Audio System

[napkinthief]

I have a set of 12" sony xplod subs with amp and they are great. I had them in my eclipse for a year and they sounded superb. I recently moved them into the trunk of a 1992 pontiac grand prix, and the sound went from great to all rattles. I will get some dynomat or similar product, but do I have to change the box sizes because of the new interior size of the car, which is now actually 2 chambers (trunk and passenger areas), compared to the eclipses large single area? would a sealed box give less rattle?

 

[94Jettameowpsst]

some cars just arent the "best" for sound equipment or bass response. I had 2 Xtant 12's in my 1g and when i sold em to some dude with a 2g......it was like night and day. IS it just me or do 2gs sound fantastic with subs?

 

[Eclipse45150]

2gs sound great because they have a layer of sound deadening material sprayed on the exterior of the car from the factory to reduce road noise, if you look on the undercarriage thats why it looks kind of like white mud or plaster is piled up on most of the under body. Im not sure if any of the other eclipses have it or not.

As for the original question, the transfer function, in other words the space that the bass waves travel and reflect is different in the grand than the eclipse, it will be different in most any application, to get the perfect sound you will need to retune your amp and dynamat the car for less vibration. Also, you will not be able to achieve the same quality and pressure because the grand has a metal rear dash if Im correct which will reflect the waves instead of the cardboard or fiberboard material in the eclipse which for the most part just lets the waves pass into the cabin.

As for a recomendation, the license plate, trunk supports on the lid, points where the trunk and body meet when the lid is closed and the rear deck are your trouble spots. Also the back of the rear seat may be a problem, I would do those areas first the see how it sounds. Oh and if you do dynamat the rear seat only put it where metal will meet metal, if you cover the whole backing you will lose a tremendous amount of sound!!

Hope this helps!

 

[Eclipse45150]

Oh sorry and you don't nessecarily need a new box, the box id designed for your subs not the area it sits in. If you do decide to go non-ported you will possibly lose bass because the sub has a limited amount of air. I would keep the box the way it is dynamat the area and then see where you stand.

 

[Talesin]

A sealed enclosure will always give you better response and performance than a ported setup, at the expense of needing more power.

And the 'sound deadening' on the underbody is just road tar and crap. If you clean it off, you'll find the originally painted chassis underneath. The sound deadening is on the inside of the car, in large patches that almost look like stickers (aka: seperate from the carpet pad). And yes, all models had the sound deadening junk.

 

[Eclipse45150]

Oh, sorry my mistake, I had not researched the material assuming that was the deadening material, on my underbody its like the spray foam you can get a home depot (not exactly but has the same consistancy and color), maybe the guy who had it before me put it on there, sorry bout the mix up on that topic