Suggestions for Getting a Great Sound at Lower SPL’s
How loud is your P.A. at the mix position? 100 dB? 105 dB? 115 dB? Do you even know? When was the last time you had a reality check and measured the average SPL for your show? Do you really need to mix that loud?
Of course you do! It’s rock ‘n’ roll, man! That’s why people come to the show — to get blasted and get blasted. Some of us live in that world, and some of us do not. Some of us live in the “meat and potatoes” world of audio: leave your attitude at the door if you want the gig to be on the calendar next year. As we’ve discussed in the past, being invited for a return engagement often means heeding the house rules — and the house rules often include an SPL limit. Maybe it’s because there’s trouble with the neighbors, or maybe it’s because you’re not the main event. Maybe it’s because there’s a portion of the audience with blue hair or because your band is playing “unplugged” for a change, but the reality is the same: sometimes, you gotta turn it down.
What? Speak Up!
Some engineers are afraid to discover how loud they mix. If they don’t know how loud it is, then they can’t hurt their ears. Without getting too far off-topic, Fig. 1 shows guidelines from OSHA (the Occupational Safety and Health Administration) for noise exposure over time.
Note how the acceptable exposure time gets shorter as SPL increases, and look at the last four entries in particular. If your average SPL is 105 dB A-weighted, your exposure should be limited to an hour. While that’s a realistic SPL for a show, the length of time is probably not (i.e., the show is probably longer than an hour), so hearing conservation is probably another strong motivation for turning it down.
Does That Thing Go Below Eleven?
Your ability to control the SPL in the house is directly related to the band’s stage volume. If you can get the stage volume down, it’s easier to reduce the volume of “band plus P.A. system.” It’s very difficult to produce a 90 dB mix at FOH when the band is at 110 dB onstage. We’ve covered these concepts in the past, but here are some reminders of techniques that help reduce stage volume:
- Plexiglas baffles in front of the drum kit help reduce spill from the stage, and keep drums and cymbals from leaking into vocal mics. Ditto for baffles placed in front of guitar amps.
- Consider using smaller guitar and bass rigs, amp simulators that can be taken direct, or use guitar amplifier load boxes.
- Move guitar cabinets off-stage or turn them around to face upstage.
- Encourage the performers to use IEM’s.
- Try to keep stage wedge mixes at lower volumes.
Whump!
Leave the “Big, Badass Kick Drum” at home. I’m gonna’ get up on my soapbox now. Sometimes, you need the BBKD, like if you’re mixing Metallica or a rap or hip-hop artist. But recently I’ve witnessed at least two different engineers for well-established national acts make their bands completely unlistenable by making the mix all about the BBKD. Really? Have you listened to the band’s records? Do you realize that the band’s hits were made long before anyone knew about the BBKD? I even heard an engineer break out the BBKD for an unplugged set from a classic rock act. Ridiculous! I’m not saying that you have to take the kick out of the house mix, but for crying out loud, turn the friggin’ thing down so we can avoid a headache after ten minutes. Walk down to the front rows during sound check and evaluate the low-end of the P.A. up-close and personal. Sometimes that bottom end doesn’t make its way to the mix position, so you think the mix is balanced across the room, while you’re killing people with low-end in the front rows.
Use Fill Speakers
Instead of making vocals and solos super loud to overcome lack of coverage for the first few rows of seats (or perhaps the balcony), use fill speakers directed into areas neglected by the main P.A. Front fill speakers become especially important when there are no vocal wedges on stage because the first few rows of the audience won’t hear any spill from vocal monitors. Instead of taking a brute force approach using the mains, dial those instruments into fill speakers directed at the areas that need them (see Theory and Practice in the July 2012 FRONT of HOUSE for more info on setting up fill speakers).
Some New Mix Ideas
Speaking of vocals, try a different technique for building your mix. We all get into the habit of dialing in our drums, then adding the bass, other instruments and last, the vocals. Try starting with only the vocals in the P.A. Listen to the mix of vocals from the P.A., and band instruments from the stage, and then add instruments into the P.A. to support the vocals. This gives you a sort of baseline regarding whether or not you’ll have to crank the P.A. just to get the vocals to overcome the stage volume. It also gives you the opportunity to see how much the bass rig contributes to the house mix. In smaller rooms, you can allow the bass amp(s) to contribute more to the mix and use the P.A. as reinforcement as opposed to amplification. In situations where the bass rig does contribute significantly to the house mix, increase the subwoofer send on the bass DI channel to restore some of the warm-and-fuzzy low-end you might otherwise miss.
That last statement is where our bottom line is drawn as far as reducing volume in the house: use the P.A. for reinforcement, as opposed to sledgehammer amplification. No one says that one hundred percent of the house mix must come from the P.A. system. It can be a combination of stage sound plus P.A. and — as you won’t be attempting to drown out the stage with the P.A. — you can keep the overall level down. If you’re worried about a guitar amp being louder on one side of the room, put it in the P.A. panned slightly to the opposite side to ensure consistency across the seating areas. And while we’re talking about using the backline as a significant part of the house mix, make sure that the P.A. mains are delayed to the backline, which can help reduce phase issues and provide more coherence between the P.A. and the backline. At times during songs, consider pulling certain instruments down to make room for a solo or vocal, as opposed to raising the level of the vocal or solo instrument.
Obviously, mixing at lower volumes benefits your hearing health, but there’s another benefit that’s not so obvious: reducing the volume of a P.A. system also reduces excitation of room modes. This enhances the consistency of the mix across different parts of the room, and avoids small areas where low frequencies might otherwise create standing waves (areas of constructive and destructive interference).
