So, having just purchased my new iPhone 4 that had replaced my 2 month old iPhone 3GS (how's that for a Headfi special!), I thought I should do some research on what to expect sound-wise and do some A-B for you guys with the following equipment:
Ety ER-4P IEMs
iPhone 3GS
iPhone 4
Cowon S9
I could have thrown in the Cowon A4 as well and even the iRiver H120 which I have here but they'd be hard to find (it's bad enough being tempted by the latest gear without having some old fogie like me raving about the H120 and boosting eBay prices
and anyway the H120 is definitely one of the greatest DAPs ever produced - quite possibly THE greatest. That aside, I think the above is a pretty solid comparison for the purposes of this thread.
I'll say up-front that the test wasn't very scientific - no blind testing and no switching box so it's still pretty subjective. Music used was a mix of electronica, classical and rock.
Soundstage
Well, the iPhone 4 surprised here - I just wasn't expecting that "blackness" that one of the earlier posts referred to. It's definitely there in spades, especially on the classical tracks.
iPhone 3GS lacked the depth of the iPhone 4 and was much more 2 dimensional. Instrument separation that was obvious on the iPhone 4 wasn't so obvious on the 3GS.
S9 had a comparable soundstage to the iPhone 4. As I said above, this aspect surprised me the most as I've never reached for a phone as my go-to DAP.
The ETYs are world class at producing detailed soundstaging so I put it down to plain old bloody good DACs on the iPhone 4.
Rating:
1. S9
2. iPhone 4 (close second or even a tie with the S9)
3. iPhone 3GS
Stereo Separation/Positioning
Here I was looking for the quality of being able to pinpoint instruments within the soundstage. Given the depth of soundstage on the iPhone 4 and S9, this process was fairly simple. Once again, a big surprise from the iPhone 4. Consequently, ratings are the same as above.
Volume and Distortion
The ETYs take a bit of power to get going so all devices needed to be played at higher volume than I'd prefer. Somewhere in the 70-85% range.
I didn't notice any real differences between the three devices in their ability to produce decent volumes. However where we see the real gap is in the distortion produced, in particular during spikes in the recorded sounds (e.g. during orchestral climaxes or going from quiet passages to loud ones quickly). On this score, the S9 moves easily ahead of the other devices, mainly because S9's well-regarded on-board amplification.
It would be impossible to pick a winner if you're using a dedicated amp but purely on the headphone outputs, I score as follows:
1. S9 (by a healthy margin)
2. iPhone 4
3. iPhone 3GS
Fatigue
This follows on from my findings on distortion - I found it quite fatiguing to listen to both iPhones after extended listenings. That might be fixed by using more sensitive IEMs or playing them through a dedicated amp but they weren't really suited to long trips. I've used the S9's already on extended trips and this is a great travelling DAP, even before you take into account the fact that the S9 smokes the iPhone for video playback.
As between the 3GS and iPhone 4, the iPhone 4 handled peaks and overall distortion noticeably better overall.
Ranking:
1. S9 - by a fair margin
2. iPhone 4
3. iPhone 3GS
Other Considerations:
iPhone is limited by codecs - the S9 definitely isn't. I'm still amazed that after the Sony Minidisc debacle of the 90's that Apple still manages to get away with codec limitations and transfer restrictions. Admittedly the corporates have learnt a lesson or two from Sony's gross misreading of the market for digital music but it would be nice for Apple to at least acknowledge the more popular open-source codecs out there such as OGG and FLAC.
All reviewed devices suffer (and I use that word advisedly) from *%&%&, $^&#**% annoying proprietary cables. Cowon made the big leap into proprietary docking cables last year with the S9 and the community has been peeved ever since. With the J3, Cowon seems to have stuck to their guns so not many players left who care about the environment and wasted cables. I did a clean out of my house last month and had to discard about 30kg of cables, power adapters and assorted paraphernalia from audio gear and unused DAPs. This would have been massively reduced had manufacturers stuck to the "standards" they developed in the first place. Rant over...
UI - S9's UI is a debacle of the first order. That's exacerbated by the underpowered on-board processor and graphics processing so the whole experience stutters and wobbles. 3GS and iPhone 4 have no problems in this area. Both phones are silky smooth both during screen-transitions and during song browsing.
Build quality - S9 and iPhone 4 are beautiful pieces of engineering, with Cowon first to use Gorilla Glass as a screen. The Cowon is significantly lighter as well. However the iPhone design and engineering is off the scale in so many ways that I'm still speechless when I put my good eyeball up close to take a look.
Conclusion:
The iPhone 4 is a surprise package - I never really bought into the whole Apple thing as I found earlier iPods and nanos lacking the audiophile quality that the competition were easily producing, time after time. Now, it seems the technology has really moved everyone closer. Apple's DACs seem to be better, noise levels have dropped and the convergence principles seem to be paying off for the consumer.
I'd hate to think what Cowon would produce if they attempted convergence and built phones into their DAPs
What they have done however is set the audio standard that a company such as Apple can use to improve the audio quality on their own devices. I think the iPhone 4 is an incredible example of that.