2006 Cobalt DD9518 Trunk Enclosure opinions?

[familyguy9877]

You mean other than the fact that DD doesnt even reccomend sealed?
Or the fact that T/S generally shows dd subs to be poor choices for a sealed alignment?

You are clearly going to do exactly what you plan anyways. So good luck

I stated in the initial post that i'm fully aware the sub isn't intended to be used in a sealed enclosure, that said, Pardon my ignorance but could anyone explain in terms or subwoofer parameters what makes the 9500 series so much different than a sub like the SSA XCON that is also around the same power handling but is supposed to do well sealed and is stated by the manufacturer to work in as little as 4.25CU sealed? I don't know much about sub parameters so this is a legitimate question for me. i'm just trying to get as much factual evidence why this will or will not work as possible and it seems like I've been getting just a bunch of opinions. Not trying to upset anyone here but if I wanted to hear that DD doesn't recommend it I would have consulted their site and been done. I came here looking for a factual and definitive answer WHY???

 

[kr15 5,000+ posts]

Qts .3

EBP over 1

= terrible choice for sealed

 

[Boomin_tahoe 5,000+ posts]

@LosIsATool is very familiar with DD subs

 

[Boomin_tahoe 5,000+ posts]

It's like trying to fit a 350 into a Geo...it'll fit, nah it won't Then tell me why lol

 

[familyguy9877]

Qts .3EBP over 1

= terrible choice for sealed

could you explain what those numbers mean?

as I said i'm just trying to learn here as much as possible

 

[familyguy9877]

Qts .3EBP over 1

= terrible choice for sealed

also QTS is listed as 0.667 not sure if that would change anything at all?

 

[kr15 5,000+ posts]

Basically, if you put that dd in a small sealed box, its gonna sound like a midbass driver. It very likely will have little extension below 40hz

 

[kr15 5,000+ posts]

That .6 is likely for ESP model only. Is that what you have?

 

[familyguy9877]

also QTS is listed as 0.667 not sure if that would change anything at all?

EBP calculates to 50 on the 9518 (36.34 fs and 0.726 QES) which is a more sealed oriented number so that confuses me even more now....

** Specs taken directly from the DD 9500 Specs page on their website.

 

[familyguy9877]

That .6 is likely for ESP model only. Is that what you have?

Also at least listed on their site there is no ESP model in the 18" variety

 

[kr15 5,000+ posts]

Which version do you have? If you have the very newest one, than Im not sure. But if its any of the other versions, i stand by what I said. Also, if the newest 9518 is non-esp and doesnt vary from the previous versions, ill go out on a limb and say the TS could be incorrectly denoted or incorrect in general.

Jeff Vue pulls TS specs often. They sometimes greatly differ from what the manufacturer posts

 

[familyguy9877]

Which version do you have? If you have the very newest one, than Im not sure. But if its any of the other versions, i stand by what I said. Also, if the newest 9518 is non-esp and doesnt vary from the previous versions, ill go out on a limb and say the TS could be incorrectly denoted or incorrect in general.
Jeff Vue pulls TS specs often. They sometimes greatly differ from what the manufacturer posts

I can definitely say I don't have the new model as mine features the older DD logo on the motor boot. I don't have any way to easily access the serial number off hand right now unfortunately. I wish I had the exact specs for my woofer. I had just assumed that they would be at least similar as they are all the same family but I could easily be wrong there. I do appreciate the more scientific explanation though of why you believe this won't work well it is what I have been after the whole time but without exact woofer specs I suppose it would be pretty much impossible to determine the EBP of my particular sub and get a for sure(ish) answer.

 

[kr15 5,000+ posts]

If it isnt the newest one, its definately going to be a lower q, higher ebp driver.

That "style" of driver is common to the spl segment. Strong motor, stiff suspension, and generally a much smaller ratio of xmax compared to xmech. Those style subs are generally ported only, or heavily favor ported.

As for the box itself, a driver like that is going to have an extremely high f3 in 3cu sealed. Meaning it isnt going to play low frequencies at all. Its literally going to want to play 45-80hz

 

[familyguy9877]

If it isnt the newest one, its definately going to be a lower q, higher ebp driver.
That "style" of driver is common to the spl segment. Strong motor, stiff suspension, and generally a much smaller ratio of xmax compared to xmech. Those style subs are generally ported only, or heavily favor ported.

As for the box itself, a driver like that is going to have an extremely high f3 in 3cu sealed. Meaning it isnt going to play low frequencies at all. Its literally going to want to play 45-80hz

Bummer. I really want to have it peaking in the 30s.... What is f3?

 

[kr15 5,000+ posts]

The frequency at which output is -3db from peak or f0.

That 18 in 3cu might have an f0 of say 55 and and f3 of 50