As with my previous review the first thing to consider is that the db rating doesn't tell the whole story. Tone, resonance and other factors can be more important than pure sound levels.
Like I have stated before, motor whine and rhythmic speed related clicking may not show up on the sound meter but when present I can confirm that they are very apparent and can be annoyingly intrusive. On the flip side you could have a fan that made no discernable whining or clicking but was 'showing' as rating high on decibels!
Once again the Enermax's tested here largely fall into the 2nd category - only the Apollish Vegas @ 12v presented a touch of motor whine.
Apollish Vegas.
Even compared to the last batch the Vegas registered as the loudest at both 12v and 7v - however, this was probably mostly to do with the higher terminal RPM speed (2000rpm @ 12v vs 1700rpm @ 12v). The motor whine mentioned is also likely to come from the increased rotational speed.
At 7v and particularly 5v the Vegas was perfectly useable as a case fan in the average quiet environment. It also seemed to display good static pressure performance - something that the specifications hinted at. At 12v static pressure was of course much better but you'd have to decide whether it was worth the increase in sound levels.
It also looked amazing with all the LED's illuminating the highly polished chrome surface!
T.B. Silence.
Moving onto the T.B. Silence the difference at 12v was quite apparent. This is a very quiet and smooth sounding fan. A rotational speed of 900rpm @ 12v is one of the lower values I've seen. Static pressure at this voltage seems pretty good... not quite as good as the Apollish at 5v but decent enough.
At 7v and 5v pressure drops quite a lot so simple case intake and exhaust fan duties is probably best at these voltages. I must say I was mighty impressed when the fan actually spun up at 5v. I didn't think it would manage it.
