Re: Bought set of tweeters, very quiet sound... are they blown/broken?
I'm not sure why you aren't getting any output.... But there are a lot of misconceptions and misunderstandings in your post. Too many to really point out for ya. If you wish to continue learning and growing in this hobby, I HIGHLY recommend you read around a lot more before you make another purchase. And read and reference this site, it has a TON of knowledge: Basic Car Audio Electronics
That being said. I have on theory. You're getting minimal noise when just the tweeter is connected. And you're getting no high-end when the coaxial is connected. It sounds to me like you have a High-Pass filter set on your amp, and it's cutting off the high-frequencies. I'd suggesting turning the crossovers to off, or full, or pass-through, or whatever option it is, and see if that changes the sound for ya.
2009 Hyundai Elantra - Budget Sound in Progress
HU- Kenwood eXcelon KDC-X994
Fronts- Crescendo MP6 mids, Vifa Ring Radiator tweets on Arc KS300.4
Subs- Single SA-10 on Mmats 2000.1 @ 1ohm
Misc- 1/0 CCA from AT, Big 3 in Stinger HPM, and AT 60 mil deadener
Bought from: Inferno333, select127, treesive, Kangaroux, DonH
Sold to: coolest user, Psychodrama, MidgetClown, mr.tigger, av83