By 1986, I don't think (??) the 4(A) would have had the Peerless silk dome tweeter, though -- do they?
At some point the Monitor 4 switched to a smaller dome tweeter; one of the once-ubiquitous dome tweeters that were, I
think, made by Audax.
I was busy with grad school & starting a family in the 1980s and kind of lost track of/interest in fine details of the evolution of Polk's products after ca. 1983 until
quite recently.
Original morph Monitor 4s with Peerless source:
https://forum.polkaudio.com/discussion/148194/opinion-on-polk-monitor-4-with-peerless-tweeters
Here's what the later morph looked like:
source:
https://forum.polkaudio.com/discussion/178594/vintage-polk-audio-monitor-series-4-speakers-4-82754
It would -- to drag
myself back on topic
-- be quite interesting (to me, at any rate) to compare
either version of the Monitor 4 with the kinda, sorta similar R200.
EDIT: Here's a cropped & blown up detail from an ad from the October 1985 issue of Stereo Review showing the Monitor 4A with the later tweeter. Note also that the other "Monitor Series" Polks were, by then, using one of Polk's own tweeters
in lieu of the Peerless. Sorry the scan is blurry
View attachment 177073
source: of
https://worldradiohistory.com/Archi...iFI-Stereo/80s/HiFi-Stereo-Review-1985-10.pdf (magazine pg. 7; part of a multipage Polk Audio ad spread!)