JonW

Anyone know what the difference (if any) is in sound quality between a CD track and an MP3 version of the same?

Some of the CD Jukebox style supliers are saying thet the quality is the same but ive heard rumours that MP3 isnt up to the job....

Jon.

john banks

Several factors are important. Firstly the quality of the encoding of the MP3 and secondly the bit rate. I can notice the difference between 128kbps MP3 and CD, but 192kbps seems very good to me. Also depends on the quality of the DAC, amplifiers, interconnects, speaker wire, speakers and listening environment. For medium budget ICE, I think 192kbps would be my preferred bit-rate. If you have nice equipment, try 256kbps and see what you think. 128kbps definitely sounds less detailed though - I suppose to my ears like putting a CD onto a chrome tape with a reasonable deck, but it is not like metal on a good deck, which to me sounds as good as CD. My wife thinks my ears are fussy, but I seem to tolerate cheaper equipment better than some folk on here

You can try the MP3 experiment yourself if you have a CDR writer. Take a digital copy of a CD and write it at 96, 128, 192 and 256kbps using one of the many encoders on the internet. Then decode it to a 16bit stereo 44.1KHz wav and write it to CD. Then go play in your lounge system, your car, and it will give you the rough idea of what rate you need and whether you like it. Certainly I prefer the sound of minidisc to 128kbps MP3, but that is partly the compression algorithms used.

Maybe one of our sound engineers will comment...

john banks

Cop a load of these:
1.

Andy Tang

iTrader: (3)

I was just going to add, MP3 is a compression format, so you will expect there be some loss in sound quality!

I was told that the losses are at the very top end and very bottom end of the sound scale, so it shouldn't be too noticeable.

That said I think John's idea would actually give you an idea of sound quality!

Andy

JonW

Wow, Cheers John! Absolutely loads of top info there... Nick, you may want to put some of this in the FAQ as even tho the debate will run and run the funsamentals are the same, ie. Quality depends on encoder and bit rate.

From what I can see I agree with John that 192kbps seems reasonable as 256 would eat too much space and 128 hasnt the quality.

Personally I dont have a burner to do the tests and what I was trying to ascertian is wether to spend my money on a CD Jukebox style machine to replace my Sony headunit and CD changer in my car. Bit of an expensive mistake if I just bought and found the quality lacking...

John, thanks again mate, top info. Jon.

john banks

What does you box run Nick?

ScoobyDoo555

Hmmm, as people will know, I'm NOT a fan of MP3. For various reasons :-

1. As it uses a form of data compression, it will NEVER sound as good as the real deal.

Yes, I'm aware that MD has data compression, but LISTEN to it. Subjective, I know, but it SOUNDS good IMHO - sounds clear, but almost 'analogue'...... MP3 definitely doesn't.

2. You have rely on someone (who may not have the audio knowledge nor the proper capabilities) to upload the track in the first place.

3. That little matter of COPYRIGHT I'm a producer and artist in my own right. It p1sses me off that little ******* are stealing my music. Period.

4. You need high end gear / Head unit to get decent quality.

All this said, in theory, it should be the perfect format for the car - bearing in mind most of us have a 2litre turbo in front of us, loads of road noise, and loud exhausts....

Minidisc or CDr are still the way forward - at least when you get to your destination, you can take the music with you. For those who say "you can take the hard drive with you" - get a life. Who wants to take a hard drive to a party or your mates!!!!!!

John - couldn't have put it better meyself.

Andy - the same theory applies to CD/Digital. A theory called Nyquist Theory. This dictates that the sample reate should be at LEAST twice the highest audible frequency - i.e 20Khz, hence CDs are recorded @ 44.1KHz. HOWEVER, John will back me up on this, there are transients and harmonics ABOVE 20KHz that affect the audible frequecny spectrum (20Hz - 20KHz), therefore the lower the sample rate the less frequencies will be reproduced.

This is VERY noticeable - audible loss of top and bottom end.

Don't even want to start on ALIASING noise!!


However, like I said earlier, bear in mind it's for the car. Nuff said.

Dan (sound engineer ))

oh yeh, BTW, you may have heard rumours of MP4 - no such thing. It will never happen. People tend to get it confused with MPEG4..... just an extra bit of useless info....

Edited for the hell of it!!

[This message has been edited by ScoobyDoo555 (edited 02 August 2001).]

Dr Hu

I bought a Kenwood MP3 player for my Impreza.

It rocks! - I rip my CD's so they stay at home for the good stereo in the lounge and the CD-Rs are used in the car where they will invariably get trashed. I encode using 128Kb's and I cannot tell the difference. A car is a very 'dirty' audio enviroment anyway - I'd defy anybody to tell the difference between MP3 and CD when you are actually driving along - stationary maybe yes - driving no way!.

If you're extra fussy rip at 192Kb's - No on gods earth would you tell then - unless you are a serious Audiophile - which I am not.

You can get about 12 albums on a CD-R at 128Kb's - so I don't even have a changer - don't need one

just my tuppence worth........

john banks

Dan - no disclaimers - someone might sue you 128-192kbps really does sound the sensible range. It will be nice when 24 bit 96KHz becomes mainstream - less quantisation and all the harmonics you could dream of up to 48KHz. I wish they'd sort the formats out though - whether it is SACD or DVDA.

But lets get real - only folk with Linn stuff or similar (no names ScoobyDoc) will notice. For a car I think Dr Hu has it sensible.

ScoobyDoo555

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by john banks:
<B>Dan - no disclaimers - someone might sue you [/quote]


Yeh, unfortunately I won't mention artists, etc. You know who you are. Just think it's bang out of order. &lt;gets his coat, picks up his keys "sh1te, no scoob..." puts 'em back in his pocket......&gt;

john banks

Don't worry m8 you'll be Scoobying again b4 you know it. Would a 4 door be easier for your ICE????? Common perhaps? LOL.... Flame suit and fire extinguisher ready....

ScoobyDoo555

Nah M8 - the thought of having to pull that bloody parcel shelf assembly out doesn't bear thinking about!!

Dan

Bagpuss

I've said it before, but I guess it doesn't hurt to say it again. Check out

chiark

Good points here, and I'll add something into the FAQ. Today is a nightmare day work-wise, but it'll get there...

My MP3 player is using rxaudio, which is part of the XAudio SDK - it's a command line version with console input/output, so is ideal to be controlled from PERL. OS is Linux (RedHat 7, though that's pretty bloated), 32MB memory, 6GB disc and a P90 processor. Soundcard is SB Live! 1024.

Nick.

druddle

Dr Hu you have mail..........

merlin

I bought the Kenwood mp3 player and have never had any regrets... Just wish it had come out a few years ago. 10 hours of music off one CDR rocks...

Before getting seriously into mp3s, I did the test suggested by John Banks (encoding some music to a range of mp3 bitrates along with the uncompressed version and burning them to an audio CDR) Playing back the results on a Naim system (expensive) in the lounge, I couldn't tell if I was listening to an mp3 version or the original with mp3 bitrates from 160kbps+. At 128kbps I could tell that it was a mp3. In the car I'm sure that 128kbps would be fine given all the background noise.

JonW

Bagpuss - Great to find someone who's bought one of the units I was looking at. Cant see a 40Gb unit listed on the website but assume it was pretty big money... Also just noticed that Empeg's web site lists prices Ex VAT... :-(

Has anyone compared this unit to the MStation either in a mag or by personal listening?

Mstation is only GBP 539 for 10Gb and the same by Rio would set me back GBP 899...

Jon.

Bagpuss

Jon,

I've replied to you in e-mail, rather than clog up the thread.

Andy.

JonW

Andy,

Ta for those, still reading links, will get back to you off list... cheers,

Jon.

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