well if one of them fail sometimes they are just in parallel, so it might still works but you can hear loss of power, or even crackles etc.

i did mentioned here before that i bought a used megaworks 550 in light faulty condition, that it pops every few seconds randomly. turns out the glue have corroded and shorts few small capacitors (lucky it's the small one) in the switching power supply board. after few cleanup it works perfectly again now... (pic is in this thread)

another problem with my speaker is the iFi, which one capacitor (responsible for the dock) fails and causes system to shutdown and pops itself. after replacement it works perfectly for 3 mths, then this time it doesn't shutdown, just pops. re-cap the whole board but still pops. lol i gave up and just send to technician.

actually, don't only judge the amplifier. but also the speaker driver. one can look very small and light, but actually produce better sound than the bigger one. not to mention some other added value such as speaker cabinet tuning. logitech have quite powerful subwoofer, but it quits around 35hz, which is a shame, just because it's not tuned to achieve lower bass.

dun call me sifu T_T
I just love sharp clean piercing trebles and I've only heard good trebles thru speakers with tweeters