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gowger
2008-08-26, 13:45
I figured this would be one forum where people might know and care about sound quality in portable digital music players.

I'm wondering if it's possible to get a sound quality as good as a slimplayer from any portable music player, that supports flac?

I have an ipod, I didn't buy it by the way! I flashed it with rockbox firmware to play ogg and flac files, which makes it a tolerable machine but I swear the sound quality out of it is totally shite!

Whenever I put on the slim player then I'm amazed at the difference with the same file, even a with 128KBps mp3s

I've heard the the Bang & Olufsen player is pretty good, but no flac or ogg support. The codecs are of course far too free to be possible to include in a commercial device.

Is there any portable music player manufacture with an attitude like Slim Devices?

I want something like the ipod with rockbox firmware and the lovely DAC that you get in a slim player.

seanadams
2008-08-26, 14:20
It is far more challenging to get good sound quality from a portable device. A good power supply, DAC, and output stage require board space, and packing everything close together makes issues like internal EMI noise much harder to deal with. The designer has much fewer components to choose from because he has to meet size and power constraints that simply wouldn't apply in a non-portable device.

There is also the problem that portable devices generally need to have headphone outputs, designed to drive some power, as opposed to line outs, which care more about driving a clean voltage at negligible power levels. Headphone amplifiers don't perform as well as a simpler line-out driver.

CatBus
2008-08-26, 14:25
Let me preface this by saying that you're very unlikely to get SB3-quality audio from a portable. So just let this requirement go, and your choices start looking better.

I'm a RockBox user myself, and I personally use an iAudio X5. For what it is, the audio quality is quite good. I've also heard good things about iRiver players, and I believe there may even be some older (and possibly discontinued?) models out there with digital outputs.

I think some questions left unanswered are: What sort of headphones are you using? This will have a huge impact on sound quality. In fact, if you're still using stock earbuds, the iPod is simply not your primary problem. And even if you're not using stock earbuds, are you using replacement headphones that the iPod can't drive, and cranking the volume? That could be a problem too.

The listening environment for portable devices tends to be different than SB3's too. Even if the audio quality was 100% identical, the portable would sound worse while jogging or driving...because you're jogging or driving. Portables are devices of convenience. Quality is job 2.

gowger
2008-08-26, 14:59
Crikey, fast reponse here!

Thanks for the interesting points folks.

I don't even know where the original headphones are for the ipod! They were irrelevant. I'm using little sennheiser ones, they kind of hook into your ear. They sound pretty good. I used to use a big pair of sennheisers but your right the ipod couldn't drive them, at all!

But where you really notice is when you plug it into something decent. Fair point on the fact that your usually jogging or driving, or in my case cycling a lot. Depends what your driving though :-) An smooth audi with bose isn't bad :-)

For cycling though someone's gotta make a pair of headphones that are aerodynamic, the wind roar is the biggest problem on the bike!

I'm kind of surprised that the good DAC in the SB (2 in my case) wouldn't be possible to fit into a compact machine, I would expect the voltage to be pretty low for the chip like. But of course there's a lot more to it than that by the sounds of things. for the sound of things :-P

I wouldn't worry about the power supply though a battery would be totally smooth I expect

I didn't realise there was much of a difference between line outs and headphone outputs but it sounds pretty unlikely that anyone would bother to engineer a proper line out supply, unless it was some kind of professional device I guess. Which would probably imply a price as hefty as it's weight.

CatBus
2008-08-26, 15:37
My next suggestion would make the entire Audiophile forum burst into flames, so thanks for posting in the General Discussion forum, for everyone's sake.

I think that lack of detail you may be hearing is not from the file format, DAC, EMI, headphone jack, or headphones. It's the wind (and let's hope also just a little less concentration on the music).

I hypothesize that if you took your audio and passed it through a dynamic range compressor, you'd be able to hear all of that low-volume detail that you think the iPod is having trouble with. Yes, it would distort the audio in a lossy fashion (for goodness sakes only do this on a COPY of your music!). Yes, even better it would clip your audio too. But I believe it's quite likely that the audio quality lost by all of these factors would be less than that lost by a poor listening environment, which is what I think your main problem is. I am 100% serious.

If you're up for experimentation, there's a Linux utility called sox, which has a "compand" feature for exactly this purpose. The sox manual gives the following example:

sox input.flac output.flac compand 0.3,1 6:-70,-60,-20 -5 -90 0.2

You can adjust the third-to-last argument to address clipping. I think -5 is too high and clips too much, YMMV. But you're not going to be able to get rid of clipping entirely in this process.

maggior
2008-08-26, 17:01
It is far more challenging to get good sound quality from a portable device. A good power supply, DAC, and output stage require board space, and packing everything close together makes issues like internal EMI noise much harder to deal with. The designer has much fewer components to choose from because he has to meet size and power constraints that simply wouldn't apply in a non-portable device.

There is also the problem that portable devices generally need to have headphone outputs, designed to drive some power, as opposed to line outs, which care more about driving a clean voltage at negligible power levels. Headphone amplifiers don't perform as well as a simpler line-out driver.

To this end, you might look at getting a portable headphone amp to connect to your iPod. Actually, that's what I use with my SB3 on my bedside table. You would be AMAZED at the difference a portable headphone amp will make. They have enough power to drive virtually anything and are generally flat in the frequency response area. Though protable, they don't suffer the design constraints (at least as badly) that Sean mentions.

I use something made by Practical Devices (www.practicaldevices.com). There are other manufacturers out there with amps at varying prices. For me, the PD offering (specifically the XM4) was a nice compromise of price and function. Go on over to www.head-fi.org for a forum that is *passionate* about the topic of headphone music listening.

RalphO
2008-08-26, 17:19
This is an interesting thread as I have been thinking along these lines. I spend a lot of time on planes and at airports. This means that I can use my laptop most of the time to generate music. BUt the sound quality from the soundcard is poor. I am considering a headphone amplifier (USB type) and using Softsqueeeze (with FLAC files). Does anyone have any experience of this and do you have a headphone amp to recomend?

gowger
2008-08-26, 17:28
Cool so you mean I could literally give it sox on the dancefloor! :D I wonder does that terrible pun translate to many different countries

Didn't know sox could do that kind of stuff actually.

Of course the only place I hear the difference with the ipod is plugged into a good system, but it'd be nice to have the SBs quality in a portable way for playing through various sound systems around.

m_l
2008-08-27, 06:03
Since you already have an iPod check this out:

http://www.redwineaudio.com/iMod.html

Vinnie modded my Photo iPod man what a difference it made. I use it mainly in the car. Compared to stock it's night and day. It's also so much better than my car CD player [Kenwood excelon with burr brown DAC's] Voices are clearer, bass is tigher and just the overall sound is so much better. Read some reviews and decide if it's worth it to you. If you are after better sound you can not go wrong. And Vinnie does great work. Oh and I also run the Rockbox firmware :)

gowger
2008-08-27, 06:47
Thanks m_l , a couple of surprises in there for me. First one is that they have a wolfson DAC in the later generation ipods! Also I was reminded there of the line out that's available through the proprietary docking socket, which given the previous points might make a difference to sound quality just by using that instead of the headphone socket.

That mod looks like something I'd definitely like to try. Even if posting a working device off to someone on the internet to break it open and modify it seems a little mad. :-)

Damn, it looks like Vinnie charges $250 for the mod! Ok so I was given this machine, but that's not far off the original price back when the apple marketing machine was peaking. Or is that the price for a ordering a modded ipod, it's not that clear from the site. I'll ask him and post the response.

I mean what are we talking inside the box, a couple of capacitors?

Nonreality
2008-08-27, 07:10
Crikey, fast reponse here!

Thanks for the interesting points folks.

I don't even know where the original headphones are for the ipod! They were irrelevant. I'm using little sennheiser ones, they kind of hook into your ear. They sound pretty good. I used to use a big pair of sennheisers but your right the ipod couldn't drive them, at all!

But where you really notice is when you plug it into something decent. Fair point on the fact that your usually jogging or driving, or in my case cycling a lot. Depends what your driving though :-) An smooth audi with bose isn't bad :-)

For cycling though someone's gotta make a pair of headphones that are aerodynamic, the wind roar is the biggest problem on the bike!

I'm kind of surprised that the good DAC in the SB (2 in my case) wouldn't be possible to fit into a compact machine, I would expect the voltage to be pretty low for the chip like. But of course there's a lot more to it than that by the sounds of things. for the sound of things :-P

I wouldn't worry about the power supply though a battery would be totally smooth I expect

I didn't realise there was much of a difference between line outs and headphone outputs but it sounds pretty unlikely that anyone would bother to engineer a proper line out supply, unless it was some kind of professional device I guess. Which would probably imply a price as hefty as it's weight.

When you plug it into other devices, like your car, are you using the dock connector line out or the headphone jack. Big difference. You can get connector cables that have the dock on one side and mini phone plug on the other. 10-12 bucks and they make a world of difference bypassing the headphone jack. You won't have volume control so you have to plug into something that does. I first discovered this with my rockboxed Nano. I almost bought a headphone amp just so I could go out of the line out for headphones too. I bought some Westone headphones instead. They are the most comfortable in the ear I've ever worn. I can sleep with them in and not notice. The sound quality is up there with the best. You might want to look into them too. I use the UM2 dual driver version. Maybe next year for the amp.

jeebers
2008-08-27, 07:11
Let me preface this by saying that you're very unlikely to get SB3-quality audio from a portable. So just let this requirement go, and your choices start looking better.

I'm a RockBox user myself, and I personally use an iAudio X5. For what it is, the audio quality is quite good. I've also heard good things about iRiver players, and I believe there may even be some older (and possibly discontinued?) models out there with digital outputs.

I use Rockbox on an old iRiver H140 (upgraded to a 60GB drive), and the sound quality is very good. It has an optical out if that floats your boat. If you're happy without colour screens, don't mind it being a bit on the chucky side etc than you can't go far wrong. Unfortunately, of course, it is discontinued, but ebay may be your friend.

I've never blindtested it against my SB3 to be honest, but maybe one day when I'm bored...

http://en.wikipedia.org/wiki/IRiver_H140

earthbased
2008-08-27, 07:54
I figured this would be one forum where people might know and care about sound quality in portable digital music players.

I'm wondering if it's possible to get a sound quality as good as a slimplayer from any portable music player, that supports flac?

I have an ipod, I didn't buy it by the way! I flashed it with rockbox firmware to play ogg and flac files, which makes it a tolerable machine but I swear the sound quality out of it is totally shite!

Whenever I put on the slim player then I'm amazed at the difference with the same file, even a with 128KBps mp3s

I've heard the the Bang & Olufsen player is pretty good, but no flac or ogg support. The codecs are of course far too free to be possible to include in a commercial device.

Is there any portable music player manufacture with an attitude like Slim Devices?

I want something like the ipod with rockbox firmware and the lovely DAC that you get in a slim player.

My 2 cents: when you go portable you are going to be dealing with background noise and hotel rooms with portable speakers. So don't try to achieve "listening room" quality. My advice is to rip to high bit rate OGG (or batch convert from FLAC), then buy the Koss Porta Pro for head phones with good bass. I use a Tivoli Songbook unit for hotel rooms and am happy with that.

earthbased
2008-08-27, 07:55
I use Rockbox on an old iRiver H140 (upgraded to a 60GB drive), and the sound quality is very good. It has an optical out if that floats your boat. If you're happy without colour screens, don't mind it being a bit on the chucky side etc than you can't go far wrong. Unfortunately, of course, it is discontinued, but ebay may be your friend.

I've never blindtested it against my SB3 to be honest, but maybe one day when I'm bored...

http://en.wikipedia.org/wiki/IRiver_H140

I second the old iRiver HD units. Sadly they abandoned that market.