iPhone 5 sound quality
Jan 25, 2013 at 10:51 PM Thread Starter Post #1 of 239

bigshot

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Check this out. The charts made me laugh. So much for iPods having a "sound signature"!
 
http://www.kenrockwell.com/apple/iphone-5/audio-quality.htm
 
Jan 26, 2013 at 8:04 AM Post #3 of 239
Not everyone is in that group, though, and it is nice to have more concrete information about various devices, and not just (usually not detailed, and often optimistic or outright false) manufacturer specs and subjective impressions.
Having said that, these measurements look flawed, <0.0002% THD at any audio frequency driving a 37.5 Ω load at 1 Vrms is "too good to be true". And it does not even increase with a real dynamic headphone load, even though it definitely should because of the output impedance. Maybe it is just a loopback of the analyzer ?
normal_smile .gif

The noise (comparable to that of the MacBook Air) and output impedance look realistic, though.
 
Jan 26, 2013 at 8:11 AM Post #4 of 239
Quote:
Check this out. The charts made me laugh. So much for iPods having a "sound signature"!
 
http://www.kenrockwell.com/apple/iphone-5/audio-quality.htm

I just looked at the chart there for the 4th-gen Touch, and it confirms what I always thought, that it was a very accurate player.
 
Jan 26, 2013 at 9:51 AM Post #5 of 239
Quote:
Not everyone is in that group, though, and it is nice to have more concrete information about various devices, and not just (usually not detailed, and often optimistic or outright false) manufacturer specs and subjective impressions.
Having said that, these measurements look flawed, <0.0002% THD at any audio frequency driving a 37.5 Ω load at 1 Vrms is "too good to be true". And it does not even increase with a real dynamic headphone load, even though it definitely should because of the output impedance. Maybe it is just a loopback of the analyzer ?
normal_smile .gif

The noise (comparable to that of the MacBook Air) and output impedance look realistic, though.

Yeah I'm not buying those THD measurements.
 
Jan 26, 2013 at 10:21 AM Post #6 of 239
Something's definitely wrong with the THD measurements. It has 3 - 4 ohms output impedance but drives a 32 ohm headphone with 0.00015% THD?
 
 
Here's a RMAA test (recorded with an E-MU 1616m I think):

 
Jan 26, 2013 at 2:18 PM Post #7 of 239
Are you guys seriously talking about the difference between 0.0002% THD and 0.0017% THD?!
 
Jan 26, 2013 at 2:46 PM Post #9 of 239


No, but the THD figures are suspect. The A-weighted noise figure was -106, which if the THD figure was THD+N would be .0005%, except A-weighting is never used for THD, so the figure should have been more like .001%.

It's not the specific numbers that's the problem, it's that they don't make sense, which then casts doubt on all the measurements.
 
Jan 26, 2013 at 2:53 PM Post #10 of 239
Quote:
Are you guys seriously talking about the difference between 0.0002% THD and 0.0017% THD?!

No, we're talking about the difference of incorrect and correct measurements.
 
 
Btw, he's getting nearly exactly the same (incorrect) THD values for the iPod Touch 5G.
 
Jan 26, 2013 at 2:59 PM Post #11 of 239
How many angels correctly dance on the head of a pin?
 
Jan 26, 2013 at 4:13 PM Post #13 of 239
If you don't think that 7 is a credible number of angles doing the pin-head shuffle, then you might also see that a measurement that looks too low for reality calls the rest of the set into question. How is it possible to get a THD plot like that when the noise measurement doesn't support it? A full bandwidth spectrum with 1KHz at 0dbfs would have cleared thing up, but he didn't publish it.

Your original point is not lost, though. Nothing in the measurements indicate a sonic signature.
 
Jan 26, 2013 at 5:54 PM Post #14 of 239
I won't comment on this from an audio perspective, but I have experience with Ken Rockwell from the camera world. He's an utter hack, and despised amongst professional photographers, partly for being a Nikon shill (I own Nikons, so please don't accuse me of animosity toward the brand) but also for the sheer volume of crap he writes. He's stated that professional photographers should be shooting in jpeg instead of RAW (there's far less leeway for jpegs in editing), doctored pictures on his site so he could claim he has special custom gear that doesn't really exist, used press-release images on his site and then stamped his logo on them so they appear like he shot them himself, and covers it all up with an "I'm just joking, this entire site is a joke, don't take it seriously" clause to legally cover his BS. He's a quintessential hack, and I would be extremely critical of any information found on on his site. 
 

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