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've always been a fan of KEF, last weekend I had a chance to listen to the much touted LS50 for several hours,IMHO it was way too forward for the Classical Music that is my main fare. Was in a friend's all ARC system which normally is pretty nuetral.
I would prefer the Dyna's myself, but could see where the KEF's might be a rockers dream.

Any particular reason that you are looking so closely at Creek? I've only heard one Creek rig. It sounded good enough, but when I researched them their specs didn't seem to indicate that the amps would have much guts.

I know that specs don't mean everything, but even taking the specs on the Creek amp at face value doesn't instill much confidence for me.

I tend to like an amp with some guts so that I, at the least, feel comfortable knowing that'll they drive any speaker that will fit into the room I'll be using.

For the price of the Creek, I just think that you could do better, especially on the used market.

As for the speakers that you've mentioned, I haven't owned either, but have heard both. The Dynaudios were nice to me. Really, nothing stood out, which I believe is a good thing.

With the KEFs, I just didn't get why so many are so excited about them.

10X10 isn't much space and it's going to be pretty easy to put too much speaker into that room. Just about any listening you're going to be doing is going to be near field. Maybe you should be considering something along the lines of the Peachtree D4 or D5 or perhaps the Silverline Minuets. All are very small speakers that have really big sound. In a room the size of yours, you may not even want or need a sub, depending on your taste in music.