Was the new fan any quieter ???
I finally got around to installing this fan(see earlier post). It was not
quieter. Also, there is buzzing noise coming from the speaker now, so I am ordering a replacement part from Mesa to try that, since the one in my 20/20 has an intermittant problem where it gets REALLY loud, like something rubbing. The one I got was 5v also, I don't know why noise is coming out of the speaker now, but hopefully with a real part from Mesa that won't happen. I do notice the original fan in the unit was .6w and the replacement I mentioned above is 1watt. I don't know if that matters or not, but there is clearly noise in the audio signal now.
One thing I notice is that these fans are dead quiet when not attached to the chassis. I think the loud sound is a combination of whoosing air through the tight space yes, but actually I think the bigger factor is the vibrations are some how transmitted to the chassis and its quite loud.
I might try to try to find some rubber screws and washers to try to mount it next, that won't be easy to find, but that is what I will try next.