Yea, speaker isolation is nice, mine costed 10$ and made a noticeable difference. I also believe that better cables and USB purifiers makes a difference, but those changes are very small and should only be considered once you have a good room with DRC, good speakers, amp and dac.
I think there are several reasons why some people don’t like digital room correction:
- They did it wrong (as did I first time), usually by only doing one measurement/channel, which will make the music at higher frequencies sound false and mess up stereo imaging. The reason for this is the short waves at higher frequencies, so moving your head/ear just an inch from the measurement spot will give a different sound.
- They did it right, but is so used to the old sound that the improvements sounds worse. For example, if your room gives a peak at around 100 Hz, many instruments like acoustic guitars will sound thinner when corrected.
- They believe that bit perfect is the way to go, and that whatever they hear when using bit perfect and expensive audio equipment equals what the artist intended (that reasoning is only valid in a perfectly acoustic treated room like a mastering studio).
- It feels expensive to spend money on a software like Dirac (better to spend them on cables right? )
I listened to some expensive stuff in an HiFi stora a while back, but in a mildly treated room with no digital room correction, and despite that the speakers, amps and dac used was about 10 times as expensive compared to what I have, it sounded much worse (some parts in higher frequencies did sound better though).