On Sunday, 4 January 2026 12:42:45 Greenwich Mean Time Nuno Silva wrote: > On 2026-01-04, Michael wrote: > > On Saturday, 3 January 2026 16:44:56 Greenwich Mean Time Alan Mackenzie wrote: > >> On Fri, Jan 02, 2026 at 15:44:06 +0000, Alan Mackenzie wrote: > >> > On Fri, Jan 02, 2026 at 10:43:05 +0000, Michael wrote: > >> > > On Thursday, 1 January 2026 21:46:27 Greenwich Mean Time Alan > >> > > Mackenzie > > > > wrote: > >> > > > Hello, Gentoo. > >> > > > > >> > > > Happy New Year! > >> > > > > >> > > > On my (no longer quite so) new PC, I've still not managed to get > >> > > > audio > >> > > > CDs to play properly. Originally I was using the program aqualung, > >> > > > but > >> > > > that gave a constant crackle on top of the music, making it > >> > > > unusable. > >> > > > (But it was fine on my old PC.) > >> > > > > >> > > > I've since moved to deadbeef (officially called DeaDBeeF), which > >> > > > though > >> > > > much better is still not right. What I get now on playing a CD is: > >> > > > (i) the first track of the CD gets ~6 seconds of crackle at the > >> > > > start; > >> > > > (ii) at each subsequent track (regardless of whether there are any > >> > > > actual > >> > > > > >> > > > gaps between the tracks) there is about 2 seconds of crackle at > >> > > > the > >> > > > beginning; > >> > > > > >> > > > (iii) if I pause the playback and restart it, there is no extra > >> > > > crackle; > >> > > > (iv) on moving the playback to a random part of the track, I get > >> > > > the > >> > > > ~6 > >> > > > > >> > > > seconds of crackle; > >> > > > > >> > > > (v) there are random moments of crackle in the middle of tracks, > >> > > > too, > >> > > > > >> > > > often ~6 seconds after an audible drive head movement. > >> > >> [ .... ] > >> > >> > I think I am just going to buy a new drive. At ~25 Euros, it's just > >> > not > >> > worthwhile trying all these things on the current one. > >> > >> Well, I've bought and installed a new drive (made by ASUS) and it hasn't > >> helped in the slightest. :-( > >> > >> Maybe modern DVD drives just aren't capable of reading audio CDs > >> properly. After moving the read head to some position on the CD, it's > >> necessary to start reading the sectors accurately straight away. Maybe > >> these newer drives positioning of the heads leaves them wobbling, or > >> something, and rely on software error correction to reread erroneous > >> sectors. On playing an audio CD, I don't think sectors get reread at > >> all, just erroneous values get transmitted to the DAC. > >> > >> Or something like that. > >> > >> [ .... ] > >> > >> > Maybe I'll get this sorted out in the next week, or so. Thanks again. > >> > >> Or, maybe not. :-( > > > > Unless I've misunderstood something, through a process of elimination you > > have concluded your audio CD crackling problem and DVD sector reading > > problem is caused by the drive itself. Your old PC DVD drive exhibits no > > such problem, but the new PC's DVD drive and the ASUS replacement you > > just bought both show the same symptoms. > > > > In your process of elimination, did you also replace the DVD drive cable > > on > > the new PC? > > > > Is the audio CD crackling evident both on new (factory recorded) audio CDs > > and writeable CDs you burned yourself? If the latter, did you try more > > expensive disc brands and different (slower & then higher) burn speeds to > > see if the crackling goes away? > > > > Another trick which may work is to increase the cache size on the media > > player, e.g. 2x, 4x, 8x. It should give more time for the drive to > > perform > > its error correction gymnastics and hopefully overcome any media error. > > > > The crackling/reading problem at the start of CD/DVDs can happen because > > of > > light scatter from the transparent edge to the initial data tracks. I > > recall reading somewhere if you use a black marker pen at the back of the > > transparent region, you can fix this problem. The difference between old > > and new PC drives could be related to cheap-ification in components, > > lower energy laser, etc. > > > > If the new drive doesn't address your problem, hopefully you should be > > able to return it. > > I'm not even sure what's the current state of affairs with drives > playing CD-DA themselves, but: > > This is all with playback outside the drive? (That is, reading the CD-DA > data and playing it.) Or is there any chance part of the problem is when > the drives themselves read and play the CD? (I.e. audio output from the > drive to the sound card. - But is playback speed (which you've > mentioned) something that can be changed in this kind of playback?) > > (Also, doesn't CD-DA have some amount of error correction data?)
I don't know much about the details of error correction mechanism, but as far as I know the (linear) data read speed is constant. This means as the audio CD is read from the centre to the outer tracks the physical rotational speed ought to slow down. >From what I have observed with some 'faulty' CDs here, a larger buffer will allow more time for the error-correction data and initial music data to be read into the buffer, verified, re-read/corrected and eventually submitted to the DAC, before the next ECC/data block is read and processed. More time available (larger cache) ought to improve this process, and less time would probably hinder it. I have observed problematic CDs take longer scanning and rescanning the start of the track before they start playing it. In my experience this applies both to audio and data CDs. However, if there are no differences between media player software and cache settings used on two different hardware (old PC Vs new PC), then logically the hardware becomes suspect.
signature.asc
Description: This is a digitally signed message part.
