Problem with JL 12W3v3 Sub

[gercho]

Hi guys, I´m looking for some help with two JL 12W3v3. I've started a thread some time ago an finally build a sub box with the spacification annunaki gave for this sub: a 5.5ft^3 enclosure with a 2.5" x 16" vent 40" long. This tunes it to 21hz.
There's two problem with this box. One i the wife, when she saw the size of the thing I have to suspend the construction of the second box for the other 12W3v3.
And the second is that I've to adjust the amplifier power between music and movies to avoid damage to the sub. Wtih music I can go almost full power (Yamaha P3500S) but with movies (Ironman movie, the F-22 vs Ironman scene) If I don´t dial the power to half, I'm in serious danger of sub overexcursion.
Can you help me with both problems? Can I make the box smaller? how much SPL I'll loose? It would be better go sealed (TLS Guy modeled them but not very encouragin results)?

Thanks in Advance for your help.

 

[lsiberian]

Hi guys, I´m looking for some help with two JL 12W3v3. I've started a thread some time ago an finally build a sub box with the spacification annunaki gave for this sub: a 5.5ft^3 enclosure with a 2.5" x 16" vent 40" long. This tunes it to 21hz.
There's two problem with this box. One i the wife, when she saw the size of the thing I have to suspend the construction of the second box for the other 12W3v3.
And the second is that I've to adjust the amplifier power between music and movies to avoid damage to the sub. Wtih music I can go almost full power (Yamaha P3500S) but with movies (Ironman movie, the F-22 vs Ironman scene) If I don´t dial the power to half the sub I'm in serious danger of sub overexcursion.
Can you help me with both problems? Can I make the box smaller? how much SPL I'll loose? It would be better go sealed (TLS Guy modeled them but not very encouragin results)?

Thanks in Advance for your help.

You need to use a subsonic filter like the reckhorn B2! Put it at 21hz and you should be ok.

5.5 is a mammoth box. You might try a smaller alignment to satisfy the wife. I wouldn't go above 4 cu ft ported unless you have a dedicated room. I think sticking to 1 driver may be the wise move here. Sell the other get a good HPF. You probably don't need a max gain on your yamaha either.

 

[annunaki]

Are you using an infrasonic filter with this enclosure? If not that is most likely your issue.

If I did not mention this at the time, I sincerely apologize.



With that design, at a minimum, a 20hz high pass 2nd order filter would do the job with 300 watts rms or so. The 20hz FMODs from PE would work for a minimal amount of $ here.

 

[billy p]

I wouldn't recommend the B2...I had to send my back due to issues(sonic bursts or loud popping when you power on/off). After further testing with additional units they appears to have the same inherent problems...so I switched to the ED eq2...fwiw.

 

[gercho]

Thanks!!

Hi guys! thanks to all of you for your advice, I'll be posting pics of the project. I've made the box just for testing, when I'm sure about the dimensions I'll be building a new pair. The problem right now is the siza of the box vs the wife. There's no way I can fit two of that monsters in my living room (5.5 cubic feet).
Do you have any suggestions? go sealed? (the 12W3v3 are good enough for that?) A redesigned slot port box of about 4.5 cubic feet?

As usual, thanks you very much for your help.
Gercho.

PS: With sealed I'll be avoiding the subsonic filter, right?

 

[gercho]

P3500s

Hi, I was checking the Yamaha P3500S manual, and have a High Pass filter from 25Hz to 150Hz, can I use this until I buy a crossover?

 

[annunaki]

Hi, I was checking the Yamaha P3500S manual, and have a High Pass filter from 25Hz to 150Hz, can I use this until I buy a crossover?

Yes you can.

 

[lsiberian]

Hi guys! thanks to all of you for your advice, I'll be posting pics of the project. I've made the box just for testing, when I'm sure about the dimensions I'll be building a new pair. The problem right now is the siza of the box vs the wife. There's no way I can fit two of that monsters in my living room (5.5 cubic feet).
Do you have any suggestions? go sealed? (the 12W3v3 are good enough for that?) A redesigned slot port box of about 4.5 cubic feet?

As usual, thanks you very much for your help.
Gercho.

PS: With sealed I'll be avoiding the subsonic filter, right?

Sealed would give you less headroom from 20-30hz so I'd not recommend it unless space or construction complexity are your reasons for going sealed. Many folks don't want the stuff on soundtracks below 20hz so if you are one of those a subsonic filter would be helpful. Slot port's require additional woodwork so keep that in mind.

 

[GO-NAD!]

...The problem right now is the siza of the box vs the wife. There's no way I can fit two of that monsters in my living room...

Umm, is the room so small that you can fit either your wife or a sub? Plus, I don't know your wife, but most women I know don't appreciate being called a monster...

 

[ParadigmDawg]

I would build a 3rd box and put the wife in it

Umm, is the room so small that you can fit either your wife or a sub? Plus, I don't know your wife, but most women I know don't appreciate being called a monster...

 

[annunaki]

You could do sealed enclosures if you wanted. A 3.0ft^3 enclosure will net you an anechoic f3 of about 35hz which is not too bad. Two of them properly placed with room gain will do pretty well.

F6 is at about 28hz and f10 is at 23hz. This assumes a 20hz high pass filter 2nd order to keep xmax in check with 300 watts rms.




Moving to a 4.5ft^3 vented enclosure tuned to 24hz (again using a 20hz highpass filter 2nd order, think FMOD here, with 300 watts rms) will result in an anechoic f3 of about 23hz. F6 would be 21hz and an f10 of about 19hz. The slot vent required would be a 2.0" H x 14.0" W x 24.60" L and yield a vent velocity of around 16m/s. You give up some extension here but still a very capable sub system. You should have usable in room response to the mid teens so long as you use a high pass filter at 20hz.

The vented option gives you a full 8.5db advantage at 25hz over a sealed option. This will sound nearly 2x as loud to the ear.

 

[gercho]

Thanks annunaki for your reply. Sorry for the long delay. I've been busy with other things.
I'm still using the test box (5.5 cu ft) I've made with a friend, very pleased with the sound (once I use the P3500S sub filter). The problem is that's a very big box. So I'll probably go wtih the box you modeled in your last post (of 4.5 Cu Ft). I'm going to built two, so I think output shuldn't be the problem. Other thing I've noticed is that the P3500S is a little too much for the JL 12W3v3 (even though it's rated 600W and the P3500S is rated 500W at 4ohms).
Again, thank you very much for your help (and the advice un humor of all the guys) I'll let you know how it goes once the boxes are built.

 

[gercho]

better late than never, this is what the subs looks like finished.

 

[annunaki]

They look nice Gercho! 4 years later isn't too bad I suppose

 

[gercho]

Thanks Annunaki! I was bless with two girls in the meantime, so that's part of the delay. I have a couple of questions. The sound of these sealed is very good for music but a little soft for HT. Would be better to upgrade to a pair of 15" using the same enclosure? or try to add a port? just for curiosity. I don't want to make the enclosures again... they are 3.9 cu.ft. (20 inch cube external)

 

[annunaki]

I would have to model them again, but I bet a couple of passive radiators added to each enclosure would do the trick giving you more or less the same performance as vented.

I will have to find some time to check some PR options.

Thanks Annunaki! I was bless with two girls in the meantime, so that's part of the delay. I have a couple of questions. The sound of these sealed is very good for music but a little soft for HT. Would be better to upgrade to a pair of 15" using the same enclosure? or try to add a port? just for curiosity. I don't want to make the enclosures again... they are 3.9 cu.ft. (20 inch cube external)

 

[gercho]

thank you Annunaki. you dont see possible to use 4 or 6 inch round ports. I was thinking downfiring not to mes with the finish.

 

[gercho]

Hello, I don't know much about using WinISD, but I downloaded and tried to model a vented enclosure for the 12w3v3 and gave me the volume of my actual box, 110.5 litres with a round port of 4" and 11.69" long. Is that correct? Would it work if I put the port downfiring instead of front firing as suggested by the design?

 

[lsiberian]

thank you Annunaki. you dont see possible to use 4 or 6 inch round ports. I was thinking downfiring not to mes with the finish.

Adding a port to an existing box will reduce the tuning of the box itself. I think PRs could do the trick, but my first suggestion is that you look into eqing the subs first you can use a BFD or MiniDSP for that.

 

[gercho]

hello Isiberian. I was thinking in a minidsp and will probably buy it shortly (traveling to us on feb.) but the eq of audyssey wouldn't be enough for the subs? what I noticed is that for stereo music I prefer Direct (bypass audyssey). today when I modeled the vented enclosure in WinISD for the 12w3v3-4 and gave me the exact size of my box I thought it was a good idea to try it with the port downfiring so the finish doesn't suffer and if I want I can seal it again.