JBL Sub 1500 15" Blowout @ PE (1 Viewer)

[Russell R]

Hello,
Just wondering if any of you looked at this driver at Parts Express? PE number 299-750.

Russell

 

[John_MackieBass]

too bad it wasnt an 8 ohm sub...

Looks killer...price isnt that impressive IMHO. Would you rather have one of those, or a pair of Adire Shiva/Tempests??

 

[Rory Buszka]

I think that the JBL could beat the Tempest in terms of outright fidelity, and that's probably why it costs so much. It probably crosses the line into true audiophile bass drivers.

 

[Brian Tatnall]

What makes the JBL have greater fidelity than the Tempest?

Saying that's probably why it costs more seems like reverse logic to me. Tempests just don't seem to be lacking outright fidelity to me.

For half the price, I'd grab a single Tempest anyday.

 

[Rory Buszka]

Well, let's have a quick rundown of the features.

Adire Audio Tempest
Cone: Kevlar-impregnated paper, with stiffener
Surround: 1.6mm thick foam
Spider: Single (flat progressive)
Voice Coil: 2.5" Diameter Kapton(tm)
Basket: 13AWG
Motor Venting: Vented Pole Piece
Motor: 7.5lb Strontium Ferrite
Power Handling RMS: 750W
Xmax: 16.4mm
VC Inductance (this makes a difference): 2.9mH
Fs: 18.8 Hz

JBL SUB 1500 15"
Cone: Kevlar-impregnated paper
Surround: Medium roll Butyl Rubber
Spider: Single (Assumedly)
Voice Coil: 4" Diameter
Basket: Cast Aluminum
Motor Venting: Perimeter Venting (under spider), cone venting, magnetic gap direct venting
Motor: 25lb Strontium Ferrite
Power Handling RMS: 800W
Xmax: 18mm
VC Inductance: 1.55mH (lower is better)
Fs: 25 Hz (IMO, the Achilles' Heel of the design)

The big thing I want to call your attention to is the much lower (almost halved) inductance of the JBL's voice coil. All the other stuff is well and good (look at the 25lb motor) but the lower inductance will help this driver have a much more musical sound. True, the Tempest may be an excellently musical driver, but then the JBL will only be more so.

 

[Jack Gilvey]

Interesting. How so?

 

[Scott Simonian]

For the price of the JBL I would much rather have two Shiva's or Tempest's.

The only thing going to for it over a Tempest is the heavier magnet. Altough I'd have to say it may be for the 4" voice coil. I doubt it is high quality. Just there for bragging rights. Even with a 50% larger voice coil the power handling is only a little more than a Tempest can handle.

You know I bet the only reason why there is such a big magnet on there is because they need that extra flux to move that big voice coil. Where is the BL comparison?

Save some of your money and get a Tempest.

 

[Brian Tatnall]

I understand that inductance (10%) is the third biggest cause of distortion in drivers after BL (60%) and Kms (40%)problems. But that's really not where I'd put foot down concerning the ability for a sub to be musical or not. Way to many other factors come into play than to just throw it down on one figure.

Also that would be 25lbs in the motor structure, not just the magnet.

And the Achilles' Heel is the price.

 

[Dan Hine]

It's JBL Pro. I'd guarantee you that it IS.

 

[Scott Simonian]

Sorry, but after owning a Tempest for almost two years I'm a little biased.

I just thought for the best "bang for your buck" in the HT, it would be a Tempest. If it were me, I could use the extra hundred for a 250w PE plate amp.

EDIT: You could also get a Stryke 15" for fifty less than this JBL sub. What do you guys think of the Stryke? IIRC, it was pretty decent.

POST EDIT: How high of frequencies do you guys let your subwoofer reproduce? I have mine @ 40hz and below.

 

[Rory Buszka]

The stryke gives the JBL more of a run for its money, but the fact of the matter is that the AV15 still has a 2" voice coil. This works for the AV12 because it is thermally coupled to the aluminum cone for excellent heat radiation. But once again, if we compare Le values, we see that the AV15 has an Le of 3.5mH, more than the Tempest. I don't know how much of a difference this 0.5mH difference makes in the grand scheme of things, but the JBL still wins for transient response, which is affected highly by Le.

 

[Jack Gilvey]

In that case, would the transient response of either be better than that of the Tumult (4.2mH)?

 

[Dean-P]

I was just at Solen.ca and they carry "aurasound".
They list the NS12-794-4a for $732CAN but it has a xmax of 18mm and a voice coil size of 3" with a le of 0.55. I imagine then that this sub is very musical...it weighs 8kg.
:star:

 

[Brian Tatnall]

Well, if all you meant by fidelity is transient response, then yes the JBL will win. But, like I said I think how a driver interacts in a system has a lot more variables to it. For example, put that driver in a box and BAM transient response abilites have changed. Which, is how most people will use the driver...in a box. When speaking of fidelity I would also include things that correspond to clarity like IMD, THD, breakup, and frequency response, which brings in many other factors other than Le.

 

[DarrenK]

I find it interesting that nobody has mentioned the DISTORTION aspect of the JBL vs. Tempest. The Tempest has a standard motor with no shorting rings or anything for distortion reduction. The JBL has several copper shorting rings on it and a specially designed t-shaped pole piece to minimize distortion. The low Le is a result of the rings, but not directly the benefit of them. The benefit is greatly reduced harmonic and IM distortion.

This low distortion is one of the key factors to providing "audiophile" sound.

I'm not saying that the JBL is the best "bang-for-the-buck", but it is certainly the superior driver from a distortion standpoint. The price is not unreasonable considering the production and engineering behind the motor compared to the other drivers that have been mentioned.

See ya,

Darren

 

[Joe Hsu]

One thing that might help put this driver into perspective for people is knowing that this driver was originally made for the Revel Ultima sub...anybody who's heard that sub before can attest to how nice of a sub it is.

 

[Jack Gilvey]

Anyone throwing around some alignments? Qts is really too low for unassisted sealed. Any recommendations Darren?

 

[Brian Tatnall]

The more I've researched the greater a respect I've come to have for the JBL. Looking at all the different design specs and all the other information I could gather from the PE catalogue, PE website, and other random tidbits on the internet it is one well designed sub. Now to go earn the $250 and compare it.

 

[Chris Tsutsui]

Just from the stats and specs I'd take this JBL over a tempest any day.

I think a new question we should ask is: Will Two tempests be better than this JBL and be worth the $50 extra.

 

[Chris Tsutsui]

Oh, should I post the

http://www.adireaudio.com/tech_papers/woofer_speed.htm

inductance link again and how it affects Transient Response. Exactly how much will that make the JBL better than the Tempest in transient response I do not know.