My recent LP4 observations

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[sfbp]

Thanks for your comments. I'd go further than that. When recorded in real time from a digital source such as internet radio, LP4 is a lot better than almost any source you can find. This is probably because the Type-R bit reallocation kicks in (in the recorder - I always use a deck and have no idea about portables). I have hundreds of hours of classical music recorded this way, and it makes beautiful listening AS LONG AS I DON'T TRANSCODE.

I find both LP2 and LP4 are exquisitely sensitive to the quality of the ripping when transcoded from WAV files that started out as CD-quality (1411kbps). I like to rip to AAL, for no better reason than that it works, and the result of transcoding from there to LP2 is acceptable.

FYI the source (of my usual internet radio) is probably AAC at 128kbps, and doesn't have any obvious artifacts on live listening to orchestral music. On opera, sometimes (quite rarely actually) it can sound a bit thin on LP4 playback, but it's really a "depth" thing and I attribute it more to the different way that LP4 stereo is captured (mono with difference, aka "joint stereo") than real artifacts.

I would never convert anything (except maybe speech) to LP4. But I'm sure you are right, it's almost as good as 128kbps MP3, and LP2 is probably better than 256kbps MP3. (Can't be sure about the last but I'm sure there are MD fans here about to go off and check it out!!!).

Stephen

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[sfbp]

After reading your post I'm wondering about LP4 in real time for FM broadcast radio...

I think perhaps it comes down to this: streams intended for the internet typically have been pre-conditioned, noise-reduced, etc so that they make the maximum use of bandwidth at the extremely low data rates most people can use. For example until very recently XM in this country only offered 32kbps internet radio (they've recently added an option to pay more for better quality, as was in the USA for more than a year I think) but I'm pretty sure the satellite transmission is at 128kbps. The BBC broadcasts outside the UK by default at 48kbps, but their home market transmission, if you have it, is 128kbps.

What am I trying to say? There's not too much point recording a 128kbps source at CD quality (yes, I have done it, early on before I "tamed" ATRAC to my liking, back when I didn't trust the LP modes either). And if ATRAC beats the others by (say) a factor of 2 (I'm not sure whether it does), then a 66kbps stream may be adequate for a lot of purposes. I **know** I won't improve on 132kbps for anything transmitted (even the sound tracks of many TV programs are essentially MP3 at 128kbps). In practice I use Hi-SP on a 1GB disk because it's the only convenient way to get more than 2hr 43m without resorting to LP4 (or of course Hi-LP), if I need to record a long opera. So that's a different sort of overkill. At least 256kbps HiMD also gets transferred to the 'puter completely unmodified. Like some previous posters, I really wonder how good 128kbps ATRAC3+ is, since it would double the times, to 4hr 40 on an 80m disk - having seen a reference to it somewhere, but I think it has effectively disappeared now.

Just some ramblings....

[md user]

Thanks for your comments. I'd go further than that. When recorded in real time from a digital source such as internet radio, LP4 is a lot better than almost any source you can find ... hundreds of hours of classical music recorded this way, and it makes beautiful listening AS LONG AS I DON'T TRANSCODE.

I find both LP2 and LP4 are exquisitely sensitive to the quality of the ripping when transcoded from WAV files that started out as CD-quality (1411kbps).

On opera, sometimes (quite rarely actually) it can sound a bit thin on LP4 playback, but it's really a "depth" thing and I attribute it more to the different way that LP4 stereo is captured (mono with difference, aka "joint stereo") than real artifacts.

I would never convert anything (except maybe speech) to LP4. But I'm sure you are right, it's almost as good as 128kbps MP3, and LP2 is probably better than 256kbps MP3. (Can't be sure about the last but I'm sure there are MD fans here about to go off and check it out!!!).

Wow! I'm really impressed that your set-up is getting LP4 good enough to listen to opera! (Is it the Type-S treatment?)

Personally, my recordings in LP4 are dull, noticeably artifacted (although, if accepted, forgiveable); my opera recordings so far have at least been LP2 - but only because SP requires disk changes (losing 10 seconds ...). Must get ANOTHER deck to do the [realtime] changeovers ...

Still, it does seem that your research and experience has gotten these compressions to work well - that's the way to do it!

Regards,

mdmad.

[sfbp]

To be fair, I don't do opera with it (except a couple of times I knew the piece well enough to know I could squeeze the last 15 minutes on the disk if I changed speeds 9-10 minutes before the end. At that stage it's better to have something than ending mid phrase ) But usually LP2.

However non-opera (orchestral, chamber) is surprisingly decent. Even things like piano, which traditionally was the bugbear of any system that didn't cut the mustard back before digital audio. Not any more.

[md user]

if I changed speeds 9-10 minutes before the end. At that stage it's better to have something than ending mid phrase

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You mean that you SLLOOOWW down the recording? How? How do you recover it?

Yes, you must be doing well; piano is a good test of a codec - it actually makes me smile when SP can make a convincing recording, let alone on LP2 or LP4 - it goes to prove how much effort and skill went into developing the minidisc concept.

ASIDE: I actually downloaded a, believe it or not, 32kbps aac[+], pop recording recently; it actually sounded less artifacted than 128kbps mp3! Albeit, it lost stereo-effect, treble, ambience &c. Nevertheless, I had to check the properties of the file TWICE to convince myself that, given a good algorithm, this was real. (It was, as the internet radio stream confirmed.) So, why not LP4? If the algorithm is good, and optimised filters are in place ...

Anyway, well done; LP2/4 kind of 'deserves' a good treatment in skilled/careful hands.

Regards,

mdmad.

[sfbp]

You mean that you SLLOOOWW down the recording? How? How do you recover it?

No rocket science here. Work out when there will be some applause (at the end of an aria), stop the recording, switch to LP4.

added: tried to send you a PM but you have disabled everything it seems. I might just send you a file for your comments.....

[md user]

No rocket science here. Work out when there will be some applause (at the end of an aria), stop the recording, switch to LP4.

Right, makes sense.

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[sfbp]

I think I previously mentioned that I didn't use LP4 for opera.

Check this out - Mahler's Kindertotenlieder. Not quite opera but most of the same characteristics.

I won't leave the file there forever. Being LP4 it's only 10MB or so, though.

[sfbp]

Here's another LP4 - Puccini Messa di Gloria. Enjoy while you can, as it is really only there for a sample, and I must remove it eventually. About 20MB.

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[sfbp]

Maybe I respond in due course. Need some more time. Quick thought - I have noticed that Sound Forge seems to correctly master the conversions. Have you considered that instead of whatever on the fly conversion you get from SS?

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I don't follow you sfbp, I don't have the pro version of Sound Forge maybe that's why I'm lost. I do look forward to your thoughts when you have time.

[sfbp]

I have only the "regular" version. It converts all ATRAC to and from whatever. And I think fixes the artifact that you (and I and others) may be seeing. You could give it a shot. If the version you have doesn't convert ATRAC, I'm sure you are entitled to some sort of upgrade.

I have this idea that the reason I get good LP4 recordings is that the original source I started with was already at a low data rate (AAC 128kbps for instance). However it varies by source, and so far my internet recordings have been better than those off satellite, in this regard.

What did you think of the 2 uploads?

S

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[sfbp]

I listened to Kinder last night and was quite surprised. Of course the sound stage was narrow but everything else was great. Imaging, noise floor, voice inflection were all great. Too bad my german has been sitting in a closet since the Cold War, lol. Would have been nice to understand what she was singing about. I do know she was lamenting.

Death of Children. Was written BEFORE his own kids died, but based on some experiences losing siblings. Infant mortality was atrocious then.

I didn't think SS would transfer a 66k file without performing even more processing, here is how I think you are putting those files on a MD:

Open the file in SF, then save as 66k. Import into SS, tag and then burn them to disc? Is this correct?

I haven't played around with SF and MD other than to test transfering files in LP2 mode, just to see if it works. If you are transfering them directly in LP4, in SF (from the file menu) I'd sure like to know how you are doing it.

P.S. I have a hunch that the developers specifically tuned LP4 for the human voice. I think they succeded.

Aaargh... too much to respond to in a single post.

Firstly, here's how I made that file:

1. Record from internet with digital output of sound card going to optical in of MDS-JB980, at LP4. I am sure a JE deck (eg Je640) is just as good, since Type-R affects recording, and Type-S does not.

2. Upload song to SonicStage using RH1. Select "As is" option which leaves the coding untouched.

3. Decrypt file using File Conversion Tool.

At this point I have the file like the one that I uploaded. Transferring it (by SS) to NetMD or HiMD with "as is" option should be a no-brainer. As long as you don't see the scary word "Converting" I think you are ok. Or if "converting" only takes about 1 second regardless of the length, it's safe to say that no bulk conversion of the bits is really done.

I actually am playing a lot of stuff back from computer into optical input of receiver these days. The medium is unimportant (to me).

If you want to do conversion of a recording you made, just pick ATRAC3 and "Save As" the right bit rate (in Sound Forge). NOTE: to get LP4 you have to work a bit harder - need to press the "Custom" button to find that exact bit rate, 66kbps, ATRAC3. You can "export to NetMD" but I have a feeling it defaults to LP2 (so no good for this). After conversion you can reimport to SS and send to the device as usual.

But as I pointed out in another post this morning, the RECORDING stage appears to be critical.

I don't think you're right about ATRAC LP4 - the human voice tends to NEED the higher frequencies to sound really good. In fact the ICD-SX750 (LPEC STHQ 128kbps) has much "better" response in the region where all Atrac codecs cut right off above 16kHz, and the result is more clarity, not less. The sibilants we have observed are some artifact.

Opera: try the Met's opera player for a month. You'll be amazed. Hard to know what to recommend as I don't quite know where you are starting from. Out of the blue, I'd say start with Bizet's Carmen or Humperdinck's Hansel and Gretel. Both had wonderful performances this last season which are available there.

Stephen