As a concert producer, I’m frequently asked which subs I would recommend. Subwoofers, like mains, are selected by the type of music you will be playing though them, and how they are going to be used. For the purposes of this article, I’m going to restrict the conversation to just Dubstep, and Drum and Bass.
Dubstep and Drum and Bass have a huge amount of content in the 20hz – 50hz range, and if you do the math, you are going to need about 5000 watts dedicated to a that frequency range to produce enough of that sound to be heard along with the rest of the music.
My larger setup is (5) QSC HPR181s across the front of the stage, (6) Martin Blackline dual 18’s for the house, and 2 Bag End Dual 18’s running 8000watts through an ELF processor dedicated to the 8hz – 50hz range through a lab gruppen amp. When I play smaller shows, I just use my QSC HPR181, which are 700 watts each, but good for ultra high volume bass. The QSC’s are self powered and take all of 5 minutes to setup, which also helps. Now I’ve heard the common wisdom, don’t mix subwoofers, but in reality, I’ve yet to find one sound manufacturing company that does it all, short of a tour package that is produced for a given show, rather than a type of music (an important distinction). That said, crossover points and keeping each subwoofer and the overall system in phase is very important when mixing subs.
Setting the crossover
Conventional crossovers, like the very common dBx DriveRack PA have a good and fairly adjustable crossover that also includes the ability to change the slope of the roll off. When matching and tuning subwoofer frequencies, I’ve noticed that although the crossover claims to have rolled a frequency off, some of the content continues to be transmitted to the sub. Clearly, when two brands of subwoofers are generating the same tones, distortion is created. I, therefore, separate the frequencies by about 5hz. Visually on the crossover, it appears that I’m losing musical content, however, with the amplification gain, in fact I’m not, and a RTA mic will confirm that the setting are correct.
Sealed box enclosures and subharmonics
Bag End is really the go to here. There are other sub systems that do subharmonics, but Bag End was first, so I’m writing about them. The Infra processor, and before Ron Wickersham left, the Elf Processor are the two key components. Dubstep and Drum and Bass require a huge presence in the 20hz – 50hz range. Most people cannot hear music in this range, but you can feel it, and you can feel the difference between 20hz and 40 hz when the signal is clear and free of clipping. The Infra processor is available in two forms. The first one has a flat response down to 18hz, the second one to 8hz. 18hz is much more efficient for larger systems. If you have an extra 20k to burn, then go for the 8hz integrator and (4) dual 18’s. You will need a substantial amount of AC Power to run the amps as well, usually an additional 20amp 220 circuit for a Lab Gruppen or four 20amp 110 ciruits for four QSC amps bridged into each sub. My Bag Ends generally pull about 3000 watts per dual 18 when generating content STRICTLY LIMITED to the 18hz – 50hz range. I should note that making adjustments to your crossover at full volume can quickly destroy all of your equipment, so be careful, and know your equipment frequency response and power handling ratings.
Subs vary tremendously in price. In the lower price range, I have heard the Peavey blackwidows, which are technically louder, but much less musical. When you are mashing up two tracks, or quickly transitioning from one to another, it is tough to hear much difference with the Peavey subs, they are just loud, not so much musical. JBL and Cerwin Vega subs are fart cans, and I think most people know this. They can rumble and shake, but they don’t have an articulated sound – a clarity in the low end that is absolutely necessary for Dubstep and more so for Drum and Bass.
Some other equipment that I’ve tried, If you are rich, the D&B (not db technologies) audioteknic Q2 subs are killer, EAW 218z subs are pretty good, McCauley does a pretty decent sub with good all around specs for Dubstep, and Bag End kills. All of these cabinets require extremely expensive amplification though. You can get 12,000 into amps alone before you can even turn on a mid-sized system of this caliber.
Another alternative, is to build your own box. This is not a beginner project, but if you love wood working, and have a spare 2500 bucks, you can build some pretty amazing cabinets. The best way to do this is to get on the forums and look at designs, then read the threads through. Often people post reviews over the course of years.
Look for a design that has a good frequency response down to 40hz, and a driver that has exceptional frequency response. OHM (brand) makes a pretty incredible driver, and there are a couple of high end RCF subs that are bad to the bone.
Listen to them before you buy them if at all possible though, using a parametric EQ and shut off all frequencies except for the 20hz to 50hz range – that is the sweet spot of Dubstep that makes it truly different from other similar music.