Like the OP, I was using MB Quart components and US Amps amps around 15 years ago. When I finally decided to upgrade my stock audio gear in my Neon last year since I've gotten tired of drag racing, I didn't know which path to take for my highs. The Hybrid Audio Clarus C61-2 seemed to the best choice for me after some research so I visited American Radio and bought me a set. Although at first I missed how bright the Quart tweeters were, I've grown to love the Clarus' tweeters now. It just sounds more natural compared to the Quarts. I did have to use the highest setting on the tweeters but toned it down with the CDA-9887. Using the mid tweeter setting and trying to brighten it up with the CDA-9887 didn't work for my ears. I'm using my 15 year old US Amps USA-442 to power the Clarus setup. I do not compete though.