Jl audio w7 13.5" vs rockford fosgate t2 12d4 vs re xxx 12"

[audioholic 5,000+ posts]

Im not saying RMS rating equals output. Nor am I implying that power handling necessarily equals quality/performance. I dont believe I even implied that anywhere here. Im simply not agreeing with warbleed and k-mart's view of the situation.

 

[k-mart 10+ year member]

Oooooohhhhh SUSPENSION travel. Heck, the sub wont ever possibly move that far since the motor cant, but oh the SUSPENSION can! So? Like I said, he's looking at only the xmech or xsus, when its the lesser of the two that dictates xmax, not the greater of the two. The W7 does not have nearly 15-20mm of USEABLE excursion over the XXX/Brahma that warbleed implied, I wonder why he tried to shed the situation in such a light, its not normally like him.
As for thermal handling, there is much more to a speaker's thermal handling abilities than simply the mass of the voice coil. Again, I know Adire and RE do not 'overrate' their equipment, and I seriously doubt JL underrates there's by the difference in advertised RMS specs, so Im not seeing any proof to contradict these manufacturer specs.

Yes, the 15-20mm more excursion is USEABLE. The motor is not completely linear (read below 71% bl) to that point, but it will get the suspension to move that far. Furthermore, it, like the XBL^2 motors has a flatter bl curve that will mean less distortion as it approaches its limits. At which point, it will be loud enough to make most distortion unnoticable due to vibrations and simply volume produced.

Actually, when we talk about thermal powerhandling, 9 times out of 10 we are talking about how much power the coil itself can take for a given amount of time. But, since you want to think otherwise, why do you think that a sub with a larger coil, more excursion capability, both motor and suspension considered here (aka xmech), and a much superior cooling system wouldn't be superior in power handling?

You wanted proof, I assume manufacturer's since there's been harping about it in this thread, so here you go.

http://jlaudio.com/subwoofers/RP_Chart.html

As you can see, the 13W7 actually is warranted up to 2000w. So, there's your evidence.

 

[k-mart 10+ year member]

Wanna see a reply.......

 

[skeptikal Premium Member]

lol my bad on the suspension comment. I kept thinking that he was talking about linear XMAX, not linear suspension. my bad on that part.

would a 13w7 really take 2000 daily?

 

[denim 5,000+ posts]

You can get a 13w7 for a hell of a lot less than the price of two Brahmas or two XXXs, people are exaggerating rather excessively there.
As far as displacement, a single 13w7 is actually capable of displacing about 10% less than a pair of Brahma 12s or XXX 12s, which equates to a difference of less than 1dB, at best.

If you do want a pair of woofers for certain though, you can certainly go with a pair of Brahma or XXX 12s, they are both exceptional woofers, and both are a better overall choice than the RF driver.

A single 13w7 can certainly get very loud ported, and if you have that much power on tap, you'll be in good shape. The 13w7s can handle quite a bit of power for musical purposes (they have a 3.5" diameter 3"+ long VC), so you don't really have to worry about hurting it.

Technically a pair of 12w7s would be capable of getting louder than a pair of Brahma or XXX 12s, but they'd also be somewhat more expensive, depending on where you buy them.

can I ask what do you think of the new RF T2s?

 

[k-mart 10+ year member]

lol my bad on the suspension comment. I kept thinking that he was talking about linear XMAX, not linear suspension. my bad on that part.
would a 13w7 really take 2000 daily?

2000 acutal watts to the sub, which would require an amp that will produce well over 2kw due to impedence rise, would be pushing it.

Most 2kw rated amps wouldn't likely hurt it too bad if you know what you're doing.

 

[wagz 10+ year member]

would a 13w7 really take 2000 daily?

most likley in the right box n such, everyone talkes about specs of the subs but im not hearing a lot about the setting the sub is in, the amount of watts a sub can handle will very greatly on that

i have a friend with a adire tempist thats 750rms, but because its in a 9.2cuft box tuned to 20hz (home audio) you hear the sub max out mechanically at less than 150...it goes THWAK THWAK THWAK //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Warbleed 10+ year member]

aright you can get one from eBay for like 600$ if you want it BNIB, but they retail for like 999$, that is why people said you could get two XXX's or Brahma's factory direct for the price of a JL W7 @ what car audio shops sell them for.



lol man are you serious? Brahma's can take 1600 RMS if you put them in a hella small sealed box. XXX's will take 1400 watts ported??? 400 watts isnt a significant amount of power?

Couple questions though....

the w7 has a 45-50mm (one way) Xmax (Since it has 15-20 mm more than a XXX)?

and since when were a 13" and 12" Sub the same size?

JL has ALWAYS rated their woofers very conservatively. You can send 1kW RMS to an old 15w3 easily, despite it being rated for 400w. JL has always done it conservatively.
I never said the W7 has 15-20mm more XMAX, I said it has 15-20mm more LINEAR SUSPENSION travel, which it clearly does.

I don't know why there are so many people harping about the XXX or Brahma handling more simply because the manufacturer rates them for more.

Remember guys, JL has ALWAYS rated power VERY conservatively, and they always will.

Thermal powerhandling is mostly determined by cooling and the thermal mass of the coil (i.e. how big a chunk of metal you have to dissipate heat), and the W7 definitely wins on both counts.

Since the W7 uses a two layer coil, that means you have 50% of the coil exposed to air at all times, vs. 25% for the Brahma (4 layer roundwire, only the outermost layer is directly exposed to the air), and 12.5% for the XXX ( 8 layer flatwound, and again, only the outermost layer is directly exposed to the air).

The W7 will handle it's rated power in far more enclosures, since it has a HUGE advantage in terms of linear SUSPENSION travel. It is EXTREMELY difficult to bottom a W7, whereas reaching the limits of a Brahma or XXX isn't that hard, since both are basket limited around 32mm.

Honestly, if you thermally fail a W7, you probably did something pretty **** stupid...

 

[Warbleed 10+ year member]

most likley in the right box n such, everyone talkes about specs of the subs but im not hearing a lot about the setting the sub is in, the amount of watts a sub can handle will very greatly on that
i have a friend with a adire tempist thats 750rms, but because its in a 9.2cuft box tuned to 20hz (home audio) you hear the sub max out mechanically at less than 150...it goes THWAK THWAK THWAK //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Yep, people forget that powerhandling ratings very TREMENDOUSLY with enclosure. I ran a Tempest in 10cf@18Hz, and it wasn't too hard to bottom it with little power. It's a fairly efficient woofer, especially in that big of a box. Honestly the lead slap was so irritating at high excursion that I'd never actually bottom it anyway. Sounded great overall in a big vented box though.

 

[Warbleed 10+ year member]

Oooooohhhhh SUSPENSION travel. Heck, the sub wont ever possibly move that far since the motor cant, but oh the SUSPENSION can! So? Like I said, he's looking at only the xmech or xsus, when its the lesser of the two that dictates xmax, not the greater of the two. The W7 does not have nearly 15-20mm of USEABLE excursion over the XXX/Brahma that warbleed implied, I wonder why he tried to shed the situation in such a light, its not normally like him.
As for thermal handling, there is much more to a speaker's thermal handling abilities than simply the mass of the voice coil. Again, I know Adire and RE do not 'overrate' their equipment, and I seriously doubt JL underrates there's by the difference in advertised RMS specs, so Im not seeing any proof to contradict these manufacturer specs.

Uhm...you're wrong though. There isn't a single thing about the XXX or Brahma that would suggest they'd have a higher thermal powerhandling capability than the W7.
The W7 has more coil (i.e. more wire with which to dissipate heat), a superior cooling system, more suspension travel (when the coil isn't continuing to move as power goes up, that SEVERELY hampers cooling ability).

If you start sending more power to a Brahma or XXX near xmax, you'll fry them pretty quickly, because they cannot more any further to promote better cooling, whereas the W7 has another 15-20mm it can move to further cool the coil. That makes a BIG difference, especially when combined with the other advantages that the W7 already has.

Don't get me wrong, I think the Brahma and XXX are both fantastic woofers and offer a much better value than the W7, but to say that they outperform the W7 is just false...

 

[denim 5,000+ posts]

I wonder when the W8 vs the new RE uber woofer will start?

 

[audioholic 5,000+ posts]

Yes, the 15-20mm more excursion is USEABLE. The motor is not completely linear (read below 71% bl) to that point, but it will get the suspension to move that far. Furthermore, it, like the XBL^2 motors has a flatter bl curve that will mean less distortion as it approaches its limits. At which point, it will be loud enough to make most distortion unnoticable due to vibrations and simply volume produced.
Actually, when we talk about thermal powerhandling, 9 times out of 10 we are talking about how much power the coil itself can take for a given amount of time. But, since you want to think otherwise, why do you think that a sub with a larger coil, more excursion capability, both motor and suspension considered here (aka xmech), and a much superior cooling system wouldn't be superior in power handling?

You wanted proof, I assume manufacturer's since there's been harping about it in this thread, so here you go.

http://jlaudio.com/subwoofers/RP_Chart.html

As you can see, the 13W7 actually is warranted up to 2000w. So, there's your evidence.

As for power handling, you got me there. I didn't realize the W7 scaled up so quickly on power handling, as the 10 and 12 dont handle nearly that much power. I do not however agree with all your cooling advantages you say the W7 has. Excursion capability for example, Im sure that seems like a huge advantage when you think it has a 15-20mm excursion advantage over the XXX, unfortunately it doesn't.

For the suspension, I still have to disagree with you. Clearly your definition of "useable" and mine are very different. So the suspension will allow the cone to travel that far, so? If the motor becomes non-linear beyond a certain distortion threshhold, any more travel beyod that point is worthless. That is why the xmax of a sub is the lesser of the xmech and xsus, not the greater of the two. The rated xmax on the XXX is 32mm. The xmax on the 13W7 is what, 34mm? Now my question is, if what you were to say were true, why would JL shoot themselves in the foot and advertise their sub as having 15-20mm less 'useable' cone travel (xmax) than it really has? The answer, because they know people who realize you cannot push a W7 to 40+mm of excursion and have anything resembling music be produced would cry foul, and rightfully so. Your suspension travel specs mean little/nothing in terms of useable displacement.

 

[LIGHTBEING 10+ year member]

*Shakes LIGHTBEING*
Wake up, sleepy head

Guys, I'm still not understanding this. If Adire states on their site that a Brahma max is 4800 watts and JL states on their site that a 12W7 is voided at 1500 watts or more and starts to reach danger zone around 1200, doesn't that tell you that a Brahma can handle more power(watts)? I mean the W7 is voided before the Brahma and XXX reach their RMS.

And my point is, that if a Brahma can't take 3000 watts in the right enclosure, which is 1800 watts less then MAX. Then the official specs are incorrect. Again like I said, 3000 watts isn't something I would use for a daily driver but you should be able to burp it once in a while, no? Like for competitions and such?

I have no experience with either, I'm just basing my arguement of the specs alone.

 

[k-mart 10+ year member]

I do not however agree with all your cooling advantages you say the W7 has.

You don't have to agree, but I'll just prove you wrong.

http://jlaudio.com/subwoofers/W7_PolePiece.html

http://jlaudio.com/subwoofers/W7_FACFrame.html

Excursion capability for example, Im sure that seems like a huge advantage when you think it has a 15-20mm excursion advantage over the XXX, unfortunately it doesn't.

Yes, it does have an advantage. As I said, the motor isn't linear to that point, but it will get out there and those SPL levels distortion becomes increasingly difficult to differentiate from distortion inherent to the environment.

For the suspension, I still have to disagree with you. Clearly your definition of "useable" and mine are very different. So the suspension will allow the cone to travel that far, so? If the motor becomes non-linear beyond a certain distortion threshhold, any more travel beyod that point is worthless.

No, its not worthless. It aides in the subs ability to handle power. Instead of running into a brick wall as you increase the power with the Brahma/XXX (ripped spiders, cone tapping spider, surround issues), the W7's superior suspension will allow the moving assembly to graciously extend to 40+mm

That is why the xmax of a sub is the lesser of the xmech and xsus, not the greater of the two. The rated xmax on the XXX is 32mm. The xmax on the 13W7 is what, 34mm? Now my question is, if what you were to say were true, why would JL shoot themselves in the foot and advertise their sub as having 15-20mm less 'useable' cone travel (xmax) than it really has?

You're wrong. Xmax is the lesser of XMAG and Xsus, not Xmech. Xmech is the point at which the sub runs into actual mechanical problems during excursion. (32mm or so for the XXX/Brahma and 40-50mm for the W7's) JL actually publishes the 13W7's xmax at 32mm, but it had dumaxed more. That, however, is not the usable throw that it has. It will indeed exceed 32mm, but sound quality will be diminished as it approaches the limits of its suspension.

The answer, because they know people who realize you cannot push a W7 to 40+mm of excursion and have anything resembling music be produced would cry foul, and rightfully so. Your suspension travel specs mean little/nothing in terms of useable displacement.

As I said, it won't sound quite as good at those extreme points of excursion, but it will produce bass. Anyone who's worried about sound quality, I mean really concerned with the accurate reproduction of music, will find a reference level of 130+db entirely too loud. Then, who cares if its bangin' some lil' john perfectly at 145db?

 

[audioholic 5,000+ posts]

As I said, it won't sound quite as good at those extreme points of excursion, but it will produce bass. Anyone who's worried about sound quality, I mean really concerned with the accurate reproduction of music, will find a reference level of 130+db entirely too loud. Then, who cares if its bangin' some lil' john perfectly at 145db?

This pretty much sums up your arguement. But Im sorry, if what you say/imply were true, JL would advertise their sub as having more useable excursion. You can say well at that volume level, who cares if its 5% distortion, or 30%. But Im sorry, that is why we have standardized (or relatively so) stats like xmax, so we can't have manufacturers take the same attitude you have that distortion thressholds dont matter at that volume level. They matter, that's why the W7 does not have 40mm+ of excursion, sorry.

As for your cooling links, great. Unfortunately I never said the W7 doesn't have innovative cooling technologies in it, I said I dont agree with all the cooling advantages you say the W7 has, that 15-20mm of added useable excursion you say the W7 say has for example.

You're wrong. Xmax is the lesser of XMAG and Xsus, not Xmech. Xmech is the point at which the sub runs into actual mechanical problems during excursion. (32mm or so for the XXX/Brahma and 40-50mm for the W7's) JL actually publishes the 13W7's xmax at 32mm, but it had dumaxed more. That, however, is not the usable throw that it has. It will indeed exceed 32mm, but sound quality will be diminished as it approaches the limits of its suspension.

Xmech doesn't affect xmax? So you are saying "is the point at which the sub runs into actual mechanical problems during excursion" has no bearing on where that sub's xmax is? So a sub could have an xmech of 25mm and an xmax of 30mm? I dont think so.

Im fully aware of the differences between a suspension limited driver and motor limit driver. If what you were saying were true, any motor limited sub could simply advertise its suspension travel as its xmax. //content.invisioncic.com/y282845/emoticons/nono.gif.eca61d170185779e0921b0faa9704973.gif

No, its not worthless. It aides in the subs ability to handle power. Instead of running into a brick wall as you increase the power with the Brahma/XXX (ripped spiders, cone tapping spider, surround issues), the W7's superior suspension will allow the moving assembly to graciously extend to 40+mm

Your definition of gracious and mine must be very different. Again, if the W7 can excurt this much, so 'graciously' as you are trying to say, why does JL shoot themselves in the foot and say it has less useable excursion? Perhaps because they understand suspension travel is not the lone determining factor in what is considered useable excursion. And perhaps because they know discriminating customers wont stand for an explanation of at 'those SPL levels distortion becomes increasingly difficult to differentiate from distortion inherent to the environment' when they complain their sub sounds like ass when pushing it hard.

I fully agree the W7 is a great sub, alot of new tech in it. But you come here and say it has a new cooling system, so it cools better. It has a heavier coil, so it handles power better. It has more suspension travel, so it has better excursion, and gets louder etc. Im sorry, but links to tech papers from JL touting their new cooling system is hardly 'proving me wrong' that the W7 cools better, worse or the same as any other specific sub. The links you posted prove the W7 has a new cooling system. Yes it looks nice. No its hardly proof it cools 'better' than another specific driver. Test it for yourself, compare the subs in question, or at least provide a link to someone that has, if you are going to prove anything to me. Otherwise you are just proving you are reading JL's tech papers.