Active EQ plugin


Review by Russell Cottier

The AE600 is the latest in the line of active EQs from this Silicon Valley based plug-in company. Offering six bands of both active and fixed EQ this is more than just your average plug-in.

The interface is a brushed metal affair with the typical McDSP Green-Screen visuals. On the left we have the Input and Output meters. This section of the GUI hosts trim controls for input and output, bypass for each of the six bands, plus HPF and LPF controls. The main area of the plug-in is taken up by a large graphical frequency plot of the ever-changing EQ curve and associated controls.

Each Active and Fixed band can be controlled separately but parameters are grouped in the six blocks at the top of the interface. There are parameters for Gain, Frequency, Q and a variety of modes, 13 in total. These modes offer some powerful options, but it is worth noting that several of the mode types are just mirror images of each other, either High or Low Pass. There is a bar meter for each band and the threshold for the active EQ can be set here or below.

Beneath the frequency plot sit the controls for each active band. The basic premise of the active bands is that once signal level from each band’s Key input exceeds the threshold, the active EQ band will start to head towards the target gain with a defined Ratio, Attack and Release speed. There is even an Invert mode which engages the band until the threshold is crossed. Quite useful for maintaining consistency across a microphone being passed between speakers at a conference for example. Of course individual bands can be muted and soloed and Keys can be auditioned by clicking the speaker icon on each band. There is the option of an external key too that can help tame just the right frequencies in relation to other elements in a mix.

In the centre of the GUI the graphical frequency response plot can be switched to Key mode to show the frequency bands and centres for each of the key inputs. It’s notable that the keys are pre EQ. One useful tool when making adjustments is the lock control, which ties the frequency and Q together for the specific frequency band.

Analogue-sounding variable Q

Let’s look in more depth at the EQ modes. Orig mode is a simple parametric EQ band, but for fine notching the 5x mode narrows the Q significantly. These notch filters sound far better than the McDSP promotional example audio would suggest, and were a pleasure to use. Q+ mode almost reminds me of my analogue console with a variable Q that tightens as gain is increased. There is a really natural and effective feel to this mode.

LS-BX and HS-BX offer Baxandall shelving EQs — a digital approximation to Peter Baxandall’s iconic circuit design — rather nice for gentle pushes, and with a smooth response. I found this useful on acoustic guitars and strings in Invert mode, to keep those high harmonics nicely present despite any movement of the musician off-axis.

LS-V and HS-V are McDSP designed vintage modes that offer a smooth bump just after the selected shelving frequency. Q controls the severity, and it was possible to achieve a Pultec-style result. With the added active controls, vocals can be processed in effective and interesting manners.

LS-X and HS-X offer an opposing shelf that inverts the gain on the opposite side of the selected frequency, almost like a ‘tilt EQ’. I mostly found use for these in the context of a synth wave EDM track, where automating these filters could give a little variety from the standard LPF sweep. L-BXF H-BXF are quite interesting, offering a Baxandall shelf with an associated HPF or LPF an octave away from the EQ frequency, this is effectively a less aggressive version of the remaining two filters — HPF and LPF — that have an adjustable resonant peak.

When used judiciously and carefully, AE600 can give some very pleasing results; keeping attack and release times relevant to the elements that you wish to enhance or reduce is critical. For individual tracks the fixed EQ can be used as a good base to shape a sound and then add the finishing touches with active EQ. For pre-mixed content or audio enhancement the active EQ can really sculpt sounds that are non-continuous throughout the audio.

The complexity available allows for radical sonic changes to be implemented on drum or guitar buses, even sampled loops can be effectively altered. I also found some great use in treating less than ideal live recordings. AE600 is available from the McDSP online store at $279 for the HD version or $179 for Native. A demo is available which is definitely worth looking into if you want that little bit more of intelligence from your EQ.