what are the pros and cons of having subs mounted w/o a box???

 

Free air subs IME are very inaccurate. No box to control the output from the rear of the driver. Difficult to tune, if you don't completely seal off the trunk, you will have an unmeasurable amount of wave/phase issues. Just curious, why are you wanting free air subs? The only real upside is all the extra trunk space.

 

dont most people with the custom trunk setups w/ the subs in the trunk well, or mounted to the back seat use free air???

 

nope, they are in a sealed enclosure, either prefab or custom made

 

There are some competitors mounting their subs on the rear deck. The trunk needs to be real well dampened and REAL well sealed off from the front of the car. It ends up becoming a real custom job and a lot of work if you're gonna do it right. You lose output and power handling but, with the right subwoofer in the right install, gain SQ and incredible low end extention. Of course, you gain a ton of space.

 

the work to do it is not worth the results imo.

 

There are some midbass drivers that are made for free-air. Or you could check out aperiodic enclosure design if you are short on space. From all I've heard, though, infinite baffle is very hard to do but can produce some amazing results. Scott Buwalda has 3 subs running IB and has won many sound quality championships.

 

Aperiodic and IB both require you to completely seal the trunk so that the back wave of the driver can not enter the cabin and cause cancellations. Very hard to do. There is a guy that posts on here from time to time that did a aperiodic enclosure on a 5th. gen. He is very satisfied with it but it did sound like a lot of work.