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Dumb question (for various reasons, I can't listen to the file at the moment). Were these cassettes all recorded on small mono portable machines? Tapes made on these almost always have a crackly or noisy right channel when played back on good decks and in stereo. The solution here is simply to play only the left channel. dl Mike Hirst wrote: > Thanks Richard, > > your advice is, as ever, well informed sagely and intelligent. I suspect > that I'm not going to find a definitives answer here, but for your > interest, and for anyone else who may be interested, I've posted a 10sec > (wav) clip of the kind of crackle I'm hearing. this sort of thing will > continue through the full length of the recording and can be heard when > the tape is played back using multiple recorders, all of which have been > tested using other tapes, which exhibit no such problems. > > http://www.mikehirst.netfirms.com/audio/rhclick.wav > > filesize= 1392640 byte(s) > riffsize= 1764036 byte(s) > format = Straight-PCM > channel = 2 > depth = 16 bit(s) > blk.size= 4 byte(s) > smp.rate= 44100 Hz > samples = 441000 > playtime= 0:10.010 > > you will note from the clip that the crackle can only be heard in the rh > channel. this is typical of the phenomenon, but it can sometimes be > heard in both channels (with a bias towards the rh ch). > > I have experimented with some of the de-crackle filters I use when > working with disc transfers and as Richard suggests, the crackle can be > removed, I am however curious as to where the crackle comes from. > > Richard L. Hess wrote: >> Hello, Mike, >> >> Tom Fine has already posted a number of good explanations. >> >> There are, however, less-common explanations that you may wish to be >> aware of, just in case. >> >> (1) If there is a mismatch between the record machine record and erase >> head track position, perturbations in the record bias and/or erase MAY >> print to a tape like this. DC-(i.e. permanent magnet) erase may also >> cause something like this, but it is usually more of a "burbling" or >> what is sometimes called "rocks". >> >> (2) Static electricity and PLAYBACK machine "glitches" CAN print to a >> tape without the recorder being in record mode. It's uncommon >> (thankfully), but it can happen. Static can be generated by fast >> winding in a very dry environment, and depends on cassette materials >> including the shell and slip sheets. This is more prevalent with reels >> than cassettes. >> >> This clicks can usually be removed (depending on their source) by a >> declick/decrackle plug-in for your favourite DAW. The Magix >> restoration tools version of this is the best I've yet owned, but I >> haven't owned either DC7 nor the high-end Algorithmix version. >> >> At 08:53 AM 2008-09-18, Mike Hirst >>> Here's a thing that's been confusing me for some time. I have spent >>> the past six months working my way through a large number of cassette >>> tapes mostly recorded between 1985 and 1995. every now and again I >>> notice light, but significant crackling. This is often more >>> noticeable in the right channel, but not exclusively so. On some >>> recordings this is louder, on most recordings this is not evident at >>> all. This is not restricted to any one brand of cassette, nor is it >>> associated with any one playback machine and/or soundcard. Can anyone >>> explain this for me? >> >> Richard L. Hess email: [log in to unmask] >> Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX >> Detailed contact information: http://www.richardhess.com/tape/contact.htm >> Quality tape transfers -- even from hard-to-play tapes. >> >