Hi forum...

I'm a newbie here and trying to get some advice about which format to use the most for DJing, as I have stopped collecting vinyl. I plan to spin with CD players and many players today will let you spin MP3s.

Here's where I'm undecided...I have music on audio CDs (.cdda format) and in MP3 format. I know that I'll continue to purchase CDs and MP3s.

My questions are:

1) For the MP3s I have, how should I archive them, meaning, should I normalize them all and then burn them to CD-Rs in .cdda format or in .mp3 format?

I assume that if I make audio CDs out of the MP3s that the sound quality will NOT get any better than they already are.

2) As for my audio CDs, should I convert what I have to MP3 format or just leave them as is and use them the way they are?

3) Or, should I just leave my audio CDs alone, use them as-is and just concentrate on archiving my MP3 files?

Overall, I want to make sure my music sounds great (sonically) and do the best I can in efficiently archiving everything.

I appreciate all advice. Thanks!

1. Keep songs that are already mp3 as mp3 (unless you have the original CD). Creating audio CDs will just waste space, if you do mp3 -> audio CD -> mp3 conversion you'll lose quality. Using mp3gain to get maximum volume without clipping (lossless volume change) might be a good idea.

2./3. Depends on *
__________
* If you want to use a CD player capable of mp3 playback it's a matter of taste. Do you want to carry a case with audio CDs and be sure of good quality or is a box of maybe 20 mp3-CDs enough?

You might want to look into using a laptop instead of a mp3-CD player. Then you could use superiour formats as Musepack (MPC) (better quality, better tagging, gapless playback ...) and store everything you need on HDD.

Hi tigre...Thanks for your advice and feedback!

Actually, I've thought about computer-based mixing and have tried a few DJing applications (both Mac and PC-based).

What I've found is that computer-based mixing does not feel "natural" to me as does mixing with CD players (or even turntables). So, I've concluded that CD players isn't a far deviation from TTs and would lessen the load. The players I'm purchasing can play both audio CDs and MP3s (Denon DN-S5000 model). However, I still don't know which format of these two will give me the better sound quality which is why I'm seeking help.

To make sure I understand you correctly, you're suggesting that I NOT make audio CDs from MP3s because I'd lose yet more audio quality, correct? (In other words, do NOT convert MP3s to .CDDA format in creating an audio CD?)

Again, my two concerns are, good audio quality and efficiency in archiving the music, with quality taking priority.

So now your suggestion would be...?

d2e_

What I meant was this:
If you make audio CDs from mp3s sound quality will stay exactly the same. Just make sure that you *NEVER* convert these CDs back to mp3. So backing up the "original" mp3s is recommendable.

About quality: using lame (vers. 3.90.2 or 3.92) and --alt-preset standard or higher for creating mp3s will give you quality without any noticable flaws. Only ppl who are trained to hear compression artifacts will be able to notice differences to the original in direct comparison of short passages. So if done properly mp3 is perfectly fine for DJing quality-wise.

Ah ok, I understand what you're saying now Tigre...but, I think I've confused you in all of my questioning. :)

Here's the overall thing I'm trying to decide upon first and foremost:

-whether creating audio CDs from my current MP3s is better (as far as sound quality is concerned) than just using my MP3s as they are now (taking into consideration some normalization and any other suggested edits to them)?

I had not planned on converting what's on my audio CDs to MP3 format because I'm under the impression that the audio CD is going to be far better quality than the MP3s I could make from the songs.

Quote:

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... whether creating audio CDs from my current MP3s is better (as far as sound quality is concerned) than just using my MP3s as they are now (taking into consideration some normalization and any other suggested edits to them)?

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Theoretically mp3s and CDs made from mp3s sound identical. But there are a few issues ...

- On music recorded on high level lossy encoding (e.g. mp3) can cause clipping that occurs in decoding step. If there is clipping in an mp3 file you can check using aforementioned mp3gain. Mp3gain can change the volume of mp3 files without any loss to avoid clipping. You might want to use this for all your mp3 files, no matter if you plan to play them back directly or burn them to audio CD-R.

- You never know how good the decoder of a hardwareplayer is. Possible problems I know of:
-- incompatibility with VBR, certain bitrates (e.g. 320kbps, <128kbps)
-- no decoding of high frequencies (>16kHz) or distortion/aliassing at those frequencies)
-- Truncation instead of dither used
Of course you can test the player you want to use to find out if it plays everything fine, but with converting mp3 to audio CD-R you have controll over these issues by using decent software for decoding.

- In theory mp3 data CDs have better error correction than audio CDs as data CDs contain an additional layer of error correcton information. Decent audio-CD players can correct/interpolate errors (e.g. caused by scratches) and make them inaudible while uncorrectable errors in mp3 data CDs will lead to annoying pops/glitches/skips.

The only + I see for mp3 is that you need to carry less CDs with you.

So I'd do this:
1. apply mp3gain to your mp3s if clipping is detected. You can even change all mp3s to the same (audible) volume (better than normalizing).
2. Decode using foobar2000's diskwriter with 16 bit dithered output to .wav (best decoding quality you can get)
http://foobar2000.hydrogenaudio.org
3. Burn .wavs to audio CD-R, decent media recommended.

(No - probably I'd use a laptop, keep the mp3s and convert my original CDs to mpc, but that's not an option for you).

BTW - me couri0us: What quality (bitrate, encoder used, VBR/CBR) are your purchased mp3s? What music style? Where did you buy them? Why did you buy mp3s (are they cheaper/downloadable/not available on CD)?

Wow Tigre, now THAT'S an answer! You have made my day. This info helped greatly, thanks...

Ok, I will go forth with your suggestion to: apply the edits to my MP3s, decode them to .wav using foobar2000, then create audio CD-Rs from the .wav files.

The two things I will need to find out now is:

-the best setting to use for my MP3s if clipping is found
and
-how to make them all the same volume.

To answer your questions, I have acquired MP3s from a variety of sources (purchased from eMusic.com, freebies from p2p sharing services and friends).

I've had the purchased MP3s from eMusic for awhile (Classic House music) and they are ALL 128kbps CBR files. However, I don't know the encoder eMmusic has used for these files and that info is not in the ID3 tags. Now eMusic sells VBR MP3s encoded with LAME 3.92, so something has definitely changed in their encoding process since getting mine.

From time to time, I'll buy files in .AAC format from the Apple iTunes Music Store.

Will this format be easy to convert to audio CD as well?

d2e

Quote:

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The two things I will need to find out now is:

-the best setting to use for my MP3s if clipping is found
and
-how to make them all the same volume.

---

At http://www.hydrogenaudio.org/index.php?act=ST&f=15&t=3274 you'll find useful information about mp3gain.

Quote:

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From time to time, I'll buy files in .AAC format from the Apple iTunes Music Store.

Will this format be easy to convert to audio CD as well?

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Yes. Foobar2000 can convert this format to .wav too. It has an integrated replaygain feature that works similar to mp3gain but works with AAC too (among other lossy compressed formats) IIRC. (Here's a thread about this: http://www.hydrogenaudio.org/index.php?act=ST&f=13&t=8789&hl=replaygain&s=652beedfd07268546170e8539390d03a)
If you need more information on clipping prevention/replaygain for AAC I suggest the FAQ and/or a search on http://www.hydrogenaudio.org (foobar2000 forum is a sub-forum of hydrogenaudio BTW).

Great, thanks again Tigre!