Depends on which LZ recording you are talking about. Some are pretty good, some are horrible. Makes a difference.
petar, I am not sure what "muffled mids" means. If there is a peak centered on 300 Hz you will get "muddy" or "thick" midrange. If there is a dip centered at 5000 Hz you will get dull midrange. Both issues can be the result of room acoustics and/or speaker issues. I doubt it would be elsewhere in the system. Speaker issues can include amplifier matching problems. The only sure way to figure this out is to get a calibrated mic and a frequency response measurement program. Then you will be able to see the problem and determine if room treat, speaker adjustment etc. are working. Another way to deal with it is a room control unit. It will come with the mic and measurement program and the ability to EQ your system digitally without any ill effect. This is a great unit, https://www.deqx.com/products/hdp-5/ DEQX also makes a less expensive unit that will also do everything you need. Once you have your system corrected everything will sound better.
He's getting great sound from other files and sources. So its NOT the damn cables!!!
I guess for you, you change out cables every time a streamed file sounds bad.....