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Unit 2, 39 Enterprise Crescent Malaga WA 6090

 (08) 9375 3902

Postal Address:

ProCopy    Po Box 991,

Morley, WA. 6943

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Wednesday
Apr162014

World's First Public Recording of Music in 1936 on BASF Tape

Looking through our library of material we came across a recording presented to us on audio tape some years ago by BASF. We've recently digitised it and thought we'd relay the fascinating story of he world's first public recording on magnetic tape.

In 1934 BASF produced the world's first magnetic recording tape.

BASF the German chemical company and AEG were working together on a research programme into magnetic recording techniques - AEG was to produce a recording machine and BASF was to solve the problem of finding a suitable recording medium.

This idea for magnetic sound reproduction was first put forward as early as 1888 by an American engineer Oberlin Smith. His theory was to magnetise a sound carrier using an electromagnet so that it took on the rhythm of sound waves activating a membrane. When re-played the principle would work in reverse - the magnetic impulses creating electric currents again causing the membrane to oscillate and so become audible. He suggested using steel wire or strips of steel to transport the sound - or possibly cotton or silk threads impregnated with steel particles.

However technology at that time was not ready to put the theory in to practice. Experiments using steel wire and steel strips as sound carriers were tried out on the early recording machines of the 1900's by Danish physicist Valdemar Poulsen but they were tangled and the unwieldly steel strips tore. In order to mend them it was necessary to weld them back together which affected the magnetic properties of the tape and reproduced a loud crackle.

These problems were almost resolved when a recording machine using a paper based tape covered with fine particles of steel was invented by Dresden engineer Fritz Pfleumer in 1928. It was a major step forward but the paper proved too fragile to be practical. (You can see the paper base on this tape recently digitised at ProCopy)

BASF 1/4 inch paper based tape

1932 AEG chose to develop this new concept and in their research for the finest pure iron particles they approached BASF in Ludwigshafen. It was BASF's idea of substituting plastic as the base material of the recording medium that was the breakthrough and the principle has remained unchanged til today.

In 1934 the first 50,000 metres of BASF's newly developed tape were delivered to AEG to be used on their specially produced recorder the "Magnetophon". In 1935 the Magnetophon was presented at the Berlin Broadcasting exhibition with the tape. By now coated with the improved iron oxide particles and named "Magnetophonband Tape.

We recently had this come in to ProCopy for digitising, we estimate that it's from the late 1940s:

BASF Magnetophonband Tape

Sound reproduction techniques were becoming more sophisticated and the following year the London Philharmonic Orchestra conducted by Sir Thomas Beecham made the first public recording on magnetic tape at BASF in Ludwigshafen. The potential of the new medium was quickly realised and tape went on to be the basis for radio, film, television, music and computer industry for the next 70 years.

The following historic recording is preserved in BASFs company archives in Ludwigshafen. 

Tape recording 1936 in Ludswigshafen (W.Germany) - Featuring the London Philharmonic Orchestra conducted by Sir Thomas Beecham. W.A. Mozart - Meneutto from Symphony no.39 in E flat (dur 4:15). Followed by a modern recording of the same piece showing the improvements in recording mediums over time.

So how does this tie in with our recent digitising job? Well the paper based tape you see on the machine above was supplied in the Magnetophon tape box by the client, dating it to the 1930's - 1940's. We threaded up the machine and played back the tape to discover that it was (Sir) Robert Menzies, newly re-elected Prime Minister of Australia addressing the WA State Parliamant. This dates the recording to around 1949/50! History caught on some of the earliest tape recording technology - a fascinating find.

Want to discover what gems you've got hidden away? Drop in to our office and we'll assess your audio or film recordings for you. Or call us on 1300 4 PROCOPY we'd love to help with your next project.

 

Monday
Mar312014

Can you repair a CD Master with Distortion?

It's not always old analogue recordings that have problems. Digital recording has it's own issues and can highlight problems in the recording process even more than older analogue recordings that sometimes mask issues.

In this example we were provided a CD master for production that was digitally recorded, mixed and mastered and at some point problems have been introduced.

These problems with the CD master were first detected when we analysed the master prior to production, and after the analysis process we delved further in to the recording to see if we could do anything simple to rectify the problem.

The initial problem indicated E32 & Tracking Loss errors on the CD master and as these are considered "fatal errors" the production of bulk copies won't go ahead with these types of errors on a master. Here's a screenshot of the analyser report. (Learn more about CD errors here)

Once we saw the error report we decided to look in to the problems further to see if it was a disc burning issue or whether something else may be causing the issues. The CD master was loaded in to our audio editing suite so we could have a closer look and several problems were immediately detected. 

As can be seen on the following image this track had severe distortion on the left hand channel towards the end of the piece.  

The corresponding audio can be heard here, The audio problem sounds a bit like a faulty speaker on the left hand channel. 

  

This sound is usually caused in digital recordings when the safe operating levels are overloaded at some stage in the process causing the signal to be "clipped". It's a rather unpleasant sounding distortion for most people. 

The issue can be seen here on the zoomed in waveform, The flat top to the waveform is what is heard as distortion.

So notes were made and it was decided to process the audio to reduce this distortion rather than re- record, remix and re-master the CD. 

Unfortunately this wasn't the only problem, The horizontal line at the top of the right hand channel in the spectrograph below also caught our attention. Was it meant to be there? What exactly was it and what was causing this? 

Zooming around the area the cause of this anomaly is found. There is a series of oscilations above and below 17KHz. This type of problem can sometimes be caused with a faulty microphone cable where the earth connection or shielding may not be as good as possible and this allows electro-magnetic interference in to the recording chain.

While a lot of people can't hear these high frequency tones (they might impress your dog though!) it's better for them not to be in the audio so a series of filters was set up to remove them.

Checking other tracks on the CD and it was found there were other tracks with similar problems on both the left and right hand channels, some clicks and some more random distortion sounds, however the process used to remove them was pretty similar and the descision was made to repair the audio for each track and recompile. 

Here's an audio sample of the processed audio with the distortion reduced and oscilations removed.

And the waveform now shows more dynamics (variations in volume) where the edge of each chord has been restored by replacing the clipped portion of the waveform with a mathematical recreation of what should have been there in the first place.

After processing all the audio a new DDP master a CD master and Reference copy was provided to the client for approval prior to replication of the final CD copies.  You can read more about CD Mastering at ProCopy here:

This was quite a challenging repair job as the problems took a while to determine and process, however it was interesting to discover that digital recording isn't without potential problems if care isn't taken throughout the whole process. 

If you have any questions please don't hesitate to call us on 1300 4 PROCOPY or 08 9375 3902. 

Tuesday
Mar042014

45 Record of band 

This 45 record was produced in the late 60's early 70's and the "A Side" looked fine, apart from scratches that have occurred over time, but the "B Side" was horrific - This record had been stuck in to a frame with double sided sticky tape to present to someone when the band stopped playing and had hung on a wall for the last 35 years or so. I guess it seemed like a good idea at the time!

First the easy process was to copy the A side, but we knew that the client would really appreciate being able to hear the B side music for the first time in a long time.

The major issue was going to be how to clean the sticky residue off the B side without damaging the surface and then trying to play the record so that we could then process the audio to reduce the noise.

Two hours later with very careful manual cleaning the B side was clean enough to play.

Alternate player: Here's the original unprocessed audio 

Apart from a few seconds at the end of the track all of the song was retrieved, As can be heard near the beginning the record skipped from time to time and there is rhytmic noise caused by the residue of glue in the grooves. Pops and clicks caused by scratches are really evident

Although there were some issues with the final end result the client and the other members of the band were really happy to hear the material that they had recorded all those years ago, 

 Alternate player:  Click to hear part of the restored track 

 

If you think one of your recording is lost to extreme damage please give us a call on 08 9375 3902, we love a challenge. 

Monday
Feb242014

Audio Restoration Project from old 33 record

Late last year we were contacted by a family in Victoria that had come across an old record that had been recorded for a radio station that contained an interview with the lady's father. 

The question was could we tranfer it to a CD or digital format so that the family could listen to it?

Of course that opens up a lot of questions,

What "type" of record was it? a 45, 33, 78 or LP for example.

How old? That might give us some idea of playability

and how well had it been stored and it's physical condition. So we could get an idea of how much time we would have to spend taking out pops, clicks crackles and other noises. 

After assuring the client we could handle their precious recording appropriaely it was packed up securely and sent to us for examination. 

Here's what we found when the packaging was opened up:

33 Record from 1958We quickly realised that this needed to be transferred as soon as possible as the surface was peeling off the aluminium base. While the big chunks that were missing were generally not part of the recording the very begining and end were in very poor shape. We also realised that we'd be lucky to get much more than one pass of each side before the disc would become more unplayable.

Very carefully the initial transfer was done and here's part of the conversation as it came off this 55 year old record:

 Click to play original record sample:  

You'll notice that the original volume is quite low and that there are a number of problems.

Lots of surface noise, small crackles and interspersed with many large clicks. Background noise due to the older recording format and there were issues where the record had to be stopped and restarted to get the information off because the surface was damaged in many places and wouldnt play all the way through.

After many different processes to reduce the problems and time taken to edit all of the small audio files together the end result is now much better and the family has been able to hear an important part of their history.

Click here to hear part of the restored audio:  

A lot of surface noise has now been reduced, the small & large pops and crackles have virtually been eliminated and the rumble caused by the warped record has been reduced. This also means you'll notice that it's possible to increase the overall volume significantly.   

If you have some family audio sitting unplayed in the corner of the lounge room, give us a call on 08 9375 3902 so that you can enjoy it too.


 

 

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