Sound Radix: SurferEQ2 Plug-In

These days, we are constantly updated with new product announcements consisting of plug-in emulations of old products. While this may be good for our ever-changing industry, it seems that truly innovative products get somewhat overlooked. Sound Radix is a company that has been quietly making modern day classics that should belong in every audio engineer's toolbox. I first heard of them a little over a year ago when I bought their Auto-Align [Tape Op #121] plug-in intended for correcting phase on multi-mic'd sources. Auto-Align works like magic and has saved many of my mixes from "lame drum sound" syndrome, which is why I felt compelled to try out SurferEQ2 by Sound Radix.

When you first open up SurferEQ2, you see a fairly standard EQ GUI with a few added features. But what's really under the hood of this plug-in is a 7-band EQ with pitch-tracking ability (auto, MIDI, or sidechain controlled), a post-EQ frequency analyzer, a spectral gate with attack and recovery times to create compression effects without changing natural dynamics, and harmonic filtering. The pitch-tracking ability means that the curve you apply to a monophonic source will change with the notes being played. In practice, you can track the fundamental of each bass note being played or keep a harsh vocal in check throughout a song by following tricky frequencies. You can also track pitch on each of the seven bands via MIDI controller, allowing for unique sound sculpting and movement. This feature is incredibly powerful and works effortlessly by catching onto and tracking frequencies exactly as I'd hoped.

The frequency spectrum analyzer is not the first of its kind, but it is incredibly smooth and helpful to use. It shows you the output signal, allowing you to see your EQ curves, in effect. This seems most important for engineers working in less than ideal rooms where deep low end can go unnoticed but is still affecting the overall stereo mix. The analyzer will also show you the sidechain source, making it easy to find the exact frequencies you want controlling the affected track. This comes in handy when track bleed is an issue and you're using the Spectral Gate feature. For example, a tom mic with bad cymbal bleed can be set to have a low-pass filter engaged when not being played, but with the gate threshold set accordingly the full tom sound comes through when the tom is played. Other useful scenarios include vocal bleed in a guitar mic or when dialing in extreme settings that can create compression-type effects on a source without affecting its dynamic range.

Another unique feature of this plug-in is its harmonic filtering, creating wild sounds with just one band engaged. This effect is somewhat easier done than said, but essentially it can boost or cut a fundamental frequency and all of its harmonics. This is useful when trying to eliminate hum from a noisy source or going wild by using the harmonic filter on a reverb send with the bass set as the sidechain source, so the reverb tail sounds as if it is following the chord structure of the song.

This plug-in was built completely from the ground up, with customized filters and algorithms that go well beyond my comprehension, but what I can tell you is that it sounds fantastic! Because of the attention to detail and a deep understanding of EQ filters, this is one of few digital EQ plug-ins that sounds great even when pushed to its limits. For such a powerful plug-in, it is not a CPU hog by any means – and for such an in-depth tool it is surprisingly very intuitive. Since discovering this SurferEQ2, I've found myself throwing it across every drum track, bass, and vocal track without any noticeable lag. It's inspired me to try things I've thought to be too complicated to set up with multiple plug-ins in the past, and it performs flawlessly. It has excellent practical use as well as deeply unique abilities that will keep me reaching for it whenever a mix needs inspiration. I highly recommend downloading the SurferEQ2 demo, but beware – you may need to cough up the money to buy it after you fall in love with it.