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Friday, January 13, 2012

Preserving your memories V - Magnetic Tape



Magnetic tape was and still is is a wonderfully versatile and fascinating medium. It wears well and will last decades if properly cared for and stored. Unfortunately all tape is not created equal and as a result some of the audio or video tape you have on your shelf might being dying a slow death and you don't even know about it.

Tape is essentially a very thin ribbon that has a magnetic oxide glued to it with what they call a binder. Over time and with mechanical wear this binding agent will dry, harden, start to deteriorate and flake off. The result is you start losing the oxide that has your sound print on it resulting in signal dropouts.  This decay can also start to contaminate playback heads, dirty and glaze rollers and guides and generally start causing more playback problems. In VHS and Beta machines it can actually start to leave visible piles of residue under the tape path.

Quality media will last longer but over the years a lot of cheap tape has been dumped on the marketplace. I have some broadcast reel to reel tapes that are over forty years old. They are still pliable and recordable. On the other hand I have customers bring in cheap VHS cassettes that were recorded ten years ago that are already exhibiting age and visible dropouts.

What is important is this. If you have memories on audio or video tape there is no time like the present to preserve them by dumping them to digital media files.

There are two really good reasons for doing this. 

First, the old stuff is analog. This means that every time you make a copy of it there is loss of quality. Making it into a digital file stops this degradation process. All things being equal (and depending on what software you use), there is no detectable loss in editing and manipulating digital files.

Second, while disc media does not deteriorate as fast as magnetic media, it will last much longer and is more robust. It is impervious to magnetic fields, is smaller and easier to store and it will outlast you if properly cared for. The thing that can damage it is strong light and of course, deep scratches. The one caveat here is quality. At my studio, I could buy media that is as much as fifty percent cheaper than what I pay. I don't. I buy the best media I can buy for mastering and duplicating because it is better quality and will last much, much longer. Saving a few pennies on any media is a false economy that you will end up paying for eventually.

So let's talk about audio tape preservation.

Reel to Reel Tape
Reel to reels generally transfer quite well but a lot depends on the recording speed. The lower consumer speeds generally are pretty muddy with very little in the way of high or low frequencies. The other problem is running time. With so many tape lengths and different speeds available it is hard to know how long your reels will run before actually running them. The time chart below shows the consumer tape speeds and will give you an idea of the variables. To make CD's from large slow playing reels necessitates breaking up the digital file to a length that will be accommodated by the maximum recordable time on a CD. (Approximately 70 minutes)

Approximate Running Time Per Track
* ips = Inches Per Second)
Length/Speed 1 7/8 ips* 3 3/4 ips 7 1/2 ips
300 feet 30 min. 15 min. 7.5 min.
600 feet 60 min. 30 min. 15 min.
900 feet 90 min. 45 min. 22 min.


Approximate Time recorded on both sides of tape
Speed/Length 150 ft. 300 ft. 600 ft. 900 ft. 1200 ft 1800 ft. 2400 ft. 3600 ft.
1 7/8 ips* 30 min. 1 hr. 2 hrs. 3 hrs. 4 hrs. 6 hrs. 8 hrs. 12 hrs.
3 3/4 ips 15 min. 30 min. 1 hr. 1.5 hrs. 2 hrs. 3 hrs. 4 hrs. 6 hrs.
7 1/2 ips 7.5 min. 15 min. 30 min. 45 min. 1 hr. 1.5 hrs. 2 hrs. 3 hrs.
Approximate Time recorded on both sides of tape
Number of CD's required
Speed/Length 150 ft. 300 ft. 600 ft. 900 ft. 1200 ft 1800 ft. 2400 ft. 3600 ft.
1 7/8 ips* 1 CD 1 CD 2 CD's 3 CD's 3 CD's 5 CD's 6 CD's 9 CD's
3 3/4 ips 1 CD 1 CD 1 CD 2 CD's 2 CD's 3 CD's 3 CD's 5 Cd's
7 1/2 ips 1 CD 1 CD 1 CD 1 CD 1 CD 2 CD's 2 CD's 3 CD's


The most economical way to do this is to capture the entire reel as one file and then subdivide it as an edit later. As in the case of preserving records you may need to process and EQ the files before burning them to CD's.

Audio Cassettes
Audio Cassettes are a little easier to process as there is a standard speed and tape lengths are generally noted on the cassette shell or label.
Here again, it is more economical to record a whole side and then use the editing software to break it down to individual tracks. This is pretty easy to do as most editing software gives you a visual representation of the recorded sounds as a waveform. You can spot the breaks by looking where the wave form drops on the timeline. You simply  highlight the track, then copy and  paste the selection to a new file.
Remember to save your work often.

8 Track Tapes
Same as above. They will be a little tricky in that you may have to search for the first track. In reality you can start anywhere and re-order the tracks later.
The big problem here is finding someone who has a working 8 track. I have one but to date nobody has ever bought one to me for transfer.

Other Formats
There are other what I call fringe formats available (such as micro cassettes). I have only talked about the most common formats that I see at my studio every day.

Here is a word to the wise. There's a substantial investment of time, money and learning for you to preserve your precious audio. What you have to decide is whether you have the time to learn and experiment in order to get the desired results.
If you have a ton of stuff and you are a real do it yourselfer, then research what equipment and software you need and buy it.  Lock yourself away with your computer and have fun.

If you only have a few reels, albums or cassettes don't bother. Find a professional and pay to have it done properly.

In future articles we will talk about video tape preservation.


Thanks for reading. Remember, if you have questions or comments please feel free to add them. Also keep in mind that KEMEdia Studios offer these transfers services should you require them.



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Mike Reid can be heard approximately once a month on the Dave Fisher Show, weekends on CJAD 800 in Montreal. Mike and Dave talk about technology and new directions during these ten minute spots.

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