"The room can totally wreck, or make, a system"

My background is in recording studios and I couldn't imagine trying to put a system together without first doing basic room treatment. Between standing waves and reverb time, I would find it impossible to evaluate gear. It's a somewhat trial and error process but there are some basic things any room should have. 

Some rooms may have a fortuitous layout with slanted ceilings or non parallel walls that provide a good foundation. But they can hugely benefit from some well placed absorbing panels to reduce reverb time. Without that there will always be smearing and lack of focus. 

Some people worry about a room being too "dead" but why would you want to hear anything that isn't from the source? The ambience you want to hear is embedded in the recording. The sound of your room only detracts from that. Consider that headphones eliminate the room so there's little reason to want to hear the room. 

@hilde45 

I understand that in the real world people are used to listening to their rather live rooms and it might sound strange in a treated room. But once your brain tunes into the sound emanating from the speakers you start hearing the room the music was created in, or at least the ambient space that was created in the mix. 

Sure, live music occurs in an acoustic space and that's an important part of the original sound. But a good recording captures that sound and that's what I want to hear. An untreated, live room distorts the sound in the recording  by adding sound that wasn't part of the original performance. No different than noise. 

A room needs both diffusion and absorption for different reasons. But the net effect of good treatment is reducing the sound of the room and allowing you to hear the recording without added noise, which is what reflections are. Noise that wasn't contained in the original recording. 

A good recording studio isn't anechoic but rather a place where music sound fabulous. Spend some time in one and see. 

 @decooney 

I hate listening on headphones. My point is that people who do like them don't complain about the absence of room sound. They like hearing the actual sound of the recording, not the sound of the room they're in. 

@hilde45 

I totally agree about a good sounding room. That's what good mixing rooms are. 

Studio recordings may or may not feature the acoustic space of the original recording. But the artist/producer/engineer work hard to create the space they want the music to be in. They want you to hear that too. A studio is not some sterile space. Most artists want to feel the emotion of the music in the studio and the closer your room is to a studio environment, the more you hear what was intended. 

Of course, every great studio sounds different so I'm not suggesting there's some standard. You create the room you like. But not intentionally creating a good sounding room limits your ability to hear the recording as it was intended.