My projector works great and all, but my fan is starting to bug me. Right now my box doesn't get over 83 degrees, so a little obstruction shouldn't be a huge issue. Does anybody have any tips on knocking down the noise from my fan?

Surround it with some cloth or other soft material. Anything vibrating attached directly to something hard will amplify the sound. Therefore, you can put some foam or cloth between any area your fan touches the wood and the sound should diminish quickly.

Anyone have any suggestions for good gasket material that might work well when installing the fan(s)? I'll be putting in my 2 Evercool PCACs soon and would like to find something good to damper the vibrating.

Make it bigger and/or undervolt it.

I bought a foam sheet (about 1/8" thick) from a local craft store and cut it into a gasket to mount between my PCACs and the enclosure. Its held in place with a spray adhesive. Works well. You can get it just about anywhere.

You can see the foam under the PCACs in this photo (click to enlarge):

Neoprene works well as a gasket material. My fans are only making air noise, so I'm not too worried about that.

A potentiometer can be used to trim the voltage to the fans. The noise level will decrease at the lower voltage. This is what I plan to do, as my fans are quite loud too. My hope is that I can run the 2 120mm fans at lower power and still keep LCD temps down to acceptable levels. I want it adjustable, though so that I can turn them up in months when the temperature is higher.

For anyone planning to use the potentiometer to reduce fan noise, I dont think it would be a very smart idea for those using 120v/240v fans, especially if you are reducing the voltage a lot.

Brain normally corrects my slightly vague knowledge of AC electrics, so it might be worth waiting for him to double check this before taking my advice

A note about the evercool PCAC's.

I just connected both of mine in my test box (1 at a time), and they create a lot of vibration. Reduction fan speed only reduces the air sound, but does nothing for the very loud noise created by the vibration. It's more of an obnoxious humm then it is a typical fan noise. I plan on finding something to insulate the fans.

If you plan on cooling your box with the PCAC's keep this in mind, as I had no idea they vibrated so much. They may have low DBA uninstalled, but once in contact with a solid surface the vibrations are amplified.

That is why people are using foam gaskets to absorb the vibrations, thus reducing the noise of the fan.

Try a large o-ring. Works good on mine.

I ended up using black craft foam from Joann Fabrics.