The proliferation of the MP3 audio compression format, for example, illustrates the extent of the digital revolution in which we find ourselves. In this space, I plan to provide explanations on how to perform certain tasks regarding anything and everything audio. To this end, I'm more than happy to receive feedback or suggestions for future articles.
This month, I take a look at recording analog devices such as tape and vinyl into your computer - converting them to digital data in the process - and how you would go about cleaning up the sound to achieve maximum clarity before burning to a CD.
There are some important factors that you need to consider before getting started. The amount of hard disk space required to manipulate and restore sound files is quite large. The more you can free up the better, but as a rule of thumb 500MB should be enough to begin while giving you a rough idea of what file sizes to expect. Processor muscle and amount of RAM will also have an impact on performance. Your sound card will need a line-in jack and as little hiss and interference as you can manage. Powerful graphics cards are notorious for interference, so, if needs be, try moving your sound card to a more distant slot. A new sound card may also be the way to go - they're increasingly more affordable and some contain gold connectors, which are widely believed to help reduce hiss.
Many soundwave-editing programs are on the market, some of the best of which appear as demos on this month's cover CD. In addition, some programs being marketed serve this particular niche of restoration alone, such as Steinberg's Clean! - links to these are on the table on this page. For the purpose of this article, however, I will focus primarily on GoldWave 4.16, so you are free to explore for yourselves anything that I happen to mention. The version we have included is Shareware and is fully functional, limited only by a cap of 150 commands in one session before you need to reopen GoldWave.
First things first. If you are using turntables, connect the outputs of your amp to your computer soundcard's line-in. If you are using a hi-fi or a device that contains its own amplification, simply connect the outs of that unit in the same fashion. Next, fire up GoldWave and press
At this point you will begin to use the Device window. If you have closed or lost this window, simply go to the device controls. From Tools you can easily access Window's CD player and volume controls or GoldWave's CD extraction utility. In the device window press the properties button (FIGURE 1) and go to the Volume Tab, selecting line-in. Adjust its volume as desired, checking for distortion, and press OK to exit. You've now tested if the line-in is working and you're ready to record. Hold
Normalisation can be used to help fix low-level recordings. Pull down the Effects menu and go to Volume then Maximize, setting a maximum level. Presets are a good place to start, as you can always undo the effect if you don't like it. However, for the same reason, best results come through experimentation and age-old trial and error. If your sound is thin and needs some beefing up - compression is also in the effects menu. To kill hiss, go to Effects-Filters-Noise Reduction. GoldWave boasts quite a fine noise reduction facility (FIGURE 2) for a Shareware program. The filters include noise gate, a bandpass/stop filter, a low pass/high pass filter (great for taking out bass rumble or treble hiss), an equaliser, a parametric EQ and a pop/click remover.
You can save your results and experiments in many formats, including .wav - ready to burn to a CD or convert to MP3. Here's your chance to listen to your favourite vinyl tracks in the car or at work. What's stopping you?
Demos on this month's cover CDs:
Groove Mechanic 2.4a
Cool Edit 2000
Pop Fix 1.06
Sound Laundry 2.1
Other resources online:
Waves Native Power Pack - www.kswaves.com/Wave Corrector 1.24 - www.ganymede.hemscott.net/Dart Pro - www.dartpro.com/DirectX Plug-in Listing - www.directxfiles.com