The 1973 is a three-band stereo compressor, with a similar set of controls for each of the three bands. You get a big knob for setting the threshold, three smaller knobs to dial in the attack, release and gain, and a switch that allows you to mute and bypass each band. You can simply solo a band by holding shift and clicking the switch's Status label. A pair of knobs are nestled between the bands that allow you to set the crossover frequencies and there's a generous range available: 50Hz to 1.3kHz for the Low crossover and 1kHz to 14 kHz for the High. As you'd expect, using the solo feature can help you set the crossover frequency correctly for any given track, but the 1973's crossover filters use a rather gentle slope, so for some, this may take practice. This is especially true if you're used to compressors whose crossover points are more obvious when solo'd, such as Ableton's Multiband Dynamics.
The Low and High bands have their own exclusive switches that bring a unique aspect to the 1973's compression signature. On the Low band, this switch is labeled "Big" and has the effect of reducing the compressor's side-chain sensitivity to low frequencies, resulting in a louder low end. The High band's switch is called "Air," which re-introduces some of the high-frequency sparkle removed by compression. These switches can certainly be useful, especially on busses, but I'd advise a conservative approach—in my tests, the effect easily jumped out of the subtle range into in-your-face territory.
There are a few other things worth noting about 1973's controls. Upon opening the plug-in, you may notice that while the threshold knob defaults to 0dB, the gain reduction metre will flash when you send through most audio signals. This is because the 1973 uses analogue-style dbVU scale metering rather than the dbFS scale used in most DAWs. This means that if you want no compression applied to a band, you need to turn the threshold fully counter-clockwise, which raises the threshold past 20dB. Another thing that may surprise some producers is the lack of a ratio knob. As you're probably aware, many compressors have a ratio amount that controls the severity of compression above the threshold. The 1973 uses a fixed soft knee ratio which automatically applies more compression as the input signal increases. So if you're after aggressive brick wall compression or limiting, you'll need to place another device in the chain after the 1976. Finally, the Fast, Mid and Slow release options are notable for allowing the release time to automatically adjust to the dynamics of the incoming signal. This is great for preventing the artefacts associated with incorrect release times, but if you want a fixed time, you still have a choice of 80mS, 300mS, and 1 second.
During testing, I was impressed with how accurately Softube modelled the hardware 1976's field-effect transistor (FET) circuitry. This isn't surprising given the fact that they worked with the original creator, Ivor Drawmer, and received his blessing on their work before releasing the plug-in. My only complaints are strictly technological. First, as anyone who has installed Softube plug-ins will attest, they use a common installer for all of their plug-ins. This means you have to download and essentially install every plug-in they offer, even if you're just activating a single plug-in. This results in a fair amount of wasted disk space, which could be a real concern for laptop producers. Secondly, the PACE iLok copy protection that Softube uses for their plug-ins is currently incompatible with some 64-bit DAWs on Windows 8.1 and Windows 10. I personally experienced this pain as the Drawmer 1973 plug-in crashed and was consequently disabled when I opened Ableton Live. Other users have reported issues using PreSonus Studio One as well. Supposedly you can work around this issue by launching the DAW in Windows 8 compatibility mode, but that has its own potential downsides as well.
Still, if you're looking for a full-featured multiband compressor, the 1973 is a great choice. It can be used both as a buss compressor to shape or tame the dynamics and overall timbre of a vocal or instrument, or as a mastering compressor. In addition, with mid-side processing capability (a feature exclusive to the plug-in version of the 1973), it can also be used for stereo width control. However, with great power comes great responsibility, and some less-experienced users could easily find themselves overdoing things or creating problems in a mix—an issue common to all multi-band compressors. To that end, if you still want the sound of the 1973 but in an easy-to-use package, you may want to give the cheaper S73 version a look.
Ease of use: 4.2