Speaker advice?

While I have no particular familiarity with any of those components, I suspect that both of the amplifiers you mentioned, like many in their price class, will not perform at their best when driving speakers having impedances that are low, or that are difficult in terms of phase angle. A good indication of that is the fact that the power ratings of both amplifiers into 4 ohms are much less than twice their ratings into 8 ohms.

As indicated in John Atkinson's measurements in Stereophile of the LS50:

The LS50's impedance (fig.1, solid trace) drops to 4 ohms at 200Hz and to 5.4 ohms at the top of the audioband. The electrical phase angle is generally mild, but the combination of 5.3 ohms and –41° at 135Hz, a frequency where music often has high energy, will make the speaker work at its best with a good, 4 ohm–rated amplifier.

I note also that the manufacturer specifies a minimum impedance for the LS50 of only 3.2 ohms.

In contrast, here are JA's corresponding comments for the Dynaudio speaker:

While Dynaudio specifies the X12 as having a nominal 4 ohm impedance, its plot of impedance magnitude and phase (fig.1) reveals that it doesn't drop below 6 ohms, and then only in the lower midrange, when it reaches a minimum value of 4.8 ohms—which, like the combination of 6.6 ohms and 30° capacitive phase angle at 125Hz, will not tax any well-designed amplifier.

So I suspect that the Dynaudio speaker would be a more optimal match for the Creek or Rega amplifiers (and most other amplifiers in their price class) than the KEF would be.

Hope that helps. Regards,
-- Al

I'd be cautious with regard to the Elan 10, Margot, for the same reason I cited with respect to the LS50. I couldn't find an impedance curve for the Elan 10, but its nominal impedance rating is 4 ohms, and impedance curves I found for some other Epos speakers show them to be a bit more difficult to drive than would be preferable with the amplifiers you are considering.

Spendor and Harbeth are certainly good names, and the Silverline Minuet has received a lot of good press. All of them should be good matches for the amplifier in terms of impedance. If your listening includes material having particularly wide dynamic range, though (i.e., large DIFFERENCES in volume between the loudest notes and the softest notes, such as classical symphonic music), I would be concerned about the ability of the Spendor S3/5se and the Harbeth P3ESR to be able to cleanly handle high volume dynamic peaks, due to their low sensitivity. I'm not saying that they won't be adequate in that respect, especially given the small room size, but that would be the main question mark associated with those speakers, IMO.

Surprisingly, given its small size, the Minuet appears to be somewhat better in that respect, and the currently produced Supreme Plus version, apparently being a bit larger than the earlier version addressed in the review, might be better still.

None of these speakers will provide much in the way of deep bass extension, of course, but you could add a subwoofer at a later time if you find it to be necessary.

I'm not familiar with the other models that have been mentioned. Re the Yamaha R9 receiver (and most other receivers), it won't fit in the space you described. Also, it is specified for a minimum recommended load of 6 ohms.

Good luck in your search. Regards,
-- Al