I am planning on getting 2 15" BL's with about 8 cubic feet of volume in a ported box to about 30 hz (I love lows, the lower the better). So how do you guys think this will perform? Also I have heard great things about Sundown and that they make great amps so what model amp or amps would fit these subs good, and what kind of electrical and front stage upgrades am I looking at to make this sound great? Also I have heard of the Q's hitting upper 140's with just one 15, so would this be that much louder if it is a good setup? Also just to let you know I come from one of those towns where everyone gets a boner for JL's and Audiobahns so I am ready to blow someone away when I get my system and show them what Fi's can do.

For a substage, sounds OK, but you'd need more for a "system".

Also I have heard of the Q's hitting upper 140's with just one 15, so would this be that much louder if it is a good setup?

That's totally vehicle and enclosure dependent.

the lower the better

So go sealed, that ported box is going to have a steep rolloff under tuning...

I completely agree with Jim, you left out the most important part of the system and that is the front stage. Subs without one is pretty ghetto.

The steep rolloff will hurt the lows, but my guess is that your definition of the low-lows isn't that low. Perhaps an example would clear that up. To me it sounds like you want some loud wanging subs, which have nothing to do with low-lows at all.

u came to the right place to get help with your first set-up

i love it here i have learn alot in the month i been on here

I agree with Jim and ///M5, the Sundown amps and Fi subs are excellent, but you should also consider the other portion of the sound being produced.

I did consider that thats why I asked what kind of electrical and front stage upgrades am I looking at to make it sound good not just loud. I don't want all bass but you can't even hear the song if you know what I mean. Also what I meant like lows is I have heard a box tuned to about 30 hz and I liked the sound but what do you mean by roll off I thought that ported is more efficient? I have 6x9's in the rear deck with 5.25's in the front doors and door tweeters. So what kind of speakers should I look at? I know nothing about speaker brands. And what sundown amp would put out about 100 watts for 6 speakers (including tweeters). And this is going to be a 3600 watt system and my car only has a 105 amp alternator so how many amp alternator is going to be needed and what brand of battery makes a good starter and good deep cycle for the trunk. I am hoping to have all the money by the end of the year and be done by maybe February so I am in no rush I just want to be able to make a list of everything I need and how much it will be, I don't want to do it cheap, if I cant get it done that soon I can't Ill just save for longer.

ok what about Boston speakers? I have heard that it is better to replace your 6x9's with just a circle speaker so should I?

It's better to forget you have 6x9's in the first place, and concentrate on what's in the doors.

The Boston Z6's and Pro60's that I've heard have been alright, but they need more than 100W per side. They're very power hungry.

well the pro 60's look like a good choice kinda pricey but worth it if they sound good. So the are rated at 125 watts each so a 500 watt x 4 amp at 4 ohms should work good. Well one thing is the only place I can buy them is crutchfield the closest dealer to me is 60 miles and I wouldn't want to drive all the way there just to price them. And also Crutchfield gives alot of extras when you buy. So is 600 too much to pay for the speaker or about right?

What kind of car?

Either way, I would try to avoid the 5.25's as well if at all possible. I don't think you need rear speakers either.

It is a 2000 Buick Lesabre Limited with the Concert sound 2 package, not bad for stock I actually get enough bass to make head lights jump in my rear view mirror. It has door tweeters also.

So is 600 too much to pay for the speaker or about right?

For those, yes, $600 is overpriced. They go for a lot less on the used market.

So the are rated at 125 watts each so a 500 watt x 4 amp at 4 ohms should work good.

I think you're misunderstanding things. 125W is the combined power rating for the tweet and the midbass, running through a passive crossover. You don't need four channels of amplification unless you're going to be using an active crossover, which might not be a bad idea anyway. Even then, I'm not sure where you're getting that 500W number from.

Well considering the way I was thinking that is was 125 for tweeter and 125 for midbass so 125 x 4 is 500 but I guess I only need about 250 at 3 ohms then if I get the pro 60's. So if I do that through a active crossover then what brand makes a good active crossover? Also should I just remove the 6x9's so that it can be a port into the cabin for the subs? if I do that should I make the subs fire towards the cabin or the lid?

Some people don't like rear speakers, strange people like me do. However like said your front stage (tweeter/mids) will dictate the quality of sound in your car, they are most important along with your HU and anything between the HU and front stage. I would do those and get your subs and amps all going and then worry about rear fill speakers if you want. A real quality 100wrms a side is pretty loud if the front speakers are fairly efficient but that is a matter of personal preference.

Ported box is more efficient and so louder, but below its tuning it gives out and thats rolloff. If you want real low tuning like 30Hz the box will be relatively large, higher tuned ported can be smaller, sealed is usually smallest. Sealed will roll off sooner but still make the lower tones when you lay to power to it. What room you have and what drivers you use make a lot of difference. Usually like my subs in a box to face away from me in a trunk, but it depends on the car and owner really and what kind of sound you want. It may or may not change it.

Active crossovers can be found in good HUs, what are you going to use? Or you might use the filter in the amp or a processor/eq like I use...or both at times.