UA’s software compressors fall somewhat into two types: vintage and simple to use, or modern with lots of flexibility. The LA-2A, LA-3A, and dbx 160 fall into the vintage, simple-to-use category. The Neve 33609, Neve 88RS, Precision Buss Compressor, Precision Multiband Compressor, and Precision Limiter fall into the more modern with-lots-of-flexibility category. Of course, I left out two big ones: The 1176LN and Fairchild 670. In my mind, these two have always straddled the two categories.
Every experienced audio engineer has their “go-to” compressor for certain audio tracks and applications. In this compressor shootout, I am going to use each compressor on a parallel drum buss. In another example, I am going to use the compressors on a vocal, and my goal is to really compress the vocal so you can hear the different qualities of each compressor. The presets for each compressor are included for downloading.
In the first set of examples, the goal is to compress the drums quite a bit and then mix that compressed signal underneath the uncompressed drums. This is a common trick that helps make the drums sound huge.
Some compressors were not able to duplicate the same attack and release times. With the Precision Buss Compressor, for example, the fastest attack and release times are 0.10ms and 100ms respectively, while the attack on the 1176LN can be as fast as 20 microseconds! Other compressors, like the Precision Multiband, are not really designed to compress the entire band, especially at the high amounts of compression I used. But I did my best to get them to sound the same by using a combination of the values of the parameters and my ears.
In the first set of examples, the goal is to compress the drums quite a bit and then mix that compressed signal underneath the uncompressed drums. This is a common trick that helps make the drums sound huge. I am going to try to make each compressor sound as similar as possible. My benchmark is a 1176LN compressor. At the settings I liked, the attack and release were pretty fast, maybe 2-3ms attack, and 10ms release. It is of course hard to tell exactly what the attack and release times really are on that plug-in! Your ears are the best judge.
In the audio examples, I first play the compressed track, then I add in the uncompressed drums, and the kick drum. The kick drum was not sent to the compressor., since it has a tendency to kick the compressor into high compression and cause some pumping effects, which I was not looking for. I also had a Cambridge EQ set up after the compressor to roll off a little high end with a 6dB/octave low pass filter at 9k, since the compressor brought out a little more of the cymbals than I wanted.
As you can see from below, I am compressing the drums quite a bit, and getting about 10-15dB of compression. I really had to crank some of the controls on the other compressors to achieve this same amount of compression.
On this vocal track, my benchmark is the LA-2A, which is probably best known as a vocal compressor. In fact, it was designed to be used in radio broadcast studios on the announcer’s voice. Many of the compressors we have did come close to matching the LA-2A since the LA-2A’s attack is fairly slow (approx 10 ms) and the release is about 60 ms. But, the release changes after it reaches the 50% point. Rather than delve into those details here, please read the July 2006 "Analog Obsession" article for more info on the attack and release characteristics of the LA-2A.