>> Oh... no, not really. I mean, sound vibrations are really, *really* 
>> tiny. (Think about it; even when the sound is turned up painfully 
>> loud, the speaker cones move by such a tiny amount you can't even see 
>> them move at all!)
> 
> Huh?  Even at normal listening volumes I can see the bass cones move on 
> mine...  Try feeding a 20 Hz sine wave in and watch the cone...  These 
> are only perhaps 6" drivers, nothing spectacular.  Mind you, I have 
> never noticed the tiny 2" cones move on my PC speakers.

I have never seen any cone on any speaker move visibly - no matter how 
much physical pain my ears were in. See, human ears are, like, *really* 
sensitive...

> Huh?  You are saying that they deliberately make speakers less efficient 
> so that a higher voltage can be used to drive them?  I've never heard 
> that before.

Yes.

> Also I have never seen much "serious" hi-fi rated at 
> anything like 200 W for home use.  IME 15 W per channel is plenty to 
> fill a medium sized room very loudly, perhaps if you live in a very 
> large house and like listening to music very loud you'd want 200 W.

Hmm, I think my amplifier (nothing special) is rated at 60 W per 
channel. (IIRC, into 8 ohms at 1 kHz.)

That's 60 W RMS by the way. Not like the "100 W" portable thing I once 
owned that was actually 0.5 W RMS. ;-)

>> The mater claims 249.98 V.
> 
> Sounds ok to me, the voltage will fluctuate a lot depending on lots of 
> factors, like how much power people are using around you etc.  Try 
> measuring the voltage at different times of the day...

Wait... the *voltage* changes depending on how much you use it? That's 
odd. I thought that potential difference was always constant, and it's 
only *current* that changes...

>> Also, 49.97 Hz. (So much for "they keep it to exactly 50 Hz to help 
>> all those clocks that use it". The frequency waivers all over the place!)
> 
> And you think your meter is accurate to +/- 0.03 Hz?

Actually, the instruction book (which is oddly large for such a simple 
device) states the accuracy for all readings. I forget what it says for 
the frequency...

-- 
http://blog.orphi.me.uk/

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