Each year, more examples of vintage-inspired EQs, compressors, preamps, and mics are made available. Big-name brands, as well as boutique manufacturers, seem to think we all have an endless appetite for clones of classic gear. Consequently, contemporary designs of bread-and-butter products are rarely introduced. Meanwhile, Wolff Audio is bucking this trend by releasing new products that speak to historical conventions and are classic in tone and feel but are also modern in purpose and functionality – a sentiment that several respected engineers have recently shared. Therefore, when Paul Wolff showed me his new proportional Q parametric equalizer, I was intrigued. Paul may be best known as the former owner of API and Tonelux, and inventor of the 500 Series API Lunchbox, the 550b EQ, and the 2500 compressor [Tape Op #52], among other studio gear staples. Like many engineers, I rely on several products of Paul’s design whenever I’m recording or mixing, and over the years, I’ve even had a few opportunities to sit in his lab and peer over his shoulder. I’m confident there are very few members of our industry who are as accomplished and as brilliant as he is.
The Wolff Audio FREQ equalizer has four bands, each with sweepable frequency; ±15 dB of boost/cut; and two bandwidth options. Nothing unique is evident upon first examination of its buttons and knobs, and it would be easy to pigeonhole this as simply another tool for manipulating the balance of frequencies. But, in reality, that’s where the comparison ends. What I immediately heard when I inserted the FREQ on individual tracks was a subtle but very musical polish to the sound, thanks to a transformer-balanced output stage that’s tuned for overall clarity while imparting a touch of body to the lows, primarily in the form of third and second-order harmonics below 40 Hz, and third and fifth-order harmonics in the lows and low mids. I instantly felt inspired as I operated the controls and heard results that, as stated above, were musical.
Over the next month, I tried my pair of FREQs on almost everything I recorded – instruments, vocals, and sampled tracks. Loving the results, I’ve grown my collection to eight FREQs and plan to add more. I’m not going to exaggerate and say that everything sounds better through the FREQ, because you can indeed make sources sound bad. But what I truly appreciate about working with an analog device like this is that you quickly learn how to make a particular track sound better or worse by freely turning the knobs without the annoyance of adjusting virtual controls with a mouse.
Moreover, several smart design decisions facilitate sonic outcomes that make this EQ so satisfying to use. All four bands offer boost/cut with a potentiometer that is tapered from the center out, such that small amounts within ±6 dB can be precisely tweaked, while big swings beyond that are available at the extremes of rotation. Because each band has proportional Q, the EQ curve becomes “skinnier/sharper” as you increase the amount of boost or cut. At ±3 dB, I observed a Q of 1, while at ±6 dB, Q increased to 1.6, eventually topping out at a narrow Q of 3.6 at ±15 dB (according to my own measurements). The middle LM (low mid) and HM (high mid) bands have a 1/3 octave switch that locks the Q at 3.6 throughout their ranges.
Meanwhile, the outer LF and HF bands offer a Wide switch that increases bandwidth to nearly three octaves. However, unlike shelving bands, the FREQ's bands in Wide mode are still bell-shaped, so you’re less likely to overload the next piece of gear (or converters) in the signal chain with excessive infrasonic or ultrasonic energy. All four bands have significant overlap in their center frequency selections: 25 to 700 Hz, 75 Hz to 2.2 kHz, 350 Hz to 10 kHz, 2 to 20 kHz.
How does all this translate to actual use? Proportional Q means that subtle boosts and cuts really do remain subtle, while more aggressive boosts and cuts become more focused. For example, turn up 2 kHz on the HF band by a couple of dB on an electric guitar part, and the boosted curve remains wide, adding presence in a nice way. If there happens to be nasty ringing or resonance in the part, use the HM band to cut by 15 dB, which automatically creates a tight notch filter, and sweep the frequency until the resonance disappears. If you want that same surgical precision but with less drastic of a cut, engage the 1/3 octave button to still notch out that frequency but with fewer dB of attenuation. If the part is sounding too muddy, start with a medium-steep 9 dB cut centered around 150 Hz with the LF band, sweep until you find the most offensive frequencies, and then reduce the attenuation to 3 dB to lightly carve out the mud without killing the actual notes played. Sure, a fully parametric EQ with variable Q can accomplish all this too, but that requires one more knob per band, which would arguably make the EQ harder to use, especially given that a 500 Series faceplate has limited room for controls.
Interestingly, the FREQ's four bands interact with each other in a manner that isn’t completely additive/subtractive but is very often musical (to reuse that word again). For example, on a singing part that could benefit from some extra vocal articulation and detail, turning up the HF band by 3 dB at 5 kHz provides what you might expect – an octave-wide bump that adds definition and clarity, especially to a vocal surrounded by dense instrumentation. But then engage the Wide button to add air around that bump, and cut 8 kHz in the HM band by 3 dB with 1/3 octave selected to reduce sibilance. What’s the result? Almost a “tilt EQ” effect – a shallow ramp-up that actually starts down at 100 Hz, is +1 dB at 1 kHz, and makes its way up to a rounded +3 dB plateau at 20 to 30 kHz, with a smooth but focused dip centered at 8 kHz. This unexpected curve can really sound wonderful, and all that’s needed is a nudge of the HM cut’s frequency; a tiny bit left or right to find the sweet spot for the particular combination of singer and mic. My advice is to use your ears instead of relying on the FREQ's faceplate markings to arrive at something like this vocal curve. Another example is a pretty drastic curve I used on a kick drum mic recently, which measured 3 to 5 dB of gain from 9 to 47 Hz peaking at 22 Hz, and a 6 dB hole centered at 125 Hz. What did the knobs read? LF band +4 dB at 25 Hz in Wide mode, and LM band -9 dB at 125 Hz.
I could share countless examples of how my eight Wolff Audio FREQ channels have surprised and delighted me in the months that I’ve had them. Even if you think you don’t need another EQ – perhaps you already have a selection of analog EQs, or you prefer plug-ins – I still recommend demoing the FREQ. This isn’t a run-of-the-mill equalizer or a clone of something that already exists. It has a subtle sonic character of its own, and is especially complementary to sounds that lean bassy but work well with anything that passes through it. Although it lacks variable Q knobs, it does offer an optimized set of controls that lead to desirable results more quickly, whether in broad strokes or precise surgical moves.