me think less and sound better.
acoustic guitar and vocals through my board and sent a stereo signal to the Mackies. Hookups to the subs are all XLR and very sim- ple to figure out. You get left and right full- range inputs with L/R thru outputs for daisy chaining and L/R high-pass outs, which I hooked up to the SRM450s. Each sub has a vol- ume knob and a phase switch. The speakers are designed for plug-and-play use, which lets
When I turned the system on and started my soundcheck, I immediately noticed the subs’ tight bass response—they really filled out the band’s sound. Even vocals and acoustic gui- tar sounded more rich and full with the added bass. During the night’s performance we got into a drum/percussion breakdown. The dance floor was full, so I went out with my wireless guitar to hear the boys play. The added low end really moves an audience, especially the girls. I know that sounds sexist, but it’s true. Need-
Reprinted with permission of United Entertainment Media, Inc. © Gig Magazine 2002.
less to say, the night was a great success. We rocked the house ‘til closing.
Though powered speakers are far from a Mackie invention, the success of the SRM450s really helped ignite the current conflagration in the market for active cabinets. Coupled with the 1500 subs, they make for a well-rounded and flexible system suitable for small to mid- sized club gigs.
(Originally appeared in the February 2000 issue of GIG)
BECOMING DOWNWARDLY MOBILE
Mixing Effectively with Powered Subwoofers
BY JON CHAPPELL
Just as surround sound has forced the recording industry to rethink its approach to bass management, so too has the subwoofer and satellite combination required SR and FOH engineers to adapt their mixing strategies to optimize the new bonanza of low-end sound that dedicated subwoofers provide.While separating the bass from the highs and mids offers advantages in tone shaping, cabinet place- ment, definition, and efficiency, it presents some challenges, too. “With a sub and satellite system, you can’t just hook up the sub to the left stereo output of your mixer, says Kyle Ritland of Mackie Designs.“Well, you could, technically speaking, and it wouldn’t hurt anything, but you won’t get the best sound.You won’t be using the sub properly.”
Though midrange cabs and self-contained three-way systems have been commingling the high and low for years, the addition of the subwoofer means that to benefit from its inclusion, you have to use it correctly.The first step is to make sure that nothing but bass goes through that subwoofer, and the easiest way to do that is to feed it only bass signals—bass guitar,kick drum,synth bass,or synth pads with significant low-end content.
“What live engineers will do is mix to the subwoofer using a post-fade aux bus from the console,” says Gerry Tschetter of JBL. “And the only things that go into the sub are things like the kick and bass, elements that have low frequency content.And it cleans up the sound.”
Yamaha’s John Schauer agrees:“Most guys won’t even run pow- ered subs as part of the main system, but if they do have bass in the mains and the sub, they can slide the sub in and out with that aux send control to accentuate certain elements.” A good example of the accentuation approach would be during a bass solo, or a solo kick drum as it plays through a stop-time or break-down section.
Fig. 1 shows one way to mic up a drum kit and use the aux sends in two ways: 1) to add reverb in the way an aux send is nor- mally used, and 2) to route the kick drum mic to its own dedicated subwoofer. If the send control is switchable between pre and post, make sure it’s set to post, or the subwoofer won’t respond dynam- ically to your fader moves.
Mixing bass through a separate system can actually solve many age-old problems of phase cancellation,too.Tschetter explains:“Let’s
Fig. 1. You can route a bass signal, such as a kick drum or a bass guitar, to a dedicated subwoofer by using an available post-fade aux send.
say you’ve got a good-sized stage and a bass rig that goes directly into the system through a direct box. But there’s also bleed from the open mics because the bass travels as sound from the amp through the air to the mics. Now, that live path takes much longer than the direct path, which is virtually instantaneous.The problem with all-in-one cabs is that both the mic-bleed sound and the direct sound are interacting in the same box.You could have some seri- ous phase-coherence problems there. So the way to fix that is take the bass’s direct feed out of the mains.You’ll still have some bass from the bleed, so you’ll have a full sound, but at least you won’t be mixing those time-shifted bass frequencies within one box.”
There are many advantages to using a dedicated sub in a mixing situation, in addition to the better sonic definition it provides. Here are a couple of tips for using a separate subwoofer that will help you improve your live sound and make mixing tasks more hassle- free.
If you must put full range material through the sub, be careful to
bury the sub during spoken speech segments, like when the singer introduces the song or engages in stage patter.“Subs are not good with vocal intelligibility,” warns Schauer. “They start to sound like the adults in the Peanuts cartoons.”
Work with your keyboardist to get his stereo patches optimized.
A keyboardist creating a stereo split will put the bass on the left and the treble on the right, because that corresponds to his right and left hands. So take the channel with the keyboard’s left output and run that through the subwoofer using an aux send,as described in Fig. 1. He’ll love you for it.
F E B R U A RY 2 0 0 2 • gigmag.com