12W6V2 Ported Box Build to JL Spec. Make it hit lower?

[nobb 10+ year member]

Ive got a JL 12W6V2 in a sealed enclosure, and it sounds great, but it doesnt feel like it hits that low so Im thinking about building a ported box exactly to JL's recommended spec in the manual. I modeled the enclosure with RE's Enclosure calculator here:

http://www.reaudio.com/speaker_box/LPort_Box_Calc.html



The tuning frequency is 30hz. Im wondering if there would be any significant benefits to making the tuning frequency lower by extending the port? Maybe something like 25hz? With the calculator, you can see that the port length required for 25hz will be longer than the length of the box.



Suggestions? This is my first box build, so I have no experience with this. Or if anyone has a better suggestions for a calculator to model this, that would be great.

Click to read more...

 

[ARSkemp 10+ year member]

what music do you listen to? I don't think your going to benefit tuning any lower that 28hz or so for most music, and will probably just start losing output/space tuning lower than that.

as far as that Calc goes, Its pretty much the most user friendly calculator around, but I think last time a tried using it i found that the tuning was slightly higher (1-2 hz or so) than when i calculated it by hand. Maybe someone might chime in with the equations and some links if your willing to do some work calculating the tuning yourself.

edit:

i would also recommend you use a little more port area than what you have in the enclosure calc. Most people recommend at least 12-16 in^2 per 1ft^3 of net interior volume. I, myself, prefer the upper range of that recommendation, but you should be fine anywhere in that range.

 

[Ryan1126]

hey man there is another member on here ( jlaudio10w7 ) that has been having trouble figuring out tuning for his 2 12w6v2's you should shoot him a pm and help him out with that.

 

[nobb 10+ year member]

Thanks for the suggestions. I dont really listen to stuff with alot of hardcore bass, but I do enjoy it being able to hit low. Ive just realized that this thing is going to be huge and take up alot of trunk space. Im thinking maybe I should increase the height and decrease the depth of the box (while keeping interior volume and port area the same).

Im actually running my 12W6V2 in a small generic 1cuft sealed box with polyfill (JL recommends 1.25), perhaps there would be more benefit if I simply built a larger sealed enclosure instead? Really would like this to take up as little trunk space as possible, but Im not sure if the benefits of having a ported box would outweigh that.

 

[ryls 10+ year member]

as far as that Calc goes, Its pretty much the most user friendly calculator around, but I think last time a tried using it i found that the tuning was slightly higher (1-2 hz or so) than when i calculated it by hand. Maybe someone might chime in with the equations and some links if your willing to do some work calculating the tuning yourself..

Isnt that mostly due to the fact that there calc dosnt take into consideration sub displacement? I also noticed that it does take port end correction into place as the one wall is part of the enclosure.

 

[SomeGuyDude 10+ year member]

It indeed doesn't consider sub displacement. I put in all my numbers that I got using WinISD and the tutorial in the installation section and it put the inner volume as just about exactly what the sub displacement was above what I wanted (i.e. I wanted a 4cu box with a sub that displaces 0.17 and this told me 4.17cu). So while it's not HUGE, it will affect the tuning slightly downward, but only about 0.25Hz.

So when using that, adjust the numbers to be tuned a little lower than you want, and the sub's displacement bigger than what you want.

 

[ARSkemp 10+ year member]

Isnt that mostly due to the fact that there calc dosnt take into consideration sub displacement? I also noticed that it does take port end correction into place as the one wall is part of the enclosure.

that might be it, its been a few months since i've built a box, and i dont remember if i compared the calculations with re's before or after i took into consideration displacement of the subs/bracing/etc.

I remember there being a couple threads about it a while ago as well.

 

[okiedokie 10+ year member]

Hey nobb,

I have a 12w6v2, mine does go low.

I have a scion tc in which most people think i have 2-12 's in my hatch, that sub will & can flex my side walls of my car.

So yes you can built a bigger box, up to 1.6 sealed, i hope you will be useing 3/4 mdf-birch or any dense wood.

your amp does play a great part to, that sub sounds best on 500-600, but it not only watts that will mak it sing, all amp arent the same.

I have JL 500/1, I really like the Slash EQ, & yes it does make a difference.

So wt im saying is if you have a solid amp, then just focus on you box & once you find it that sub will hit hard & go low...

For me sometime that has to much BOOM for my taste, I like more SQL without all the BOOM BOOM BOOOOMMMMMM

 

[nobb 10+ year member]

^Isn't 1.6 sealed a bit big since JL only recommends 1.25? Do you guys think there will be a noticeable (perceived) difference if I were to go from a 1cuft sealed enclosure to a 1.6cuft? With my 1cu.ft enclosure, it's definitely tight sounding, but occasionally I do like a touch of boomyness. I ran a frequency sweep, and I swear I could hear it starting to roll off after about 40hz with my current setup. All my home speakers have subs that can hit 25-30hz at -3db, and that's what Im trying to aim for.

I think maybe having a ported box wont be feasible due to how big it will be. Im powering the sub with an Alpine MRP-M850 (800 watts rms), but I almost never push it that far.

 

[SomeGuyDude 10+ year member]

I wouldn't suggest going much above what they suggest for the sub. I mean, maybe the thing can handle it, but going higher than what they say risks having the thing start to act like it's got more free air than it can safely flap around in.

 

[okiedokie 10+ year member]

you can call JL & they can give real world specs.

every sub is different, Since i have a 12w6v2 i can give what i've done with that sub.

1-A 1cubit foot box will not go as low or you want have much boominess,

2-1.25/1.6 is where that sub starts to shine.

When i give advise it isnt because of something i just read or something someone to me.

I will say one thing i like about the 12w6v2 is that it is a well built driver.

I had a alpine amp 500watts pushing that sub & it didnt sound good to me.

But when i added my Jl 500/1 on it that sub came to life.

funny flap around???

I think the 12 & 13w6v2 are JL's best sounding subs.

 

[alexregalgs 10+ year member]

sealed ftl...and im having a hard time believing this "500" watt alpine wouldnt sound the same as the 500 watt JL...i think the difference was user error(ohm load)

 

[JL duB 3's 10+ year member]

When using JL's specs to make a box you will not get the most outta that sub. jl creates specs that will prolong the life of a sub rather than have the sub reach a higher spl

 

[nobb 10+ year member]

When using JL's specs to make a box you will not get the most outta that sub. jl creates specs that will prolong the life of a sub rather than have the sub reach a higher spl

Is this just speculation, or is there a source of information for this? Unless someone knows an actual engineer, it's really hard to tell. I doubt having a box slightly larger or smaller will significantly affect the lifespan of a subwoofer.

 

[GlocksRock 10+ year member]

Vitveet built me a JL spec box for my 2 12W6V2s and it sounds amazing, it's tuned to 32.5 hz. and sounds amazing, and also gets very loud.,