ATC scm 19 vs ATC scm 20SL?

Almost the entire line of ATC products has the same signature sound. As you move into the line, you get better integrated bass, better dynamics and transients, and better build in the cones and cabinets. But unlike most brands, these have a very similar sonic footprint around being very precise and uncolored, and truly, there are subtle improvements through the line. They are both inefficient speakers and require heavy duty amps to drive them. Tubes are not a consideration. The 19s are different than the 20s in that they appear to break in faster. The 20s take at least 800 to 1000 solid hours to burn in; the 19s about 500. Both throw a wide soundstage and play a wide variety of genres well. If space or room dimensions are limited, I would go down a level and look at the 16As.

Agree with the last two postings. ATC speakers are somewhat unique in that they are very neutral and unforgiving, qualities that professional sound engineers value. I have owned many versions of this speaker, all the way up to the 150s. I presently own the 16as at work and for the money, I think they outperform most speakers in the price range, and along with the 11s and 19s, represent the best consumer oriented speakers. I buy mine from their pro distributor in Las Vegas. They are bombproof in build quality. They are made for audio bays/worker cubes, and remember, most tracks are mixed down around the vocals. To Pani's point, you can easily distinguish them in a honest fashion, and from a engineer POV, where they are fusing together different takes to make a holistic song.

The only other speaker I have heard that match the ATCs are the new Sony speakers that grace the cover of the new Stereophile Magazine. Heard them at the T.H.E.Show in Newport two weeks ago and they were jaw-dropping beautiful, driven by Nelson Pass electronics. They are 27 thousand, a little bit shy of the price of 50s and 150s, but a beautifully smooth cross-over and very dynamic.

Will reflect the sonic signature, so it will color your music with a warm tubey glow. I can recommend their pre-amp or a Benchmark DAC1.