JM Labs Electra 946 lack of high-end detail


I have a large open-plan home theater room that I could not fill with enough sound from my Boston VR-M90 mains. My (5th) sub, an SVS PB2 Plus, was up to the job, but overwhelmed the Bostons. So after reading the critiques in this forum I bought a used pair of Electra 946s. With a single Adcom 5802 they lack all high end detail. Bi-amping them with the Adcom 5802 bottom and 2 channels of an Adcom 5503 (a bright amp) brought out a lot of detail in the speakers, but they still lack the finesse and detail of the Bostons. (I like the Boston sound.) I use an Outlaw 970 pre/pro.

Any suggestions as to how to brighten up these speakers would be appreciated. My beef in partivular is with the single 5" midrange speaker and tweeter, which sound dead.

These speakers are the '80s speakers I couldn't afford back then: big stupid bass, as someone has pointed out, efficient, loud, but not refined.
lmhlaw
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.
Aball, the "main" line-of-sight area in which the HT/listening area is located is about 75x25' and there are another 1000 or so sq. ft. of rooms with doors branching off this center "nave".

Arnold, I have suspected the Adcoms and the pre/pro too. The Adcoms vary considerably according to model. I have had several, from the 565 monoblocks to the GFA 7000, which sounds the best to my ears but overheats easily even with bookshelf speakers (Bostom VR-M60s). Would I get more bang for the buck buying a different pre/pro first, say a Krell HTS 7.1, or changing the amps? (I currently have an Outlaw 970 pre/pro).

And Zaikesman and Undertow, thanks again for the helpful suggestions.