I wonder how well an 8 track would compared? My first car audio install when I was 16, Motorola 8 track and Sparkomatic 6x9's, I am going to be 71 in a couple of months
I used to have a modified stock cassette deck in a very high end mobile audio competition system as a decoy though is sounded very good on just some decent 5.25 and tweeters. Below that was a high end CD player with a flip over face so just looked like a blank filler, flip the DTPD switch hidden under the dash, it flipped over and the real system turned on preset to blow away anyone that ever heard it, really did so
I fooled top audio judges with the cassette, they thought it was the real system until I did the hidden switch system change.
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Dang fine reviews indeed, I will be looking into DIY versions of all your designs if the XDS8's do not work out in my rather restricted space.
I love ribbon tweeters, have used them in competition installs and have used the woofers as well that you chose to use in these, dang good speakers for great prices!