Enclosure fill Question

I've seen the same things and it is a confusing issue.  I read one manufacturer's manual last night that said to fill with 1 1/2 lbs per cu ft!  I can barely fill with 1/2 lb without thinking it's too stuffed. 

It is confusing, especially since not all enclosures really NEED polyfill.  I always use it, and always use 1lb per cuft.Support the12volt.com

Do I have to add any enclosure space to accomodate for the fill? Or is all that taken into account when they release the proper volume?

Strangely enough, a driver thinks it is an enclosure that is LARGER than it really is, but you can only fool the driver up to about +10%. (example: your box is one cube net, unstuffed and the driver will think it is a box that is 1.1 cube, after stuffing) The amount of stuffing you use to get this figure will depend on the stuffing material, and the original unstuffed volume of the box. Smaller boxes will take more stuffing per volume than a larger box. If you get to the +10% point, and you continue to add stuffing, you will actually start going back the other way. Also the ONLY way you can tell when you have reached that magical point is to TEST the driver in the enclosure, not with your ears, but electrically. It is difficult to say that you have gotten there by listening. Also, if you stuff a vented enclosure, (ideally, you never "stuff" a vented enclosure, you should just tack a thin layer of batting on the walls, for absorbtion of higher frequency energies) you need to make certain that the stuffing is nowhere near the inside mouth of the port... it'll jack with your tuning.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

thanks