Want to improve the sound from your door speakers?

Then you must install F.A.S.T. rings. I don't know why I waited this long to install them. They made my midbass have more impact, the mids sound louder, and eliminated all the door panel vibrations I have been chasing. It focuses all of the sound energy into the cabin, and not the door panel. This will sound weird, but it also improved the sound from my sub. Because the reflections between the speaker and door panels were eliminated, many of the phase issues between midbass were also eliminated.

http://fastringsinc.com/

There's three pieces. One goes on the door outer skin behind the speaker (which I could only use half of because there's a bar there and the window will hit the top half), the second goes between the speaker and adapter, and the third piece goes in front of the speaker to seal against the door panel. I had my speakers pretty well sealed against the adapter so really the third piece is where I saw the greatest benefit. It went on pretty easy and fit my 6.5" Legatias very well.

Here's a pic of the outer ring on speaker:


It's a very cheap upgrade, so definitely a must have for your door speakers.

I don't work the company so I'm not trying to sell some marketing BS. I'm just a car audio lover who wants to share something I found that you should really consider. FAST rings have been around for a while and I have seen them many times across all the car audio forums. I don't know why I waited this long.