ipod and dac?


Has anyone used an ipod or similar device with a high quality d/a converter? I love the idea of the convenience with the ipod and duplicating my cd collection, but I hate the idea of compressing the data and losing the sonic quality. I welcome any ideas on this topic as well as ideas relating to how to make the ipod and the like a high quality digital source. (Can you modify the recording rate to make the music quality better?) thx
emster
I use Media Center -> http://www.musicex.com/mediacenter/ to load WAV files onto my iPod and all tag information is retained.
CWLondon, Do you generate the WAV files using the Apple iTunes software? I thought that iTunes knows how to tag WAVs and AIFFs just like MP3s and does so automatically. (Have you also tried ripping a track to AIFF and see if it can be tagged?)

Personally, I would be wary of sending CDs off to someone else to rip them .. it's just so easy to use iTunes or a quality program such as Exact Audio Copy with the LAME encoder as a plug-in.
http://www.exactaudiocopy.de/
Lame: http://www.mp3dev.org/mp3/
Onhwy61

Thank you. Probably not so I will check the downloads.

To clarify my other comments, my "skipping" was not from vibration or jarring.

It is a brief pause or dead space in the music -- only on WAV files -- that seems to relate to the mechanical movement of the internal hard drive. Annoying.

Dont think this would be resolved by firmware. By the way, the chief guru I have met on this subject is a visitor to Audiogon.

Following a previous iPod thread on the tedium of ripping CD's, he has set up a service where he does this for people. UPS your CDs and he will send it all back to you, conveniently copied onto a portable hard drive.

I have no affiliation with Stuart, but have found him to be extremely knowledgable and a very good guy:

stuart@braiman.com

He, too, seems to think that tagging WAV files is not perfectly straightforward.

So I am still a big fan of the iPod device, but do look forward to progress in the lossless schemes and external DACs.
Cwlondon, do you have the latest firmware and software updates? Downloads are available at this site.

Here's a competitor to the i-pod that has a digital out ---

http://www.tnt-audio.com/sorgenti/iriver_e.html

It has 20 Gig capacity, but it says a 40 Gig unit is coming soon.
Gunbei, File fragmentation should be the least of your worries on an iPod. The unit has a 20+ minute "skip protection" buffer, and even at 10MB/minute, reading uncompressed audio shouldn't be that much of a challenge for the on-board hard drive.
That said, I'll second StefH's comment that if it's an issue for you, you can always delete and re-sync your iPod.
The iPod is a wonderful device and using an external DAC is a great idea, but here are two other problems I have had with mine:

Even using a cable into my car stereo in a fairly noisy Porsche convertible, the difference between WAV files and LAME compressed MP-3 files were clearly audible to me.

The MP3 file sounds, well... COMPRESSED. Honking and fatiguing in the midrange, and lacking in dynamics.

Another thing I realized -- even with my car stereo -- was that the MP3 files create a vague, wandering image compared to the WAV files on my iPod.

So I would also rather have 20-40 CD quality WAV files than a zillion MP3s.

On the WAV files, however, I seem to get a "skip" on every song and I also have not been able to grab the tagging information from the web, so the files are not categorized like MP-3s which is one of the main reasons to use the iPod in the first place.

Or am I missing something?

So please do let us know when WAV files can be easily tagged, they dont skip, and an output on the iPOd will handle a high end D/A.

Nonetheless, a very cool toy.
Thanks guys for putting the proper perspective on everything. Like anything I guess, it all comes down to smart usage and good file management.

Onhwy61, using your scheme of mass copying and deleting, fragmentation should be quite minimal. And, if it does happen to occur, Stefh42's advice oughta clear things up.

One thing I will avoid though, is the practice of combining music files and high traffic data files on the same iPod. I see some people doing this, and this is an instance where fragmentation could easily rear its fractured head.

Thanks again!
Thanks for sharing Onhwy61. I guess the next step is figuring out what kind of soundcard to get that has digital outs. Since I have a laptop, I'll have to find either a USB card or a pcmia card. In the limited research I've done, it seems USB cards suffer a little sonically.

Looking around the web, I've been seeing professional systems from Digidesign, tascam and others that are geared to digital multitrack recording with Pro Tools. They feature a/d, d/a converters and de-jitter devices, and come with plenty of analog and digital in/outs. Digidesign, in particular, has a unit that looks pretty good, and at about $450 on e-bay, comes with Pro Tools. Since I'm a musician, that would be a FUN accessory.

Any experience, thoughts on these recording-based systems as a way to get a digital stream out of my laptop?

D
Gunbei, you need to take into account how most people actually use their iPods. To get music into the iPod you need a computer that already has the ripped CDs. I use iTunes and the computer stored music is organized into various playlist (by artists, genre, favorite tunes, etc). When I want to transfer music to the iPod I typically select a group of playlists from the computer and wholesale replace those existing on the iPod. A month could go by before I alter the iPod again. Effectively I'm swapping 28Gb (the actual storage capacity of my 30Gb model) of data at a time. It takes 15-20 minutes for the entire process. So even though files may be written and rewritten over and over fragmentation just doesn't become a practical issue.
If you're afraid of fragmentation on the iPOD, just copy all the files onto your desktop computer, wipe the iPOD clean and copy the stuff back to the now empty iPOD. Then everything will be stored in nice continuous chunks.

Any idea which filesystem iPOD uses? Microsoft (as usual) did a pretty bad job in this area. Both FAT and NTFS are very prone to fragmentation, but maybe Apple did a better job here...
Well said Johnmcelfresh.

However, I think we are underrating the iPod as a critical playback source. I have heard much worse. I have it feeding into my system via the Monster cable (which is the best available for the iPod) and it is pretty close to my standard cd playback. Again, I don't think it can compete with my turntable, but then again, I don't even use my regular cd player much anymore for "critical" listening.

I like to think I have quite a fine home system, and there's no doubt my iPod doesn't come close for critical listening. Nevertheless, I LOVE MY IPOD. I have the 40GB version and have ripped over 900 CDs into iTunes at 128K AAC files. There's no doubt that AAC is better than MP3 (much like MP3Pro).

I could have gone to a higher bit rate, but bear in mind where I listen to my iPod - during ny commute, on the train mostly - 45 minutes, twice a day (plus some time at the office).

I think the buds that came with the iPod are nice, but I chose to add a pair of Etymotic ER4P in-ear phones. For those who don't know about these, they're wonderful. They actually insert into the ear canal, so they block ambient noise beautifully (very important on the noisy train filled with noisy people). I can actually listen to gentle, quiet music and read in my own little world.

The purpose of a device such as an iPod is to allow you to enjoy your music collection, with the best fidelity available, on the road. I would only use it at home as a music server for a party.

One added benefit: since I have most of my music collection on the iPod (over 8200 songs and growing) I have a ready reference when I go into a record store shopping for new CDs. No danger duplicating titles, as I can quickly check to see if I already own a disk. Maybe that's not an issue for some of you, but I've passed on a title more than once, thinking I may already have it, only to find that it was the ONE title from a given artist that I don't yet own.

To me, the iPod is a lifestyle item - like a dishwasher, or automatic garage door opener. Now that I have one, I would HATE to give it up.
Rsbeck,

After searching around a bit, it seems the iBook doesn't have a Cardbus slot like the Powerbook, so an expansion card for this area is out.

According to Apple Developers info, the AirPort card does support DSP so it's possible this area may work.

I also did see some cards for digital processing that can be used via USB connections.

Now, for the downer. I don't know if any company makes such devices that are iBook compatible.

Anyone out there know?
I have a pretty high end home system. My CD transport went down and I have been using my laptop and i-book in its place. Plugged into my system using the Headphone out split into the stereo inputs of my pre-amp -- which is not a real high quality connection, it sounds amazingly good. Granted, part of it is the supporting components and speakers,
but still...I'm getting a wide sound stage, good imaging, detail, speakers disappear, etc. In *this* system, I can tell the difference between different sample sizes, the difference between MP3 and AAC, etc. I have done experiments. Uncompressed sounds great. The first thing that goes when you compress the music is air. The soundstage shrinks, dynamics are lost, instruments combine and congest, losing space between instruments, the music becomes rooted to the speakers and the
music becomes far less involving. This is anecdotal evidence at its worst, but with uncompressed, I find myself bobbing my head with the music and with compressed, I find myself saying, "this doesn't sound that bad..." But, I am less relaxed, less involved. Surely, not a scientific
study, but that's what I have. I have *not* done the same experiement with Headphones, nor through a car stereo. I would be curious to see.
But, I like having the ability to plug my laptop or i-pod into my home system -- it is great for background music, parties [open a playlist and
let your guests pick the music from your entire collection -- they love it]
and my wife and kids love the simplicity -- plus -- when they use the
computer or i-pod, they're not taking my CD's out. So, even though I
don't use it for critical listening, it would bother me, knowing it would
sound even better, uncompressed. So, for that reason -- and -- because I believe the capacities of these things is going to keep growing,
I am storing my music uncompressed. But -- that's me. I still say that
AAC at 320 kbps is the next best thing to uncompressed and you can store 400 CD's on a 40 Gig i-pod at that sample size. Pretty amazing.
Can one of you guys explain to a computer illiterate like myself how to get a digital out from an Apple i-book or power book and how to change the sound card?
Thanks for the response Onhwy61.

You mention that fragmentation with 2-channel playback isn't an issue, but what happens to that drive when songs are written, then deleted and other songs are written over the same blocks where the deleted files once resided?

I realize that when a large number of songs are written/downloaded to device like the iPod, they are initially done so in a contiguous fashion. But what happens when songs are deleted from various points in the middle of those large blocks and new ones written/downloaded? I'd imagine those vacant areas of the drive will eventually be written to, and in the case of large sound file not in a contiguous manner. When repeated over and over, fragmentation will eventually occur.

In my field I work with multiple drives and many of my files can exceed a gigabyte. When diagnosing and testing for problems on my drives, the ones that store the large files experience less fragmentation, but take a while to get into a severe state. The drive that always has the most fragmentation is the start up drive which in my case I've counted up to 200,000 miscellaneous small files scattered all over the place. Severe fragmentation can occur in a few months.

Since my computer doesn't support enough RAM to hold an entire file in RAM, we use large fast scratch disks with speeds in the 10,000-15,000 RPM range. Since these disks temporarily hold information and release it once the file is closed, fragmentation isn't an issue with them. However, a small number of invisible files are still written to them. This is something I can see when running a test using a disk utility like Norton's. Since a scratch disk won't incur the level of file residue a storage sevice does, I don't defrag these devices, but instead wipe them of all files.

However, isn't the iPod basically a storage device no different from any hard drive? I'd think a 40GB iPod that can store up to 10,000 songs [according to Apple] is prone to the same negative issues as any hard drive storing thousands of files.

The reason I raise this issue is that I have owned a DirecTivo unit for two years and have noticed hitches, stalls and pixelization while using the navigation tools. This was non-existent for the first 6 months or so, but has increased greatly with time and usage. This has nothing to do with recording a dropped out transmission because of poor dish to satellite viewing at the time, because this is happening on already recorded programs and doesn't happen in the same place twice.

To me an iPod would be similar to a Tivo unit or any other hard drive. They all store data, are read from and re-written to in a permanent manner. Wouldn't they all be vulnerable to fragmentation and eventually need optimization?

Please let me know if I'm completely wrong or just not getting it.

Thanks!
Dean
Disc fragmentation isn't an issue with 2 channel audio playback. Any 7200 rpm HD with a 2Mb buffer can easily handle the task of 2 channel playback at any of the common consumer bit/sampling rates. In a recording studio where multitrack recording/playback is important, than disc upkeep becomes increasingly important. In that enviroment nearly everyone uses a dedicated HD for the music data and defragging is commonly performed. But then again, the playback of 2 audio tracks is trivial compared to the simultaneous playback of 16 tracks and the recording of 8 new tracks (with effects), a task that can be readily handled by hard disk systems.
I was talking with a friend of mine at work regarding the issue of hard drive based music sources, and the question came up about fragmentation.

He's a graphic designer and I am a retoucher and all our work is created using Macs with tons of RAM and fast hard drives. Because of the nature of our work we wage a constant battle with disc fragmentation.

However, since the small hard drives used in devices like the iPod just store and play back music, am I correct to assume fragmentation shouldn't be a problem since files are not being written, read, deleted and re-written on a constant basis?

Or, do these devices have the ability to delete music files and have those same spaces/blocks re-written over which could prevent future files from being written contiguously and therefore leave open the possibility of fragmentation down the road?

Thanks.
To answer Dkidknow, a well setup hard drive playing uncompressed digital files will rival the sound quality of a high quality audiophile type CD transport. The key is having a high quality soundcard with low jitter digital outputs. I would recommend RME or Lynx. They are somewhat pricey for soundcards, but well worth it. Alternatively, Apogee (the pro digital company, not the old audiophile speaker manufacturer) and Wavelength both offer D/As with built in USB ports for connecting to a computer.
The iRiver 120 model has digital output. There is an online review of it by a self-claimed audiophile, but it's a pretty worthless review as it does not use the digi-out to a dac....I've tried the Philips, iPod and Samsung players in my main system, didn't like any of them. Hoping the iRiver into a good dac will change things, but not too optomistic. I believe they have a new model coming out with over 50 gigs of HD and digital out, but very pricey....
About 2 years ago I decided to go “all digital” and rip my entire CD collection (500 CD’s and counting) to a dedicated file server. At the time I used and continue to use EAC to rip and LAME to compress to 224 VBR MP3’s.
I tossed and turned on whether to compress at all, choose a more obscure “loss less” compression such as Ogg or go with a propriety compression such as WMA or later AAC. MP3 won out for a numer of reasons, and I still stand by them:
1. Across platform and multi device compatibility.
2. Additional associated data possibilities, such as “comments” reviews and album art.
3. There is significant blind test data that shows that a compressed MP3 file at 224 VBR is indistinguishable from the original WAV file at 16 bit (native format for CD’s),
4. there is no way I am given Bill Gates and to a lesser degree Steve Jobs any say as to when, where and how I can play my music files, $!&% fair use and embrace open format.
5. MP3 may not be the best option out there but it is the MOST versatile.

To answer you question about an external DAC being required for hard drive audio, the answer is YES YES YES. There is a significant difference in sound quality with an external DAC, even a cheap one like and old soundstream / krell DAC1. With a good / great DAC I personally can not tell the difference between a CD transport and my hard drive, Add to this the incredible flexibility of spooling music files to any room in my houses over my home network, and immediate access to over 5000 files and I will never be going back.
As an aside anyone who claims that they can hear the difference between a AAC file encoded at 224 and an MP3 encoded at the same bit rate with a playback on an iPOD (ie relying on the ipod internal DAC and less than perfect headphones, compounded by ambient noise, is clearly delusional.
If I had access to a $100,000 rig in a perfect sound room, then perhaps I would have chosen differently, but given my current mid fi system, I think I have found a great balance. If you are interested in external DAR’s to spool mosaic files to a DAC then check out my thread in this forum on an Audiotron. With web enable wifi access you can also control the entire system from a wireless PDA.
And finally, I also own a new version 30gig Ipod and I love it, not in a carnel sort of way, butin a “wow” this is great piece of industrial design. I also think that it has by far the best user interface for an MP3 player out here. Try scrolling through 2000 titles with a forward and back button
I'm so glad this thread was started.
RSBECK wrote: "The Holy grail will be when you can get a digital out from your i-pod and/or your computer. Are you listening, Apple?"

I'm very interested in using my laptop PC and its 60GB hard drive as a storage device (not getting rid of cds yet, though). There are various PCMIA soundcards that offer digital outs, so although the laptop is bigger than the ipod, it's still portable. Back to the original question, assuming I rip cds using EAC or something similar with no compression, will I do well getting a good dac to link between my laptop and audio rig? I guess what I'm asking is whether digital audio coming off the hard drive, assuming no compression, will equal the output of a quality cd player or transport?

D
It does appear that the iriver models have digital in and out, which should make them work with a dac. I would suppose that would ameliorate the compression problem to a degree. does anyone have experience with the iriver models?

I do understand that an ipod and the like is not for real high fidelity, but it would allow me to duplicate my home music collection for the office, and the system is good enough that the compression will matter somewhat. thx
Peter_S, do you mean that the Headphone sites have issues with the compressed audio quality, or the headphone amplification and output?

I would think that anybody who's a serious headphone listener would probably have something like a set of Grados and a Headroom headphone amp .. if a listener's used to that level of fidelity, I doubt that anything less is going to satisfy.
I use Sennheiser 580 precisions. Best thing to do is rip a CD using several different rates of compression and then one straight to the hard drive, uncompressed and see which is acceptable to you. For me, other than straight the the hard drive, uncompressed, the next best thing is to use AAC at 320 kbps. At that rate, using AAC, you can fit 400 CD's on a
40 Gig i-pod and it would be about the next best thing to uncompressed. It is an interesting experiment, though, to see what is
missing at different rates of compression.
Gunbei, The supplied earbuds are good quality for their size and weight, but if you're used to Grados, you'll want to stick with them.
I do not like the Apple supplied earphones. They sound okay...but do not rest comfortably in my ear. They might work for you though. For me, after a solid hour of listening, my ear hurts from the way they rest.
OK, I'm getting ready to pull the trigger.

I guess I'll have to experiment with different compression schemes [uncompressed, better quality v. compressed, more songs] to determine what works best for me.

But I'm wondering, are you iPod users happy with the supplied Apple earphones or do you use something like the Grado SR60s I use at work?

Thanks.
I own two iPods, a 1rst Gen 10 Gb, that I gave to my wife...OK so I own one now, and a second Gen 20 Gb (bought from MacMall for $259 when the new versions came out) I absolutely love them, but would not use them for critical listening.

I think some of you are missing the point. I have 3465 songs for 9.6 days of continuous music on my 20 Gb iPod (I used 192 mbps MP3 until AAC, which I use the same rate for) This thing has saved my sanity more than once on transAtlantic flights!!! No, it's not 'audiophile' gear. The convienence of having so much of my music available is the reason I never travel without it!!! I even carry a current converter with me abroad so I can charge my digital camera and iPod so I never am out of batteries.

As for the batteries lasting, mine are two years old and work fine. Ed is right, you can change the batteries yourself, though I've not done it. I am reminded of how much I love my iPod when I sit next to someone on a plane who has to dig through their bags to find CD's, while sometimes what they are listenming to sounds good to me and I just call the album up and start listening to it right away...no hassels, and seemingly endless music to boot!

This is why I use iPods........as for MAC's, well if you don't know why I use them....
On some of the headphone sites, where they spend alot of time talking about portable audio, people seem to say that the ipod is not the top of the group in sonics. One that is purportedly better is the Rio Kharma, which holds 20 mb and can be had for $250 if you look hard. It doesn't have the industrial art of the ipod, nor quite as good a navigation system, but still rated as pretty darn good.
This is an excellent thread! Great points both pro and con.

As a daily working Mac pro, it's amazing that I've totally missed out on this. Probably from being overworked and not watching TechTV enough! You guys have given me much to think about. It'll be interesting to see how the tech trends develop and what the next CES Macworlds reveal.

Thanks for educating me!
Dean
If price is an issue, there are other companies, like CREATIVE, that have hard drive players like the i-pod that cost less. As far as Hard Drives failing, I have had a lot of lap-top computers and have been working with external hard drives over the last few years. I travel around quite a bit and always take a lap-top with me. I've never had a hard drive fail.
.

The Holy grail will be when you can get a digital out from your i-pod and/or your computer. Are you listening, Apple?
The iPod is an excellent means of accessing music when on the go. Unfortunately, it's not really an audiophile product because it doesn't offer a digital output and the built in D/A is adequate, but no better. Despite that it's still an excellent product well worth the $300-500 dollars they sell for. I use a 30Gb model and after experimenting with uncompressed AIFF files I eventually settled upon AAC 192kbps mono files as my preferred file format. It works wonderfully in the car with no sense of compromise in such an audio-adverse environment.

I believe some of the iRiver products have digital I/O.
That´s also my case, Troutki, I have a 24 months old 10 Gb Fist Gen. iPod and it works absolutely fine (Daily using)
And I subscribe your opinion about the topic.
I use an iPod with my collection and have been very happy with its performance. For critical listening sessions, I go vinyl only, so I primarily use the iPod when I have get-togethers or want background ambience.

Emster, I too have wondered about the possibility of using an outboard DAC with the iPod. Would love to know if anyone has and what results they got. This topic needs to get away from "is the iPod worth $400" and "hard drives fail". Like any device, it can fail. However, I have two friends that have generation one iPods and they are going strong.

just another way to look at this, a $300 15GB ipod will give you access to 300 cd's, thats easily a $4500 investment. So for anyone who likes to listen to their music when they are away from home, traveling, commuting, at the gym, beach, etc. it is easily worth another $1 per cd to have that music available to you anywhere in the palm of your hand.

I have a 2 year old original 5GB version, no hard drive or battery problems. I also use it at least 5x times more than my home stereo as I travel a lot for work and use it every day at the gym.
The Ipod uses a very small HD, so the price comparison to the Maxtor (a larger format drive) is not valid in this case. There's only one manufacturer that makes the small drives, last I checked.

the case and software certainly is worth $400+ I think, in this land of multi-thousand dollar power cords and speaker cables - in fact taking that into account it seems a total bargain. No one does user interfaces as well as Apple. The case and final product are a piece of industrial art, like most of the stuff they have made.

Batteries are user replacable, but it voids any warranty - there's a place online that sells them. It's a risky job to replace them though. I believe Apple has made improvements to the battery situation since the 1st gen ipods came out. It would be nice if they were designed to be user-replacable, though.

Sure, HD's fail - but so do CD players, etc. Assuming you had the original CD's that were copied to the drive, you are not losing anything (except time) if the drive dies.

I dont' have an Ipod yet either, but I think it's just a matter of time. A digital output from the unit would be a great thing to have too, btw.

-Ed
Jeffloistarca:

You make some very thoughtful points that are very much worth considering. I too, haven't gone the iPod route either for similar reasons.
Three things have kept me from buying an iPod:

The first thing is price, iPods are VERY expensive re-packaged hard drives. A 40 gig hard drive (40.9 MAXTOR 7200 LIQUID 6E040L0) sells for $60. A 40 gig iPod sells for $499. Nice case, batteries, and some software wrapped around the hard drive, but certainly not $439 worth of value-add.

Secondly, it's been widely reported that the batteries in iPods fail (18 months seems to be the reported timeline when the batteries in an iPod give up the ghost). Since the iPod has a 12 month warranty you're out of luck. These batteries are not user replaceable and cost $100 for a fresh set.

Finally, hard drives fail. They are mechanical devices that generally speaking don't like being hauled around and subject to jostling etc.. Hard drives fail just sitting in a desktop PC. Anyone who chooses to use hard drives to store their music collection will be disappointed when the device quits. Hard drives fail, it's just a question of when.

You sure an iPod is worth the expense and hassle?
Also, Alpine is coming out with a car stereo that will interface with an i-pod, take over it's functions, and keep it charged.

AAC, which sounds much better than MP3, at 320 kbps, will give you very good sound quality. At that rate, one CD takes up about 100 Megs. On a 40 Gig i-pod, you could fit 400 CD's.

Using AIFF, which rips the CD to your hard drive, uncompressed, one CD takes up about 500 Megs. On a 40 Gig i-pod, you can fit 80 CD's.

I am ripping my CD collection, which is over 1,000 CD's, to external
hard drives, ucompressed, using AIFF. With the cost of external hard drive space coming down, capacities going up, and the hardware getting
more and more compact, I figure it is better to rip my music uncompressed. I'd rather have 80 uncompressed CD's on my i-pod than
400 compressed. Using my external hard drives, I can circulate music
through the i-pod -- and carrying 80 CD's around is enough to keep me happy. Just a few years ago, the idea of having 80 uncompressed CD's in the palm of your hand was unthinkable.

You can also set up your car stereo to connect with an i-pod. In that sense, having 80 CD's beats the hell out of any 6 or 10 CD Changer.

Do you really need to have access to your entire music collection on a
typical commute?

Even on a long distance trip, 80 CD's can go a long way.

Plus, capacities will keep going up.

If you can't wait, buy two or three i-pods and carry them with you,
rotating them for variety.


Everyone knows that the iPod is both an MP3 player and a portable hard drive, but for audiophiles, it's a pretty versatile unit.

iPod is compatible with WAV and AIFF, so you can dump your CDs directly to iPod at full quality. There's no need to compress your music at all.

To adjust the compression settings in the included iTunes software, go to Edit-Preferences-Importing.

Granted, you might only fit 25 albums on the 20 GB iPod, but this is a very easy choice if true "CD Quality" is essential.

If you're still interested in pursuing compression, iPod supports:

AAC (16 to 320 Kbps), MP3 (32 to 320 Kbps), MP3 VBR, Audible, AIFF (Mac only) and WAV
iPod Specifications

Using a high-quality MP3 encoder such as LAME, you may find that at very high bit rates (256 Kbps) you can achieve sound quality that you're comfortable with.

I haven't tried the AAC format that Apple touts as a higher-quality alternative to MP3, but that might work for you.