2006 Cobalt DD9518 Trunk Enclosure opinions?

[familyguy9877]

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

How are those numbers determined?

 

[kr15 5,000+ posts]

If you want to try it with polyfill, give it a go. Id go bigger than 3cu if you can. 3.5cu if you can spare the space

 

[familyguy9877]

If you want to try it with polyfill, give it a go. Id go bigger than 3cu if you can. 3.5cu if you can spare the space

I was planning on getting as much size as I possibly could (probably closer to 4CU i'm hoping) and using poly fill. You seem to know what you're talking about a hell of a lot more than I do and i appreciate the more in depth explanation of everything. If you believe there's a chance in hell this could work and peak somewhere decent (like in the 30s) I am more than willing to give it a shot and post results this weekend!

Can't overcome an issue if you never even try I guess lol that's where i'm at

 

[kr15 5,000+ posts]

Idk where it might peak. Ive literally never known someone to try a sealed 9518. If its something you want to try, go for it.

But ease into it power wise. High bl, low qts subs can sometimes destroy themselves in a sealed box. Generally with a ported box, the port actually keeps excursion in check thru a portion of the bandwidth. You wont have that luxuary sealed.

So just start low and pay attention mechanically

 

[LosIsATool 5,000+ posts]

For F)&ks sake

 

[Boomin_tahoe 5,000+ posts]

lol

 

[familyguy9877]

For F)&ks sake

interesting. do you disagree?

 

[Boomin_tahoe 5,000+ posts]

So I don't fully understand why your trying to make an 18" sub made for a ported enclosure only into a sealed enclosure. I understand you have it, but that doesn't mean you gotta use it.

 

[familyguy9877]

Idk where it might peak. Ive literally never known someone to try a sealed 9518. If its something you want to try, go for it.
But ease into it power wise. High bl, low qts subs can sometimes destroy themselves in a sealed box. Generally with a ported box, the port actually keeps excursion in check thru a portion of the bandwidth. You wont have that luxuary sealed.

So just start low and pay attention mechanically

When you say to pay attention mechanically what should I look for? just bottoming out at certain frequencies or sub getting warm? Not sure what you mean exactly?

 

[Boomin_tahoe 5,000+ posts]

Yes bottoming out...aka voicecoil hitting the backplate...it'll sound like metal hitting metal. In other words, that's bad...kinda like sub behaving badly.

 

[LosIsATool 5,000+ posts]

Ok I’ll end this.

Listen or not.

It will sound like crap. The F3 will be over 50hz. It will be a complete waste of time. Some DD woofers will work sealed, that one will not.

No it won’t hurt it. At all. Unless you clip it to death because it won’t work.

Recone it or trade it.

/End thread

 

[familyguy9877]

Ok I’ll end this. Listen or not.

It will sound like crap. The F3 will be over 50hz. It will be a complete waste of time. Some DD woofers will work sealed, that one will not.

No it won’t hurt it. At all. Unless you clip it to death because it won’t work.

Recone it or trade it.

/End thread

Okay will post results if I get bored or curious enough to try it. Thank everyone for the helpful input here it has broadened my understanding quite a bit.

 

[Papermaker85 5,000+ posts]

Because generally speaking you can drastically reduce box size and retain some degree of efficiency with a sealed box. I'm set on it because of that fact, the space I have to work with, and the woofer I already have.

Wasting your time

 

[YukonXL04]

I have a DD 9518g in 7 cubes net with 2 6" flared aero's in the trunk of my Acura. It's on a m2a. It's a beast. However I can say I would never bother with trying to build a sealed box for it.

Your not listening to what everyone is suggesting. So just go buy some wood and build your sealed box.

 

[hispls 5,000+ posts]

I'm not dead set on anything just really want to run that 18 at least for a while. /QUOTE]
Nobody stopping you. Go buy a sheet of wood for 40$ and build your sealed box and see what happens.

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.

Those specs may work OK for sealed box, but what size? Also the other big issue with a big box in a trunk is not having enough space for the sound to actually get up into the front around the box. Seriously, if you have 3 cube to work with you'll do better with a single 12 in a proper box.