DD 2508's Just Released!

[Bettr n' Revrse 5,000+ posts]

Just some rough thoughts based on the pictures posted here. At some point we have to realize bigger isn't always better. Once a coil is fully saturated, making the motor bigger (the slugs, or the number of slugs) provides little or no help in generating BL force. Again from those pics, I have to assume the coil is a 2" (maybe 2.5"), and my over-saturation-meter starts kicking in. Or, they are going with a larger 3" coil, and then we have to worry how well such an undersized spider will hold up to use/abuse. I would also be concerned about how well the spider would hold up if its suggested the third slug in the motor is meant simply to allow for more rearward vc clearance (a common reason extra slugs are added, contrary to popular belief).
Im not saying I have this sub all figured out just from a couple pics. But again the pics do raise a few red flags in my mind.

It is a 2.5" coil... Everyones first thought is the spider but my 3" coil has a single spider and still has had no problems...

 

[audioholic 5,000+ posts]

It is a 2.5" coil... Everyones first thought is the spider but my 3" coil has a single spider and still has had no problems...

3" coil on an 8" sub? With about a 6" spider landing? That wouldn't leave much room for excursion potential.

 

[wenn_du_weinst 10+ year member]

It's a 2.5'' coil and it's a DD they don't need tons of spider to get loud. I really do not see the sa being able to keep up if they can keep the stamped basket from failing.

 

[audioholic 5,000+ posts]

It's a 2.5'' coil and it's a DD they don't need tons of spider to get loud. I really do not see the sa being able to keep up if they can keep the stamped basket from failing.

Getting loud requires air movement. Air movement requires excursion. Yes there is obviously more to getting loud than high xmax (especially in vented situations), but I really dont know what it being a DD has to do with anything I mentioned.

Where would you expect the basket to fail?

 

[Phoenix Risen 10+ year member]

it would be awesome to see a side by side test of them.

 

[wenn_du_weinst 10+ year member]

Getting loud requires air movement. Air movement requires excursion. Yes there is obviously more to getting loud than high xmax (especially in vented situations), but I really dont know what it being a DD has to do with anything I mentioned.
Where would you expect the basket to fail?

Being dd has always been low excursion high force design. Spl does not require high xmax at all, it can use speed to create the same amount or in many cases more spl just like DD always has done. Basket wise I'm not sure if it is strong enough to hold that motor and not bend when mounted horizontally.
I have been planing to buy both the sundown and this for a while.

 

[audioholic 5,000+ posts]

Being dd has always been low excursion high force design. Spl does not require high xmax at all, it can use speed to create the same amount or in many cases more spl just like DD always has done. Basket wise I'm not sure if it is strong enough to hold that motor and not bend when mounted horizontally.
I have been planing to buy both the sundown and this for a while.

How would cone speed increase db's? You will only increase cone speed one of two ways, by increasing the frequency so it has to move more times a second, or increase excursion so it has to move further each cycle.

Traditionally DD has been successful in SPL by using a high BL design that helps improve excursion while burping at or very near enclosure tuning, where cone damping is at its maximum (thus requiring more force to reach full excursion potential). This has nothing to do with cone speed somehow increasing output.

Mounting it horizontally, I agree. I thought you meant as in it would fail due to operating conditions. But even a better cast alum frame can break if it has an overly large motor, is mounted horizontally, and the motor is not supported inside the enclosure. Ive seen many 12-spoke frames broken from this. The difference between the stamped basket and a cast one is, the stamped basket would bend or warp, while the cast frame simply snaps in two.

 

[pro-rabbit 5,000+ posts]

This thread has the lulz for sure.

Let me dig through my contact I signed and how it would apply to this situation. I would love to "shed some light" on this topic haha.

 

[wenn_du_weinst 10+ year member]

the force of the cone moving (which is what I meant by speed) will increase db's. There is a very detailed paper out on this but I can't find it. DD's bl and xmax are far less then the lms but a 9518 will kill the lms in spl. Same goes for the 5200 vs the 9500. I'm sure you already know mass times acceleration = velocity, which is what dd uses to create high spl. Also I have snapped tons of 12 spokes with my sigs I think I still have 2 or 3 broken ones. Problem with stamped steel is some one new might not know that the basket is bent out of shape if he blows a sub do to coil rub, where a cast basket it's pretty obvious that it's broke. I won't support motors in my box or use bracing nothing that will interrupt airflow is allowed inside my enclosures.

 

[twistedchild420 5,000+ posts]

I thought this was the 2508?

 

[Mitch86 5,000+ posts]

I thought this was the 2508?

Someone on caco said that was a joke someone pulled...a reconed JL w7 8 with a DD dustcap. Dont know how true that is..?

 

[twistedchild420 5,000+ posts]

Someone on caco said that was a joke someone pulled...a reconed JL w7 8 with a DD dustcap. Dont know how true that is..?

It was meant as a joke....lol Also none of the pics ITT are legit...lol

 

[Mitch86 5,000+ posts]

It was meant as a joke....lol Also none of the pics ITT are legit...lol

Doh! //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif These things are "available" so where the hell are the real pics?! Notice the first pics are a used motor with the standard mounting holes for a large basket.

 

[pro-rabbit 5,000+ posts]

Doh! //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif These things are "available" so where the hell are the real pics?! Notice the first pics are a used motor with the standard mounting holes for a large basket.

lol

The pics are of a stamped basket sitting on a motor that was laying around. Not saying there is no such thing as a 2508 but the likely hood that it would be a functional and cost effective project is a farce. Not to mention that even though others may feel that there would be much to gain from an idea like this, the real outcome is less then most would desire and the 1508 would out perform it in almost every case.

I think that is about the most I can comment for the most part.

 

[wenn_du_weinst 10+ year member]

DD has so much **** that is ''coming out'' it isn't even funny.