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RH10's MP3 decoder: what the...?

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clorenzo

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Ok, so I've just got my new RH10 and decide to do some comparisons between ATRAC and MP3. I take one of my favourite test tracks ("Fonkalishus" from the Bluesiana II album, Windham Hill Records, great, natural recording with lots of low level detail), encode it with ATRAC3+ @ 64 and 256, MP3-CBR @ 128 and MP3-VBR at different qualities (I use Creative Media Source where for VBR you specify a quality percentage, 50% giving approx. the same file size as CBR @ 128), download the lot on the RH10 together with a WAV file for reference, plug in my reference Beyerdynamic DT-880 headphones.

I do a sort of blind test (set it to random, listen to part of the track, make notes, then look to see which one is it, go on to the next track, etc.) and on a first quick pass listening to just a few seconds and not thinking much I get this:

VBR 40% - no treble, splashy

CBR 128 - no treble, splashy

VBR 100% - no treble but good

WAV - perfect

VBR 80% - no treble but good

ATRAC3+ 64 - lots of artifacts, useless

VBR 10% - no treble, some artifacts, splashy

ATRAC3+ 256 - almost perfect, some very subtle artifacts

VBR 60% - no treble, slightly splashy

So, I think, "boy, that MP3 thing just throws away all the highs!", double-check in my computer with Windows Media Player, and nope, the highs are there, with more or less quality, but the quantity is practically the same as in the WAV file.

What are they on about? Is this just to promote ATRAC over MP3? I mean, even with the very recessed treble, I prefer MP3 CBR 128 over ATRAC3+ 64 (which is a joke), and when you compare the "good" MP3 from Media Player it's just no contest, but I can see where in listening tests people may prefer the livelier presentation of ATRAC3+ 64 if the test was carried out through something like an RH10 or a similar software implementation of the decoder. That's naughty, Sony <_<

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Sorry for the bandwidth guys, I hadn't come accross that thread.

I didn't buy this thing primarily as an MP3 player (it's for recording my band's rehearsals and gigs) and I've managed to get a reasonable balance with the custom eq, but this is unacceptable, they shouldn't be allowed to put that MP3 sticker on the unit! Is there an e-mail address where I can write to Sony and give them a piece of my mind about this issue? Maybe if enough people complain they'll come out with a firmware update or something (I know I'm dreaming, but it's worth a shot, right?)

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Weird situation when it happened to me. At first all I tried was MP3 and had my custom EQ cranked in the highs.. and I thought Atrac3 was just really bright. Then it eventually occured to me. I agree it's unacceptable.

I also realize this is old news, but it has yet to be corrected and I truly don't see why it cannot be fixed via firmware upgrade. I'd even pay for it.

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Ok, so I've just got my new RH10 and decide to do some comparisons between ATRAC and MP3. I take one of my favourite test tracks ("Fonkalishus" from the Bluesiana II album, Windham Hill Records, great, natural recording with lots of low level detail), encode it with ATRAC3+ @ 64 and 256, MP3-CBR @ 128 and MP3-VBR at different qualities (I use Creative Media Source where for VBR you specify a quality percentage, 50% giving approx. the same file size as CBR @ 128), download the lot on the RH10 together with a WAV file for reference, plug in my reference Beyerdynamic DT-880 headphones.

I do a sort of blind test (set it to random, listen to part of the track, make notes, then look to see which one is it, go on to the next track, etc.) and on a first quick pass listening to just a few seconds and not thinking much I get this:

VBR 40% - no treble, splashy

CBR 128 - no treble, splashy

VBR 100% - no treble but good

WAV - perfect

VBR 80% - no treble but good

ATRAC3+ 64 - lots of artifacts, useless

VBR 10% - no treble, some artifacts, splashy

ATRAC3+ 256 - almost perfect, some very subtle artifacts

VBR 60% - no treble, slightly splashy

So, I think, "boy, that MP3 thing just throws away all the highs!", double-check in my computer with Windows Media Player, and nope, the highs are there, with more or less quality, but the quantity is practically the same as in the WAV file.

What are they on about? Is this just to promote ATRAC over MP3? I mean, even with the very recessed treble, I prefer MP3 CBR 128 over ATRAC3+ 64 (which is a joke), and when you compare the "good" MP3 from Media Player it's just no contest, but I can see where in listening tests people may prefer the livelier presentation of ATRAC3+ 64 if the test was carried out through something like an RH10 or a similar software implementation of the decoder. That's naughty, Sony <_<

Yeah, I noticed the same thing when I got my RH10. MP3s sound good on comptuer but not on Hi-MD. Basically it's just Sony promoting ATRAC3+. They figure if you compare ATRAC files with MP3 files, you'll choose ATRAC based on the sound quality, but the unit is biased. Unfortunately, you have to convert the MP3s to ATRAC and then transfer and you'll get all the highs back. Some people say some sound quality is lost during conversion, but in my opinion it's hard to notice. These are the conversions I use:

MP3 128 --->ATRAC3+ 256

MP3 192 --->ATRAC3+ 256

MP3 256+ -->ATRAC3+ 256

Edited by Chris G
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Yeah, I noticed the same thing when I got my RH10. MP3s sound good on comptuer but not on Hi-MD. Basically it's just Sony promoting ATRAC3+. They figure if you compare ATRAC files with MP3 files, you'll choose ATRAC based on the sound quality, but the unit is biased. Unfortunately, you have to convert the MP3s to ATRAC and then transfer and you'll get all the highs back. Some people say some sound quality is lost during conversion, but in my opinion it's hard to notice. These are the conversions I use:

MP3 128 --->ATRAC3+ 192

MP3 192 --->ATRAC3+ 192

MP3 256+ -->ATRAC3+ 256

Well, all my music is currently on CD so I can use ATRAC3+ directly. The reason I wanted to go with MP3 is the VBR option, which makes a lot of sense to me (why send 128 kbps of zeros during a silence?) and should give better quality/size ratio than CBR compression.

However, I must say that after further tests comparing MP3 VBR in my computer (so no eq issues) with ATRAC3+, I have concluded that I actually prefer ATRAC3+ 192 to MP3 VBR @ 100% quality (which sizewise is roughly equivalent to 200 kbps), so I'm not concerned about this problem anymore. If I ever get anything in MP3 only (which probably means that I don't care too much about quality anyway) I'll either use the eq or, if it's a mixed MD and don't want to bother with changing the eq setting back and forth, I'll do the conversions you suggest.

This actually means that, at least the way I perceive it, ATRAC3+ is indeed better than MP3 at equivalent bit-rates and even with the advantage of VBR for MP3 (though the ATRAC3+@64 = MP3@128 claim is a blatant lie), so I wonder why they can't simply let the technlogy speak for itself instead of playing tricks that do no good to their reputation. I guess it's the old Sony schizophrenia at work again: great engineers, lousy marketeers. Oh well.

Edited by Cabirio
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With a properly tweaked EQ and some high quality vbr mp3's (preset standard, or extreme), the RH10 is capable of some good sounding playback in my opinion. True it sounds slightly "duller" than the Atrac version, but this is not necessarily a bad thing, depends on the type of music your listening to.

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I think this essentially shows that if you use any sort of MP3 you need a computer which can be a nuisance at times.

For ripping CD's direct to MD or direct recording of your gig etc then you won't have a problem with MD if you record in realtime (analog / optical) or us SS for transfers at a decent bit rate.

One can argue that it might have been better for Sony to have ignored the MP3 option altogether rather than include it but give it a "poor" performance -- after all would you buy a Ferrari if it had a Ford Fiesta engine in it.

MD is a bit more than just a "playback" device. For just playback maybe another device might suit you better but as a recording medium MD still rules the roost --now that DAT is "officilly dead".

For those toying with the idea of "Solid State" players -- an 8GB card costs around a cool 450 USD. What does 1 1GM HD disk cost -- you can get them for as low as 8 USD each now if you source them correctly. Audiocube sells a pack of 50 1GB HI-MD disc for 399 USD -- thats around 8 USD a piece.

http://www.audiocubes.com/product/Sony_HMD...k_(50_pcs).html

If you download highly compressed poor quality music from "ICHOONES" riddled with DRM issues a playback only device like an ipod might be your best bet -- I wouldn't use a MD device for listening to MP3 tracks anyway --wasn't designed for that purpose.

Use WAV / WMA and convert to ATRAC3+ (or ATRAC3 losseless at highest bitrate). You'll get a much better sound quality --leave MP3's for Ipods etc.

The MP3 playback was just added as an afterthought --Sony have no commitment to that format so you won't get the best encoding in any case.

Cheers

-K

Edited by 1kyle
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  • 4 weeks later...

I think it has to do with the D/A convertor used in HiMD's.

This type of sigma-delta converter always has problems with compressed high frequencies.

It's like taking pictures of moving objects:

a slow moving object will be seen more clearly then a fast moving object.

In HiMD when analysing frequencies of frames:

a low frequency will be more accuratly registred then a high frequency.

I don't kwow if MP3 conversion is typically difficult with a Delta Sigma convertor though.

Maybe atrac compression puts more emphasis (less compression?) on high frequencies then mp3 conversion?

Just a thought but i'd still like to know if anyone thinks the same or has a different idea?

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Here's what I'm talking about by imperfect compensation...

[attachmentid=1545]

As the legend says,

RED = UnEQ'd 320kbps MP3

Magenta = Subtractive EQ only [see below]

Blue = Additive EQ only [see below]

Green = UnEQ'd PCM of the same sweep [spikes cause by FFT window size I was too lazy to change]

Subtractive EQ only:

<pre>- |-|-|-|-|-|-|

- |-|-|-|-|-|-|

- |-|-|-|-|-|-|

0 |-|-|-|-|-|=|

- |-|-|-|-|=|-|

- |=|=|=|=|-|-|

- |-|-|-|-|-|-|</pre>This would be fine for loud source material with high-sensitivity 'phones. I usually use this as, even though it's a bumpier ride so to speak, I tend to stick to subtractive EQ only [it comes from working with analogue equipment]. The effect on the low end is also similar to old-style mega-bass.

Additive EQ only:

<pre>- |-|-|-|-|-|-|

- |-|-|-|-|-|=|

- |-|-|-|-|=|-|

0 |=|=|=|=|-|-|

- |-|-|-|-|-|-|

- |-|-|-|-|-|-|

- |-|-|-|-|-|-|</pre>As you can see, neither is anywhere near perfect.

Once again, the RH10's artificial sweetening of the high-end can be seen with the PCM sweep. Loopback measurement of the same signal is perfectly flat.

I think it has to do with the D/A convertor used in HiMD's.

I don't think the DAC has anything whatsoever to do with it. I think it has to do with Sony having imperfectly [to say the absolute least] programmed an MP3-decoding algorithm for the DSP used in 2nd-gen HiMD units. Had they coded the decoder correctly, we'd get flat response, period. My own speculation is that this may have come about by being a rush-job before the units' release.

post-3514-1143450372_thumb.jpg

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I think I need to visit an ear specialist! I'd never noticed this! (Although when I used my RH10 for a player more I tended to use the original Sony in the ear things and most of my library is Atrac). But comparing to computer and my HD5 it is quite obviously duller. Nowadays the MD is for recording anyways - HiSP or LinearPCM.

>>Off to have ears syringed!

JC

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Sorry for the bandwidth guys, I hadn't come accross that thread.

I didn't buy this thing primarily as an MP3 player (it's for recording my band's rehearsals and gigs) and I've managed to get a reasonable balance with the custom eq, but this is unacceptable, they shouldn't be allowed to put that MP3 sticker on the unit! Is there an e-mail address where I can write to Sony and give them a piece of my mind about this issue? Maybe if enough people complain they'll come out with a firmware update or something (I know I'm dreaming, but it's worth a shot, right?)

Nope they'll do nothing. You don't use it as a player so its not really a problem. for band recording its perfect.

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