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SP "Compatibility Mode" -vs- LP2 (Atrac3 132kbps)

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There has been some debate over what exactly "SP Compatibility Mode" is... The general consensus has been for some time, that it is only LP2 quality (132kbps) wrapped in an SP container. There has also been speculation that the quality is still "True SP" because the encoding/recording is done by the unit, not by SonicStage (which is why it takes longer, and why SP recording can be done with 2nd gen Hi-MD units via a hack).

I decide to find out for sure, using the frequency analysis feature of Adobe Audition. I recorded the same track (Aphex Twin - Girl/Boy Song) onto MD in LP2 format, and SP compatibility mode (being sure to delete any temporary files SonicStage may have created). I also recorded the same track in True SP via my Sony MXD-D40. I had to use TOC-Cloning in order to be able to import the files transferred via SonicStage, due to it's restrictions.

Seen below are the following:

Untouched WAV file extracted from CD

LP2 via SonicStage

SP Compatibility Mode via SonicStage

SP via MXD-D40

post-1817-1181151670_thumb.jpg

As we can see, clearly there is a difference between True SP and SP Compatibility Mode (which in this example looks to be slightly worse than LP2).

I cannot stress enough however, let your own ears decide! If you can't hear a difference, numbers don't mean a thing. This experiment was simply for the technically curious.

Another experiment I may add to this later is a comparison that includes SP recorded on my RH1 itself, vs compatibility mode. Also perhaps a comparison between SonicStage's LP2, and my MXD-D40's LP2, etc.

Hopefully now this beast can rest! :)

EDIT:

Below I have compared SP -vs- Hi-SP. Both recordings are the same track recorded optically via my RH1.

"True" SP (Atrac3 292kbps)

Hi-SP (Atrac3+ 256kbps)

post-1817-1181229224_thumb.jpg

Edited by raintheory
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Well, I think everybody knows this already, ever since the starting of NetMD. Sonicstage cannot/doesn't have the codecs to deal with SP. When transferring to SP compatibility mode, Sonicstage basically converts the tracks to LP2, presumably decodes it and transmit it as raw data via USB to the NetMD recorder, and the NetMD recorder will encode the track to SP. End result is you got double transcoding (1 by Sonicstage, 2nd by the unit). This is pretty much the worst case scenario, having double transcoding, and double the filesize.

If you cannot tell the difference, that means LP2 is transparent to you, and pretty much applies to most people, simple as that.

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I've been using SP compatible to make discs that I can use in my car, some are mp3 converted some are cd's, AFAICT they sound pretty good to these 55 year old ears, had a couple of people somment on the sound of the system and were quite surprised that there were still minidiscs around.

MD's rule

Bob

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Well, I think everybody knows this already, ever since the starting of NetMD. Sonicstage cannot/doesn't have the codecs to deal with SP. When transferring to SP compatibility mode, Sonicstage basically converts the tracks to LP2, presumably decodes it and transmit it as raw data via USB to the NetMD recorder, and the NetMD recorder will encode the track to SP. End result is you got double transcoding (1 by Sonicstage, 2nd by the unit). This is pretty much the worst case scenario, having double transcoding, and double the filesize.

If you think about it, it really makes no sense why they have it set up this way... If you import a WAV file into SonicStage, why wouldn't SonicStage simply stream that data to the unit, rather than streaming LP2 data to the unit. Being that the unit itself does the encoding.

No point trying to understand SONY's software department I guess.

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If you think about it, it really makes no sense why they have it set up this way... If you import a WAV file into SonicStage, why wouldn't SonicStage simply stream that data to the unit, rather than streaming LP2 data to the unit. Being that the unit itself does the encoding.

No point trying to understand SONY's software department I guess.

My guess is the NetMD units only understand the specific data decoded by Sonicstage, not just any data like WAV files. Remember NetMD was developed when Sony is still gung-ho about DRM, check-in/out, and against uploading. Yeah, there's no point in trying to make sense the stupid decisions of Sony.

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It looks like the True SP and the CD are head to head at 18khz , whitch is the basic limit of normal human hearing .

The rest drop off substantially well below that freq , Which is another vote for the MZ-R50 which only recorded in SP and did so very well .

Everything I have done in SP mode on older decks sounds as good if not better than any of the newer decks I have used.

At least the stuff from the R50 . I can hear the difference in the OUTPUT of the RH1 , the amp is nice , very broad in dynamics , but for recording R50 at SP , RH1 at PCM The RH1 gets just a Little more Headroom , but you have to listen very closely for it, and with Good phones.

I also have a Digital Amp and Reference quality speakers , again My R50 line out is solid and detailed .

I have No probs with SP whatsoever , and practically NEVER erase a Disc once it has been recorded properly ( might explain the size of my collection) LP2 -LP4 I reserve for Daytrip discs, bacpacking , or train rides, Or when recording Conventions and spoken word , lectures etc. , But for Collecting and archiving music SP mode almost exclusively .

It will then play on ANY player , and be better than anything an mp3 player will ever produce.

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I cannot stress enough however, let your own ears decide! If you can't hear a difference, numbers don't mean a thing. This experiment was simply for the technically curious.

To make this a bit more clear, let me add the following:

The high frequency cut-off is the easiest to analyze and make visible via graphs. It can by no means be a direct indicator of perceived sound quality though since it is just one of many methods lossy compression utilizes to reduce file size. If inaudible content is excluded like in a 18 or 20k cutoff, the saved bits can be used elsewhere to retain quality in the best possible way.

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Ishiyoshi already did this 2 years ago:

http://www.atraclife.com/forums/index.php?showtopic=49

How did he compare "True SP" to 352kbps without the RH1 being available? Are you thinking Hi-SP vs 352?

EDIT: I'm not @ home currently, but I'll gladly update the thread with True SP vs Atrac3+'s various formats/.

Edited by raintheory
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Per richyhu's request, here a comparison of True SP -vs- Atrac3+ @ 352kbps:

If I am interpreting correctly, then the ATRAC3+ 352 is technically superior to True SP?

I know that might not translate to audible difference, or preference, I just want to be sure of that I am seeing here.

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If I am interpreting correctly, then the ATRAC3+ 352 is technically superior to True SP?

I know that might not translate to audible difference, or preference, I just want to be sure of that I am seeing here.

A less aggressive high-cut can not be a direct indicator for technical superiority or better quality. Lossy codecs need to save bits somewhere. A high-cut is just one of many methods. The higher the bitrate, the less information needs to be left out.

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If I am interpreting correctly, then the ATRAC3+ 352 is technically superior to True SP?

I know that might not translate to audible difference, or preference, I just want to be sure of that I am seeing here.

again the bottom ;ine is not to believe what you see, but believe what you hear,

Bob

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Thanks Rain Theory, but there is two things I'm unsure of. What is the source file for the LP2 and SP compatability files, I'm assuming it was your WAV, but assuming makes a... Also what was the unit you used to make SP compatability track? HIMD or Net MD? Later, POE. :unsure:

Edited by poe
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Thanks Rain Theory, but there is two things I'm unsure of. What is the source file for the LP2 and SP compatability files, I'm assuming it was your WAV, but assuming makes a... Also what was the unit you used to make SP compatability track? HIMD or Net MD? Later, POE. :unsure:

Yes, the source file for all of the SonicStage conversions was the original WAV file. I also was sure to purge all traces of the file from SonicStage's folders between conversions to be sure the program wasn't transcoding from a file it already had.

I used the MZ-RH1 to transfer from SonicStage.

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