The speaker can be easily attached to the monitor and matching monitors with current output (in the Dell U2713HM) need no extra power supply.
The sound is ok. I think he is now no better than the tiny speakers in the notebook. Therefore, a point deduction.
And what Dell is mitliefert as "manual" a joke - but a very bad. Although there already is quite funny but if you get a pure machine translation, which translates itself the company name. And there's not a man of the remarks ... Embarrassing .... This is another point deduction.
Here are some examples
"Please ovens Packaging and examine the artikle within."
[That were here a book review I would ask: "What would we started with these lines say?"
"Please do not stick the speaker on the screen, and put the in appropriate position." [No, it does not stick it with adhesive directly onto the screen, so you see nothing more.]
"Please connect speakers with adapter or connector fitting of Stock says."
[Here probably has the computer "Dell" translated "fitting" ...]
"Roll clockwise to turn the speaker on."
[I have now rolled me half an hour around the room, but the speaker is still out ...]
If anyone here by the company "fitting" reads: They certainly have enough staff in the countries in whose languages they translate. Let's make the translation of a man and not by stupid computers!