One of the most important components of a great mix is getting the bass drum and the bass guitar to connect as a unit. Sometimes it’s easy; other times it can be a struggle. Most of the time it’s about the sounds, but the playing skills of the drummer and bass player also play a large role. You need to understand how much of each are a factor in this.
We’ve discussed the issue of phase with drums and how that works in getting good sounds. When you have more than one mic on any instrument it’s important to make sure they add together. And what I mean in this post is that when the bass drum and the bass play at the same time they should sound like a single instrument. You don’t hear two things, you hear one.
But no matter how great the engineer is, if the drummer and bass player don’t groove well, there will be problems making that happen. It’s then time to break out Beat Detective or whatever you prefer to get them to where they’re locked and you’ll then at least have a chance of the mix sounding good.
But assuming they do play well together there are a few things you can do to help make them sound like one unit. Of course EQ is a major one. I wish I could tell you the secret frequencies to add or subtract to make that happen. And while there are general guidelines, like pulling out 300-400Hz on a bass drum, that only works if the original sound had too much of it. So be cautious of generic frequency suggestions. They are based on assumptions which may not be the case in your mix.
Of course to start with you need to have the drums phase coherent. Remember is Recording Tip 23. “When using multiple mics, always check phase.”
By following those guidelines when recording you should have your drums in good shape and have phase problems resolved within the drum kit. And when mixing tracks you didn’t record you need to do similar checks with the drums recorded to make sure each track adds properly.
Ideally, when the drums are all in phase, a hit on the snare or kick (providing the system is set up properly) will cause the speaker to move toward the listener. Personally I don’t worry too much about that. While one can test it, all that really matters is that the drums are phase coherent within themselves. Once that’s done and you’re working with the bass, you may feel the bass guitar is moving opposite in phase polarity to the bass drum. (i.e. the speaker moves away from the listener when played) If I’m not not having success in getting the bass drum and bass to sound as one, I’ll try flipping the phase (polarity) button on the bass. If you have an amp and direct signal, of course you need to first make sure they are in agreement. This is something you must always do whenever you have both an amp and a direct signal. Listen to both signals, and flip the phase of one of them. I normally suspect the amp is more likely to be wrong and flip that first, but be sure to check one of them. It will be pretty easy to hear if they are adding or cancelling.
Once you have the bass phase resolved and you want to check it’s phase against the bass drum, you will need to flip both signals to see if that helps make the instruments sound as one. Don’t flip the phase of the bass drum, as you should have already checked that and gotten it right.
I will admit more often than not I’ve not needed to flip the phase of the bass. But on occasion it has done the trick. Hopefully the first order of business is there, the players are locked up and grooving. And if that’s so and you can’t get those elements to connect, give the old bass phase flip a try.