Klipsch Speakers for a low power tube amp.

I've used Klipsch speakers with my 5 and 10-watt tube amps. The combination sounds good providing one likes the sound of horn speakers. I know there are some out there that don't care for the sound of horns, or Klipsch.

20 watts is nothing to sneeze at. Klipsch speakers like the khorns, etc. are VERY efficient and only need about 2W to get going.

In other words, with 20 watts, you have many opportunities besides Klipsch.

Cornwalls work great with 17.5 watts.

Just about any of the models and especially the most talked about models do not need even 20 watts believe it or not.. however some of the larger woofers, or Multi driver woofer klipsch models can sometimes benefit from more power simply due to having some better current running through them for better bass output and control, but they will all play plenty loud, maybe just not as deep without the higher power amps.