On Thursday, April 29, 2021 at 7:19:13 AM UTC-4, Miguel Giménez wrote:
Good morning

I own a LG 42LW5500-ZE Smart TV about ten years old. It worked OK until
about two weeks ago, when the sound quality started to degrade and has
worsened from day to day. It sounds as a mix of saturation, crossover
distortion, box resonation and loudspeaker cone broken. I will open the
set this weekend, but before I would like to know if anybody has any
experience with this.

The sound make me remember class AB discrete amplifiers, when the bias
was not properly adjusted and the transition of one leg to the other was
not smooth, but the TV amplifier looks a class D one (NTP-7400L).

TIA

--
Saludos
Miguel Giménez

Bad speakers. LG made their own and they were crap. Even if you find some on ebay, they're just as old and likely to sound like garbage. Just add a cheap soundbar or powered computer speakers/sub. Even a crappy soundbar will sound a lot better than the LG did when it was new. The rest of the TV is well made.