Article about the relationship between impedance matching of sources and IEM/headphone.
The Westone W4(R) responds well to resistance or output impedance. The iPod Touch 5G has one of the lowest output impedances of DACs. This accounts for everything you are hearing. In essence, although the 5th generation Touch may be worse with the W4, it is generally more flexible to the true nature of most (if not all) headphones.
Also, where did you find this? I've read that the ipod is either 5 ohms or 7ohms. I haven't seen anything indicating it is lower... ?
It is. Just adding cream on top, throwing some impedance ratings/figures out there just in case :p
ahhh. :-P i'm curious is anyone has a link to the ipod impedance... output impedance that is. i can't find anything anywhere on the 5th touch other than a blog or two saying "it's 5 ohms".
So you think the touch is "higher" quality? I know from experience with all these headphones that impedance is definitely important on the device output. I even talked with someone from one of the major IEM companies who is an engineer. He said it will have an enormous effect on the headphone's sound signature. He asked not to be named for certain reasons, but he gave some technical reasons as well. Needless to say, in other posts where I've mentioned the impedance of my duet causing problems, he said that was indeed a problem having a 32ohm output and the IEMs.
So, here's the odd part. My duet and ipod classic sound identical as far as I can tell with the 4R. And they aren't even far from the touch. But the touch sounds like an mp3 compared to lossless to me. I put lossless files on it, because I though maybe the 4R was actually revealing the differences between the aac files I had on the touch. It was not the file format. The lossless on the touch sounded like a compressed file in that all the super micro details were lost. There is no "noticeable" change in the overall frequency curve. In other words, the touch doesn't sound like the treble is rolled off or anything, but instead just missing the micro details that add to the depth of a songs environment. The bass is also more 'boomy' sounding.
It's hard to explain perfectly, but I've tried a lot of headphones on all three devices and they all had different frequency curves on each device, but usually the duet show the most variance, while the classic and touch were very close to the same. In this case they all sound very close to the same, but the touch has the flaws. If this is an impedance issue, then something is odd, because they sound better on the other two devices. And when I say better, I don't mean that I prefer the frequency response, but rather the "quality" is better. The bass is tighter and more accurate, the micro details are there, the overall song sounds more 'flat' and 'reference' in quality, while retaining the same frequency signature almost identically.
I would pass it off as impedance, but it seems odd that so many different headphones sounded worse on the touch compared to the classic. In some cases the duet threw some frequency range way off, but that was to be expected based on the impedance and charts showing the effects of higher impedance on the specific headphones. However, even in headphones that showed no change on an impedance graph, such as some dynamic drivers I have, I hear the same differences in micro detail loss and boomy bass. I have a feeling "something" in the touch is lower quality. Perhaps the frequencies are most accurate due to the low impedance, but there must be some other shortcoming somewhere? No?
I also find that the touch is more fatiguing at higher volumes than my classic. Things start to become less distinct and detailed when they're louder. This is almost more noticeable than the micro detail loss. Has anyone else here compared the 5th gen touch to the classic?
I forgot about this post, but I just wanted to say now that I have my C5 amp it was indeed the ipod touch. Both are extremely low impedance outputs, but the c5 noticeably "clears up" the details and spaciousness with the touch's line-out. I have read reviews and seen graphs and everything looks great with the 5g touch, but there is "something" in the amp somewhere that is masking a bit of micro details. It's almost as if the super clarity is being smeared a bit or something. Or perhaps there is just less space between things in the soundscape. Incredibly small difference, but as I said, noticeable. Oh well. I have my C5 now so I don't really care. haha. :-P