Are you sure your cone filter is contributing to your excessive sound? What type of exhaust do you run?
My car has a 3.8L run with Haltech, and runs a cone filter. The exhaust system is S Car Go headers mated to some Phase 9-type mufflers. It is very loud, but when I add a large secondary muffler, I can run at Laguna Seca and make 92 dB with no power loss. The cone filter does not contribute enough noise to be an issue. This may also be the case with your set up.
The airbox that was in the car when I bought it is shown below. It is a modified '95 airbox, with an aluminum intake snorkel to get air from right under the deck lid, which in my case is a 993 3.8 style unit. I am not sure whether the snorkel would fit under a stock type deck lid... but it could probably be modified if it doesn't. I think the potential advantage of this modied airbox is that it should get cooler air. It is sitting on a shelf in my shop (it is for sale if anyone can use it).
My current set up is a cone filter housed in a custom carbon fiber box I made in an attempt to get colder air in. Works well.
Modified '95 airbox:
