You're not the first person to put your hands behind your ears to hear something better, doing so increases the highs and attenuates the lows. Why? It's because your hands aren't big enough to reflect a 34 Hz sound wave
$75 ain't that much coin, id pick it up and still look for another forte or a heresy,
I used a rc3 for a center between fortes untill I found a more appropriate speaker.
During final testing at the klipsch factory sometimes it is found that a particular speaker performs especially well with a certain style of music. The tester may put a code on the lable indicating their findings.
In the past I have seen on labels
RB..rhythm & blues
HR..hard rock
BG..bluegrass
Could RV be "rap voiced"?
@coyote is always looking for DM which we all know stands for Donny & Marie
Don't try to weld over the stripped threads.
That much heat could destroy that end of the horn.
I would bore that end out to 1.500 to 1.501, make a sleeve with 1.500 od x 1-3/8-18 id and press it in using sleeve adhesive.