Engineering nightmare gets 80%
Fail 1: Acrylic turns cloudy and shatters when it absorbs oils. Touch those horns and the'll be destroyed in two years.
Fail 2: 65W with a thump and a hum? It sounds like they used the reference schematic for a cheap 5-pin amplifier chip. Both of those failures are caused by grossly asymmetric circuits and/or multiple signal grounds. Even in high school I could make a 100W amp that was perfectly hum-free and thump-free. It doesn't require muting or filtering - just a decently balanced circuit with a single audio ground.
Fail 3: How much copper for a measly 65W? Power semiconductors are fine running very hot. Keep them thermally isolated from the more sensitive components and you need very little cooling metal for 65W.
Fail 4: 50Hz cut-off? Was that an attempt to lessen the amp's line hum? That won't do for music, movies, or video games. I'm sure it sounds awesome with Skype.