2006 Cobalt DD9518 Trunk Enclosure opinions?

[familyguy9877]

Hello I have a 2006 cobalt and a DD9518 I currently threw the sub in a RIDICULOUS 3cu gross ported box (so probably 1cu net) and the setup just clamped today around 1800RMS between 31-40hz. The issue is this box CLEARLY is not a good fit for this large of a woofer and as a result is not nearly as loud as it should be (i'd guess around 139DB as it sits) but I am severely limited on space because the vehicle is my daily driver and I will not build the box into the trunk. I was wondering everyone's opinion on how the sub would sound in a 3 to possibly 4 cubic foot sealed enclosure (possibly with some poly fill inside as well). Before anyone mentions it, I am fully aware DD doesn't recommend any less than a 5-6 CU ported enclosure and doesn't recommend a sealed box at all for this woofer but I got it for a steal and cannot physically achieve that size without a B pillar in my daily which will never happen, I already have another car for that lol.

I did have a very nice sounding 18" Fi Q back in the day in a 3CU sealed box but thats the closest comparison I've personally witnessed.

Any ideas or experience with large woofers in very small spaces would be greatly appreciated.

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[LosIsATool 5,000+ posts]

Get it rebuilt into a 12.

 

[Boomin_tahoe 5,000+ posts]

I still don't understand why people are fighting to put a single large dia sub in a trunk given it's required airspace and some trunks today are rather small. I would just sell it and use that $$ for a couple high power ported 10's. Make it easy on ya.

 

[familyguy9877]

I thought about rebuilding as a smaller woofer but the sub is fully functional would be kind of a shame to tear into it...

 

[familyguy9877]

I still don't understand why people are fighting to put a single large dia sub in a trunk given it's required airspace and some trunks today are rather small. I would just sell it and use that $$ for a couple high power ported 10's. Make it easy on ya.

The woofer was a great deal only reason I bought it versus something more fitting, I suppose I could resell but would much rather just make it work as there isn't a huge market around here to sell/trade or even find 10s or 12s that'll handle the power I want. just wanted to see if anyone has attempted to put a big sub like that in a sealed box just to get an idea or if I would be the first here?

 

[Boomin_tahoe 5,000+ posts]

The woofer was a great deal only reason I bought it versus something more fitting, I suppose I could resell but would much rather just make it work as there isn't a huge market around here to sell/trade or even find 10s or 12s that'll handle the power I want. just wanted to see if anyone has attempted to put a big sub like that in a sealed box just to get an idea or if I would be the first here?

And taking the chance of ruining a perfectly good driver....and not to mention it won't sound great either? I myself aren't willing to take that chance.

 

[familyguy9877]

And taking the chance of ruining a perfectly good driver....and not to mention it won't sound great either? I myself aren't willing to take that chance.

How would a sealed enclosure ruin the driver?

 

[Boomin_tahoe 5,000+ posts]

How would a sealed enclosure ruin the driver?

Well for one it's not recommended for it and too, you put it in an enclosure way smaller then the recommendation.

 

[familyguy9877]

Well for one it's not recommended for it and too, you put it in an enclosure way smaller then the recommendation.

They recommend enclosures based mostly on output efficiency from what I understand so i'm not particularly concerned I'm going the damage the driver by placing it in a sealed box.... I just would like to know if anyone has done so with a similar power handling 18.

 

[Boomin_tahoe 5,000+ posts]

They recommend enclosures based mostly on output efficiency from what I understand so i'm not particularly concerned I'm going the damage the driver by placing it in a sealed box.... I just would like to know if anyone has done so with a similar power handling 18.

Doubtful. That particular 18 or another 18? Why are you so mindset on a sealed inside a trunk?

 

[familyguy9877]

Doubtful. That particular 18 or another 18? Why are you so mindset on a sealed inside a trunk?

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.

 

[Boomin_tahoe 5,000+ posts]

Yeah I know sealed boxes take up less space than ported. What's your goal here? SQ?

 

[familyguy9877]

Yeah I know sealed boxes take up less space than ported. What's your goal here? SQ?

Realistically I would like the best of both worlds, SQ is nice for the daily but I want some efficiency and loud as well, i'm replacing a BL 15 because it was too quiet for my preference and current highs setup, like obviously the box it's in now is unacceptable for me (2000RMS and sounds like less than 140DB) but i'm aware I will never have a super efficient setup with these ingredients at the same time. trying to get it to work the best I can with what I have just looking for ideas

 

[Papermaker85 5,000+ posts]

What series is it. I'll buy the woofer if it's a I series

 

[familyguy9877]

I'm not dead set on anything just really want to run that 18 at least for a while. if theres a way that could operate more efficiently in 3-4CU with that sub I'm listening I just feel that is my best bet, but thats why I'm here. For everyone's opinion on how this sub could work in the the car even just for the time being maybe until I find something better fit. I would like to hear if anyone has done it with that sub or just any 18 somewhat similar like an HDC3 or a mayhem or any other 3" coil 18 really.