Hi-MD vs. Ipod?

[lufs]

I like to point out that iPod's have a 30mW output compared a usual standard of 5mW for most current MD and Hi-MD units. I've heard from a good number of people that iPod's sound "flat", but I've yet to even touch or hear one myself. Any iPod owners care to speak about this a little more?

-1 thing I know is that Apple doesn't care to give out the S/N:Ratio of the iPods.. ..and in my experience the iPod (3rd gen. 40gb..) did have a noticeable hizz/noise when I turned the volume up a bit, and no matter if I listened to AAC, MP3 or WAV.. Earplugs used: Etymotic ER4-P.

One device that seemed to have good enough S/N:Ratio was my old MZ-R91, there was no hizz/noise in the sound of that device. I have owned a MZ-R700 too, and that one clearly was below desirable S/N:Ratio.

It might be I have very sensitive ears but in that case I'm not the only one out there because I've read several times that ANY sound-device with a S/N:Ratio below 95db will produce a disturbing hizz to sensitive ears (AND phones/plugs!).

Most MP3-players (as well as even "high-end" portable cd-players ) have a S/N:Ratio of 90db. For me it is of no joy to have a powerful amp in the portable device if the noise/hizz is powered up too.. As far as I know, the only HDD-player out there to overfill my and many others criteria is newer players from Creative, they all have a S/N:Ratio of 98db... Now that's what I call sound-QUALITY! :smile: (other players of sound-quality are Cowon's iAudio-players, but those are not HDD..)

[psych]

although the c.labs are technically decent, and actually have a user replaceable battery, they are meant to have one of the worst menu/navigational systems yet. no quality claims can overcome this.

as for the cowon players, they do have a hdd based model out now, the m3. which seems to have taken its inspiration from a md. a superthin sleek silver body, with a remote providing all the controls

sadly, batterylife is nowhere near md standards, otherwise this might have been a nice alternative.

[skyther]

First off, the technical limit for S/N ratio for MP3s is 90dB, in fact all digital audio is rated for 90dB. That's the simple reason why almost EVERY mp3 player manufactured is rated at 90dB, sans the unscrupulous ones. Second, every manufacturer uses different methods of measuring SNR. Creative has a rubbish method for measuring SNR, I can assure you that. Most of their listed specs are pure marketing, aka. BS. They have a history of misleading users (Audigy 1's pseudo '24/96'), so I don't see why anyone should trust them anymore. There's also no point in advertising a SNR of 98dB overall if your product is sold as a MP3 player.

The wolfson chip in the iPod is rated for 98dB SNR, but it is definately not guranteed that your output SNR will remain the same. The quality of the components used, from the DAC, the opamps, up to the headphone connector jacks will cause a drop in SNR. There is hence no official standard for measuring SNR.

The static you hear is caused by excessive gain, and has absolutely nothing to do with SNR. SNR in this case would be primarily affected by the source of your music.

Sweeping statements you have there.

[jadeclaw]

First off, the technical limit for S/N ratio for MP3s is 90dB, in fact all digital audio is rated for 90dB.

No. Standard CD is 96db. That's the limit for 16bit. MP3 can have more or less, depending on the source material and of course the bitrate - low bitrate means additional noise and distortion.

Some theoretical limits:

16 bit : 96db

18 bit : 108 db

20 bit : 120 db

24 bit : 148 db

The maximum useable and useful would be 120db - absolute silence to standing next to a running jet engine - at full thrust...

And that's, where the technical limits are.

That's the simple reason why almost EVERY mp3 player manufactured is rated at 90dB, sans the unscrupulous ones. Second, every manufacturer uses different methods of measuring SNR. Creative has a rubbish method for measuring SNR, I can assure you that. Most of their listed specs are pure marketing, aka. BS. They have a history of misleading users (Audigy 1's pseudo '24/96'), so I don't see why anyone should trust them anymore.

Some people call Creative Labs 'Uncreative Crap'. Add some other braindead things like constant compatibility problems, Resampling via DA -AD conversions, switching off of the digital output, when playing back DRM-infested material and you understand.

The wolfson chip in the iPod is rated for 98dB SNR, but it is definately not guranteed that your output SNR will remain the same. The quality of the components used, from the DAC, the opamps, up to the headphone connector jacks will cause a drop in SNR.

That's true. However, SNR is not the only value interesting here, as the manufacturer decides, which one to publish.

And the SNR should include Distortion as well, but that is left out, as that is the sore point of low voltage headphone amps. You can quickly lose 20db through distortion alone.

There is hence no official standard for measuring SNR.

Well, it is simple, if nothing else is stated, it is the difference between quiescent noise and full signal (Maximum digital value). What we really need, is seldom given - the dynamic range - the difference between the signal and everything else, including noise, distortions, converter nonlinearities etc. Often enough, soundcards rated better than 90db had a dynamic range well below 75db.

One of the reasons, why cheap 24bit/96kHz soundcards seldom live up to the promised expectations...

The static you hear is caused by excessive gain, and has absolutely nothing to do with SNR.

In fact, it has. Why? To just hear the noise, the maximum sound level possible is as loud as a pneumatic hammer.

If you hear noise at normal volume levels, then something is wrong with the equipment. Or the source material.

SNR in this case would be primarily affected by the source of your music.

Of course, it affects as well, but listening tests should be done with clean source material. And since most rip from their own CDs, this is usually the case.

[skyther]

Heh, you got me there. But like you said, those are technical limits. CDs at 96dB would clip.

The published SNR (of cheap audio products made by poor manufacturers) is often the rated SNR of a single audio component used in the product, not the SNR of the final output. Even then, the speakers/headphones used would make a difference. The SNR figures are already taken from the wrong place, so what use is providing the dynamic range and THD doing? As you said, the technical maximum SNR for CD is 96dB. Yet a good number CDPs are quoted for a >100dB SNR. Is that even possible? Did they measure that at the outputs? No.

Now if you turn the volume up but your source is quiet, is it fair to deduce that you have a low SNR? AFAIK, the iPod does NOT produce any noticable hiss at normal volumes.

This is where it gets interesting. My MP3s are gained to 87dB. With the volume set at ~80% of the scale, there is no hiss or background noise. I'm certain that it's not the equipment, and I'm also certain that lufs' observations are not based on identical sources used on the various equipment he listed. And TBH, I doubt the majority of HDP/MP3 player users play only tracks which are self ripped.

[jadeclaw]

Heh, you got me there. But like you said, those are technical limits. CDs at 96dB would clip.

Not exactly, 96db is full level. Anything above will clip. And that is done deliberately on some Pop-CDs to make them sound louder.

The published SNR (of cheap audio products made by poor manufacturers) is often the rated SNR of a single audio component used in the product, not the SNR of the final output.

It is cheaper to read some data sheets, that to measure the final product.

Even then, the speakers/headphones used would make a difference. The SNR figures are already taken from the wrong place, so what use is providing the dynamic range and THD doing?

It doesn't make sense for cheap chinese junk. But reputable manufacturers usually measure at the output connector. And that's the point, where it makes sense...

As you said, the technical maximum SNR for CD is 96dB. Yet a good number CDPs are quoted for a >100dB SNR. Is that even possible? Did they measure that at the outputs? No.

If it is stated for chinese junk, it's a lie. If it is stated for quality equipment, it is possible. Since we have a digital signal, a series of numbers to be exactly. And what can you do with numbers?

Calculations. Basically, the key here is Oversampling and Noise shaping. First we use oversampling to calculate the steps between two consecutive values of the original data. With that, we push the Samplerate up and the resolution as well, therefore reducing Quantisizing noise and nonlinearities in the DA-converter.

The next step is to push existing noise outside the audible frequency range, where it can be filtered out using relatively simple audio filters. That's what the Noise shaper does. But there are more tricks possible, the most well known is HDCD. Here, additional information is encoded into the data stream, which is used on the playback side to improve dynamic range and resolution. However, the cd-player needs a HDCD-chip as well to decode this data.

Before you ask, HDCD and lossy compression are NOT compatible.

The HDCD-data is lost...

Now if you turn the volume up but your source is quiet, is it fair to deduce that you have a low SNR? AFAIK, the iPod does NOT produce any noticable hiss at normal volumes.

That's a simple go no-go test...

This is where it gets interesting. My MP3s are gained to 87dB. With the volume set at ~80% of the scale, there is no hiss or background noise. I'm certain that it's not the equipment, and I'm also certain that lufs' observations are not based on identical sources used on the various equipment he listed. And TBH, I doubt the majority of HDP/MP3 player users play only tracks which are self ripped.

Filesharing is commonplace and one doesn't know, how a certain rip has been created. So all forms of additional problems can be introduced here. However, quality of the Players can vary as well and they may not been build with audio in mind and the harddisk introduces problems of its own kind...

[ruecker48]

ok, so ive read alot of these debates, and im looking to but either an ipod or a minidisc player (the mz-n10 md). now, i dont know what an hdd is or any of that lingo. anyway im a skatboarder, and plan on doing alot of active things with whatever i buy, so what i need answered is what the stats are for each of them, and which would be better for me, I DONT LIKE USING COMPUTERS IF NECESSARY AND DONT MIND HAVING TO CHANGE A DISC WHEN I WANT, BUT WHICH SOUNDS BETTER, LOUDER DOESNT SKIPP ETC.

email me at ruecker48@hotmail.com. thank you for your help.

[skyther]

I didn't think you got my point. Besides the fact that 'junk' equipment state false SNRs, every manufacturer's SNRs are measured with different standards. Using SNR as a comparison will not be fair. And btw, let's not refer it to 'Chinese' junk. I know of some pretty good chinese stuff, and I don't think it's fair for you to categorize everything of Chinese make as junk.

When you measure SNR, are you measuring a digital signal? No. How then can you measure the level of noise? If SNR is measured at an analog output, can it be accurately compared to a clean digital source? How do we know if one manufacturer's measurement equipment is more accurate than another?

Oversampling = interpolation. Usually it's also an excuse for poorer filters in equipment. While this allows for a higher theoretical SNR, it doesn't always work. Garbage in, garbage out. Your output will always be limited to the quality of your input, and that's the general rule of thumb. Not to mention that oversampling is done at the DAC, and by this time the signal has already passed through the DSP. There is really no point in claiming a higher SNR from the use of 'imaginary' data.

Noise shaping, to what I know from my limited knowledge, adds extra noise to smoothen out existing noise. This could possibly raise the noise floor.

Both these techniques may result in colouration of the output signal.

That's a simple go no-go test...

Exactly my point. You assumed that most people ripped their own CDs. In this situation, that's a very wild assumption. The comparison was obviously not done very scientifically, so it's not fair to conclude that the iPod has a low SNR just because you 'hear' hiss when the player is set at a loud volume. Maybe I should use gain, since volume would be more appropriately used to refer to the actual volume at that point of the track.

It's useless to introduce oversampling and noise shaping here. The iPod only utilizes digital filtering. Oversampling works mainly for CD players, not Digital Audio Players. You have numerous formats that can be encoded at various sample rates with varying resolutions. Introducing oversampling would be introducing extra complexity and cost.

The iPod isn't just a thumbdrive that's been converted to play MP3s. It was designed from ground up by PortalPlayer on contract with Apple. And no, the hard drive does not cause interference, simply because everything is played from the buffer memory.

[devo_ji]

Both of these units sound fine. The real difference will show up about 2 years from now. Just like the first gen Ipod's have problems with holding a battery charge, what will everyone be saying as the HD units start failing. There is a reason we are all supposed to back up our HD's regularily, and those units just sit in big boxes that don't move. I can't wait for the crying to start when user's entire music collections are gone with one bump, knudge or grind.

[Christopher]

I used an iPod the other day for the first time and I was absolutely amazed. I believe that each device has it's own merits and characteristics that set it apart from the other, so it's not really a matter of which is better - it's more or less if the overall functionality of the device applies to you or not.

[BJ]

Yeah, it always boils down to whatever appeals to you and your music-listening habits. If your music collection resides on your computer, it makes more sense to buy an iPod. I own originals of all the music I listen to, so I'm more interested in the stand-alone MD, since my PC is for word processing and graphics. I don't even have any video games installed (I know, blasphemy, but that's what my Gameboy is for).

ruecker48, I'd vote for the MZ-N10 for skating. It's smaller & lighter, you can edit/delete tracks whenever you want, you don't even need to own a PC to record on it, and it'll probably be a little more resilient if you wipe out.

But you know, the choice is up to you. And the iPod is still a top-notch product.

[crazeybt1]

MR .."ruecker48" i skate..n i fall hard...i've never owned an mp3 player..cuz i've been skating(rollerblading) every since..n cuz they came out all big n clumsy(Nomad) i never went down that road but stuck to disc mans n migrated to mds in 99 never went back..trust me MD is the way for the rugged road....i promise u it will not skip...u can skate with a G-protected MD n i assure u" it will not skip" ( if ur not satisfied u can return the product for a full refund:grin: ) unlike some G-Protected disc mans that can't take the constant bumps on ur legs when u push which results in the lens bumping up n down not left n right...talk about wipe out..take my advice purchase a cheap md say an MZR 700..it's rugged n perfect for the job.i wouldn't advise investing ur money in a high end unit cuz after a while it's gonna look all bumped up, dented, scratched...n just not cute..so if having it look new n stuff matters to u n u do purchase a high end unit..always keep it in it's carrying case :grin: ...i alwyas have 2 working units 1 to sport with n 1 2 skate with...if u can afford it..u can do that..presently i skate with my MZR 70 still...n my MZN707..on the contrary if skating with eggs in ur pants is ur thing then get an MP3 player and i wish u all the best :smile: .....( i forgot 2 mention MDs don't need a computer to record.. u can record from any souce. u can plug ur optical cable to ur sterio n record straight snail way.or what ever suits u.. MP3s..uhh...still lacking tsk tsk. so far i think u still "need" a pc to do all audio recordings)

[FinoFX]

I would love either one and be happy with either. Im sure both are great and anybody that had either one would be more than happy with their purchase/item.

iPod

*Nice to have most/all music on one device, no swapping, nice and lazy

Hi-MD

*Security, iPod crashes you got nothing. Hi-MD crashes you simply exchange it for a new one (hoping you purchased the extended warranty).

I would go with the MD anyday, lil cheaper and just safer in my opinion.

[clarkeda]

I think Sony have missed a trick with taking so long from the Hi-MD announcement in Jan to the GA of the machines. It gives people like me too much time to consider the other options :-)

You get the sense that this is a continuing development from Apple, and that your investment in an iPod will not be wasted. I was impressed with the Airtunes hardware annoucement for example. This shows a level of innovation that Sony just don't seem to be able to match these days. Hi-MD just feels too much like a "last throw of the dice", which should have happened two years ago. Any sound quality advantage Sony might claim is going to be hit by the increasing use of lossless encoding in the years to come, as HDD capacties increase.

[tekdroid]

Both of these units sound fine.  The real difference will show up about 2 years from now.  Just like the first gen Ipod's have problems with holding a battery charge, what will everyone be saying as the HD units start failing.  There is a reason we are all supposed to back up our HD's regularily, and those units just sit in big boxes that don't move.  I can't wait for the crying to start when user's entire music collections are gone with one bump, knudge or grind.

So true. I think they'll be called Crashpods in 2-3 years (as will many of their competition building HD-based units). I bet there'll be a far higher ratio of perfectly functioning 2004 model Hi-MDs than current iPods by then.

Sony does need to go way beyond 1GB pretty quickly though. Hi-MD will be their interim format to milk some economies of scale they developed with MiniDisc before switching over to something a fair bit more advanced, IMO (which is no doubt being worked on as we speak). 1GB just doesn't have the same appeal it would have had 3 years ago, especially considering the reduced time recording losslessly.

Sony's (big) advantage is their ability to build robust removable optical media, which most of their competition can never hope to manufacture, let alone market successfully. Until HDs are replaced with something a hell of a lot more reliable, I don't think anyone can underestimate Sony's advantage here, especially when/if they increase storage densities and speeds...

[Jimmix]

Not to mention it's ability to become a media for usage with other devices as cameras (with cheap storage of 1gb) and as a replacent for floppy disks (no more flashdrives :laugh: )!!!