Despise conventional dome tweeters

Lonestarsouth,

I had B&W P6s for years. You're right, the tweets did disappear nicely. I suspect though this had more to do with the voicing (overall tonal balance) of that particular speaker and how it played in your specific system more so than the tweeter itself.

You're probably getting a somewhat brighter tonal balance with your current Quads in the same system compared to the P6s I suspect.

Short of changing speakers (those Quads are fine speakers IMHO) you might be able to get the sound you're looking for out of the Quad 21Ls with different interconnects perhaps first.

You might try DNM Reson interconnects, which are not too expensive. These ICs are very British, refined and mellow sounding on the top end. When I use them in my system the sound reminds me greatly of the highly unobjectionable top end of the P6s when I owned those.

I tend to listen first to systems. Then, when I hear something I like, I dig in to understand the technology behind it and why it delivers the sound it does.

I think its counterproductive to get too obsessed with a particular tweeter design alone. You have to look at the whole system and how everything sounds together, be patient and listen for a while to really hear what's going on.

Tell us what tweeters/systems have you heard that you like and I suspect you will get a slew of recommendations of things to try.