Can you tell me why I didn't like the Reference 3a MM's?


So I recently asked about a new amp on the Amplifier forum.  I got a lot of good advice and ended up with a Pass XA25.  I really like this amp and the sound.  I have been told by Reno Hi Fi, Pass Labs and B&W, all of whom I contacted, that the XA25 is under-powered for my B&W 705S2 speakers.  But it sounds very good.  However a little flat when the volume is low.

So I am looking for some more efficient speakers.  I tried a used set of Reference 3a deCapo MM's, but they did not have the clarity of the B&W's and sounded a bit muddy at times.

I am looking at Omega Super Alnico HO's.  But I am wondering if the full range driver sound is what I didn't like.  

Am I wrong in thinking more efficient speakers will sound somewhat better at a lower volume?  Can you possibly tell my why I didn't like the MM's?  Something about their design or build?

Any thoughts on the Super Alnico HO's?  I don't want to move down the speaker sound chain.

Thanks much!  Any other speaker suggestions welcome!  But not horns.  I am not a Klipsch fan.
128x128jgoldrick
I think you need to specify what version Reference 3A MM De Cappo you were listening to as they've been around since 1980! and have gone through numerous iterations of upgrades since. The latest being their 40th Anniversary edition with Beryllium tweeter, cabinet reinforcement, heavily reinforced rear and side panels, modified woofers, capacitor and wiring upgrade. I find the sound very smooth articulate, musical and non fatiguing.
That's a fair point regarding the many iterations over a long lifespan.  I have owned three versions spanning from the late 80's into the mid-00's and I never experienced bloated one-note bass, except when my wife insisted that they reside in the bookshelves in our living room.  I only sold them because the bookshelf location became non-negotiable as soon as I got my own dedicated listening room (fair enough trade!).  If you hear such bass from these speakers you aren't using them correctly, I'm guessing.
One of the problems with the older 3A MM’s is the soft dome tweeter sounds a bit wooly. This may be attributed to an inferior dome material or perhaps the 5.18uf Russian military capacitor used in the high pass crossover. A friend of mine is currently retrofitting a new pair of Morel Elite ET-338 tweeters into his De Capo i speakers. The big green Russian metal can capacitor is being replaced by an equivalent value Miflex copper foil capacitor. This should clean up the sound quite a bit. The hand coated Acuflex dome Morel tweeters from Morel sound amazing and are a tad less hot sounding than the Eminence ASD1001 compression drivers used in my Zu Omen DWII speakers. If Morel made a 97db acuflex dome tweeter, it would immediately be retrofitted into my Zu DWII’s. With regards to the impedance mismatch between Pass XA25 and the Omen DWII’s, Zu provides a guide for selecting snubber resistors to reduce any impedance mismatch. Gauging from the chart provided at the link below, perhaps a 20 to 22ohm pair of loading resistors would level up the impedance to match the Pass XA25 amplifiers 8 ohm output impedance to the 14ohm charcterisitc impedance of the Omen DWII’s. You can always call Gerrit or Sean at Zu. They are always helpful in answering any questions you may have. They are great ambassadors to this hobby!

https://www.zuaudio.com/diy/loading10r