Funny you should mention it. I have been going back and forth among my different Omega speakers. I have put off the RS5 vs. Alnico comparison for now and have focused on the single driver Super 3 (original wide baffle) vs. the Super 3HO (dual driver, narrow baffle).
My review context is Chord Mojo or Schiit Bifrost/MB feeding a Redwine Audio Signature 16 or Fi 421A SET clone. Speakers are more or less in the corners (within 2 feet of both boundaries) of a 15’ x 22’ room.
With both DAC’s and both amps I found the midbass to be too much with the Super 3HO’s. I’m sure that pulling them out into the room would help, but it resulted in a thickening of the sound and made the already dark-sounding RWA sound muffled. It also seemed to lose some of the midrange forwardness that make single driver speakers sound alive.
I swapped in the Super 3 wide baffle speakers with RS5 retrofit drivers. This is slightly (7%) larger than the current Super 3, but turned sideways like the CAM. I’ve only used the 421A amp so far with these. Right off the bat my impression was that they produced about 90% of the bass as the HO models. They sounded lively and dynamic and more balanced than the HO models. However, I noticed dynamic limitations almost immediately. I am unsure if it is the 4.5wpc amp running out of steam or the speaker reaching its bass limitations. The latter is not unlikely; the 421A amp is surprisingly powerful in the bass despite its low power.
I think that while I prefer the essential character of the single driver speaker, I don’t think it can move enough air in this particular room. While the dual-driver speaker does a much better job dynamically, it does not gel with either of the two amps I have used in this comparison. My preference ( and the topic of a future comparison) would be to supplement the single driver speakers with active stereo subwoofers. Ideally this would allow for the ability to high pass the Omega’s to relieve load in the bass, but my subwoofers (Rythmik F8’s) only have low pass crossovers. I’ll need to break out an amp/preamp combo to high pass the speakers.
A last note:
I believe the dual-driver Omega’s are a less than ideal for both of my amps for a couple of reasons. The RWA amp doubles power when impedance is halved and I think it is simply putting out too much power in the mid to upper bass region. The 421A amp already puts out great bass. Being transformer-coupled it couples really well with the single driver, giving it surprising bass. The HO model does develop more bass power, but not enough to warrant the loss of immediacy of the single driver.
That is not to say the dual driver HO is not for me. I just received a NP Amp Camp kit that I think would match really well with the HO speakers. I also have the strong suspicion that high-quality Class D would sound great with these (The Denon HEOS AVR is tempting for a five channel HT setup. It puts out a real world 20wpc or so and has native Tidal support). I would argue that the HO model will work better in configurations suited for conventional speakers, albeit at high efficiency. It would excel as a substitute for a KEF LS50 that can accommodate low power amps. I think you could pair it with almost any Firstwatt amp and be satisfied.