Hey everyone,

I have pinpointed the source of some poor sound quality coming from my empeg during the playing of certain songs... looks like i was not careful during some ripping and used "Joint Stereo" instead of true Stereo MP3 encoding.

The joint stereo sonds awful on songs from the 60s and 70s when artists did a lot of heavy stereo-tweaking sound work. But, the only way i can see to fix this is to reencode ALL of my local MP3 files and re-upload them.

That's ok, since the empeg can't encode files itself... but can somebody please tell me of a tool that can do this in batch format... instead of me having to inflate all MP3s to wav, re-encode with the Radium Fraunholfer codec, and re-edit all ID3 tags.

Desperately seeking a better way,

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

What about the program MusicMatchJukeBox
www.musicmatch.com

Musicmatch will create MP3 files on the fly, without the WAV file first.

I've been using it since version3 and I'm very pleased with it.
Or you could read some of the many other posts here on the board regarding
the same thing, but with other programs/encoders.

Good Luck
TommyE

hmm... a search on the word "encoding" in the forums didn't turn up much help... but that music match sound like it could work for me... thanks!


- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

well, music match seems to only let you process one directory at a time... i haven't yet found a way to recurse the directories.

ah well, i'll keep looking around for another tool.

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

Er, I'm not sure if this is what you're implying, but you can't simply expand the MP3 files to WAV and reencode them to sort out the stereo -- the joint stereo encoding already threw away the relevant information.

You'll need to start from the original WAV/CD.


Roger - not necessarily speaking for empeg

I find that MusicMatch sometimes creates some awful noises when encoding that has scared the life out of on more than one occassion whilst I've been driving along.

_______________________

Steve - 18GB Mk II Amber

...i'll keep looking around for another tool.

Before you do that, read Roger's post above where he says: "...you can't simply expand the MP3 files to WAV and reencode them to sort out the stereo..."

He's not kidding about that. Once you've made the omelet there's no way to put the eggs back in their shells! Your only course of action (if you wish to maintain any semblance of sound quality) is to start with your original CDs or .wav files and re-encode them.

tanstaafl.



"There Ain't No Such Thing As A Free Lunch"

looks like i was not careful during some ripping and used "Joint Stereo" instead of true Stereo MP3 encoding.

I highly doubt that. The difference between Joint Stereo and True Stereo is incredibly subtle and difficult to pick out, especially at decent bit rates.

I believe that if you're having stereo image problems with your MP3s, then the problem is your combination of computer/drive/ripper/settings. The ripper is actually ripping the files incorrectly, skipping bytes here and there and causing the stereo image of the audio to mess up.

The faq entry on the subject is here, check it out.

___________
Tony Fabris

I would agree with Tony. I've got over 2000 songs on my Empeg (not many by some peoples standards, but quite a few none-the-less), most of which have been encoded with Musicmatch in joint-stereo. I think I'm quite sensitive to things not sounding how they should and I haven't noticed any wierdness in the stereo image at all in these files. So to reiterate what Tony's said I don't think joint-stereo is your problem.

ahh... I must update my signature. Just slapped in another 20GB drive. That makes 32GB
Thanks to everyone who contributed to the "Adding a drive" FAQ. I couldn't have done it without it

beaker
12 gig blue/magenta/orange/yellow (at the moment :-))

I'd be surprised if it's Musicmatch causing your awful noises. As you can see from my previous post most of my 2000+ songs have been encoded with Musicmatch and there's only one track which had a brief "squeak" at the start of the track which wasn't present in the intermediate WAV file. So I'd suspect something else is wrong with your setup / procedure. Generally I've been very impressed with the speed & quality of Musicmatch.

beaker
32 gig (various colours)

exactly

If you are on Linux, Lame and a few lines of script would do what you are looking for. On windows, err.... also Lame and a bit of scripting

Of course, the main problem (especially timewise) is ripping, not encoding.

Good Luck!

Dragi "Bonzi" Raos
Zagreb, Croatia
Q#5196, MkII#80000376, 18GB green

I believe the fhg codec truncates most sound above 16khz, especially if you are encoding with a 128 bit rate. That may be part of the reason the music sounds strange. If you think the JS algorithm is causing the problem, then please try encoding the file from the original wav using lame 3.88. JS in lame sounds much better to me. You may want to try EAC, it has a secure ripping mode which will read the cd over and over again until it reads successfully. It will create a wav then encode it using lame if you tell it to. Another ripper option is audiograbber, its not a giant fancy program like MM but it will do the job of ripping to wav and sending to an encoder.

Don't try to take the mp3s and turn them back into wavs, you will lose quailty in the process, and if you are right about the stereo imaging, its gone. You will have to re rip from the original cd in order to encode to mp3 with the results you want. Sorry if its not the answer you were looking for, but encoding to mp3 should be considered a one way road.

If you need help setting anything up, just drop me a message.

Sean

I've specifically encoded the songs off CD in Stereo, Joint Stereo, and Dual Stereo... and the Joint sounds like ass. I am using the Radium packaged Fraunholfer codec ripping from my CDs in a SCSI cd-rom.

dunno what else could cause that so much.

(btw... i realized what i said about inflating to wave and then re-encoding after i posted... yes, i now see how that wouldn't work... thanks for pointing that out.)

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

I've specifically encoded the songs off CD in Stereo, Joint Stereo, and Dual Stereo... and the Joint sounds like ass.

Okay, good test, but you didn't say some other important pieces of information that would help us narrow down the problem:

- What bit rates are we talking about here?

- Did you ever compare the ripped WAV file (before encoding) to the CD to make sure that it's not simply errors in the rip?

- What exactly are the problems you're hearing? Can you name a specific passage in a specific track (preferably a popular one that we all would have) that demonstrates the problem?

The different encoding methods might simply be amplifying a problem that's coming from the ripping software/hardware combination. And higher bit rates will tend to improve the quality more than Joint versus Stereo.

___________
Tony Fabris

It sounds like maybe the bit rate you are using is too low, especially if you are using cbr.

i encode at 160 bitrate...

an example song is Steppenwolf's The Pusher (easy rider soundtrack) it makes use of a lot of heavy stereophonic mixing, especially in the beginning. (guitar only in left channel... cymbals only in right, etc)

i'll try to post my audio test clips somewhere soon as i dig 'em up. (i may have deleted them after emploding them to the empeg)

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

I don't have that track specifically, but in case someone else does, can you describe the exact problems you hear?

___________
Tony Fabris

right near the beginning of the track there is heavy usage of stereophonic editing... the right speaker has none of the lead guitar and just a subtle percussion track. however, when played with Joint Stereo encoding, my empeg outputs a garbled version of the guitar out of the right channel, along with horribly distorted cymbal sounds.

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

To me, this doesn't sound like normal behavior for an encoder at all. Especially at 160kbps. This shouldn't happen at all, and even at very low bitrates this sort of thing shouldn't happen to a degree as extreme as you've described.

I think that you've got more problems, above and beyond the choice between Joint and True stereo encoding.

Perhaps there's something wrong with the codec, or maybe it's not set to "high quality" (some codecs have a speed-versus-quality choice you need to make).

And I still suspect that the problem might lie in the ripping stage rather than the encoding stage. Have you checked the raw wave file to make sure it's not hosed?

Also, have you tried other encoders/rippers?

___________
Tony Fabris

i am retrying soon with the latest Fraunholfer codec and i am double-checking the settings this time to make sure they are all at the highest quality.

the source wav file comes from ripping right from CD using a SCSI cd-rom drive. (matsushita, specifically)

thanks everyone for all the advice, i'm sure that the second time around will be flawless.

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

the source wav file comes from ripping right from CD using a SCSI cd-rom drive. (matsushita, specifically)

But you didn't say whether you listened to the wav file to make sure it was correct before you encoded it? That would narrow the problem down to either the rip or the encode.


___________
Tony Fabris

I'm suspecting Dixieland has found the problem right there and is afraid we'll all laugh at him if he told us... Come on, tell us, did you listen to the WAV and is it OK?
I'm occasionally experiencing cut-off MP3's when I hear them for the first time in the car. The track time is ok, but a bit of the end isn't there. When I then go back to the WAV (if it's still on my harddisk) it sounds ok. Thus while encoding (Feurio! with LAME dll 3.88beta) sometimes it goes wrong. Oh well, it has just happened to me twice...
Concerning the ripping... I use two Plextor burners (12432S & 121032S) that produce excellent results. The burn app Feurio, which is specialised in audio CDs, reports when there were rip-errors/warnings. In this case you always end up with 'clean' WAVs.

Edwin de Vaan
mk2 rev.7 Trillian # 080000263 6Gb blue/red

i must have missed something... i thought that i said a while back that it certainly wasn't the WAV. i tested that first. also, i fail to see how it could be the wav, considering that i can specifically manipulate the encoding process to introduce the noise or to prevent the noise.

CD to WAV
WAV == perfect

WAV to stereo MP3
MP3 == perfect

WAV to joint stereo MP3
MP3 == shitty

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348

I'm occasionally experiencing cut-off MP3's when I hear them for the first time in the car. The track time is ok, but a bit of the end isn't there. When I then go back to the WAV (if it's still on my harddisk) it sounds ok.

I believe this is actually a known problem with the current player software which will be fixed in 1.1 (like everything else ). 1.1 has a new mp3 decoder, from ARM I believe.

(list 6284, Mk1 S/N 00299 4GB blue [for sale]. Mk2 S/N 080000094 6GB blue)

Okay, then. As long as you're sure about that, then it's time to look for a different encoder, or (as you said), update the current encoder to its most recent version and check your quality settings.

Have you tried LAME? I have had good results using high-quality variable bit rate encoding with both the LAME and Xing encoders.

The problems you describe shouldn't happen even with Joint Stereo encoding, provided the encoder is behaving itself.

The reaon I say you should use Joint Stereo if possible, is because it makes a more efficient use of the bits and allows higher quality within a given bit rate.

___________
Tony Fabris

I'm occasionally experiencing cut-off MP3's when I hear them for the first time in the car.
I believe this is actually a known problem with the current player software

As far as I know, the released 1.0x software has no problems with cutting off tracks. This is what would be considered a "show stopper", and I don't thing empeg/rio would publicly release software that had a problem like this

I think if he's getting cut off tracks, it's not the car player software that's at fault.

___________
Tony Fabris

...you should use Joint Stereo if possible, is because it makes a more efficient use of the bits...

But only if the material is not 'very much stereo', i.e. the difference of channels is small compared to their sum, IIUC. That wouldn't be the case in Dixieland's example. That said, I never noticed problems with joint stereo encoding myself, even on albums by artists who occasionally use quite drastic stereo seperation (e.g. Tomita, Rick Wakeman, Walter/Wendy Carlos, Pink Floyd).

Dragi "Bonzi" Raos
Zagreb, Croatia
Q#5196, MkII#80000376, 18GB green

Try another encoder.

Sean

I think if he's getting cut off tracks, it's not the car player software that's at fault.

You're right, the problem lies in the MP3 files themselves, forgot to explicitly mention that. If I play the MP3 on the PC the same error occurs. Thus, the encoder is at fault. Then again, encoding the WAV for the second time goes without flaws.

Edwin de Vaan
mk2 rev.7 Trillian # 080000263 6Gb blue/red