Can the JL 12w6v2 handle the powah?!

[leon 10+ year member]

A single 12w6v2 mated with an alpine MRD-M1005 putting out ~850rms at 13.5v?

sealed enclosure, about 1.25cu. I know I'll have to play with the gains but any other ways I can keep the JL happy and not blowing it to bits?

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[helotaxi 5,000+ posts]

With the gains very conservatively set and playing music, it should be fine.

 

[cotjones 10+ year member]

A single 12w6v2 mated with an alpine MRD-M1005 putting out ~850rms at 13.5v?
sealed enclosure, about 1.25cu. I know I'll have to play with the gains but any other ways I can keep the JL happy and not blowing it to bits?

well fer a start that amp isn't going to give you 850 watts at 2 ohms and 13.5 volts often without setting the gains so high it's clipping... but set the gains right with no bass boost and you should get at least 800 out of it commonly...

now for the sub taking that power... it can but you need to put it in a slightly smaller box, because 800 watts can push a 12w6 into mechanical failure before the coil burn.... go for a 1.15-1.20 cube box... if it turns out to have a weaker low-end than high end... add a little polyfill and it should sound perfect...

as far as polyfills go, id go with a small amount of something dense... like a small peice of a foam pillow... but poly fill is tricky so play with it...

 

[leon 10+ year member]

Will I have to keep off the volume a majority of the time? I want to be able to crank it up most of the time and hear loud, clear bass.

Should I do a 1 cu box to play it safe? would a ported enclosure keep my JL alive?

Also I put ~850 for my amp to play it safe. It's rated 1000w at 14.4v but people have said it's slightly underrated and some have gotten birthsheet scores of almost 1100w at 14.4v. I don't have a birthsheet so I do not have an accurate picture of my amp's powah.

 

[cotjones 10+ year member]

will i have to keep off the volume a majority of the time? i want to be able to crank it up most of the time and hear loud, clear bass.
so should i do a 1 cu box to play it safe? would a ported enclosure keep my JL alive?

no don't go ported, w6's do better in a sealed and it will be safer with that amount of power... i personally would go more toward 1 cube, but you will almost HAVE to use polyfill to make the low-end bass keep up with the high end... so split the difference and go 1.05 er 1.1

and set the gains with a dmm...

the way to do this is first find your target voltage by using the formula: square root of (resistance x power)= volts

so if you wire your sub load to 2ohms...

and aim for 800 watts...

you get sqrt(1600)= volts

and finally= target voltage= 40v

so now that you know what your target is, with substage off, turn up the volume on your HU so that you can find the maximum level you will ever play your frontstage at (everything but subs)... this is completely system dependant... but we'll say for disscusion purposes that level is X%

so now you know what your maximum target voltage and maximum level of volume on the headunit...

now hook up the dmm to your speaker outputs (without subs connected) and play a 45hz (or close) test tone in your radio at that predetermined level X%...

(make sure you start with your gains all the way down)

if the x overs on your frontstage are set right, you won't hear anything, maybe a slightly audible hum...

raise the gain untill the DMM reads 40V...

mark this point on the gains with a pen and number it (your instruction manual of your amp should have a place for notes in the back... put down the number of the mark you made, and lable it (gain setting for 800watts @ 2ohms...) now you won't have to figure that out... but don't guess using that figure to set the gain for an output other than that, re-use the dmm to do it.. and then mark it again

now you have correctly set the gain so that when the volume on the radio is at the highest level you will put it, your sub will be getting exactly 800...

now 800 watts is way above the reccomended power ratings so before you go booming away, hook up your subs... (with the HU and amp powered off) and then play the system starting at a low level and going back to check the subs movement... turn it up untill you get unacceptable distortion, or you get to your maximum pre-determined level...

if you get to a point of unacceptable distortion or the subs are over-powering your front stage not to your liking, turn the gain down... (never up past your max gain..)

 

[leon 10+ year member]

no don't go ported, w6's do better in a sealed and it will be safer with that amount of power... i personally would go more toward 1 cube, but you will almost HAVE to use polyfill to make the low-end bass keep up with the high end... so split the difference and go 1.05 er 1.1
and set the gains with a dmm...

the way to do this is first find your target voltage by using the formula: square root of (resistance x power)= volts

so if you wire your sub load to 2ohms...

and aim for 800 watts...

you get sqrt(1600)= volts

and finally= target voltage= 40v

so now that you know what your target is, with substage off, turn up the volume on your HU so that you can find the maximum level you will ever play your frontstage at (everything but subs)... this is completely system dependant... but we'll say for disscusion purposes that level is X%

so now you know what your maximum target voltage and maximum level of volume on the headunit...

now hook up the dmm to your speaker outputs (without subs connected) and play a 45hz (or close) test tone in your radio at that predetermined level X%...

(make sure you start with your gains all the way down)

if the x overs on your frontstage are set right, you won't hear anything, maybe a slightly audible hum...

raise the gain untill the DMM reads 40V...

mark this point on the gains with a pen and number it (your instruction manual of your amp should have a place for notes in the back... put down the number of the mark you made, and lable it (gain setting for 800watts @ 2ohms...) now you won't have to figure that out... but don't guess using that figure to set the gain for an output other than that, re-use the dmm to do it.. and then mark it again

now you have correctly set the gain so that when the volume on the radio is at the highest level you will put it, your sub will be getting exactly 800...

now 800 watts is way above the reccomended power ratings so before you go booming away, hook up your subs... (with the HU and amp powered off) and then play the system starting at a low level and going back to check the subs movement... turn it up untill you get unacceptable distortion, or you get to your maximum pre-determined level...

if you get to a point of unacceptable distortion or the subs are over-powering your front stage not to your liking, turn the gain down... (never up past your max gain..)

sweet! thanks for your help!

now i cant wait to see how good this baby sounds //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[cotjones 10+ year member]

hope it turns out right! w6's are some really good woofers, i have 5 of them in my other car, they shouldn't let you down, just be carefull with that 800 watts

 

[helotaxi 5,000+ posts]

Which is why you set the gains conservatively for say... 600W rather than 800W. A little added margin of safety. You could also set the gain by ear. You're not worried about clipping, you're orride about overdriving the sub. Start with the gain at min and play a song with a good loud bassline. Turn up the volume until the front stage either gets painful or starts to distort (ie the loudest you'll ever listen to it.). If the sub is still really quiet, slowly tun up the gain until the sub starts to distort or gets loud enough for you whichever comes first. If the sub starts showing signs of distress before the volue is where you want it with the gain at min, you need to turn down the sub output on the deck (if it has one). If it doesn't have a sub output you'll either need a new amp or an attenuator for the sub amp. You can get an attenuator here