Audio Systems: subwoofer enclosure, high density particle board, inch subs

Question
I asked a question about a week ago about my 8 inch subs and how i couldnt hear them well. reasons for this are: the trunk is well sealed and much sound does not come through, i did not have them bolted down to the trunk and upon inspection of the enclosure, i found some small holes on the side and the corner is cracked and smashed in a bit. the enclosure its self is small too because it was built for my friends jeep. I would like to build a new enclosure for them. I was wondering where i could get a good set of plans to build an enclosure, and what materials are best to use. any help would be great.

Thanks,
         bradley

Answer
Presuming that the subs are ok, the leaking enclosure will be much more of a problem than the trunk being sealed.
As long as the box fits and is made well, it does not matter that much what vehicle it is/was 'built for'. *This may be a situation where you are expecting much more bass than those particular 8's can deliver.
It seems you said you have a large auto, so 8's may not be the best choice for the higher SPL you seem to be seeking.
That said:
The first thing to do is get the model numbers from the 8's you have, send this info to me, and we'll see how well they will perform based on their Thiel-Small parameter specifications.

Enclosure Loading (box plans):
I would need the specific model number of the woofers to be of any real help as to loading it properly. It would also be nice to know the exact power amp make/model you will be using. Then (and only then) a proper enclosure may be designed for them.

Enclosure Material:
For professional caliber subs with high power, I would use 3/4" medium density particle board for the enclosure.
In the case of these 8's, you may be fine using 1/2" high density particle board, but I would rather have it overbuilt than underbuilt, so I suggest 3/4". Either configuration should involve some internal bracing to ensure rigidity while it is cranked.
There are more rigid materials you can use such as Metite, but they are VERY dense and heavy to haul around at $3.10 for a gallon for gas. With 8's you should not need such exotics.

Let me know about the speaker/amp model numbers and we will see what we can do.


Sincerely,
Jerry Mael