Macintosh How To

Which iPod has the best quality audio?

For me the number one criteria for buying an iPod is audio quality. Some people will go for looks, size, or battery life, but for me it’s simply a matter of which iPod sounds the best – not just through the headphones but also into my stereo.

This article discusses the reasons for the difference in quality of the sound output of the various models of iPods and iPhones, which iPod sounds the best, and why.

Firstly, The Results:

First place goes to the 5.5th Gen iPod.

(Be careful not to confuse this with the 6th generation ipod called Apple iPod ‘Classic’ which looks almost identical. The 6th Gen has the aluminium front.)

First place: the 5th Gen ipod family including ipod 5th gen and 5th gen enhanced with plastic front case. A1136

Second place goes to the good old 4th Generation iPod family including iPod photo, iPod colour and U2 edition iPod.

Second place: The 4th Gen ipod family including ipod photo, ipod color and ipod U2 edition. A1059 and A1099.

Third place for best audio quality – the first generation Nano!

Third place: the 1st generation nano! A1137

STOP PRESS: Since this article the 7G Classic has been released and some  people prefer the 7G ipod to the 5.5. There’s a great debate about the 5.5G vs 7G here and here. It seems the 7G is more accurate and precise, 5.5 is warmer. But read on!

Which iPod sounds the best?

Last holidays I was driving along listening to U2 on my iPhone 3GS. I wanted to change to a different song that was on my nano and instantly I noticed the sound quality was much better than on the iPhone. I have since done some side-by-side tests using the same song on the iPhone 3GS and the iPod nano and the iPod Nano definitely has better quality audio. It clearly has a better bass response and is not so harsh in the high-end. So not all iPods are same, this got me wondering why.

There are two main things that contribute to the sound quality of an ipod. One is the audio chip that is used, the  other are the components along the audio path from the audio chip to the headphone jack – a mixture of op-amps, capacitors, resistors and inductors.

The iPods I like the best seem to be those that use the Audio chips from the Scottish company Wolfson.  When I detected this difference I didn’t not know what a Wolfson chip was, but I could hear a difference and so I did some research. It turns out my Nano and 4G iPod (which I like) both have a Wolfson – the iPhone 3Gs does not.  All listening tests are personal – some people like huge bass, some like a warmth. I like clarity. I like to feel like I am there. I am also sensitive to any slight increase in the midrange or treble that will make the music sound  harsh – especially over long periods, and I like to hear the very low bass, I’m not a bass head who want’s it loud, but I want it to be there.

Cirrus iPod vs Wolfson

Some people claim the Cirrus Audio Chips are better, but that’s not what I hear. Here is a great article by  Marc Heijligers who also noticed a decrease in sound quality with the 6th Gen iPod, and he explains why.  He writes “I noticed that the 6G sounds precise, crisp, but lacks 3D image and has an electronic haze to the sound. At first, this might sound like an improvement (crisp, detailed), but when listening more carefully and for longer times, it becomes fatiguing after a while. The 5G sounds less precise, but its timbre contains more harmonic information and sounds less electronic. For me, the 5G is closer to how I experience acoustic music in real life, and for me is the better sounding device overall.” He then goes on to do some measurements to back up his findings.

Of all the iPods that use the wolfson chips, the 5th generation iPods appear to be the best, followed by the 4th Generation iPods. Check out these comments by Vinne from Red Wine Audio. Red Wine Audio offer mods of the 4th gen and 5th gen iPods where they will replace the output section of the iPod with high quality Black Gate NX-Hi-Q capacitors. According to onheadphones.com the output audio quality rivals that of $1500 CD-players, with improved bass response and clear high end.  (There is an excellent forum here on how to do the mod yourself!)

The sound quality of course depends on more than just the chip that is used, so it’s not just about which chip is in the iPod. My Shuffle model A1204 (non-wolfson) sounds great, as does the iPhone 4S.  It’s rumoured  that with the iPhone 5 Apple will be returning to the Wolfson chips, but we’ll see!

If you want the best possible audio quality, try and get hold of one of the fifth generation iPods – model number A1136.  This includes the iPod 5G, iPod U2 5G, iPod 5th Gen enhanced and iPod 5th Gen with video. They sound great!

Which iPods have a wolfson audio chip?

iPod 1G & 2G (WM8721), 3G (WM8731),  4G(WM8975),  5G  (WM87588G) and 5.5G (WM87588G)

iPod nano 1G (WM8975G), 2G (WM8975), 3G (WM1870)

iPod Touch 1G (WM8758BG) 

iPod mini (Wolfson 8731?)

iPhone (WM8758BG) and the iPhone 3G (WM6180).

In summary, all the early iPods up to 5G Classic used Wolfson chips.

Which iPods have a Cirrus Audio Chip?

ipod ‘Classic’ 1G , 2G & 3G  (CS42L55) (These are also known as 6th 7th and 8th gen iPod)

ipod nano 4G (CS42L58), 5G (CLI1480A), 6G (CLI1544C0)

iPod Touch 2G (possibly CS42L58)

iPhone 3GS (CS41L61) and 4(338S0589), 4S (338S0987)

iPod Shuffle 4th Gen (CLI1544C0)

Conclusion: The Best

iPod 5G (wolfson WM8758)

(iPod 7G might fit in here, see discussion here.)

iPod 4G (wolfson WM8975)
iPod nano 1G and 2G (wolfson 8975), iPhone 4S, (wolfson WM8758).

UPDATE: This article was first written in 2010, Apple keeps improving with every iPod released, but I think these results still stand.   Check out this thread for some other raves about the 5.5G iPod.  There will always be new models coming out – keep an eye on head-fi forums and so on for reviews.  Here some people prefer 7th gen (thin 160G) Classic  to 5.5th Gen.

I have an phone 4S and even though it doesn’t have a Wolfson chip it sounds incredible.  This test shows iPhone 4S has better specs the  iPod Classic 6G and better than iPad 2, but I can’t’ find any direct comparison with the 5.5G iPod.

Some Measurements:

Conclusion:

If you want good audio in an iPhone the current iPhones (4, 4S) are the best.

If you are after good audio in an iPod the older ones are the best. (especially the 4th and 5.5th Gen classic era)

Wolfson chip in an iPhone

RECORDING ON AN IPHONE

On a final note, here’s some frequency response graphs (note these are of a complete loop – recording AND playback so they include the frequency rolloff of the microphone.)  Look at how bad the low frequency roll-off is on the iPhone 3Gs. It’s -3dB (half the output power) at 200Hz – no wonder it sounds so thin. The iPhone 4 response is a slight improvement over the 3GS. Flat is good – so the original iPhone wins! 3G bad at high frequencies, 3GS bad at low. So for listening the original iPhone and the 4S  are the best, but the original iPhone is much better for recording. The 3GS is terrible.

iPhone frequency response from faber acoustical 1st: iPhone  Last:iPhone3GS

Now don’t get me wrong – the iPods and iPhones are still great music players.  Comparing the iPhone with other phones is like comparing apples with oranges. Even the 3GS – the worst iPhone –  leaves most other phones for dead in terms of music quality. But comparing apples with apples, first prize goes to the 5th Generation iPod, with the 4G iPod a close second.

Of course if you want better than ipod quality you might try  5G or 4G with the red wine mod.

Other notes: Cambridge Audio and Harman Kardon use Wolfson DAC chips in their CD players. Pioneer, NAD and Onkyo use wolfson in some of their CD players. Marantz use Cirrus Range. It’s not just about the chip – the other audio components will make a difference too.

www.lampizator.eu/lampizator/REFERENCES/Cambridge%20Azur/Cambridge%20Audio%20Azur%20640C%20ALmpizator.html

www.polkaudio.com/forums/archive/index.php/t-100139.html

www.vasiltech.nm.ru/files/cd-players/CD-Player-DAC-Transport.htm