JM Labs Electra 946 lack of high-end detail

Thank you all for the instant feedback. The mid-range speaker is indeed 6.5" measured from to the outer edges (beyond the screws). It just looks approximately like a Boston 5" speaker. At any rate, on your suggestions I unscrewed (use metric hex) and pulled it out a bit and to the side to make sure it was working. It was, although it may be blown for all I know. I then examined the 6.5" mid-range in both speakers and noted that the cone was detached from the center concave post "button", i.e., the cone moves back and forth along the center shaft. I've never seen an arrangement like this, but it seems right, since the center convex hard plastic button does not move in and out to the touch.

In sum, unless the mid-range is clearly damaged, I may just replace the tweeters and see if that improves the high end. Any suggestions where to get them? (I understand this is a grossly subjective judgment, but what I mean by high end is a certain bell-like clarity which may be an artifact of the Adcom/Boston combination.)

Lastly, by '80 speaker I had in mind the big Infinitys -- the kind of speaker Cream sounds just right on (as opposed to, say, The Clientele.)

Yeah, the midrange is supposed to work that way. So, you're getting plenty of sound from both tweeters and both midranges if you put your ear up to them? Hard for me to judge what you're hearing wrong then, because I certainly never heard "a bell-like clarity" to the high end of the Boston/Adcom combo back when I used to sell that stuff, but that was 11 years ago now. Anyway, the JM Labs shouldn't sound so deficient, so it seems to me the most likely candidates are either damaged but partially working drivers, or somehow damaged crossovers. Really the only way I can think of that both crossovers would be 'damaged' the same is if somebody deliberately altered them. This doesn't seem very likely either though. Only other easily conceivable option, as has been mentioned, is that your perception of hearing the speakers is what's off. Who/where did you buy these from, and have you recontacted them about this? I think what you may need at this point is a second, in-person opinion from an experienced listener.

You can get exact driver replacement from Zalytron.com in new york, if they are still in business.. Also back when I had some Midrange drivers from Focal, I think they were what is called the Polycarbonate type or something, basically had a grey sand like feeling surface, they did not have the greatest quality control for some reason.. I would get a driver here and there when building kits that would actually make a scratching noise when moved by hand in the piston like pumping motion, this was a hung up or slightly out of center voice coil, and I guess it would make them not perform as well as a super smooth piston movement and made them sound like More Restricted..

I ended up getting them replaced and then they sounded better, I would assume having something like that out of whack and supposedly being the Hi quality tolerance FOCAL driver the gap and resistance.. etc in the speaker was off. By the way JM labs are FOCAL drivers, and can be found at other places as well, like Madisound.com ..

Other than that Zaikesman could be correct in the crossover, maybe a out of tolerance resistor or Cap??

Sounds to me like there is a problem with your Electras. My 946s have a very detailed midrange and treble. Infact I have even heard complaints about the Electras being too detailed and bright sounding. I find my 946 Electras to sound neutral although some components and cables can make them sound bright and forward. IMO Bostons are good speakers but not in the same league as JM Lab and Adcom equipment is decent quality but not the last word in high end resolution. Could be you are just used to that particular sound. I am using Threshold power and pre amps with my 946s and have no complaints and have heard various Electra models driven by amps such as Pass Labs, Krell, and Belcanto and all sounded very good. The 946 Electras do have a lot of bass energy though and it could also be that your room needs some tuning as the bass could be overpowering the higher frequencies causing them to sound dull. As someone mentioned it might be a good idea to get someone else to listen to them who is more familiar with the sound of these speakers before you start replacing drivers. In any case if the speakers mechanicaly check out fine and after a bit of room tunig they are still not your cup of tea, you should have no porblem selling them and getting most if not all of your money back and stick with the Bostons.

Lmhlaw - what size is your listening room?