Get some carbon fiber or Fiberglass strips. Some epoxy. Lay out the epoxy and put the strip down. smooth it out. Let it cure. Sand and paint. Bedliner would work or flex seal.

Ugly way would involve a strip of metal and a rivet gun. You could use threaded rivets, so bolts could be used.

You cant just use someone elses eq settings that they used on a completely different speakers. They used mics to calibrate. They used crossovers to get the tune. You and everyone else need to just eq to taste. Not a curve you cant measure for. With a mic.

I find its more fun to find cool old headphones on Ebay etc. Bought several pair of well built 50 year old headphones. Old Pioneers are fun. Working or not. New speakers can be bought cheap and installed.

Headroom is simply having more power than you will need. Powering a 25 watt rms speaker with a 100 watt rms amp leaves 75 watts of headroom. If that amp is putting that 100 watts rms out with .005% THD. Imagine what the THD is if the amp is only putting out 15 watts. Probably not measurable at all. Definitely is not audible. So there is plenty of headroom for distortion also. Which is the important one really.

I have a working Compaq Laptop that might run that PCI card. Runs windows 98. Thinking about finally upgrading to Win 2k. Have an unused copy of that also.

That person has OCD. Not audiophelia. There are benefits to having quality made gear. There is also very limited returns on spending tons of money on even more expensive stuff. Sure using the best electronic parts that are made will have measurable results, but not with any human ear. None of them.

Alice in Chains S.A.P. is a good one. I haven't seen it on a service yet, but "The Cure Deluxe Album has a second cd that is all acoustic studio tracks. Same songs as the 1st cd, just acoustic. If ya like the cure.