Originally Posted by TedO
My VMPS speakers are not the series II but older versions. From my understanding, the Series II in the RM40 and RM2 only added the waveguides to the mid panels and tweeters which can be done to any set of existing VMPS speakers. I hesitated doing this upgrade because the benefit it gives is a wider dispersion of the high frequencies, giving you a larger sweet spot in the room. I'm thinking a more pinpoint focalization of the sound is better, if you're the one in the sweet spot.
The VMPS Series II generally offer the following:
1) The New CDWGs that fit on the drivers themselves\\
2) Improved cabinets and bracing
3) Side Firing Passive Radiators in the Floor Standing models instead of the slot loaded PRs before.
I bought my RM40s second hand and they came with spiral tweeters and TRT caps. I have done all the upgrades except for the series II and the ribbon tweeter. I have a set of Aurum Cantus G3 ribbon tweeters that will be replacing the spiral tweeters as soon as I can find time.
Speak to Brian prior to perfroming any surgery on your cabinets. The twin Spiral Ribbons have a higher (longer) space than the single FST (newer) tweeter. In the frequencies these operate in the spacing between drivers is critical to a smooth response and anomalies like comb filtering. Brian could be more help in making sure you're on the right trac before you start.
As well, I beleive there is an XO change for the two models. I know the FST crosses at 5.9Khz. I think the Spiral Ribbons might be different.
My living room system has a set of RM30's and a Larger subwoofer. The series II upgrade to the 30s is a little more involved and I plan to do that some day.
Good luck and have fun.