Field Report: Bias Soundsoap 2

May 1, 2005

Soundsoap 2 is the latest upgrade to Bias' family of software designed to clean audio. It runs as a stand-alone program or as a plug-in for one of the many popular audio editing software packages available. However, it will only allow installation on Windows XP or Mac OSX. It will not install on earlier operating systems.

Soundsoap 2 is noise removal software. It will not fix the problems of poor equalization or poor equipment, but it is designed to remove hiss, hum, buzz and clicks. Bias has other products to deal with other audio problems.

I evaluated Soundsoap 2 using a laptop PC running Windows XP Pro with Service Pack 2 installed. I used the software in stand-alone mode and as a plug in for Adobe Audition 1.5.

Getting started

When the program is first run, the window that opens looks a bit like a radio. The controls are few and it is easy to understand their function.

On the left of the screen is a vertical slider called Remove Click and Crackle. This does exactly what it says it does. Use it in the manual mode to get rid of record clicks and similar problems.

Performance at a glance
Easy to use
Reduces clicks, crackles, hiss, hum, buzz, rumble and most other noise
Works stand-alone or as a VST, RTAS, Audio Units plug-in
Works with most audio editing software
Runs on Windows XP or Mac OSX

To the right of the slider is a knob called Noise Tuner. To the right of that is an oval window split into left and right halves. To the right of that is another knob called Noise Reduction. The two knobs are used together to tune out and reduce broadband noise such as tape hiss. The window gives a visual representation of the audio, the left half being before Soundsoap is applied and the right half being after.

To the far right of the window is another vertical slider called Enhance. The Enhance slider is a multiband compressor with a bass and treble boost to raise lost frequencies from poor or old recordings.

Below the knobs and the oval window is a series of buttons. The Preserve Voice button modifies the automatic processing algorithm to minimize the effect of the noise reduction on voice. Music tends to mask the effect of the noise reduction, so it is not necessary on music.

Next is a series of three radio buttons marked Broadband. They are Off, On and Noise Only. One of these buttons may be selected to activate, deactivate or monitor the characteristic of the filtering of the audio.

At the far right of the oval window is a button marked Remove Rumble. This function filters low-frequency noise. To the left of that is another series of three radio buttons marked Remove Hum. They are marked 50Hz, 60Hz and Off. Use these to select the type of hum filter.

At the bottom of the Soundsoap window is a series of controls to control the play of the audio, show the progress of the audio and the elapsed time. There is also a button marked Apply to apply the filtering.

Feel the power

The most powerful button in the Soundsoap window is in the middle of the oval button window. It is marked Learn Noise. To use it, simply open an audio file, press the Learn Noise button and then play the audio. As the file plays you will hear the audio being modified and the buttons and controls will change as the filtering is applied. For audio files that have changing noise characteristics, break the audio into segments using the Edit pull-down. By setting a Set Point I and a Set Point O, specific sections of audio can be affected. There are also controls on the timeline that users can grab to divide the file into areas for different levels of processing.

The program screens are similar whether it is used stand-alone or as a VST plug-in.

I tried Soundsoap 2 with an old 78 record I had as a kid. It was a recording of train sounds with a station call of the Pennsylvania Railroad's famous Broadway Limited. I played it for hours on end while playing with my trains. One day I was pulling out the record and it stuck a bit and as I pulled harder a piece broke off. By this time I was old enough to work with glue, and actually managed to glue the piece back on. From that time on the record always had a click-click as it passed over the glue joints. There was also a general layer of surface hiss and noise from repeated mishandling. My wife recently pulled out this record and I tried to put it on a CD for my grandson who is a budding train fan as well.

My earlier attempts to clean up this record were moderately successful, but I could never really get it to sound as good as I would like. I tried it on Soundsoap in the automatic mode and was amazed at the results. The click and hiss were totally gone and there was no audible change in the audio. This is particularly amazing because a good part of the audio is steam escaping, which is hard to distinguish from white noise. I tried using the manual controls and was able to achieve the same results, but using the Learn Noise button was much faster. I was not able to improve on the results the program came up with.

I tried another audio file, which was an interview originally recorded on a portable cassette recorder in the 1970s with a hand-held microphone. Soundsoap was able remove the tape hiss, but, as expected, did nothing to improve the quality of the desired audio.


In summary, Soundsoap 2 is an excellent product for what it does. It is priced low enough that even those only needing to clean a few files can justify the purchase. If you are in a position to be restoring or cleaning a number of audio files, it is a must-have piece of software.

Carter is chief engineer of WFMT, Chicago.

Editor's note: Field Reports are an exclusive Radio magazine feature for radio broadcasters. Each report is prepared by well-qualified staff at a radio station, production facility or consulting company.

These reports are performed by the industry, for the industry. Manufacturer support is limited to providing loan equipment and to aiding the author if requested.

It is the responsibility of Radio magazine to publish the results of any device tested, positive or negative. No report should be considered an endorsement or disapproval by Radio magazine.

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