Pre amps can either turn your livingroom into a symphony, or give your speakers more buzz than the coffee I'm drinking.
I've found that with pre's -- the more friends you have with them, the better. Borrow at least a dozen of them and have a preamp party.
Pick something that you listen to OFTEN, and make sure it's complex. Classical is always good. If you're into rock, choose something with as many layers as say, Dark Side of the Moon. Don't test a pre-amp listening to a power trio.
I usually test my system with Floyd and West Coast sound -- like Steely Dan. Because that's what my ears like best.
Oh -- one thing about preamps. Nothing will make your Amplifier sound worse than a good preamp. If you're *that* into music, find the resident audio-geek in your town and listen to what vacuum tubes and transformers can do.
I'm glad you're not using the subwoofer. I wouldn't so much as let a sub inside my house -- throws off the entire listening experience. If you have good speakers, the crossovers will take care of all the bass you need. And REAL bass will move *through* you, not bounce *off* you. (Hard to describe, but you'll know it when you feel it.)
For my money, this is where transmission line speakers shine -- bass response. By creating resonance within the speaker itself, bass is clean and bright without that "thumpa thumpa" flatness that I hear in every over-powered car stereo in North America.
(Kind of like the "bass boost" buttons on amplifiers. Never use them. Better yet, get a good amp.)
Incidentally, the reason subs are so popular is that GOOD woofers are very expensive. (A good 8-inch woofer will run about $150, then you'll need a $300 coil in the crossover to make that $150 woofer sound better than the speaker in your PC case.)
Subwoofer fans usually think it is acceptable to shoot the *really* low frequencies out of a cannon than worry about the 20-80 hertz range. As far as "bass for the buck" goes, I suppose it's a sound strategy. Subwoofers are cheap. Good woofers and crossovers are ridiculous. I'm more interested in a smooth bass curve.
Getting back to testing a preamp (or your whole system, for that matter):
My favorite way to test systems for classic rockers is to put in Dark Side of the Moon -- Great Gig in the Sky. There are three voiceunders on that track that are so faint they may as well be subliminal.
"And I am not frightened of dying, any time will do, I
don't mind. Why should I be frightened of dying?
There's no reason for it, you've gotta go sometime."
"If you can hear this whispering you are dying."
"I never said I was frightened of dying."
If you can hear them, you've got your highs and midrange down, and then it's just a question of bass preference. I usually tune my speakers using the female soloist from Great Gig (always use a female voice for tuning speakers, IMHO) Keep tweaking until it sounds like she's 10 feet behind your listening room wall.
Then to make sure I've got what I want, I put in Steely Dan's Aja and make sure Donald and Walter sound good, too. Finally, I drop in Beethoven's 6th -- probably the best way to see the interplay between high treble and low bass.
From then on, if the music sounds bad, it's probably the musician's fault. Not my equipment.
ScoopKW
PS -- Silverwind -- I just looked at GR Audio, and I'd pass. They don't tell you what's in the crossover, nor the crossover schematics. They only mention response levels. I'd go to
www.madisound.com and look at the Audax AV kit if that's what you're into. Prices are about the same, and you'll *probably* get better sound. (There are no substitutes for hooking both sets to your system and testing them. Usually, that's too cost inefficient.)
EDIT -- Added the above advice for Silverwind.