Bias SoundSoap 2

What Is It?

SoundSoap 2 is an affordable noise reduction utility designed for simplicity of use while providing a sophisticated set of DSP tools under the hood. It can operate in standalone mode on either Mac OS X or Windows XP or as a plug-in (RTAS, VST, Audio Units, DirectX). It can operate on a variety of media files including both audio files (AIFF, WAV) and movie files (MOV).

User Interface

The user interface is simple and direct, with a spectrogram display (the "Wash Window") and a handful of parameter controls: Remove Click & Crackle, Noise Tuner, Noise Reduction, Enhance, Preserve Voice, and Remove Rumble.

The Wash Window resembles the window of an old fashioned washing machine and is divided down the middle to show unprocessed audio to the left and "cleaned" audio to the right. Color is used to differentiate the noise from desired signal, with blue signifying desirable signal and red representing noise.

Remove Click & Crackle: This single fader controls the degree to which both clicks and crackle are removed from the signal. Ideal for cleaning up vinyl surface noise or electrostatic signal contamination.

Noise Tuner: This is a large knob for tuning the noise detection threshold, with low values to the counterclockwise end and increasing as you turn it clockwise. Signal above the threshold is considered to be noise (and is shown in red in the Wash Window).

Noise Reduction: This second large knob on the opposite side of the Wash Window from the Noise Tuner is used to set the amount of noise reduction, with clockwise representing maximum reduction. The degree of reduction is about 30 dB.

Enhance: Described in the documentation as restoring "sparkle" back into older recordings, raising the Enhance slider adds both high (above 7 kHz) and low (below 250 Hz) frequencies to the signal.

Preserve Voice: This button invokes a special pre-filtering mode that removes frequencies outside the range of the human voice (mainly above 8 kHz).

Broadband: Three "radio buttons" under this control are off, on, and noise only. The latter is especially useful because it allows you to monitor what part of the signal SoundSoap is removing.

Learn Noise: While activated, this function analyzes the noise profile in order to then remove it from the signal. This is best used in conjunction with the Noise Only setting in order to monitor the noise that is being removed and to avoid taking out useful signal.

Remove Rumble: Cuts frequencies below 40 Hz by about 20 dB.

In Use

SoundSoap is designed so that most of its controls can be used with minimal analysis or tweaking. For instance, if you are cleaning up unaccompanied recordings, such as voiceovers or interviews, just click the "preserve voice" button to filter out frequencies outside the voice range. Similarly, if you are restoring an old vinyl record with a lot of surface noise, simply turn up the "Remove Click & Crackle" slider until the transient grit disappears (and the program material is still acceptable). You can treat "Enhance" and "Remove rumble" similarly; just turn the former on if you need it and find a setting for the latter that makes your program material sound as "good" as possible.

Use of the Noise Tuner and Noise Reduction controls takes slightly more thought (and listening!) but is still relatively painless. You can approach these parameters in either of two ways, with the "learn noise" function or without. The "without" strategy presents you with a default noise profile that is flat. You can then turn the Tuner knob to discover (by ear and by using the Wash Window) an optimum setting and then dial in the degree of reduction with the Noise Reduction knob. The alternative is to click twice on the "learn noise" button to capture a sample of noise for analysis (be careful to capture just unwanted background noise or SoundSoap with try to remove some of your program material!). Once you have captured a noise profile you can tweak the Noise Tuner and Noise Reduction knobs.

I found it is best to do a little ear training first by selecting some test files. I have some noisy sound effects files, some voice files, and an assortment of music clips that offer a wide range of noisy and pitchy sounds. I found it especially instructive to explore a sound called "airplane interior" in order to hear what SoundSoap does with nearly pure noise. By varying the settings of Noise Tuner I was able to induce a pitchy quality in the noise source (this suggests that SoundSoap's algorithm is actually "killing" uncorrelated noise elements while reinforcing correlated pitchy components) but whether or not your are a DSP math wonk you'll be able to hear what's going on and establish some intuition about how to apply these tools to your particular projects.

Installation, Documentation, And Support

Installation from the CD is easy and is well documented in the manual. The Authorization scheme is based on a combination of entry of your Serial Number, and on-line registration (you can delay the registration for up to 14-days).

The 66-page users manual comes as a PDF file on the installation disc. It is clearly-written and fully illustrated, and it contains sections specific to working within host environments such as Peak, iMovie, Sound Forge, Garage Band, etc.

BIAS support has always been good, but as with other growing companies they've had to accommodate to the support needs of a large customer base. As a result there are limits on free technical assistance (90 days for a single incident). After this you'll have a choice of a fee-based system with phone support, or an Internet-based system with FAQ, forum, and mailing list available free. Personally, I think the mailing list is one of the best support systems I've seen. It's active, with five to ten message a day.

Summary

SoundSoap 2 is an inexpensive and easy-to-use noise reduction utility that has more power than one might expect. It is designed to accomplish a range of the most common clean-up and restoration tasks in audio and video files. The control interface is fairly intuitive and the noise reduction algorithms are effective.

Have more questions about this product? Please write to us here.

Or to be kept informed of all the latest news, reviews, articles, and more, click here to subscribe to the audioMIDI.com newsletter.