When old recordings were released on CD in the 80s and early 90s they were often just a flat copy of the original master tape, with no thought of how the tape may have aged in the past 10-20 years. Obviously there was no dynamic compression either . Analogue tape tends to lose its frequency extremes with age, the bass and treble simply fades away (print through can also be a problem).

Today shop bought remastered CDs are a big gamble, and not always available, so I have been remastering some of my old AAD CDs at home with positive results.
The original master tape would have had test tones at 30Hz, 1KHz, and 10KHz?

It would help me if anyone knows the theoretical frequency response of a 10 year old analogue tape. Where does the tape start to Roll Off? 3dB down at 25Hz & 16 KHz etc?

Thanks.



PS Going away for a few days next week so it may be a few days for me to reply.

I'm interested in your remastering processes. I've been shying away from newer remasters...I've found some older releases that brag about being a pure flat copy+dither, and while they don't sound broken like the newer releases, they do sound like they could use a little work. In any case, I bought them because the sound of old tape was light years beyond overprocessed junk.

Shopping around on iTunes is an interesting experience. Sometimes you can find the original release, and two or three different remasters, and most of the time the samples are from the same portion of the song, making comparisons easy. The original usually sounds like tape, while each successive remaster sounds louder, and often clips. Occasionally the mix seems different; the drums stop fitting the mix like they used to(i.e. they pop out of the analog tape sound, while the rest of the instruments stay inside it). I found one case where the master tape was played back at slightly different speeds on different releases. Talk about sloppy!

Blue Öyster Cult - (Don't Fear) the Reaper (lots of remasters)
Squeeze - Tempted (I believe different versions are played back at different speeds, I seem to remember the drums 'poping out' of the tape sounding mix on some of the remasters)
(Album) Counting Crows - Counting Crows: Films About Ghosts- The Best of... (heard this the other day, much newer source, probably not even analog, but a good example of using iTunes to compare remasters. The drums just don't sound right in this remaster compared to the original albums)

I found those the other day. Some of The Police remasters come to mind as good iTunes examples too, but I don't recall which(again, the drums were the biggies there). There used to be a perl script that allowed you to download the sample AACs(with no protection), which made ABXing them easy.

I didnt want to hear that about the Counting Crows, I will have to look out for all the originals now. I thought that Hanginaround on Films about Ghosts sounded a bit distorted.

Remastering is only needed on a few CDs from the 80's and early 90s where the original master has lost its edge from being stored for 10-20 years. Very little needs to be done for a big improvement as long as they used a decent master on the original CD.
A gentle slope from 8 KHz upwards giving a maximum gain of 1.5 dB at 20KHz often does the trick on muffled CDs, a further boost at 18KHz can also help. At the other end a very slight bass lift around 20-30 Hz. Each recording is slightly different, but a set preset on a digital EQ can be a useful starting point, often less is more. Make sure your using decent speakers.

Try listening to a later release from the same artist and compare.
As test tones aren't available on CDs I dont alter the speed (Except on a Sheryl crow Bootleg I once did).

Keep the originals as you may want to come back to these in the future.

My only experience is from working in the Hi-fi industry and my love for music. A recent hearing test showed I have excellent hearing so I am not compensating for that.

I am using B&W speakers that have a excellent frequency response.

You may wish to read this article by Steve Hoffman: Lesson 1: Equalization.