(OT) Adding a ribbon tweeter to my speakers?

[bowtie427ss]

You lost me? why would I want to run them out of phase?

A 2nd order high pass filter by nature of it's function inverts the absolute phase 180 degrees.

If you trace the wires on any properly wired high pass section in a 2nd order Altec network, you will see that the red wire(+ for the horn driver) is actually connected to the ground(- minus) side of the input.

I bought that 3 set of Onkyo surround speakers and they have small dome tweeters in them that I could just pull out.

Pretty doubtful that domes will be sensitive enough. The majority of them run in the very low 90db range while the average sensitivity of your 604's is going to be ~100db.

I wonder why the HF section of my 604's aren't doing it for me? 60 year old Phrams probably. : /

Could be tired phragms, weakened magnets, or even simply the midrange forward sonic character of the 604's themselves.

For me personally, if i were going to stick with a passive network on my 604's i'd have to strongly consider cloning the 604K network which has a MF adjustment that can be dialed back a bit. Sometimes taming the mids down a bit can increase perceived VHF output.

Do you have an EQ in system such that you can try pulling down the mids a few db in the XO frequency region?