clipping waveform from CD line out!

[tschrama]

Hi

Just a idea but I did this:

made a audio CD with some test-tracks with 'goldwave' software to test my DACs.... some -90dB, -60dB, -20dB and 0dB tones, some squares (really square), etc etc ... The 0dB tone reveiled that the CD-rom (analog out this time) clipped assymmetrical... this was not the case with my DACs or CD-players... so it must have been the output stage of the CD-rom...

Maybe you could do the same thing to see what is really happening...

Regards,
Thijs

[bqc]

Thanks all for your replies. For those who could not see the
clipping waveform, I appologize for the fuzzy pictures. The pictures
I took was high res, but the forum software limits the size of the
of the image file so I had to resize it and losing resolution in
the process. The clipped waveform I am referring to in the first
picture is the one in the middle, the tallest waveform has a
flat top instead of rounded. The one in the 2nd picture is
also in the middle and extended all the way to near the top
of the picture , it also has somewhat wavy flat top.

[nar]

For me it was very clear . Thanks bqc

[catrafter]

Check out the Jayhawks - Rainy Day Music cd. Nearly the whole cd is recorded well into clipping. Ethan Johns should know better!

[mrfeedback]

I once said to a muso friend "Your cd is full of digital clipping" and he replied "That's good isn't it ?!!!"

Even this one is full of digital clipping...

Eric.

[jeff mai]

Nothing unusual here. I have analyzed some discs using Cool Edit and found literally *thousands* of instances of digital clipping on one three minute track! Also some CDs are compressed so severely that the average signal level is -4db relative to max signal!

This is a result of the current "louder is better" view of many artists and record companies. Mastering engineers who refuse to do this sort of butchery will soon find themselves with no work.

[purplepeople]

So, now what? Do we have to figure out how to make speakers that can deliver DC?

:)ensen.

[tschrama]

I did the same test with Billy Corgan's CD of his new group 'Zwan' ..

I suspected him to manipulate the hell out of it sound-production wize .... but behold: the 4th track does reach the highest or second highest sample-value many times, but no longer than one or a couple of samples long.. I wouldn't wory too much ... how about a classical music recording.....


so no DC-reproduction needed yet


Regards,
Thijs


PS
when I practise guitar, on overdriven tube amp offcourse, my dynamic range probably is less that 4 dB.....

[jeff mai]

Originally posted by tschrama
when I practise guitar, on overdriven tube amp offcourse, my dynamic range probably is less that 4 dB.....

The release in question did not have an overdriven guitar in it. It wasn't head banging metal or loud rap. It should have had a much more normal dynamic range.

[eplpwr]

It's interesting to see that others also have experienced the problems with digital clipping... About a year ago I upgraded from some cheap consumer stuff to DIY tri-amped speakers & amp. I was really happy with my new system, but after a while I noticed that there seemed to be a problem, i e bad electrical contact, to my tweeters, since certain music produced harsh "chirp" sounds. What I found out many troubleshooting hours later was that this is the distinct sound of digital clipping.

Recently I bought a decent soundcard for my PC, RME DIGI 96, and with this card comes some pretty amazing piece of software called "Digicheck". With this software I can now view peak, RMS, crest values et al for a digital source, and also look at something called a "Goniometer" which makes it very easy to see which recordings that are bad; the recordings that make my tweeters sound awful are the same that show clear signs of digital clipping.

Although there are exceptions, I'd say that when it comes to mainstream music, the newer the recording, the worse the sound. I've seen examples where the maximum level was -0.1 db, but this was nothing else that clipping at 0.1 db below the CD:s max limit, probably some lousy engineer had some equipment limiting the max amplitude to -0.1 db and thought that by using it he would never run in to clipping problems.

Unfortunately, I don't know of any way to figure out the sound quality of a recording other that buying it, and I think that trying to return a CD to a store claiming digital clipping as the defect, would just make the salesperson think that I was the defect one...

BTW: My tweeters are Vifa D25AG-35-06's. The recording that
clips at -0.1 db is "The Brand New Heavies: Shelter".