D amps. heh At one point he had to stop giving the demos and re-tighten the screws on some of the subs which were falling out!

Do an impedance sweep?

Dip into the red too often and the amps' power supply will eventually give out. Voltage drop is baddd

Exactly. Or two 40's and watch the volume?

This won't work because the 40 will pop first. They need to be the same size if you're paralleling multiple fuses.