It is not so much an issue with Dell, but an issue with the computer industry in general. On a previous notebook computer I used as my main notebook, a Thinkpad T21, it had a single speaker and at maximum volume it could be heard clearly throughout the house (granted while not a booming sound from true stereo speakers good enough for a notebook computer so I could keep hearing it as I moved about the house) and to this day sounds good with minimal distortion, however with a newer notebook, a Thinkpad T500, its speakers were starting to crackle after barely a year of usage. However the speakers that most computer manufactures are using nowadays are a lot cheaper so they limit the power that goes to them thereby limiting the volume and in some cases that can make watching a movie on the computer impossible without headphones, external speakers, or boosting the volume through EQ adjustments or the volume boost function of VLC.
This issue is not limited to Dell and IBM/Lenovo but is true for many manufactures computers, especially in notebooks without a premium audio option which include beefier speakers and sometimes an additional woofer speaker for better low range. The real fix would be to use a higher quality speaker that can take a little more power (I mean we are only talking about a few watts of power so how hard can it be). Therein lies the problem, with notebook computers being commodity products these days and the majority of buyers looking for the best price, the manufactures skimp on quality. Because of said skimping on quality leads people to use bandaid fixes which in turn exacerbates the issue and leads the already prematurely prone to failure speakers to fail even more prematurely.