PSP Tilt-Q

Sometimes the simplest ideas are the best, and tilt EQ is a good example. If you haven’t encountered it before, it’s a way of adjusting the entire frequency balance of the programme material. The user specifies a pivot frequency and a positive or negative gain value. The amount of boost or attenuation gets progressively greater as you get further from the corner frequency, and is symmetrical about it, so as you apply a treble boost, you’ll get a bass cut and vice versa. When the resulting EQ shape is plotted on the usual logarithmic representation of amplitude against frequency, it looks like a straight line sloping upwards or downwards. In other words, tilt EQ literally tilts the spectral content of the source either towards the treble or the bass.

I’ve come across a few implementations of this idea before, which I believe has its roots in 1970s hi‑fi amps. Tonelux, for example, made a hardware unit called, appropriately enough, the Tilt EQ, which has been ably emulated in plug‑in form by Softube, and there have been other hardware models. Some general‑purpose equaliser plug‑ins such as FabFilter’s Pro‑Q allow EQ bands to be set to a tilt response too. But they remain relatively thin on the ground given how useful the effect is, and so it’s nice to be able to welcome a new candidate.

PSP’s Tilt‑Q retains the essential simplicity of a tilt equaliser, but adds a second band labelled Contour. This is operated in the same way, by specifying a centre frequency and then dialling in a positive or negative ‘amount’. However, whereas the Tilt band makes treble and bass boost mutually exclusive, the contour band either emphasises or attenuates both ends of the spectrum together. Positive Contour values thus impose a ‘smile curve’ response, whereas negative values introduce a midrange boost. The Tilt and Contour bands each offer a choice of three shapes, plus gain controls. Their centre frequencies can be set anywhere between 200Hz and 2kHz, and can be linked so that moving one moves the other too.

The feature set is topped off with low‑ and high‑pass filters, polarity toggle, an output gain control and a button to enable soft saturation on the output. The graphical display is also pleasingly configurable. On a stereo track, Tilt‑Q can be set to process either both channels at once, or only the left, right, Mid or Sides channel. The factory preset library numbers more than 80 settings, many harvested from well‑known engineers, which is pretty good going for such a simple processor.

What’s great about it is the way that it can reveal another perspective on your source in an instant.

By itself, tilt EQ is a relatively limited tool, but what’s great about it is the way that it can reveal another perspective on your source in an instant. You have only to sweep the gain control to discover whether things are too bright or too dark, and adjusting the centre frequency will often get you surprisingly close to the EQ you need to correct them. That is as true here as it is in other implementations I’ve tried, but what makes this one special is the addition of the Contour control. PSP have rightly intuited that this is the perfect complement to the Tilt band, especially when used on the mix bus. The main down side of a positive tilt curve — which, let’s face it, you’ll be using 99 percent of the time — is that gain settings that are right for the upper midrange can lead to the very high end being overcooked. Contour allows you to offset a tilt curve either with a broad midrange hump, or with a scoop lower down in the midrange that nicely refocuses the treble emphasis.

The point of tilt equalisation is instant gratification rather than detailed tweaking. The Contour band extends its usefulness considerably without compromising the turn‑and‑go immediacy of the Tilt band at all, while other features such as the filters stay out of the way until you need them. The only thing I’d have liked to be able to do that isn’t possible with the Tilt‑Q plug-in is to apply different settings to the Mid and Sides bands within a single instance of the plug‑in. As it is, you have to create two — not that that is a great hardship. All in all, Tilt‑Q is a great‑sounding, genuinely useful plug‑in with a slick user interface, and it’s also very keenly priced.