I just purchased a pair of the new RST28F-4 tweeters because they are on sale and I happen to have I pair of the Visaton round waveguides I want to use them with. Right out of the box these are no RS28 tweeters that we use to know and love...
1) Visual inspection of them, their faceplates are not centered or clocked correctly. The 4 attachment screws heads are not centered in their counter bores, not even close.
2) These are the fabric dome version, not the aluminum dome version, yet they have a phase shield. Why?
3) I did a DATS impedance sweep of them. They aren't even close to the published curves that show a single well defined impedance peak at Fs. Both of the tweeters that I got have a double peak Fs curve that peaks at 425 Hz and then again at 1100 Hz, but the peaks are only 5 ohms. There is another blip at 1500 Hz.
Anyone else measure a RST28F-4? Does their .zma measure close to the published curve or are they more like the pair I got and measured? I'm not going to monkey around with these (i.e. try to center the domes) because I plan to return these as defective. Just curious if this is just bad luck on my part or if we have truly lost an old go to product.