Dave Rat - Roadies in the Midst

Here we go Blink 182 and cool rock show. I have not really figured out my direction yet as far as blogging and adventures but in the mean time, I may as well rock on the tech side of things. Will work on losing my mind later.

The Los Angeles Forum was the playground for testing and getting things dialed in.

So what is new for this tour? Well, the new K1 rig is a monster! Truly some breathtaking horsepower, V-Dosc with nitro boost. Aside from the significant jump in clarity, it can pump enough low end from the main hangs to make the subs almost optional.

Similar to the Peppers rig, I am once again using an 8 foot by 8 foot sub array with a blow through aluminum grate on top that doubles as stage wings. It is a really cool way to go as it gives me a lot of freedom with the sub design without eating up valuable floor space while keeping the setup clean visually. My goal once again is to attack the issue of whimpy low end off to the sides of stage and while gaining control over how much power alley there is.

For those non-soundy humans, power alley is the term used to describe the area down the center of the venue where the low end tends to be more powerful than elsewhere. So in itself I guess a 'power alley' is good for the humans hanging out there but that also means that everywhere else is not a power alley. For some odd reason, it has become a commonly accepted practice to have a strong power alley. Personally, though I love the low end power, I really work hard to get the sound as consistent as possible throughout the venue. Forget power alley, I want a Power Valley and I want everyone in it!

Easier said than done. Turns out that if you stack horizontal sub arrays on the left and right sides of the stage, they will be loudest midway between them while off to either side of center the low end drops off quickly. One solution is to put all the subs in the middle which works fairly well and also tends to completely wipe out the band on stage with low end. Also, the center sub thing tends to really smear the heads off the humans parked in the front rows.

Another method that is becoming more common is to fly vertical line arrays of subs. This solves the blasting the front row humans issue quite well, offers improved low end off to the sides and a more reasonable power alley. The issues are that the vertical sub line arrays create these cancellation nodes that project like spokes just to the left and right of audience center. The cancellation nodes can be quite pronounced to the point where there are areas with almost no sub right next to areas with powerful sub sound. Another drawback with flown subs is that they create a sideways power alley. By that I mean that there is a power alley effect that offers strong low end at floor level that tapers off as you increase in altitude. You see, the floor acts like a mirror to subwoofers. When you stack subs on the ground, the subs are sitting on the mirror, in effect doubling the energy radiated.

Just as power alley occurs in the horizontal plane (wide vertical, narrow horizontal) with subs stacked side by side on either side of the stage, a vertical power alley is created when subs are flown in a vertical line (narrow vertically, wider horizontal) caused by the interaction between the flown sub array its reflection in the mirror (floor). Since power alley is in effect most pronounced for the locations horizontally equidistant from the subs, with a flown sub line array, the subs are loudest for humans vertically equidistant from the subs and their reflection. In other words, there are challenges in the vertical coverage with the center of power alley at your feet dropping with elevation. For a flat field show this is not really an issue, and can be an asset but in arenas and venues with humans up high, the reduced vertical coverage can be a significant issue.

Several years back I was doing a show where the sound vendor swore up and down that we needed to fly subs. Even after I killed the idea, I was surprised to not only find that they were flying subs when I arrived, but they went on to tell me they were going to fly twice as many. Why? Well, they went on to explain that they were having trouble getting low end into the balcony area of this huge indoor sports venue. After a bit muscle flexing and much to their dismay, I pressed the issue, made them drop all the subs and we ground stacked. I then personally walked the balcony with the head sound tech during the support act. "Better?" I asked. He was quite surprised and fully agreed that the subs to the upper sections issue was solved. The price? Well, I had power alley back in the horizontal again which meant the lows dropped to the sides. But for that venue which was not very wide, the percentage of people that heard solid low end was significantly increased.

Alright, time to fly, more to come tomorrow as I try and regain some bloggery momentum.

 

Dave Rat