PreSonus Blog

Compress Only the Bass’s Midrange

A bass’s low strings typically produce more energy than the higher strings. So, the low frequencies will push a compressor into compression before the higher strings produce enough level to be compressed. This can overcompress the lower strings, which doesn’t let them ring out and sound full.

Fortunately, there’s an easy solution—thanks to the Compressor’s internal sidechain filters. Enabling the Low Cut filter, and rolling off low frequencies (fig. 1), reduces how much the low frequencies are compressed. (This tip complements the tip on Frequency-Selective Guitar Compression, but doesn’t necessarily need its optional sidechain-based version.)

Tip: Cutting the internal sidechain’s low frequencies can also be useful with drum tracks. This prevents the kick drum from triggering heavy compression that dominates the rest of the drums.

Figure 1: The Compressor’s internal sidechain filter is reducing compression at low frequencies. The Low Cut filter is rolling off frequencies below 250 Hz.

Fig. 2 shows the effect of the above settings. The left image’s response is with the Low Cut filter bypassed. The compression is more uniform over the entire frequency range. The right image’s response has theLow Cut filter enabled, which tilts the response toward the bass. Although the levels are about the same above 200 Hz, the low-frequency lift below around 100 Hz is due to the less-compressed, lower frequencies.

Figure 2: (Left) 250 Hz Low Cut filter bypassed. (Right) 250 Hz Low Cut filter enabled.

Note that the spectrum analyzer’s vertical scale covers a wide range, so the boost is around 3 dB—enough to make a significant difference. So, next time you want to compress your bass, but not lose the power of the low strings in the process, let this technique give you the best of both worlds.

For more tips on how to get the most out of Studio One, check out the series of Studio One eBooks that cover tips & tricks, creative mixing, recording/mixing vocals, dynamics processors, and recording/mixing guitar. Remember, just like software, eBook owners can download the latest “point” updates for free from their PreSonus account (or Sweetwater account, if purchased from there). Owners are also eligible for new editions at a reduced price.