Welcome to this new article for Age of Audio where we aim to give you tips for your digital purchases. The subject of this “session” will be a Universal Audio plug-in for UAD platform, released a year ago, software emulation of the incredible API 2500, an extremely versatile compressor with a unique and unmistakable character.
The 2500 API it owes its fame, as well as to its own constructive characteristics, also to some devices that make it a “smart” instrument, with surgical precision, character or creative depending on the occasion.
I will focus on the illustration ofhardware in itself, to then give space to the audio examples, in order to grasp the importance of the modeling done by UA.
Universal Audio chooses to model this compressor, which had already been emulated by the Israeli Waves years ago.
Thanks to Waves' aggressive discount and offer campaign practically 365 days a year, Universal Audio has a tough nut to crack, both in terms of price (Waves API 2500 can be purchased at dollars 59 against i dollars 299 of UAD) and for dissemination.
Let's start with the examination of the software panel and we analyze the points of contact with the hardware counterpart, trying to understand why this compressor is so irreplaceable, beyond the tonal characteristics.
The first detail that intrigues me, as usual, is the very small potentiometer HR located on the left of the API logo. This is the only real difference with the hardware (along with the potentiometer MIX for an agile law/dry). For those who have read my article on the comparison between Manley Vari Mu hardware and software, this element will not be new. In fact it is a feature that UA it is feeding on new processors with some regularity.
By adjusting the screw of thehead room, we can adjust the operational level of the compressor to any input signal, without necessarily having to raise or lower the level of the track content, making the harmonic distortion levels relative to a certain operational level shift according to what is needed. . A great help.
The section "compressor”Contains all the classic functions we expect from a compressor, such as threshold, attack, ratio (ranging from 1.5: 1 to infinity: 1), and two knobs "release“, One that takes a step from 50 ms a 2 seconds and the other which (once the first knob has been set to "variable") allows, with a continuous control, to vary the release from 50 ms maximum 3 seconds.
This section is the part in which we will impose the timing on our gain reduction and its range of action.
The next section, namely "tons“, Is the focal point of most of this compressor's smart tools.
We have an knee simplified in 3 positions: Soft Drinks, Medium e Hard, which allow to conceal the intervention point of the compression with greater or lesser effectiveness.
The “thrust” panel is an elaborate filter system on the internal side chain.
Normal Medium and Loud (see figure) identify three possible situations of sidechain filter to move the gain reduction on the part of the spectrum that interests us.
Normal corresponds to no filter, i.e. the side chain is not present, the input signal is read as we listen to it and the gain reduction behaves as expected, driven by the elements that produce a higher RMS. In Medium mode a low cut and a boost on the high frequency range are introduced, so that the compressor is less responsive to the nuances of the bass and more incisive on the peaks of the highs and mids (I often use this function to get the same gain reduction for both kick and snare). Last, but not least, is the sidechain Loud curve, which introduces a filter of -15db at 20hz and one of +15 at 20khz to completely shift the focus of the compressor from the lows to the highs in an extremely incisive way.
The last functions of the "TONE" panel concern the "type", The type of circuit we are using: feed forward o feedback.
FEEDFORWARD= NEW = the circuit of sidechain which analyzes theRMS of the input is fed by the uncompressed signal, so compression is faster and more aggressive. The envelope of the gain reduction is less readable in the output signal, therefore everything will be less processed by the compressor envelope but more aggressive, impulsive.
FEEBACK = OLD = the sidechain circuit that analyzes the RMS of the input is powered by the signal already compressed by the VCA, therefore the compression is softer since the detecting is driven by already damped transients, but the compressor envelope is more readable at the output.
The quality of this modeling is evident when we pass by OLD a NEW and we realize how dynamic the response of the processed signal is with both settings. Incredible!
On the panel "LINK”We find another useful tool: the aforementioned panel, with a step knob, allows us to undo, in percentage terms, the link between the gain reduction of the two channels. If it is true that this operation is counterproductive when we have a stereophonic image with a strong central protagonist, whether it is a voice or any solo instrument, it is equally true that, when we have a central panorama free from elements, it can be useful to completely interrupt or the stereo link of the gain reduction as a percentage.
API not only gives us this tool, but goes much further, giving us filters with which we can exclude part of the signal from the stereo link. The keys bearing the low-pass and high-pass symbols (which when pressed at the same time obviously form a band pass) allow us, for example, (by pressing the low pass filter and keeping the correlation to the 100%) to exclude all high frequencies from stereo correlation, while the rest of the spectrum works normally with fully correlated gain reductions.
The panel "OUTPUT"Of the UAD modeling bears three different switches: IN, BYPASS e GAIN which correspond exactly to what the other party does hardware.
IN it is a button that allows you to turn off the attenuation circuitry but that allows the signal to pass through the machine while still using its color; BYPASS allows you to listen to the input signal without being processed by the compressor, a hardware bypass that carries the signal from the inputs to the outputs directly; finally, GAIN allows you to automatically adjust the output level (if disengaged and with the MAN indicator off) depending on how much gain reduction is introduced (yes, the API 2500 is a analog compressor with autogain, to compensate for broadcasting needs).
My personal opinion on this modeling of Universal Audio is absolutely thrilled: the precision and character that in just one slot (representing over the 32% of a processor) this plug manages to give is truly irreplaceable. Like hardware, it is not absolutely situational, it can be used on any type of material, both in the complex corrective phase (where a fabfilter proc-2 would be the master) than to color a bus or to impose a particular timing on a master. It manages to break down the tip of a particularly aggressive kick through a mix, without interfering with the rest, or to glue a group of drums to emphasize too weak accents. Obviously, using a external processor, should be used sparingly in a prudent management of resources.
My personal view of this processor in the mix in the box it is particularly related to bus compression: I often use it on groups of items in acoustic contexts, where you have to come up with strong but not aggressive harmonics, especially on groupings of main voices and choirs, or on acoustic drums in a modestly colored context that must be compressed in a decisive way, bringing out never coarse harmonics.
Another way this processor performs at its best is parallel compression of percussions e guitars, as he manages to be violent in the intervention and in the envelope but (also in NEW mode) polite with saturation.
Notes on audio demos attached.
The guitar file provided byAmarcord Studio , on which we worked, has a sound suitable for a guitar and vocal song, given the delicate nature of the performance. Applying a compression to this element may seem extremely redundant but we chose it for this reason, because any difference can seem like a flaw making everything extremely more readable.
We applied the processor in three different ways: one "transparent”, In which we only tried to control the transients of the instrument without going into depth and changing its envelope; one more aggressive, with a fairly slow attack, and a last one, which introduces a net pumping, but it is useful to perceive the harmonic content that is transformed.
Once again I thank Age of Audio and the studio L 'Noise art for giving me the opportunity to write this article and to be able to compare the software with the hardware.
Guitarist: Claudius Roman
Good music to all.
John Rome
Useful Information:
Producer: Universal Audio
Distributor: Online only
Model: API 2500 Bus compressor
Price: € 299,00
Audio demo
