Remember that a "free air sub" doesn't mean that you can just sit the speaker on the back seat.

A free air sub still needs an enclosure, it's just that the car's trunk works as the enclosure. You need a solid mount with a complete air seal between the car cabin and the trunk. For instance, it wouldn't work on the rear deck of most hatchbacks because that's not an airtight seal between the trunk and the cabin.

Make sure to call Crutchfield and talk with their phone reps about what's best for your car and your budget. Don't rely on just the catalog or the web site, their real strength is their people. Talk with them one-on-one and ask them all your questions. They'll be able to help you out.

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Tony Fabris