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[billsburgundy]

AV83.....ok riddle me this then...lets says it IS a large flat panel...and lets say the fiberglass was a centimeter thick and YOU were trying your best not to mess the fiberglass up....would you choose a sealed box in a sealed trunk, sealed box in an open trunk, vented box in a sealed trunk or vented box in an open trunk?

 

[av83 10+ year member]

AV83.....ok riddle me this then...lets says it IS a large flat panel...and lets say the fiberglass was a centimeter thick and YOU were trying your best not to mess the fiberglass up....would you choose a sealed box in a sealed trunk, sealed box in an open trunk, vented box in a sealed trunk or vented box in an open trunk?

It's dependent on what subs and how much power are you putting on them? Ive seen two twelve's sealed make metal panels go nuts. but I wouldn't feel safe even driving a car that couldn't handle a system out of fear of breaking/cracking it. If it can handle vibrations caused by everyday driving without cracking up , it can handle some bass.

 

[billsburgundy]

ok. and now ill be honest with you...this is a purely cosmetic issue...I think it looks stupid when you see someones car trunk shaking and physically moving but I do love a lot of bass. it's about 1000 watts RMS per sub. the fiberglass is quite sound and the car is safe I just want to be able to crank it a bit and not have it look like trash from the outside while driving...I dont care about rattling i just dont want it to be seen.

 

[akadj 10+ year member]

I'm assuming behind the back seats you have a large hole? if so, this is what I mean.

The box is port and subs firing forward, into the cabin, completely sealed off from the trunk itself.

x2 or 3.. or what ever the score is.. but because the trunk isnt flexing anymore probably means now your doors and roof will flex and vibrate. . or as you say.. "trash look"

you need sound deadening as well

 

[ThatChevyGuy 5,000+ posts]

pics of vehicle?

 

[av83 10+ year member]

ok. and now ill be honest with you...this is a purely cosmetic issue...I think it looks stupid when you see someones car trunk shaking and physically moving but I do love a lot of bass. it's about 1000 watts RMS per sub. the fiberglass is quite sound and the car is safe I just want to be able to crank it a bit and not have it look like trash from the outside while driving...I dont care about rattling i just dont want it to be seen.

Then face the subs (and port If you have any) forward into the cab. you'll lose some of the low frequency response, but you shouldn't have much trunk flex. But, tbh, 2000 wrms is going to equal body flex somewhere. You are going to have to do some bracing and such to prevent the roof from having the same problem if you have them firing into the cabin. I'm pretty sure cld tiles, dynamat, etc won't help with fiberglass as much as they would with metal, either.

 

[keep_hope_alive Premium Member]

to get a serious answer you need to share pics of the vehicle and space available. a generic answer to a generic question is not going to be very useful. it would also be helpful to see what you currently have that you are not happy with. getting good bass out of a sub system is heavily dependent on execution.

high SPL will pressurize the cabin/trunk and something will give. if the vehicle is not air-tight, then that pressure release will alleviate some of your concerns, but can also tune the cabin as a bandpass enclosure.

custom vehicle or not, fiberglass is much more stiff and stronger than the sheet metal of modern cars. if you want to ensure stiffness, glass some ribs on the larger pieces to enhance strength. but a concern for vibration is independent of vehicle strength. vibration is caused by two pieces vibrating against each other - such as door/trunk latches and body seams. doesn't matter how strong a singular piece is, it can still move in it's entirety in lieu of flexing in a wave-like motion. strength at seams/joints is independent of individual piece strength.

just about any SPL can be attained with any combination of subs/sizes/quantity. how you integrate the sub(s) into the vehicle and how they are powered is key.

 

[billsburgundy]

thanks to everyone! vehicle is unfortunately in storage. I believe i will just dynamat trunk and use vented box. i dunno.

 

[mlstrass 5,000+ posts]

not many trunk cars will fit 2 15's, so why is that your choice? Single 15 ported or 2 12's off the power you have should be fine.

 

[pickup1 5,000+ posts]

Any pic of said fiberglass trunk panels?