subwoofer having trouble "rolling" into low frequencies

[mac336 10+ year member]

Have a JL 8" w1v2 (in a small sealed box). On some songs where there is a bass that rolls off into the low frequencies, the sub rolls fine but once it gets into the lower end of midbass the SPL tails off. It is still hitting the low frequency, but it cannot maintain volume at the low frequencies. Is this a problem with all w1v2 or just the 8" because its smaller; or does the sealed box have anything to do with it. I have to stick with 8" to keep space in my car, so I was wondering if going to a 8" w3v3 would solve this issue. Any input would be appreciated

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[CAT MAN 5,000+ posts]

its the crap box... build a ported for them tuned around 32 for those low lows

 

[mac336 10+ year member]

So the sealed box design is crappy, or do sealed boxes in general have trouble doing this?

 

[CAT MAN 5,000+ posts]

So the sealed box design is crappy, or do sealed boxes in general have trouble doing this?

both

 

[mac336 10+ year member]

Would going with a w3v3 in better sealed box work, or should I just go ported. I kind of want to keep the punchy high and midbass, but I want it to hit those low frequencies and roll off when a song calls for it.

 

[TaylorFade 10+ year member]

Small sealed is great for that "tight, punchy" bass, but lacks low end extension. Sealed boxes are "tuned" just like ported boxes, but by the size of the enclosure. The best frequency response you'll get is a Q of .707 and is probably where JL recommends the box be built (whatever that size may be). I assume since you said small sealed that it's on the smaller side of that (which will hurt your lows). The flip side is that if you go larger than recommended, you'll lose the upper range that you seem to enjoy.

You can get or build a bigger box, or a simple solution may be to stuff the box with polyfill. This "tricks" the sub into thinking it's in a larger box. I believe the standard is 1lb for 1 cube?

I'm not sure on the difference between the w1 and the w3, but if it's higher power handling, that will definitely help with low end extension.

But like CatMan said, if you have the room, just go ported.

 

[goingdef 10+ year member]

I don't know how well that speaker is going to take you want it to do in a ported box it's a low power low excursion driver. I have destroyed T2's trying to do what your going for it takes a good amount of power and cone space and a box set-up to do it.

http://i186.photobucket.com/albums/x81/animalnut1310/P5310060.jpg

I destroyed two of these^

but was able to do this> http://i186.photobucket.com/albums/x81/animalnut1310/P6170006.jpg

it sounded like you where talking into a fan at 15hz! ripped a ton of sheetmetal in the trunk and back decklid and busted through three trunk latches and of course the windshield I played that until you couldn't see through it about 5 minutes, they cost a good amount and cost even more to keep fixing the car and replacing bulbs but they where worth every penny! but ever since having my kids there always something more important that needs to be tended to.

 

[mac336 10+ year member]

Ok so I need to get a ported box if I want the lows, but I want to keep the tight SQ and atleast a little bit of punchiness. Maybe a 8w3v3 or 6w3v3 in a small ported enclosure will do the trick. Would a 6" sub have trouble getting low frequencies?

 

[goingdef 10+ year member]

Ok so I need to get a ported box if I want the lows, but I want to keep the tight SQ and atleast a little bit of punchiness. Maybe a 8w3v3 or 623v3 in a small ported enclosure will do the trick. Would a 6" sub have trouble getting low frequencies?

Maybe the RIGHT 6" but not just any and it's going to need a 100% perfect box design to do it.

 

[mac336 10+ year member]

6w3v3 is what i was looking at.

 

[TaylorFade 10+ year member]

Generally speaking, the smaller the sub, the higher the resonant frequency (Fs). So, smaller subs have trouble getting low like larger subs. It's not 100% true 100% of the time, but it's a good rule of thumb.

If you look at a properly modeled sealed vs ported box on a frequncy response chart, all you'll really see is that the F3 is much lower for the ported alignment. The F3 is where the box is -3db. IIRC, for sealed that's usually around 40hz for an "SQ" oriented design. And depending on the rolloff, you could be looking at -6db by the time you get to 30hz. That's huge.

I say build a ported box and see how you like it. I bet you will.

 

[goingdef 10+ year member]

Generally speaking, the smaller the sub, the higher the resonant frequency (Fs). So, smaller subs have trouble getting low like larger subs. It's not 100% true 100% of the time, but it's a good rule of thumb.
If you look at a properly modeled sealed vs ported box on a frequncy response chart, all you'll really see is that the F3 is much lower for the ported alignment. The F3 is where the box is -3db. IIRC, for sealed that's usually around 40hz for an "SQ" oriented design. And depending on the rolloff, you could be looking at -6db by the time you get to 30hz. That's huge.

I say build a ported box and see how you like it. I bet you will.

the only reason I say "some" is because years ago about 16 to be exact I loved my home audio and I had a carver receiver and a carver amp all thx certified and I started with cerwin vega dx-9's but after tearing the cones on both woofers in a 6 month time span I went ahead and saved up again and bought REAL jbl's they where dual 6"s in each enclosure with a bi-radial silk dome tweeter with a special(at the time) port on the bottom they cost a couple grand but man they where bad@ss they hit not quite as hard as the vega 15's but so much cleaner with the most awesome low end excursion you could imagine out of such a small speaker, I pulled one woofer out once and the motor was the exact size of the box cutout and about 4" thick, they where by far the best sounding speakers I have ever owned totally bi-amped so I had tons of control over each aspect of the sound and 500rms running to each!

sorry for the rambling I was just re-living my youth, d@mn it was fun!