What are some of the specs u recommend for 2 12" in a trunk car.

This will go in a 1998 Nissan Altima....

My bass race vehice..

I assume ported? What is your resonant frequency? What space do you have to work with? What kind of power will be going to them? And in addition to that.. what electrical upgrades have you done?

You're leaving out vital information here.

Tempests are 15 inch.

Yes, the Tempest (and Tempest-X) are 15", whereas the Shiva (and Shiva-X) are 12" in diameter.

In addition to what the other guys have said, take a look at the Shiva Applications and the Tempest Applications. They will give you a good idea as to what enclosure sizes they need for both ported and sealed applications.

My apologies I meant Shiva-x...

I have a saz-1500d for power on tap...

hc-2000 in the rear 2 runs of 1/0

Duralast gold up front..

So you don't recommend ported enclosures for car audio applications?

If you have enough room to accommodate a ported enclosure then they are great.

kyle, so could you post some good box recommendations for a pair of shivas'? sealed and ported? for good daily driving, not comps or anything.

There are links to the .pdf's for both the Shiva and Tempest in post #5 in this thread. Dont be too concerned when it says "automotive use" or "home theater use" at the beginning of various applications in the .pdf because they are merely guidelines. As with any DIY driver you can experiment and find out what will work best for your application by running various simulations. Again, these are merely guidelines to possibly start from...

There are links to the .pdf's for both the Shiva and Tempest in post #5 in this thread. Dont be too concerned when it says "automotive use" or "home theater use" at the beginning of various applications in the .pdf because they are merely guidelines. As with any DIY driver you can experiment and find out what will work best for your application by running various simulations. Again, these are merely guidelines to possibly start from...

thanks. think i'm going to try a single shiva in a 1.5cuft. box sealed first. maybe after that i'll try it ported, about 2.5cuft. tuned to 28-30hz. both getting about 600-650wrms.

The ported box you mention is perfect for the Shiva.

The ported box you mention is perfect for the Shiva.

Thanks as I was looking to see what size enclosure should I use and at what tuning frequency. Looking at the pdf Acoustic-Visions made they had the enclosure at 3.5 cu ft with an Fb of 20hz...

I don't mind tuning low but I thought with an fb that low its more suitable for HT use..

So I want a flat output from these subs so what tuning freq would u recommend to achieve this for a pair of Shivas with and enclosure about 5 cu ft..