Bay of Isles Computers Support and Technical Tips - Removing the noise from Music conversion.

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Getting a Sharper Cleaner Sound

(From the APC Mag.)

When converting music from vinyl or casette to digital format, analog "noise" often comes along for the ride. APC mag writer, Daniel Winter, demonstrates how to turn it down.

Using specialised software and a PC, you can remove tape hiss, electrical hum, equipment clicking and vinyl popping from these recordings. A link is included to download a trial version of GoldWave 5.06 for this purpose.

Make a connection
First, make sure all equipment is connected correctly. Ensure that RCA leads are plugged into the output of your hi-fi amplifier. If you don't have RCA jacks on your equipment, the headphone jack is an adequate substitute.

The other end of your leads should be plugged into the line-in of your soundcard, which is usually blue. Ensure that the audio mixing software has the line-in enabled and run an audio test on the equipment - the analog recording should play through the PC's speakers.

Software and Plug-ins
Two separate functions need to be executed - Recording and Restoration - and GoldWave 5.06 performs both. For advanced noise reduction techniques, GoldWave relies on plug-ins that utilise features in Microsoft's DirectX technology.

Make sure that Windows uses the line input of the soundcard as the default recording device. If it doesn't, go to Control Panel > Sounds and Audio Device Properties > Audio and set the default sound recording device to your soundcard. Flick back to the Volume tab, and select Advanced. In order to minimise system noise when recording, mute any other inputs in the Volume Control app.

To ensure the correct device is used within GoldWave, select Options > Control Properties > Device and ensure that Primary Sound Capture Driver is selected. This ensures the Windows defaults aren't overridden.

Step up to the Mic
Create a new file in GoldWave and configure it to be stereo at a sampling rate of 44,100kHz. Set the initial file length to a time that is a few minutes longer than the side of the cassette or LP you're copying.

After playing the tape or record for a few seconds, test that everything is set up properly by clicking on the Record button in the floating Control window. Check the peak levels - if the bars go too far into the red, a distorted sound will be recorded. If necessary, adjust the soundcard recording volume using the recording mixer.

Once you're satisfied with the recording levels, stop recording. Start recording afresh with these final settings and commence the cassette or vinyl playback from the beginning. Makes sure there are a few seconds of silence at the beginning of the recording. When the recording is done, click Stop and the finished recording should be displayed.

Clean out the Noise
Next, select the entire file (Ctrl+A) - and then Effect > Filter > Noise Reduction. Pick the hiss removal preset from the list and use the Play icon to preview the result. If you aren't satisfied with the default presets, tweak the noise reduction settings. Clicking the Plus icon saves any custom settings you've made. After tweaking, click OK to render the noise reduction to the file.

If the recording contains audible clicks and pops, select Effect > Filter > Pop/Click. It's worth experimenting with the tolerance slider here while previewing the results. When you're satisfied with the sound, click OK.

Once you're happy with the noise and click removal results, save the master file. Burning an audio CD? Save it as a WAV file and use an application such as Nero Burning ROM to write to CD. IF you plan to use a personal music player or PC, save the recording as a compressed MP3, Ogg or WMA file.

If you're backing up a large number of cassettes or records, use the hiss and click removal presets from your first recording when batch processing the rest. Simply select File > Batch processing, add the files you want to process, select the presets and click Begin. using this method gives clean and lean backups of your music collection in no time.