Kirstyn

Shiva in a 3cubic ft ported box

Hey all, just a quick question for someone wiyh Shiva experience.I have a 3 cu ft box with 2,3 inch by 10 inch long ports and a blown driver. My question is whether a Shiva would perform well in this box or would I have to modify my box or just start from scratch and build a new box. I am powering it with the PE 250 watt amp and don't really want to build a new box unless the old one will not work out well. My main use is 100% HT.Thanx in advance for any and all assistance.
Yours Greatfully K.R.

JoelTW

I think Parts Express sells a 3 cubic ft box, ported, for their titanic driver...I suppose it would work out but I'm not going to say so because I'm a newbie

Jack Gilvey

By my rough calculations, those ports tune that box to ~32Hz and create a big 5dB peak at 42Hz. Not an alignment I'd recommend.
I think it might be worthwhile to close off/stuff one port, that would result in something fairy close to the Adire alignment described in the Vented Shiva application notes from Adire. If the port isn't flared, you could replace it with the recommended Precision port if at all possible.
No reason you couldn't also try it sealed just for fun, with both ports blocked off.
Which PE amp is this?

Kirstyn

Thanks for the replies. It never dawned on me to try it sealed, I might have to try that idea. As for my amp - its the 250 watt plate amp from parts express with no boost.If I went with one port do you think that one 3 inch port would be big enough??Wouldn't I get alot of port noise??
Once again thanks for your shared knowledge, it really cuts down on the guess work!!!

K.R.

Jack Gilvey

You might get some, although one 3" flared is what Adire recommends for the alignment I mentioned. A 4" flared is ideal, but you really couldn't fit the required length. The two 3" you've got are good as far as airspeed, but the tune is not even close to what I consider "good".

Peter Jessee

You might try the Dayton 12" DVC instead of the Shiva. The DVC works in smaller boxes than the Shiva. Check out my website for a 3 cu ft DVC 12" project I helped my cousin build. It uses a 4" port that's 24" long, which required TWO elbows to fit in the box. One 3" port about 18" long should give you about the same tuning, but you might get some port noise at high SPL's. It really is a kick-butt HT woofer, though.

Have fun!

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