Looking for new speakers


I'm looking to upgrade my Thiel CS3.6s -- I never thought I'd say this, but I think they are not good enough for the rest of my system. 

Within the last two years, I've upgraded my amplification to a Luxman L-509x integrated amp, and upgraded my turntable to a Luxman 171a. Overall my system sounds pretty good --- MUCH better than before the upgrade. However, there are some recordings on which there is definite distortion, particularly especially well-mastered 45s. For example, Diana Krall's Look of Love has so much distortion it's almost unlistenable. Even in the 33s, I can now hear a low-level distortion.

My theory is that when the Thiels were manufactured, the electronics were not quite as good as they are now, and definitely the recordings were not mastered as expertly, so these weaknesses did not show up. They were great speakers in their day, but, alas, I think maybe that day has passed, at least in my system.

I'm looking for something in the $10K - $15K range. Not sure if there's anything in that range that would be enough of an improvement, but I'd love some suggestions. It's been many years since I've looked at speakers, so I'm not really up on what's available at that price point.
theo714
I haven't read all of the responses but it does sound like there are some problems in your new set up.  It is rare that something becomes unlistenable unless there is a problem before the signal gets to the speakers. I had Thiel 2.2s for a long time and generally loved their sound.  They could be a little bright at times.The 3.6s had a similar sound but greater bass.  When I moved my system into a dedicated music room that was 17x32 with a cathedral ceiling and a truncated back wall, the Thiels were just not big enough to fill the room.  Added a Sunfire subwoofer but getting the integration right was difficult.  I listen to Krall, jazz and R&R.  I listened to and bought Legacy Focus speakers that had two 12" woofers in each speaker and love them.  They have been replaced by the Focus SE in the Legacy line.  Legacy speakers continue to have great reviews with the higher cost Aeris model and those above it.   I certainly would  listen to them once you find the "bug" in your set up.
Theo,
The great news is that if you have an itch for new speakers, a strong market exists for your current Thiels. That is a nice problem to have. You can find some pretty amazing speakers for $10-15K, but I do wonder if you would be happier. I would highly suggest you hang onto the Thiels for a bit if you do change to avoid sellers remorse. Many on the Thiel thread have speakers dating back to the 90's being run by SOTA amplification and sources.
This might have already been covered, but do you have another source besides the turntable?  CD player or streamer to hookup to the Luxman 509x and check, if the same distortions are heard on same tracks?

that is what I would do before getting new speakers. 
Are you using the phonostage in your 509x?  If you are that is probably not so good match with a low output Koetsu. The loading of 100 ohms is probably not optimal for that cartridge. I know it was not for my Ortofon Cadenza Black. You probably need 400 ohm loading. 
That cartridge with is 5 ohm internal impedance is perfect for a trans impedance type phone stage such as a Sutherland Little Loco. That is what I currently use. It is amazing! 
You could always go the route of a step-up transformer and then go into the MM of the Luxman. I have used Bob’s devices in the past and they are awesome quality too. 
Jason
Post removed 
@millercarbon is a troll trying to push his ideas and equipment choices on everyone else. If that doesn’t work he’ll bully you. He doesn't have a life but has plenty of money if you believe what he says. He spends his time posting on Agone, whatch his posting numbers, they go up a couple hundred to thousands every week.