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NuGen Audio PC Plug-ins

Visualizer Analysis Tools & SEQ Linear Phase Equalisers [Windows] By Martin Walker
Published January 2008

We test a selection of impressive and affordable Windows mastering tools from NuGen Audio.

Visualizer provides a comprehensive set of functions with some unusual options, such as the Mid/Side spectrum analysis and stereo spectrogram, shown here above a pair of more traditional correlation and level meters.Visualizer provides a comprehensive set of functions with some unusual options, such as the Mid/Side spectrum analysis and stereo spectrogram, shown here above a pair of more traditional correlation and level meters.NuGen Audio is a new name to me, but over the last couple of years the company have been quietly building an enthusiastic following for their range of elegant and sophisticated VST plugins, building on the success of their first three products. Stereoizer enhances the width of both mono and stereo inputs, Stereoplacer is a parametric equaliser whose bands can be individually placed in the stereo field, and Monofilter can highlight and correct a wide range of bassend and phase problems to give your mixes more definition and solidity.

The three products under review here are the SEQ1 sevenband parametric EQ plugin and the SEQ2 'spline' EQ, which are both linearphase designs, and an extremely comprehensive audio analyser tool called Visualizer that can help you highlight and solve many mixrelated problems. The range is currently PConly, but beta testers are currently being sought for Mac versions.

Metering Matters

Audio metering and analysis plugins are not glamorous, but can contribute greatly to the quality of your mixes, and help pick up on problems such as subsonic rumblings and phase issues. Many audio editors and DAWs now bundle spectrum analyser plugins, but in my experience these tend to be fairly basic affairs that can be frustratingly inflexible. Visualizer is in a different league altogether, being incredibly versatile yet easy to use.

There are seven main analysis options in Visualizer's arsenal: Level Meter, Spectrum Analyser, Stereo Spectrum Analyser, Spectrogram, Stereo Spectrogram, Vectorscope and Correlation Meter. By highlighting the appropriate icons in the righthand View Selector column, you can enable these in any combination to be viewed in the main display area. As you enable or disable each option, any others on screen resize themselves to make room, so you always end up with the optimum window arrangement with the minimum of fuss. There's also a global switch between Compact and Large sizes for the entire plugin. The 10 supplied presets give a good overview of possible arrangements. A set of Edit Control Panels allows you to tweak various aspects of the displays, such as digital or channel options, ballistic response and colour choices, so you can customise things to your preference and intended use.

I was really impressed with the clickanddrag scrolling and zooming functions offered by the four spectral displays, since this makes homing in on problem areas really easy. A Link button ensures that the frequency ranges of all visible spectral displays remain perfectly aligned with each other. You can also use the A Store and B Store buttons to capture displays for later comparison.

With seven bands of traditional knobs, plus extras like overall depth and M/S mode, the SEQ1 linearphase plugin offers a lot for the money.With seven bands of traditional knobs, plus extras like overall depth and M/S mode, the SEQ1 linearphase plugin offers a lot for the money.The stereo Level Meters can be displayed horizontally or vertically, and offer peak, RMS and KScale options, as well as margin and clip indicators. They cover most eventualities, although a M/S meter option would be useful. However, the versatility of the four spectrum displays more than make up for this lack, especially since the Spectrum Analyser provides a Mid/Side display option of its own, alongside more traditional ones such as left, right, maximum and average. The response options let you adjust the attack/release times of the display movement, while the Peak Hold has variable decay or infinite hold, which is useful when you want to build up a picture of what's going on during an entire track.

The Stereo Spectrum Analyser display is one I've not come across before, but within a few seconds I was really appreciating its stereodifferential views: you can quickly see how the stereo bias varies with frequency across the entire frequency range, with frequencies biased to the left appearing above the centre line, and those shifted to the right below it. A classic application for this meter would be spotting skewed bass sounds that would ruin a vinyl mastering session.

I've long enjoyed Spectrograms, which display a scrolling sonic fingerprint of your frequency spectrum over time, with the level of each frequency indicated by a spread of colours (typically 'hotter' levels are red, while quieter ones shade down to blue. Pure continuous tones appear as straight lines, which makes it easy to spot unwanted background whistles and hums, while drum hits produce wider bands of information. Because the scrolling display may well encompass a minute or more of your track, you can examine how compression is affecting the spectrum of your drum hits over time, for example, and spot masking problems when two or more instruments are fighting for the same part of the spectrum. There's also a Stereo Spectrogram that displays how your frequency spectrum is spread side to side in the stereo image over time, although I didn't find as many uses for this.

All four spectrum displays can be switched from highresolution to octave, thirdoctave, sixthoctave and chromatic options, plus various psychoacoustically derived Bark/Mel scales, with narrower bands where the ear is more sensitive. I found the thirdoctave setting made it easy to spot audible problem areas without getting lost in hundreds of individual peaks and troughs.

The Vectorscope display illustrates the stereo width and phase characteristics of your mixes, and also offers some handy extras. There are both the more familiar Lissajous (oscilloscope) and Polar (like Waves' PAZ) view options, and there are manual and Auto Zoom functions for the Lissajous display, so even lowlevel mixes can provide fullscale displays.

The final display option is a Correlation meter with an optional scrolling History, which can help you spot phase problems. If, for instance, you spot a dip in the meter each time a particular drum is hit, its close mic is out of phase with the others.

Visualizer is completed by a Stats/Setup panel that provides a readout of various clipping parameters, and lets you add various weighting (including A, B, C and D curves) to the spectral displays and change various FFT parameters. By rightclicking anywhere on a spectrum display you can also generate a sine test-tone at any frequency and level, which I found really useful in confirming what notes or harmonics caused particular spikes in my mixes.

I already have a small collection of meter and analyser plugins, but I can honestly say that within a day of receiving NuGen Audio's Visualizer I was using it almost exclusively. At $89 it's excellent value for money, given all that it offers.

SEQs Lives

Compared with conventional EQs, linear phase designs can achieve more transparency, preserve transients better and retain a sharper stereo image, but they do this at the expense of increased processing overheads and latency, so they are more suitable for mastering than mixing.

Nugen Audio currently offer two linearphase EQs, each available in Standard or Master editions. SEQ1 provides five parametric bands, two with shelving options, plus high and lowpass filters. SEQ2, by contrast, is a 'spline' equaliser. This means you can draw in your own freehand curves, although the high and lowpass filters are also present. All four offer 64bit internal processing and support sample rates up to 192kHz. Some parametric EQs can suffer from lopsided frequency curves at the top of their range, but NuGen's are claimed to avoid this.

Drawing in a suitable EQ curve using SEQ2 is easy and painless, while the integral spectrum analyser helps you spot problem areas that need treating.Drawing in a suitable EQ curve using SEQ2 is easy and painless, while the integral spectrum analyser helps you spot problem areas that need treating.Nice user interface touches include multistage undo/redo buttons and A/B memories so you can easily compare two different EQ curves. SEQ1 has a useful 'solo' light, so you can hear the effect of any single band in isolation, a neat Order button that shuffles the bands into frequency order if you happen to have dialled in your settings randomly, and a very useful Depth control that can make the entire response more extreme or more subtle without changing its overall shape. In both, a large graphical display offers the same versatile clickanddrag zooming and scrolling functions as Visualizer.

SEQ2 is simplicity itself to operate: you just draw in the desired curve, with fine changes greatly eased by the horizontal and vertical zoom functions. The number and distribution of control points is determined by the dropdown Banding selection, which offers the same wide range of options as Visualizer (chromatic, thirds, sixths, plus Bark/Mel alternatives). There's also a Depth control similar to that of SEQ1 that provides global 'compression/expansion' of the EQ curve, and a Contour setting that 'sharpens' or 'smooths' your curves. I found this particularly handy for ironing out the inevitable kinks in a handdrawn response. In SEQ2, the graphical display can optionally act as a spectrum analyser, so you can immediately see the results of EQ changes in your audio output as you change the curve.

A natural limitation of most linearphase EQ designs is that as you move down the spectrum, the maximum Q of your notches or peaks drops. If you need to dial up something 'tighter' to cure a hum or roll off the low end more sharply, you may need to increase the resolution. Unfortunately, each doubling in resolution doubles the latency of the entire EQ, so you need to choose wisely. NuGen's Standard models offer three of these 'quality' settings, while the Master Editions offer nine, enabling much tighter lowend tweaks if you need them, but at the expense of more sluggish audio feedback. Other Master Edition features include additional 64bit dither options, a frequency range of 10Hz to 30kHz (Standard offers 20Hz to 20kHz), and a more accurate WYSIWYG graphical display.

The Master Editions also offer an extra Mid/Side stereo EQ mode, which lets you do clever things such as frequencydependent stereo-width adjustment, or reduce the noise in an FM broadcast signal, which mostly occurs in the Side signal. You can EQ the left and right channels separately, or define different initial responses but then add further linked changes. Overall, the SEQ family is remarkably versatile, and I look forward to trying the eightband SEQ3 with individual band placement in the stereo image, designed for restoration of elderly mono or poorly recorded stereo material.

Let's Phase The Music

All three linearphase designs in my collection offer noticeably more clarity than conventional EQs, but there are still definite differences between them. To my ears, Waves' LinEQ has an uncanny knack of being able to alter spectral balance without adding any character of its own; if you dial in more bass, for instance, you get more bass, but the sound somehow doesn't seem to be any 'warmer'. This absolute neutrality is ideal for some mastering applications, but not universally enjoyed. PSP's Neon HR, by contrast, has its own definite character, a sort of analogue-esque 'sheen'. To my ears, SEQ1 and 2 fall somewhere between Neon HR and LinEQ, with a noticeable but very subtle character. I particularly liked the M/S options; Neon HR also offers these, but few other EQs do, in my experience. Like all linearphase designs, the response to changes in settings can become sluggish once you increase the resolution for higherQ bass tweaks, but I do think the Master Editions are worth the extra money for their various other options.

Overall, I'd say Nugen Audio's SEQ1 and SEQ2 have a very pleasing yet reasonably transparent sound, and are about the most versatile pair of EQ plugins I've ever used. This means it takes slightly longer to get your head around all the options, but once you do, the SEQ series can turn its hand to jobs that many other EQs couldn't attempt!


  • Visualizer offers virtually all the audio analysis options you'll ever need, including some you won't find elsewhere, within one colourful yet easytouse window.
  • SEQ 1 and 2 provide more clarity than conventional EQs, but still offer a little character too, with highresolution options that allow narrower bassend EQ tweaks than some competitors.


  • Like all linearphase EQs, SEQ 1 and SEQ2 have high latency when used at higher-resolution settings.


All three of the NuGen Audio plugins reviewed here are professional and extremely versatile. They offer various useful features, such as Mid/Side options, that are not found in many competing products, yet they remain very reasonably priced.


Visualizer $89; SEQ1 and 2 $119 each; SEQ1 and 2 Master Editions $219 each. Various discounted bundles also available.

Test Spec

  • NuGen Audio Visualizer v1.3, SEQ1 & SEQ2 Master v1.1.
  • Intel Conroe E6600 2.4GHz dualcore processor, Intel DP965LT motherboard with Intel P965 chip set running 1066MHz system bus, 2GB RAM, Windows XP with Service Pack 2.