I've got a freind that is looking at running 4 of the 10" JL Audio free air subs because 2 different stereo shops told him to use them, but neither one of us have ever heard them. Are any of you guys running them? What do you think about them? Anyone how of a place in Socal where they have a demo setup to be able to hear it? Thanks for the help in advance

They do not sound bad but if you have room for a box any box use it. Free airs always sound like crap compared to sealed speakers. It's just physics. The speaker needs compression from the rear to really make it work. You can do all the phasing tricks in the world and it never really comPares.

Sound level and quality will depend on where they are being installed. Keeping area behind cones sealed from area in front of cones is a must.
I have found free-air installs using the compartment under the rear seat as the "enclosure" sound better than side panel installs. Easier to seperate and seal the air from each side of the speaker.
Free-air JL's can sound good and play loud, if the best install option is available.

They have to be mounted correctly or they will not sound good. Free airs can sound excelent if done correctly. If not they are not worth anything. Subs with enclosures are prefered because you can control the sound better, but you loose a lot of room for storage. Free airs can be a great compromise.

Exaactly. A friend of mine had 2 under the seat in a 35 Fountain and we were shocked at how good they worked. If your seat doesnt fit real tight, may lay a line of weather stripping or something for it to seal. Best of both, storage and bumps.

I have X2 of them in my 42FT Fountain and I love them, I know the box is the best solution but for my application they where the best solution. I do not have a big custom system but it works for what I want. I think they sound awsome!

I'm running a set under my back seat and they sound great. As said before, they need to be installed correctly. The JL subs don't hit as hard as some other brands but they sound crisp. I like em.

I have one under my rear seat as well, sounds great!!

We have installed 100's of JL Subs in many different locations some with some sort of enclosure and some without. Trick is that in order for them to sound good you also need a high quality sub amp along with a radio that has a sub output. Depending on the situation with the proper set up they are great. You will not be disappointed. They are also avialable with a fiberglass enclosure as well.
Good Luck

Thanks for all the great feedback guys