What did you change?

For some reason, the Mode switch on my amp had been set to L+R Sum, which
is
where you're meant to set the amp when driving a Mono Bass or Center
channel. I
switched it to Stereo, which widened my soundstage by 200% and created
real
stereo definition. There's another switch, next to the crossover dial
which
reads "full", "high" and "low. They had it set to "high" and I've been
doing
listening tests with it set both to "high" and to "full".

Geez you've been suffering in mono mode! The diff between the full and
high is that at full the xover lets everything through while at high it lets
only freqs. higher than what the xover dial is set to through...shouldn't
change your tweets at all just remove a bit of midbass. Once you get a sub
it will sound a whole lot better. As good as the Dyns are you still need a
sub to get the "complete" sound. If you leave it on "full" until you get a
sub just be careful when you play a really bass heavy song...