KU40

Hello

Hello

This is where it gets tricky. Take the example of both of them being at 80hz/24dB. It'll still be at 80hz/24dB. If one is set to 160hz/24dB and the other is 80hz/24dB however, the point of the 160hz point will overlap the 80hz one. Which effectively makes the 80hz point useless. It doesn't combine. hmm. Maybe it's different than I think. How is it determined which one is used in the 80 hz and 160 hz example?

So the port comes up the inside of the box then rotates 90 degrees and fires out the front? I don't know that you'd want to do that because your port may act differently than you predict. But I guess you can try it.

wat is ac ?

the crossover reduces the signal by an amount so if the amp is getting a signal that is already reduces it will be further reduced from the original. but it doesnt just drop off from 80hz if it is set at 80hz. if you have a 12db cross over its 12db down from an octave away. there for 40hz would be 0db down 60hz 6db down 80hz 12db if you set the other crossover at 160hz odb would be at 80hz but 80 is already 12db down 160hz would be 24db down from the first crossover plus 18db or whatever the second crossover is, making 160hz 42db down from the original signal I think the slopes do add together because the second crossover (amp) doesn't know that the first crossover is there (head unit). I think it still just crosses it over as it would without the first one there. I think this only works with active crossovers. Passive crossovers vary because the capacitors and inductors would interact with each other differently whether you wired the crossovers in series or parallel (just like dual voice coils). Your crossover points would shift. http://www.bcae1.com/ on page 54 shows the passive crossover stuff. I may be wrong on active though. hmm. The more I think about it the less sure I am. haha. However, dbjunior, I think you're incorrect on the specifics of the crossover slope. In your example, if a 12db crossover is set at 80 hz, it doesn't start reducing the signal from one octave down, 40 hz. The crossover point is the -3db point. So 80 hz would be -3db. But then 160 hz would be 12 db down, 320 hz 24 db down, etc. Where the crossover begins reducing the signal varies depending on the crossover slope. Page 27 of bcae1.com shows a graph with different crossover slopes in it.

hmm, it's snowing. We have about an inch right now, maybe a bit more. This is wild. I was driving around with my windows down on wednesday and thursday, and by the forecast, will be doing it again by Tuesday of this week. Winter just had to get one last thrust in I guess.

what is with everybody posting the DCR of the subs as if it's the nominal load? "I have dual .7 ohm coils......" no, you have dual 1 ohm. "My amp is seeing 1.4 ohms...." No, it's seeing at least 2. AC vs DC people.....

it's not dry rot. It would probably take at least 20 years for that to happen. With a tune at 45 hz and that obvious suspension damage due to overexcursion, 95% chance they played well below tuning and were too deaf to hear the stressing.

and maximum dimensions that the box can be?

well, i believe they do add together in sorts, but at the slope side of things, not the frequency. In that case you'd have a -18db slope from 80 hz down from your head unit, then 36db slope down below 200 hz. It won't hurt anything to have it like that. It's just a steeper slope.

have you ever used box modeling software? Download winISD pro alpha and play with it. you can see the response curve differences with different tuning frequencies of a box. Lower tuned boxes have a more flat response, higher tuned boxes have a greater peak just above tuning. The response curve you'll see on there isn't exactly what you'll find in your car since that graph is based on the enclosure basically being out in the middle of a field and your car will have its own acoustic properties that will affect the response curve. But it's a decent general idea. But if you're wanting the best SPL, it's like Adrian said. Lots of testing.

I'm not even sure how to answer the questions you're asking because I don't rightly know what you are actually asking.

Can't compare house power to car power. There's a huge difference in wire size needed because of the current loads between the two. It's a heck of a lot easier for a wire to run 120 volts than 120 amps. To the OP, I think you'll be fine with your 150 amp alternator and two batteries if you use 1/0 and upgrade the big 3.

OMFG, how can somebody be that stupid? The people on that forum are apparently very mean, or else that kid did something really, really bad to them. He did something extremely stupid. He welded the pinion to the ring instead of the spider gears together. Plenty of pictures of welded gears and he couldn't do it right. This morning I only read the first few posts, but just now I went back and read a few more pages. I think on page 4 he says it was a joke. The vehicle this was coming out of was really messed up (unfixable) so he decided to play a joke on the forum and welded them together then came on the forum and claimed to be naive.

if your box blows apart it can be blamed more on not having enough bracing than not having screws, even if it comes apart at the seam. The reason your box blows apart is because the sides bow out too much from internal pressure. If you brace your box well enough so that the box walls don't bow out, you don't need screws or anything. On every box I've built and tore down, when I broke it apart it broke apart just like an inch from the seam. The glue is stronger than the wood.

OMFG, how can somebody be that stupid? The people on that forum are apparently very mean, or else that kid did something really, really bad to them.

wtf? is the owner going to dry hump her when he gets lonely? Could he not get real chicks?

I'd face it forward and seal it off behind the front baffle. That way you don't have to pressurize the air in the trunk. and I'd personally do the ported box, if that 3.5 cubes is after port and sub displacement.

i'd choose two level 3s.

I'd try cutting some holes in the back to help the pressure escape (but not so much that it makes the deck weak and rattle more), then cover the thing with a bunch of deadener. Really you just need a bunch of mass to put on it to help stop the vibration.

Yeah they may have been touching. Take the sub out and double check your wiring. If you have the two coils out of phase the sub won't move. And if any of the wires is touching the basket of the sub it will send the amp into protect.

That wasn't posted here, was it? I thought I remember it being somewhere before.

ah so you were doing it right and using xmax for port area. I'm so used to hearing people use the 12 sq. inches per cubic foot that I was thinking you were using xmax for length or something. me. Wiring in threes, that's an interesting solution.

and I came home today to literally at least 25 ladybugs crawling around my bedroom window and the wall it's on. Ugh, kinda gross even though they're just ladybugs. I was squishing them for like 15 minutes. I don't even know how they got in, my window is halfway plastic-d up for the winter (ran out of plastic, ha. last window in the house I did).