kaygee

Old post. Not sure if you (or anyone) still looking for a response, but I am in a similar boat, and I'll let you know what I've found so far. The tweeters are held in by two allen bolts (not nuts). The allen is SAE, not metric, but I can't see what the size is. The bolts unscrew and the tweeter falls out to the front. Nice and accessible. Behind the tweeter, between the plastic molded piece holding the tweeter and the MDF cabinet, is a rubber-ish washer. Behind that is the extruded aluminum heat sink, which slides neatly into a cavity in the MDF, and is supported by "shoulders" on the heat sink. There is a substance which looks like a light oil on the heat sink, where it contacts the back of the tweeter. The tweeter on the VR-M50 is the "lynnfield" model, 1" aluminum dome. I know it is shared by a lot of Boston VR series speakers (most? all? idk). Some are anodized black, some are not. They have a plastic bit in front of the dome called the AMD (amplitude modulation device I think?) which is supposed to help with dispersion. IMHO this tweeter makes the speaker. Problems: The AMD is fragile and has been broken off on lots of used speakers that share this tweeter. A healthy VR speaker is not without value, so you can't find donor speakers for super cheap. (I'm in the same boat because I just bought a VR-MC center and a pair of VR-M50s on that auction site for super cheap... because two of the three tweeter domes were collapsed.) Most of the VR series (the vr-m975 and 965, I personally know) use a four-bolt mounting pattern for the tweeter. You can actually find these on that auction site. However, the VR-M50 (and M60) need two bolts on either side, and those are nowhere to be found. Solution: It looks like the Micro 90x speakers use the same tweeter with the same bolt pattern, so my next step is to find a pair of Micro 90xs, have a little memorial service, and then sacrifice them to my M50s (i.e. pull the tweeters out of the Micro 90xs and attempt to transplant to the M50s). Alternative: make a four-bolt tweeter fit. Some drywall screws and bondo should do it.