Polyfill and tuning

If polyfill tricks the sub into thinking the box is larger, how does that affect the tuning of the port. Also, if you build the maximum sized sealed box will the polyfill make the sub more inefficient?My wife will never understand why, lucky for her!

Polyfill doesn't "trick" the sub.  Since it adds massive amounts of surface area and dampening inside the enclosure it forces the air to move more slowly (or rather it makes the air travel farther than it would without the material present.)  This causes the enclosure to function as if it was larger.  It can increase the effective size of the enclosure by as much as 40%.  Yes, it affects the port tuning as it changes the effective size of the enclosure.  And yes, if you are pushing the maximum size of a sealed enclosure, you can easily exceed the requirements of the woofer and lower its power handling capability, as well as make the system sound really flabby.  For this reason, I suggest building your system and experimenting with the amount of polyfill to achieve the correct balance.  Often, my ported enclosures use none.Support the12volt.com

DYohn- My Fosgate RFR3110's that I am about to install, specify exactly .625 for sealed box. I built the box exactly to spec, so would adding a little polyfil be a No-No? Or just unnecessary since the enclosure is exactly the correct volume?boom, boom, boom boom....