CEDAR Audio CAM21 Broadband Noise Reduction Bundle with NR-4, NR-5 and CAM3/A, Download

Broadband noise reduction
There's a tendency to think that digital dehissers are all equal - magical processors that somehow remove all of the noise without any side-effects or damage to the wanted audio. This isn't true; it's quite easy to remove noise, but it's very difficult to do so without introducing strange artefacts, and even more difficult to do without reducing the high frequency content of the wanted audio or introducing unwanted compression.

CEDAR's 'NR' and Auto Dehiss processes are based upon a sophisticated core algorithm than concentrates on minimising artefacts, dullness and compression. These have been used on countless music tracks, film and TV soundtracks, forensic recordings and much more.

- NR-4 and NR-5 -
It's not possible to remove all of the broadband noise from a signal while leaving the wanted signal completely unaffected. But, when quality is the defining criterion, NR-4 and NR-5 embody related algorithms that can reduce noise to a remarkable degree while leaving the desired signal sounding natural and undamaged. Both processes are equally applicable to CD remastering, film soundtrack restoration, post-production, and forensic audio investigation, but whereas NR-4 is often the better solution when there is significant low frequency noise, NR-5 is optimised for signals with greater high frequency content and bright transients.

Although the algorithms that lie at the cores of the two processes are different, we have provided almost identical controls for the two so that users will be able to use both with equal skill. The clear screens and easily mastered controls belie the capabilities of the underlying algorithms, which remove more noise than ever before with even fewer side-effects or artefacts.

The Noise Fingerprint
Although it is impossible to know the precise amount of noise at each frequency at every moment, an accurate fingerprint is a useful tool, and can help to define the amount of noise removed by the system. Should it be difficult to capture a sample of noise, or if you have caught a small amount of signal as well, you can edit a Fingerprint or create one manually using the drawing tools. These provide powerful opportunities to achieve the best possible results, especially when used with the integrated Spectrum Analyser, which helps you to create or edit a Fingerprint that most closely resembles the contour of the noise spectrum.

The Noise Reduction EQ and Noise Free EQ
The Noise Reduction EQ re-shapes the noise content contained in the input signal. Typically, you will want to concentrate the noise reduction in the range where the hiss is most intrusive, while leaving other areas relatively untouched. This is very different from lesser systems that attenuate the noise content equally at all frequencies.

Although capable of acting like a conventional parametric equaliser, the Noise Free EQ is a mastering quality EQ that acts only upon that part of the signal identified as genuine signal. You can say, therefore, that it is like a filter that shapes only the true signal content of the input signal. Common uses for this include mild boosting of high frequencies to counteract any loss of perceived brightness caused by the noise reduction itself.

Modelling & Brightness (NR-4 only)
The three modelling options control the behaviour of the NR-4 algorithm. The audible differences between these models can be very subtle depending on the nature of the signal and noise. The Brightness control gives you some flexibility to determine the nature of the dehissed sound, balancing the amount of noise reduction with the risks of side-effects.

- CAM3/A Auto Dehiss -
Digital dehissers that used no fingerprinting or noise reduction profiling are prone to side-effects known sometimes as twittering and glugging, the 'underwater effect' or even 'space monkeys'. In the past, it was sometimes possible to avoid these unwanted sounds by careful and judicious use of the available controls, but it remained very difficult to remove broadband noise correctly with no detailed user intervention.

Today, Auto Dehiss embodies a more advanced algorithm than any previous dehisser and has a unique Auto mode that enables the software to determine the broadband noise content, removing this without the introduction of those unwanted side-effects or artefacts. Nonetheless, it retains a manual mode that allows you to control all of it parameters and fine-tune the noise reduction should you wish to do so.

It's automatic dehissing that actually works.