Sunday, December 14, 2008

A technical note

On  this blog,  I have from time to time made available extracts from broadcasts I have heard on the radio.  Various experiments have,  I hope,  lead to an improving quality.
A related topic is:  how do you move on from the old,  familiar methods of recording from analogue radio to cassette tape?  The question was asked recently in the Radio Times and one of the answers was to get a special memory card to record from a digital radio.  Well, blow that:  there are other ways to transfer sound,  with standard audio devices,  a PC and the odd connecting cable.

Supposing you have an audio device,  such as a cassette player,  it is possible to connect the headphone socket to the line-in (blue) port, using a 3.5mm jack cable. You have to be careful to adjust down the output levels of the source device,  so as to avoid distortion (clipping).  My laptop does not have a line-in port,  only one for microphone and I found it impossible to adjust  the levels adequately for this.  See discussion here.

The Audacity free software is a convenient way of recording and editing sound.  The problem is that my desktop PC (which does have a line-in port) is fairly old and runs Windows ME:  "Although Audacity is billed as working for Windows 98 through Windows Vista, it has been found to consistently crash Windows ME by going into a loop and generating endless temp files until the hard drive is full." ( I don't get that, but it does just hang up after 1 to 2 minutes of recording.

So I end up using Sound Recorder, which comes with Microsoft's Windows, to capture the audio.  This creates a WAV file (by default SR records for just 60 seconds,  but if you create a blank (silent) file of say 10 minutes,  you can leave it recording for longer periods with no worries). The WAV file can be imported into Audacity and,  after any editing required,  exported as MP3,  using the LAME plug-in.

Other source devices can be used:  my digital radio has a line-out socket and that gives excellent results.  Many programmes,  from the BBC for example,  are available as MP3 downloads, but sometimes they are just "listen again" (RAM files). To record these, you can just connect the green (speaker / headphone) port back to the line-in port (all for the purpose of fair quotation and comment,  of course).