BKOLFO4

So the port is 20.5" high. . . You are tuned a little higher than 31 Hz. Also, the sub has to loosen up a little. About 1 hour of hard playing and it should sound different. You could add a piece of wood to the port to make it 4.25 inches wide and see if you like how it sounds. Add it to the inside port wall and run it into the box so it is 5" from the back wall. Also - What is your crossover set at? Not going to hit higher notes if the crossover is set too low. Brian

Does the box sound good when you are not a full volume? Clipping will occur when you are going beyond the amplifier's limits. . . Does not matter what your battery voltage is, you can still clip. Can you post up the box dimensions, including the port dimensions? Brian

Box is a little bigger than I would have made it. Most 18's I have used sound good in 6-7 ft net. For your box, I come up with a tuning around 36 Hz if the port is 20.5 x 5 x 15.5. . .maybe it is not 20.5 high? If the dust cap is getting hot on 1000 watts, you are clipping pretty hard which is another reason it sounds bad. The dust cap getting hot is not related to the box size. That is a thermal issue. Brian

Those amps love low ohm loads. With impedance rise, you would have been better off with dual 1 ohm coils. It was a very noticable difference when I went from dual 2 ohm to dual 1 ohm coils runnning my amps at 0.5. You are not far off with your port area, so it should not be a problem unless you are not tuned where you think you are. If you make a port plug, it might or might not make it sound louder. the change in tuning frequency would make the difference more than the amount of port area. You could strap the amps on all 4 coils in parallel just to see how loud it is. That is a 1/4 ohm, but with impedance rise, those 20.1's should handle it just fine for long enough to see if you just want more power to get the output you are looking for.

I bought my 4 used and they were all over the place for sale. . . Man I am thinking about buying 4 more. Hope I can find them.

x2

2.5 ft @ 32 Hz will work great. I would not go 3 unless you are not running much power. . . I run my 15's in 3 ft @ 35 Hz and they sound awesome. Brian

Pair of Havocs?

You can always add angles in the corners for airflow and to take up volume if the box is bigger than needed. I do that on boxes where the depth is close and I do not want to add the 90 in the port. Make the box deep enough for the port and then fill the corners to remove airspace. you could do the same thing with aeros. . . Brian

http://www.soundsolutionsaudio.com/forum/i...?showtopic=7158 I would guess it might be an extra day or two with the extra orders for the new product. . .

You may run into issues with the port if you are planning on one port against one side of the box. A 26.5" port length puts the port 2.75" from the back wall. If you leave it 8" from the back wall, it calculates to be a 30" port length, but in my experience, it seems like when they are that wide it does not always work out exact so you may be ok. If you put the port in the middle and ran it in so it is 4-5" from the back wall, it would work better. . . And better yet, you really do not need that much port area. 6.5" wide is plenty for 5 ft^3, so you could redesign with less port area making the port length shorter. Take width off the overall box to keep the depth for the port.

Those amps are under rated, but 1500 watts at 2 ohms seems high. With impedance rise, I doubt it is actually producing 1500 watts, but any increase in impedance would also decrease the rated output power of the amp. . . Does you meter read true RMS? What frequency did you use? Were the subs connected while you measured? Brian

Now we are talking the same language. . . .

Why do you have to go larger, length of the port? what are your dimensions?

I do. I hope you understand what I am saying. . . .

I think I said "if they are installed correctly". For a standard designed box in a daily driver application, I do not see a pair of 12W7's on 2000 watts ever being louder than a pair of 18" BTL's on 2000 watts. If they are, the BTL's are not in the correctly designed box. With that much power, the maximum excursion of the drivers is not going to be a big factor (both have more than enough excursion), but the cone area of the BTL's is a big advantage. When I first got them I ran all (4) on a single 40.1 (I only had one), so that was around 1000 watts each. Sounded awesome. Yes, right now I run around 16,000 on them, but I can guarantee you that 75% of the time they are only getting around 800-1000 each and they are more than loud enough and sound awesome. Brian

Man you guys kill me over and over. 2000 watts is the rating of a BTL, but it does not have to have that much to sound good. I am not saying everyone needs a BTL, but over and over people post "don't buy a BTL without having at least 2-3k watts". They sound great with 1000+ watts. I personally love they way they sound for an extreme daily driver. If the BTL's are installed correctly, there is a 99% chance (2) 18" BTL's on 1000 watts each will be louder than (1) 18" BTL on 2000 watts, and they are going to kill the 12W7's in SPL. Brian

ZX2500 is a very nice amp. . .great match. Just be sure you get dual 2 ohm coils. Wire each driver's coils in series, then parallel them for a final load of 2 ohms.

You have more than enough room for (4) 15s in that box. If you have a true 1500 RMS per sub, I would add the BP power. If you are good at controlling the volume and keeping the power clean, you should be ok without it. Just remember, no warranty for burnt coils Brian

I tried that a few times, but there was more than once that it gave me the wrong info. . .be sure to manually check it once you have the design. Brian

I design mine the "long way", but it always works, and it is just how I like to do it. Determine NET box size required. Determine max dimensions, which will be used to determine the port height and width (using 12-16 sqin per NET ft^3 of box). Calculate port length here: http://www.carstereo.com/help/Articles.cfm?id=31 Add up port displacement (include the port wall), driver displacement, and net required volume. Determine W x H x D required for the calculated gross volume (If not enough room for gross volume - rethink the net volume required and/or smaller port. If it is still too low, consider a smaller/different sub). Make sure the port and sub will fit when determining the true W x H x D. Calculate true net volume with the port actually placed in the box. Make slight adjustments to the box size and port length as required for target design. Finished After you have done a few, it is pretty darn easy. I can put together a standard slot port box for daily driving within a few minutes. Brian

What vehicle? What box size? What amp(s)? (4) 12's is more cone area, but with enough power, I think the 15's would have more potential. Brian

Man, pictures cannot capture the beauty. I was going nuts when I got this thing uncrated. This is a 15". The picture HAS NOT been resized in any way. The motor is just so big it makes the picture of the sub look flat. It is just crazy. . . Seriously. Anyone that thinks it looks funny will eat their words the first time they see one in person. Crazy. . .still can't believe it. . .

I run 3600+ watts RMS and don't have any problems with heat until I start clipping pretty hard. I can play mine for a long time (longer than I want to listen ) without any problems. Dust caps will barely be warm. Brian

Mine do not. Scott just told me quickly it is an aluminum ring for further heat inductance. I did not get enough info from him to try to explain how it is setup and works. . .