It’s a catchy song lyric that implies a bootylicious good time but it’s also a great way to approach the beginning stages of building a mix.
We’ve all been in a sound check where the kick and snare felt like they were going to crush your skull, and the cymbals sound like an amplified band saw. Once the instruments are added in there’s no way to get the vocals loud enough to hear without the mics feeding back. No doubt we all have the grandiose dream of mixing Lead Zeppelin and U2 in a massive stadium for 30,000 + screaming fans slamming the worlds largest PA at 135dB. The reality of it is we are not the U2 front of house engineer and Zeppelin doesn’t play many shows anymore. This doesn’t mean that we can’t build powerful mixes that surround us and convey the power of the music.
I often receive compliments about how full and large my mixes sound without feeling overwhelming. I mix a large range of shows from a small barn to theaters and arenas. Although the bands vary in style and the sound systems range from small trap boxes on tripods all the way to multi zone line arrays, I still obtain a consistent result. I believe it’s because of a carefully considered gain structure during sound check.
I begin every event by checking to see what the desired volume level is for that event and evaluating the PA system to see if it’s achievable. I then run a few songs at low volume through the system to see if it functions correctly. If the system is good to go I will then increase the volume of the music to or near the level of the desired total volume. I then walk the room listening for any unusual sounds or reflections. This next part I find to be very important. I will mute the music and listen to the reverbs and decay of the sound. I will do this several times in a row and each time focus in on a certain frequency range. This will tell me how the room naturally amplifies sound, what aspects will quickly become loud, and what aspects will require more power from the PA.
My current job has set a volume range that is very generous and allows me a great deal of freedom. Even still, it is very easy to go far above the limit that has been agreed upon. I approach staying within the volume limit similarly to how our friends in the recording studio approach a final mix. For this example let’s say our limit is 100dBA. These volumes are to show the concept and approach I use. Often times the levels will change greatly depending on the style of the music and the audience that is listening.
I’ll start with my drum kit and bring each drum up to a good volume around 88-92dB. Then I’ll do my wizardry with EQ, compression, and gating with my goal being to come out with a drum kit averaging around 90-92dB. Then I’ll move to the bass. With this single instrument following the drums, the temptation will be to bring it up in volume to complement the drums. Doing this will give you a very powerful and loud bass guitar. As a rule of thumb I would aim for 87-90dB with the bass giving you some room for the lows of the drum kit to breathe when they are played together.
Now moving to the guitars and keys. Electric guitars can be pesky when it comes to volume and tone. For the rockers that need to shred and wail we need to give them a wide path. I still aim for 87-90db but I use a specific requirement to determine who gets set to what volume. The brighter the tone of the electric guitar the lower they are set in volume. The darker, the louder it is placed. Brighter, higher pitched sounds will be perceived as louder and closer than darker tones. The same rules apply to keyboards and synthesizers.
Depending on the style of music, you can place the keys or guitars on top. I always ask my players to go through their range of sounds to determine if they have a tone that will change through the course of the performance. Hopefully, when you combine all these instruments, you should land comfortably in the 92-95dB. This gives you 5dB of headroom for your vocals. That doesn’t sound like much, but it’s often more than you need for most modern rock style music.
With vocals we want to set (in a soloed situation) them in the range of 94-97dB. Setting them 2-4dB louder than the band’s total volume will give them enough power to be heard over the music. It is worth saying that for every vocal mic you add to a live environment you generally lose 2-3db of gain before feedback. This means with one mic you can run at 95dB with no feed back potential. With two mics you would have to lower the level to 93dB with three mics 90-91dB. There are ways around this principal and the type of mic will affect this, but it’s a good rule to keep in mind when building a mix.
So by keeping our individual volumes at lower levels and allowing the summation of the instruments and vocals to build on each other, we can build a large, full mix with room for everyone to be heard and not fight for positioning.