Jlw7 help

[Fat...Lac]

I got two jl 12w7 and two I'd 1x1000 jl jx. I will upgrade to the hd someday. First off. The subwoofers get incredibly low. Whole car shaking reiw view mirror fell off in a matter of seconds. So here is the deal. With low long bass lines it sounds great. Like three 6 mafia who run it sounds amazing. But a song with short burst bass like bow down by west side connection the sub distorts and does does not hit real hard. I quickly lowered the volume. The box is not double chambered and is about four cubic foot after port and displacement. It is tunned to 35 hrz. So need some advice. Is it the box or my settings? My crossover is set at 80 -12db. My gain is about a fourth of the way turned up along with the bass boost at 1. Any advice would be great. My past three subs have been sealed and I'm now thinking of going back to that

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[LosIsATool 5,000+ posts]

Probably has to much port area. That's why it seems so loud.

 

[Fat...Lac]

So you would suggest a new box?

 

[Papermaker85 5,000+ posts]

What your experiencing is called a underdamped response. Now determining if it's the sub or the box or port area is more so experience.

Those spiders are soft but very linear and you must use a much smaller enclosure in order to keep the damping critical.

Try 1.4 tuned to 32 with 35in^2 per driver if you wish to use more port area lower the box volume otherwise it's going to do the same thing

 

[VWBobby 10+ year member]

Also turn off the bass boost and set your EQ flat on your head unit. 80hz LPF is a good starting point, but you may need to bump it up or down to get the right blending of the sub to your comps.

It may help, but I think Papermaker has the best answer.

 

[Boomin_tahoe 5,000+ posts]

4 cu ft seems a little small for 3 12's.

12W7-3 - Car Audio - Subwoofer Drivers - W7 - JL Audio

 

[Massive spl]

Turn bass boost off. It's prly trying to boost and causing distortion... I would not put it in a 1.4cube box like recommended above... Most likely it's your amp settings or HU settings. Just need to tune it in

 

[Boomin_tahoe 5,000+ posts]

Almost sounds like the subs are struggling each other in that enclosure.
@CSCStang for a design.

Post up a current pic of yer box.

 

[Massive spl]

4 cu ft seems a little small for 3 12's.
12W7-3 - Car Audio - Subwoofer Drivers - W7 - JL Audio

I think he only has two 12s

 

[Papermaker85 5,000+ posts]

It's a damping issue. 4 cubes is about 1 cube to big unless you want a bloated lowend. The alignment I offered will give him a wide flat response..

 

[Boomin_tahoe 5,000+ posts]

I think he only has two 12s

Oh ya...yer right. Why I was thinking 3 who knows. Imma go stand in a corner for 10 mins and think about what I did wrong.

 

[Boomin_tahoe 5,000+ posts]

[quote name='papermaker']It's a damping issue. 4 cubes is about 1 cube to big unless you want a bloated lowend. The alignment I offered will give him a wide flat response..[/QUOTE]
@Massive spl likes lowend....and that's what subs do. Provide lowend.

 

[Papermaker85 5,000+ posts]

[quote name='Boomin_tahoe']@Massive spl likes lowend....and that's what subs do. Provide lowend.[/QUOTE]why did you quote me? I'm trying to help the original poster. Unless you have an answer for the op or you are correcting me you have no relevance..If you want me to explain why I'm suggesting I'll be glad to..

 

[Massive spl]

why did you quote me? I'm trying to help the original poster. Unless you have an answer for the op or you are correcting me you have no relevance..If you want me to explain why I'm suggesting I'll be glad to..

Your attitude is getting old around here. Your givin bad advice around the forum.. In another thread u said put a sp4 15" in 4.25cubes tuned to 40hz on 1000watts... Umm no that woofer is a big box low end woofer. More like 6cubes tuned to 30hz on 1000watts would hammer.

Same goes for these jl w7s just because it has a soft spider doesn't mean they need to go in 1.4cubes... That's small for these high excursion low distortions woofers. 2-2.5 ported is nice for these w7s each. The OP problem either lies in his tuning/settings or his port is off.

 

[Papermaker85 5,000+ posts]

Turn bass boost off. It's prly trying to boost and causing distortion... I would not put it in a 1.4cube box like recommended above... Most likely it's your amp settings or HU settings. Just need to tune it in

Its supposted to be 1.5. And FYI if you don't understand dampening and how it affects frequency response I'll be glad to help..

The stiffness on those drivers really aren't ideal for vented alignments. Although they do have ways around it there just not ideal..

You have to have a certain stiffness to mass ratio for vented alignments to obtain critical damping. This causes a underdamped response. Making the enclosure smaller lowers it's compliance to compensate for the softer suspensions used.

The higher qe also means that it has a wider bandwidth electrically wherein the driver resonates and this naturally means easier low frequency reproduction visit great sensivity..

And I'm talking in the sub bandwidth we

Here in the human perception is ruffle 20hz to 100hz typically closed to 30-70hz cause most people know next to nothing about speakers