Dumb question about Logitech z623 2.1 speaker system

[sonyzz]

So its rather bizzare thing but i happen to own Logitech z623 2.1 speaker system (which i bought 1 year ago off amazon here in UK) which doesn't have ''Volume'' and ''Bass'' writing next to its dials on right satellite speaker, it does have ''THX'' logo, it does have ''Logitech'' writing under its left satellite speaker... it came in a theyr ''new'' blue box design saying ''400w peak'', i was looking online and in youtube videos and all of them had writings on theyr satellite speaker. My brothers owns same speaker set he bought 3-4 years ago, it came in older green and black box, also his has writings ''volume'' and ''bass'' and, his system kinda plays louder also, he can go for prolonged sessions like 1 hour or 2 for 80% volume with 60-70% bass while, mine is connected to Asus Xonar STX soundcard (unlike his to motherboard output) and when i play at 80% with 60% bass after like 40minutes or so i can smell like something burning or some strange smell so i never play them more than 50%, should i be concerned about missing writting and strange smell? because i live in the house where its connected to other houses and we have old people living in other houses so i don't play loud music much...p.s. i was thinking maybe dedicated soundcard is giving like too much input for those speakers thats why? since mobo gives lower output for speakers

[Wilfred f]

im realizing this to mine right now and i was kinda wondering if it means anything bad or not