Need a little help

[Bumpin300 0]

Hello,

I am new to these forums and to Fi, but not the car audio scene. I am looking for some help with my particular set up as I do not know much about Fi. I have read many good things about the product and have read most of the articles in these forums, however, I find myself stuck on a difficult choice.

First a little background is in order. I do prefer SQ over SPL. I have had many systems over the years, all with the primary goal of SQ with a little bumpin from time to time . My last car (a 97 cobra) sounded really great as I removed the rear seats to build my sub box. I had 3 12" JLw6's with a PPI PCX 2400 running them in a custom fiberglass sealed box. The subs got signal from a ppi frx456 x over and from an alpine 7969 headunit. The bass was really tight and had great extension.

Fast forward a few years and I now have a different car a chrysler 300c (kids ya know). I wanted a little bump back in the car so I went out and got a pair of 10" JL w3v3's and put them in a sealed box with a PPI pcx 2200. To say I was dissappointed was an understatement. The bass was almost non existant compared to what I was used to but it was tight. I have never had to deal with such a large car and a truck car. I realized I needed some bigger guns so I went shopping again. I live in Vancouver, BC so some brands are not sold around me. I ended up finding a Digital Designs dealer and having done a little research about the company, bought a 3512 (in a slot port 2.25 cf @ 40hz) and an M2 amp (1700x1 @ 1 ohm). The result - the output was improved greatly, however, the bass sounded muddy and slightly off beat (i know i can fix the off beat with time correction. i have an 880prs). so now i have a louder car but not the tight, punchy bass I like.

So I did a little more digging and found a lot of rave reviews about the Fi product line and now I must ask for some help. I am interested in the Q line as it sounds like what I am most after. I will be upgrading the M2 amp that I have to an M3 (2700x1 @1) very shortly so lack of power will not be an issue. I have room for 2x 12" Q's in 1.5 cf net sealed boxes or 1x 15" whatever in 3.5 cubes net @ 35hz. my delema is thus. which set up to go with? I like the tight bass of a sealed box but I am worried about output as this car I drive is large and has a well deadened trunk. I like the output of the ported box, but I do not like the muddy sound it creates (maybe that was a function of the driver as well?). Keep in mind that I do like to turn it up from time to time . So 2x12" sealed or 1x15" ported?

Thanks in advance for your replies.

[johnnylemoine 0]

are you sure u cant squeeze a 4 cuft box tuned to 33 for 2 12's?? im a sucker for ported boxes i usually tune to about 30-35 but if u cant fit 4 cubes i say got with the 2 12's sealed.

[Fi Car Audio 64]

If not... the pair of Q12s will do great. Id do them in about 1 cuft each after displacement. It should have similar overall output to the 3512 (slightly less around tuning, and then more above and below) and should meet your SQ requirements nicely. The Qs do take some time to break in and really open up when they do.

[dopey 0]

I'd go as big a ported box as you can fit with a 15" BL or BTL.

The BTL is closer to what you'd want wattagewise, but is considerably more expensive. (Loaded=$469) But still cheaper than 2 12's.

[Bumpin300 0]

Thanks for the replies. The space that I am willing to give up in my trunk is about 4.5 cubes gross internal volume. So that nets me a maximum net internal volume of about 3.5 with driver and port at 35hz. Not quite enough for the 2x 12" i think. If the Q 12's only need 1.2 cubes each sealed, what do you think about 2x Q 15" sealed in 4.1 cubes? Is the 15" musical at all? Is 4.1 cubes too small?

Thanks

[dopey 0]

I'd use 1 15 ported. Which one should be determined by what you want to acheive.

Q for SQ, BL for SPL, and BTL...well I just LOVE my BTL. Great SQ and it's LOUD as all get out! With only ~900 watts, I freak ppl out when they find out it's one sub, and <1000w. I've had MANY people tell me thats the loudest system they've ever heard.

So I'd suggest a fully loaded BTL 15. In 3.5 net, that sub would HAMMER, yet still sound great.

The BTL is a VERY "tight" driver. The bassdrum kicks are controlled yet authoritative. Dave Matthew's band sounds great, as does old Police. Metallica's "One" breakdown is SOOOOOO clean. I really like the way the sub can handle 10x the wattage I've put on it, that means I can WANG the crap out of it and not worry about damaging it. VERY tough driver.

Edited May 28, 2007 by dopey

[tejcurrent 13]

I vote the 2 12s. If you can't fit them ported then go sealed. If you can fit 2 sealed 15 Qs then I'm a sucker for larger subs-I'd vote that way. I think you'd get a lot more output and plenty of sq. I know my ported 18 btl sounds crisper than most 12s I hear, so 15" Qs should sound very nice in a well built sealed enclosure.

I like ported enclosures myself, but if you could only fit one sub that way I'd think the BTL would like the power you have better than the BL, unless you just want a lot of overhead (which is good for SQ- so your call). I'm happy with the btls sq.

Good luck either way.

Edited May 28, 2007 by tejcurrent

[Bumpin300 0]

OK,

I went to my local box builder and we worked out a box that is 5.02 ft^3 gross internal volume using 3/4 MDF. This does not include bracing/driver displacement/or port volume if used. So now knowing the limits of the space provided, how should I proceed? 2x12" ported? 2x 15" sealed?

[dopey 0]

1x18" BTL ported.

A bit shy of perfect...but good and loud. And cheaper than 2x12 or 2x15. However....2x15" Q's would be damn nice.

It really doesn't matter...you'll be MORE than happy either way.

[dopey 0]

NVM...5cubes gross is ~4cubes net. @33hz.

Back to 15" BTL....loaded.