bkolfo4

As long as you have enough room for the second 18, it will definitely be a nice gain. If you have an issue with airspace for a pair of 18's, you may get more output, but change the frequency response.

x2. Never foamed. Just build the baffle 3" thck and make it fit!

You say NET volume. So is that a ported enclosure? How big is the port, and what is it tuned to? Maybe that is GROSS air space, or you are looking at sealed?

I would not go with 7 cuft with SMDs. 6 is enough with 5k per woofer. Save the extra volume for more port area. 100 sqin per sub would be closer to what you want, not 100 sqin total.

Almost four years ago I bought my now 13 yr old son a cheap Chinese 4-stroke dirt bike. This week it was time to upgrade. . .paid $400 for the cheap bike, and sold it for $400 on Sunday. Bought the 04 YZ85 that is like new (very few hours on it. Motor is like new, original tires, chain, sprockets, brakes, etc. all like new) yesterday for $725. Doing pretty good considering the old bike did not have a clutch and nowhere near this much power.

I have a few if them new in the box out in my shop. PM me a zip code and I will figure out a price. Brian

Just figure the length of an equivalent area square port.

That is 4.5-6 cuft net volume after port and driver displacement. You need to determine the exact dimensions your box can be and decide if you might be better off going with a 15" driver.

If you are building your own box, try different setups. Everyone said my suburban would be loudest subs up, port back. Turned out subs back, port back was almost a full dB louder. MDF is cheap if you are really want to figure out what is loudest.

Are you set on RE? Sounds like a good fit for the AA Chaos. . .

If underpowering damaged subs, you would have to listen to them at full volume all the time or they would get damaged. Had a kid call me and let me know that crutchfield said that logic is not true. "A 600 watt amp outputs 600 watts all the time. It is just the voltage that changes."

Good job! There are a lot of people that have no idea what it takes to get from 150 to 155 and how much more pressure that is sitting in the vehicle!

Does not matter if it is 2 crossovers. If they were in the same case and/or on the same board, they are still individual circuits. Inductors increase in resistance with frequency, caps decrease in resistance in frequency. If you draw out the complete schematic and analyzed the circuits, you would see that over the frequencies the midbass is playing, the mid and tweeter circuits are a very high resistance, so the fact that they are in parallel with the midbass does not affect the overall impedance in that frequency band (4 ohms in parallel with several hundred ohms is still pretty much 4 ohms. Add the crossover component resistance, an it actually looks like more than 4 ohms). Same thing in the mid band - midbass circuit and tweeter circuit have a very high resistance. And the same over the tweeter operating frequencies. Not trying to beat this to death - just trying to help everyone understand how a crossover works. Not only does it provide low pass and high pass filters, but when it is designed correctly it will maintain an even load to the amp. I get this question a lot - people think they need an 8 ohm mid and an 8 ohm tweeter to build a 4 ohm component set. . .

If it is a true 3 way setup, it will be 4 ohms. If the mids are not bandpassed, then it will be 2 ohms over the frequencies where the midbass and mids overlap, but 4 ohms above the frequencies where the midbass speakers are low passed. Brian

Is that an actual 3 way setup, or a 2 way setup and you are going to add a low pass crossover and midbass driver?

Depends on the crossover design, but yes. The caps and coils in the crossovers filter AC current. A DMM will measure DC, so it will not measure correctly, since a charged cap has an infinite DC resistance. An example - measure a 4 ohm tweeter with a cap in series - it will be a really high DC resistance, but will be 4 ohms at the frequencies above the crossover frequency when playing music.

You will not get an accurate DMM reading through a crossover. Caps will look like an open circuit with DC applied, so DCR will be infinite. If the crossovers are designed correctly so that the frequencies between the 3 drivers do not overlap, the amp will only "see" each driver within it's frequency range. This means they do not act like drivers in parallel. Any frequencies that the crossovers allow over lap between drivers, the amp will see those two drivers in parallel. If there are resistors in series with any drivers, it would affect the reaistance over the frequencies that driver plays. Coils in series will add some reaistance, but normally well below 1 ohm.

Are you sure it is not FW and FC? Flat wound and full cooling

1000-1200 each? I am guessing for a pair? $300 each, or for the pair?

Please explain. . .

Have to look at what will fit and how much power you plan to use.

Mayhems are awesome subs!

I ran 2 Mt 18's in 13 cuft on 16,000 watts. 2x4's are 1.5" x 3.5" 1.5 x 3.5 x 13.5 / 1728 = 0.041 cuft each

Subsonic filter The larger box will reduce the mechanical power handling.

The SMD runs better in a smaller box than the old RE HC. 7 ft is fine, but the SSF will be required with that much power. You may still have thermal power handling issues, but at least you can control the mechanical power handling with the SSF. Definitely brace at least from the top to the bottom next to the driver opening. You could make the top of the box 1.5" thick and lengthen the ports. You should still have ~6.5 cuft net volume.