Back in the good old days when I was a songwriter with deals with Casablanca, Chappell-Intersong, EMI, and other publishers, I was in different recording studios with different engineers all the time recording and producing my songwriter demos. (Boy, do I miss that!)
Generally, the recording studios would have several compressors like a Urei 1176, Teletronix Audio LA2A, and a DBX 160. (No, I never actually saw a Fairchild 660 or 670 of Beatles fame, too expensive I guess.) And of course, the SSL, Neve, Harrison, and other recording consoles in the studios all had their own built-in compressors on their channel strips.
In those days, engineering in general and compressors specifically held little interest for me and I was totally focused on singing, songwriting, and producing my recordings of up to 4 demos a day, with an eye on the clock, that I had no mental space to learn from the engineers about the decisions they were making. Also I was more than a little intimidated by the world of frequency ranges, decibels, and all the circuitry and wiring of consoles and standalone effects. So I had no clue why the engineer would reach for one compressor rather than another for a specific musical task. Later on, as budgets shrunk and I had to do my own engineering at times, I became much more interested ☺ and started to learn to hear the differences that the various compressors could achieve. Here is part of what I learned.
My Over-simplified Overview of Compressor Types
The LA2A is a tube Opto (optical) compressor. These kind of compressors have a slower response and are considered to impart warmth to a track. Typically, you would use on vocals, pads, even electric bass, but less frequently on drums and percussion.
The DBX 160 is a VCA (voltage controlled amplifier) compressor that controls levels cleanly and consistently without coloring the sound much. They are frequently used on drums and percussive elements as they have a quicker response than an Opto. I actually owned one of these and it served me well in my own studio as a Swiss Army Knife type of tool. SSL consoles also are VCA based but a less vintage take on the sound.
The DBX 160.
The 1176 is a field effect transistor (FET) compressor. It has very quick response and is great for aggressive sounds like rock vocals, drums, electric guitars, etc.
These have been emulated in software by Universal Audio, Waves, Steven Slate, Softube, and many others. All have their passionate advocates and passionate detractors. Even the stock included DAW compressors, like Logic Pro X’s Compressor do a decent job in the minds of some users . But are the differences as significant in software as they are in hardware? Some say yes, others say no. I will provide some examples with the software and let you decide how much difference you hear.
Even the stock included DAW compressors do a decent job in the minds of some users.
This listening experience for you will admittedly be flawed as my level matching will not be precise and I will be using only two pieces of source material, and I cannot provide you with versions recorded with the hardware to compare them to, which I know from my experience would yield some pretty obvious and dramatic differences. But I have received some conclusions about this and I will be really curious to read yours.
Here are some audio clips of a simple vocal part created with Realitone’s Realivox Blue, There are versions bounced with the Logic Pro X Compressors emulations of Opto, VCA, and FET compressors as well as the UA versions of them (LA2A, DBX 160, and 1176) with no EQ, reverb, or messing around with the settings, other than input adjustment to approximate level matching. You may want to do some further level matching in your DAW.
UA LA2A (Vocal):
UA DBX 160 (Vocal):
UA 1176 (Vocal):
Personally, I hear little or no difference between all the versions with all the different emulations. What do you hear?
So maybe it is the source material? Maybe those simple sampled vocals are not an ideal illustration.
Here are examples done with a basic drum beat with Logic Pro’s EXS24 Standard Dry Kit, a very different kind of source material.
UA LA2A (Drums):
UA DBX 160 (Drums):
UA 1176 (Drums):
Again to my ears, not a lot of difference, maybe a little more however than with the vocals. What do you hear?
Am I saying that there is no need to own more than one software compressor because they all sound the same?
So, am I saying that there is no need to own more than one software compressor because they all sound the same? No. The more you work with them and start tweaking knobs for input, ratio, threshold, etc., you may find that they react rather differently and you very well may decide that you are able to more quickly dial in the sound you want with one or another because of the way they react to your adjustments and your reactions to the GUIs. For me, having some familiarity with the hardware, the UA emulations get me where I want to go very well, and I will definitely reach for an LA2A, for smooth sounds, the 1176 for aggressive sounds, but rarely the DBX 160. Just personal taste. Also, the UA Fairchild just gives me something for ’60s type stuff that I really like very quickly, and you may like it as well, or the UA Manley Vari Mu, especially if you are familiar with the less common type of compressors known as Vari Mus.
However, the bottom line for me is that with software emulations of hardware compressors, I have concluded that you probably cannot get a sound with one that you cannot get very, very close to with another, and that is not necessarily true with the hardware.
What do YOU think?