DIY With DHI: Which comes first? EQ or Compression?
With EQ and compression being the most basic and commonly used tools in the audio engineer’s tool box, there’s often confusion when working with the two of them together. And just like the ol’ “chicken and egg” debacle, there are a few view points on whether or not to EQ before or after compression. And whether you’ve wondered about this for yourself, I’m here to clarify the differences for you.
EQ Before Compression:
Maybe you’ve noticed that even on stock Pro Tools’ EQ plugins, there’s an “output” meter showing you how much any change, plus or minus in frequency vs dB, affects the overall signal level. For instance, if you crank 100Hz on a bass guitar by plus 12dB, chances are, your signal is now clipping. Aside from the rabbit trail topic of trying your best to not have to drastically EQ a source, if you place your compressor after that EQ in the signal path, you’ll hear that compressor reacting to that bass boost in a somewhat “uneven” fashion. The same would be if you dramatically high passed a frequency on that same track. Try using a high pass filter at a ridiculous frequency on that same bass guitar at say…400Hz. If you didn’t change the settings on your compressor from the previous low end boost, you’ll notice that same compressor reacting completely differently. In fact, you’ll need to increase your input level/threshold since you severely cut signal by removing everything under 400Hz.
EQ After Compression:
On the contrary, by putting your compressor before your EQ in the signal path, your compressor is not the first processor to react to the incoming signal. Let’s stick with the bass guitar track. By allowing for the entire frequency range to be first compressed, often times, you’ll be able to make more accurate EQ’ing decisions. “EQ Artifacts” is terminology used to describe that “EQ’d sound” and also explanation for why a track can sound dull after applying compression before the EQ. Since, in this instance, we’ve applied the compression before the EQ, adding 4dB of 80Hz to the bass guitar is actually resulting in a more accurate low end frequency gain since there’s nothing restricting that frequency once EQ’d.
Trust me, compression is a tough enough thing to hear on it’s own if you’re just starting out. It took me a long time to finally identify “that sound”. In fact, there are still subtleties that I gain understanding of every time I talk to a more experienced engineer or producer and each time I hear their work. The key is to keep practicing, keep making music, and most of all, remember-this is supposed to be fun!
Sean Rogers is the Director of Student Services at Dark Horse Institute as well as a seasoned producer and audio engineer. He has over 7 years of career counseling experience and is credited for his work on major label projects for artists such as Lady Antebellum, Dierks Bentley, Eric Church, and more.