Thanks ref the blade count. It's critical to this sort of work.
The good thing is we do get a 14 day return window. I know some people said it took a few weeks to start but it seems most people heard the problem quickly.
Certain frequency resonations have caused bridges to collapse as well. At least from watching the Discovery Channel I've learned this.Wanna bet? Read my post again. When I stated that resonant frequency can be dangerous, I said where vibration analysis is an engineering concern in certain settings, not specifically regarding the Studio. Example: Aircraft, helicopters in particular, most of which are also made of aluminum. See, e.g.:
525 Probe Points to Vibration, Frequency Response in Fatal Crash - Rotor & Wing International
Investigators have found that Bell Helicopter’s 525 prototype experienced rotor system vibration and frequency resonance in its airframe and flight control system seconds before the aircraft broke up in flight last July, killing its two test pilots. Three people briefed on the investigation by...www.rotorandwing.com
Even so, if the root cause of the whine is somehow a potential fire hazard like some of Apple's batteries have proven to be, I still wouldn't be too cavalier about it until the issue is fully explained, and addressed if needed.
You're lucky it only sounds like a car. Get a Mac Pro "trash can." It not only looks like a jet engine, it frequently sounds like one. I've been in cockpits with engines running at full takeoff power and they made less noise than the one I'm currently typing this reply on sometimes does!
I didn't realize there were two different power supplies. Are we sure it's the power supply and not the fan?
I don't think anyone here is sure one way or the other. Just a lot of guessing going on.
If it's a airflow resonance thing, which is what I suspect, taking the machine apart invalidates pretty much everything because it changes the airflow. This will not be easy to do and no private individual would have the equipment to do it.
Totally useless and offensive statement. If you don't hear the noise, congrats, not everyone is so lucky.
There's actually an xray in google images, but it's not clear enough to count the blades. It's a centrifugal fan with a LOT of blades.
Thanks. If that blade count is correct, then I'm not sure what to make of it...yet. Just a quick rough calc says that would mean a 2.2 KHz. sound from a fan with 67 blades = 1970 RPM, which sounds too high. However, there is at least one video that shows the whine freq. increases with fan speed. Maybe I'll see what a rewatch of that yields.
I note @handheldgames contributed constructively to one of the lines of ‘inquiry’ in this thread, rather than come here purely to poke fun at those with the problem. That being so, a little levity might be permitted yes? Certainly, in work situations where SNAFU reigns, a little joking has helped a lot IME!
No. It's making fun of people that have the problem, and making fun of people is never okay.
If they are in sync, or nearly so, then no, not really, but that can cause another type of noise (a wow-wow warble), but not this "whine." If one is running measurably (significantly) different from the other, it would be seen as two peaks i/o one. With the right software, expertise, and techniques, unless the sync is perfect, even small differences can usually be discerned, as can just one of the fans failing completely, or almost anything in between.
I believe I see where you’re coming from; you mean the status game function of humor where it is used to belittle, bully and so on? I agree.
I was thinking more in terms of the ‘beats’ being 180 degrees out of phase (worst case) and thus producing an additive or doubling rather than just a difference effect. However, I take your points. Good stuff.
Mainly, yes, that's what I mean.
I can't change how I feel about bullying and don't really see how it can possibly enhance in-group building, but whatever.
Could be.
I've gotten used to mind, but it wasn't as bad as some. I read somewhere that Apple had done a lot of working to tune the airflow for it to be whisper silent, and that's where I think the problem is, something in that tuning that is introducing some kind of resonance on some of the Studio's if they are are out of spec. Hard to tell though, but I can definitely say mine is not whisper quiet!