Dave Rat - Roadies in the Midst

Jones Beach. I remember the first time I ever did a show here was Lollapalooza 1992, the first of two shows went on with out a hitch but for the second show our little friend Hurricane Andrew decided to drop by for a visit and lay a category 5 wind and rainstorm on top of all the wires, speakers, lights and humans. Talk about torrential downpour! I have some old video of it somewhere that have been meaning to post. Pretty intense seeing the lights and PA swinging and mashing into each other. Big chunks of gear blowing over into foot deep puddles flowing in a cascading waterfall off the stage while sideways rain blows away tents and any attempt to protect the not so thirsty gear.

So I have settled into two subwoofer designs and hope to be able to flow one or the other into the rest of the tour gigs. The Vortex or Orgasmatron setup gives me a bit more control over coverage and allows me to disperse low end over a very wide area. Also the Vortex gives me excellent rejection on stage and directly behind the subs. Our other setup which I guess I will call the Slotfire Cannon. It is similar to the Sub Cannons I used to fire to the sides of the arena's on Peppers tour but they take up less depth, are more efficient and offer a bit better control. Being four feet deep and about 14 feet wide, the Slotfire should be able to drop into most sheds fairly easily. The has quite good control over widening coverage but offers very little cancellation behind the arrays. So for venues that have a wall behind the subs, the Slotfire is a good way to go. Conversely the Vortex work best if there is open space behind them.

Perhaps you noticed we spun the Vortex (Orgasmatrons) 45 degrees? Ahh for this gig it gave us better sighlines, so therfore better placement downstage and a bit more control. So here is the basics of the Slotfire setup as done morning of the show;

The theory on the Slotfire is to space two acoustic centers at 1/3 of a wavelength of the desired center frequency. For this I chose 45hz due to the sub design and program material I am sending, so about 8.5 feet or so. Then if I delay the outside acoustic source by 3.6 to 7.2, I gain a tremendous amount of control to steer the low end to the outside. Zero time delay gives me a figure 8 pattern, which I do not need as I want to steer outward and reduce power alley. Here are some simple predictions for one side

A 3.6 ms delay is 1/6 wavelength at 45 hz so if you apply that to the outside subs and add that to the 1/3 wavelength physical spacing, we get that 1/2 wavelength virtual spacing that gives nice cancellation towards the stage and steers low frequencies outward

And as we increase delay further it steers more outward.

So super simply I can control how wide the coverage is while reducing power alley, just by adding delay.

The trick though to get this all to work efficiently is to create two nice LF point sources with the subs. Ahhh, and that is where the super cool part comes. Because to get an 8.5 spacing of acoustic centers with 4 foot wide boxes means the stacks would only be 6" apart. Basically one big wall with some time delay mushing it up, which is lame and boooring! So what I did was to point the subs at each other with 12" spacing. Now I have two very clean 12" wide acoustic centers to work with. And wow! This setup kicks butt!

The sound of this setup is really solid and powerful, more so than the Vortex. But, keep in mind, the Vortex offers more control. If I setup the Slotfire in an arena, poor Steve and everyone else behind the subs would be completely obliterated. Never forget that the key is using the right tool for the right job.

Haa! I got to be the guinea pig for the flying drum riser test drive!

I think this was Montreal

May as well start introducing the awesome Rat crew out here putting up with my antics. Meet Jim, also known as Ice, not sure why but hey, nicknames rule. He is my FOH tech and the one who directly gets my world dialed in. I do put a lot responsibility on my tech, and really appreciate him keeping it together. Oh, Nick the Fly was out here but he went back to home world and was the front end guy that helped me get my wacky designs all dialed in.

This is Robert, he rocks the stage wire world

Scott Sugden (top left) came out for a few days to hang with us and Roz (working with Scott) is our laser room measuring K1 system design guru now that Nick is gone.

Manny is out here too promoting corn chips mainly but I think he does some PA setting up as well.

Re ran the orgasmatrons at Jones Beach. Good news is Mark Hoppus went inside during the show. Bad news is he tripped over the strap that holds them together and fell inside with his bass on mid show. Fortunately he did the party roll and landed on his back and seemed ok.

Hello Me

Jessica is our wonderful production assist and awesome to work with.

May as well toss some show shots in the mix

After the gig, we Blink fans all hang out waiting for the band.

Not really related but some say Pigeons are like flying rats, so I figured I would toss some props out to our flighty friend here.

Okey dokey artichokey. See ya soon for more brain twisting adventures soon.

Dave Rat

Oh so many things going on. Probably the most life affecting adventure for me coming up is a 10 week US tour with Blink 182. Ten or so years ago, I was mixing Blink 182 as they grew from clubs to arena's before returning to do a Peppers tour. Here we are a decade later and it is pretty cool to join them again for a North America shed and arena run. We are going to be moving fast and covering lots of ground with over 40 shows.

So what is the plan rubber band? I have been putting some thought into sound, as one in my position would and pondering what if anything outside of the norm I could or should do. The double hung PA worked amazingly well on Peppers and I am a bit remiss to return to a single hung system.

But hey, each band/tour has unique aspects and based on the dynamics at hand, I have different plan this time out. But, while we are speaking of double hung PA's though, check this out!

 

U2 is doing a stadium tour in the round. Check out that PA, notice anything? There are 3 PA hangs, 2 hangs of Clair full range boxes inside and a hang of Clair subs to the outsides.

Well alright, U2 is touring with a double hung PA, how cool is that! Well actually that would be four double hung PA's. My good friends MC and Paddy who are out with Snow Patrol were kind enough to give me the low down. And yes, it is truly being run the same way as we did on the Peppers with the vocals in one system and the instruments divided between the two systems. That rules, the largest tour in the world right now has a double hung PA! And the desire to shout "see, I am not crazy after all!" while running around doing a naked victory dance is very tempting.

But back from the past, lets look at now and Rat has this cool new L'Acoustics K1 rig that I know is louder and clearer than V-Dosc. Blink is an energetic fun rocking band, so from a sound perspective, I am going to approach it from a clean and simple angle. Nope, no double hung this run. I am excited to take the K1 toy out and see what it can do in a conventional setup before I go getting all wacky with concepts. I am thinking that the new K1 system and it's added clarity and volume, may be able to give the double hung V-Dosc rig a run for it's money.

But I get bored to easy not to do something special so I have been working some sub layout designs, trying to fine tune and improve the sub cannons so if your interested in that sort of stuff, I will post more on later. Also, I have finally put together a little system for measuring venue acoustics in various locations so I can see setups and coverage works as predicted.

In the mean time, the storm before the calm sets in as I realize some sad goodbyes and bearing down upon me. October! , yikes, wont be home till October, that is a rough concept to get my head around, anyway, my little pals that are gals that are going starting high school before I get home.

Meet Taco the little dog pal my daughters have convinced to adopt me and has been hanging tough and keeping my company.

And without looking back cause it hurts my heart, off and away for many days in far away places.

 

Hmmm, wondering if the L-Acoustics K1 Coachella system be referred to in the male or the female context. What do ya think? I can think of some big reasons it could go either way. Though I am tending towards pushing the feminine angle and so with that said, how about we take a good look at her bottom end?

**** Begin Un Censored Sound Nerd Speak ****

RATED Triple N (Must be an advanced nerd to read)

Quite a bit of thought was put into the subwoofer setup for Coachella Main Stage. I had the honor to work with Scott Sugden from L'Acoustics on the subwoofer design and it was really fun. The first thing we did was outline the goals to be achieved:

1) The design must be appropriate looks and location wise. By that I am referring to avoiding an awkward sub setup like one that pushes the barricade out too far or those super tall sub stacks that block video screens and look terrible. The goal is for speakers to be heard, not seen and if it is seen, it should look clean and fit into the look of the stage.

2) The design must be repeatable. I wanted to avoid a 'custom Coachella setup' that relies on taking advantage of unique aspects of the event or placement locations. The goal was to design a sub configuration that could be dropped into any field show and archive impressive results.

3) The design must be scalable. This is pretty simple to hit, but important none the less.

4) The design must be simple to implement. I wanted to avoid a setup that requires taking a bunch of complex time consuming measurements and extensive onsite testing that requires blasting subs for an extended time frame. We want simple, easy and very little room for error.

5) The design must have flexible dispersion/coverage capabilities. One of the coolest aspects of the sub cannon setup I used on Peppers tour was that I could easily widen the sub coverage pattern by increasing the level of the side firing boxes. If the arena sold farther around the sides, I could easily increase the coverage to well beyond 180 degrees. For the Peppers field setup with sub cannons, I could widen and narrow the coverage. We wanted to retain that flexibility while improving other aspects.

6) The design must not involve destructive sound. By that I mean that I did not want any boxes that are used to cancel out sound. Out of polarity rear firing speakers used create cardioid patterns are an un acceptable solution. I also wanted to avoid that whole beam steering thing where a whole bunch of graduated delay times are used to electronically focus. One or two delays I am fine with, but beyond that, too scary and my experience with electronic beam steering is it is one of those 'two steps forward and one step back' scenarios where side effects of db loss and complex coverage patterns negate many of the advantages.

7) The system must be able to convert to conventional sub woofer setup without moving speakers. There will be over 30 engineers mixing on the system at these festivals and we need a setup that will make everyone happy, so it needs to be able to switch to a normal-ish sub setup, should any engineer so desire.

8) The subwoofer coverage of the event must be impressive. The big challenge with subwoofers is that you are fighting two main issues. First is that the wider the subwoofer setup is, the narrower the coverage is. Secondly, the reduced horizontal coverage issue can be addressed by stacking the subs into two tall vertical arrays BUT, those vertical arrays cause these huge V shaped cancellation nodes. If you have mixed on a system with vertical subwoofer arrays, I am sure you have noticed those huge holes just to either side of power alley where there is practically no sub lows. To me, that is an unacceptable ramification.

9) The design must utilize the L-Acoustics SB28 sub woofers. Hey, they are part of our new K1 system and we are keeping the whole deal together and matched up and these subs are awesome!

10) The design should minimize low end bleed onto the stage. On a show this size where we are pumping low end over long distances, it is critical that we can deliver the needed energy deep into the audience with out overpowering our musical friends on stage just a few yards away from the subs.

So as the ideas bounced back and forth, it began to evolve in what seems in retrospect to be the obvious path. Lets combine the SB28's cardioid configurations with a version of the sub cannon configuration.

Before I go on, it is important to note that the L-Acoustics cardioid sub setup does not implement out of phase sound to cancel the rear propagation. Rather, it the rear firing sub is set at zero time delay and the front fire subs 'wait' for the sound of the rear sub to wrap around and then augment that sound. That means that in front of the cardioid array, all 4 boxes are in correct time. But as you walk around behind the boxes, the is a time error increases. This causes an effective cancellation behind the boxes while in front of the boxes it is all in time and good, hence 'cardioid.' Basically it is the same concept as the sub cannons except it requires less physical depth.

So the first thing we did was run some analysis on the arena and field sub cannon setups as well as numerous other interesting and cool sub layouts that Scott has implanted and pondered. What we ended up with is a 6 cluster setup. The primary cardioid sub cluster consist of 6 forward facing and 2 rear facing SB28's set at what we will refer to as 'zero time delay.' The next set of clusters had acoustic centers located 1/3 of a 40 hz wavelength to the outside of that. These outside clusters are the 'cannons' and are laid back in time by 1/6th of a wavelength at 40 hz, such that they augment the sub energy radiated 33 degrees off axis and create a cancellation on stage. These outside clusters consisted of 4 SB28's forward with 2 rear facing.

Finally, there are two small 2 box cardioid clusters just to the left and right of center. These serve two purposes. They act as center fill subs to even out the low end hole that created by being off axis to the main subs and also they act allow us to widen power alley and create an extremely smooth subwoofer coverage.

So maybe that sounds complex or maybe not but either way, the result is simple. Turn up the outside clusters and the coverage expands wider, turn them down and it becomes narrower. Turn up the center sub cluster and the power alley effect is reduced, turn them down and power alley increases. All this was achieved with only two very time delay settings and well thought out but simple stacking locations.

Ha! Well hopefully that got your mind spinning!

**** End Un Censored Sound Nerd Speak ****

While were are diving into all kinds of cool and exiting stuff, check out the MicroWedge 12 Case design. What do ya think? A one human operation to open and close the case.

Plus storage inside for cables, tripod mounts and MicroLegs means the case is fully self contained with all you need after the amp.

Here is the bottom storage, there is another compartment up top as well.

 

I am not through yet, much more to come, like a whole series of arm reach self photos with cool Rat crew and the rock stars of the sound nerdery world. And lastly but not leastly, I would like to mention a new drink that a few of the sound crew has come up with. Vodka straight shots followed quickly with a Vodka straight chaser. Gotta be quick though and hit the chaser before the burn of the shot sets in and be sure to use two different kinds of vodka. Ha! Just kiding or maybe not.

Dave Rat feeling a little mini road fun that I so miss and so happy to be hanging with 'my people.'.

Ooooh, check out the sexy picture of main system for Coachella:

Here you can see the mains and side hang systems and also the 6 cluster subwoofer setup as well. There are quite a few new implementations of innovative theories in the design of the K1. The actual purpose and importance of the K1 Subs in the array is something that people are having a tough time getting their head around and I must admit that early on I was thinking "Why get any K1 Subs and not just buy more K1's, do we really need a third box type?" That was even further reinforced when I heard how much low end the K1 's can reproduce without any subs.

So what do these dual 15" boxes that are identical in size to K1 bring to the table and why do we need them or want them? Heck, for the most part, they are just K1 boxes with the mids and highs missing and I find their existence very interesting. In the mid 90's V-Dosc was new and the only large-scale line array on the market. Then, over the years nearly every major manufacturer has since staked their claim in the line-array bombardment of products. Each attempting some rehash and to add an asset to set themselves above the fray and to be honest, some really nice systems have come out of it by building upon the perceived starting point set by V-Dosc.

So taking a layman's look a line array theory, it basically says that the higher you stack up speakers the more control you can gain over the vertical coverage. With this vertical coverage control, you can do some interesting things like point more speakers far away and less speakers closer. This is cool because you can make it so that it is nearly the same volume far away as it is up close. Iimproving volume consistency throughout the listening area is a huge asset and we like huge assets.

In fact, a line array can be set up such that the volume level stays the same, even as you get farther away. Ahhh, but like everything in audio and life, obtaining something so desirable comes with a price to pay. Up to now line array designers have been addressing the entire audio spectrum with full range boxes plus subs. But the demands of the lower frequencies in the line array vary drastically from the demands of the higher frequencies. To put it in maybe something easier to visualize, the wavelength of the lowest notes we hear are about as long a one of those big rig tractor tailor trucks, including the motory part where the driver sits. The highest notes we humans hear have a wavelength maybe somewhere around the width of your thumb. Hmmm, how many thumb lengths to a big rig?

Anyway this vast differential in the wavelength creates many challenges. One of these challenges relates to the physical length a line array need to be to gain control over the various frequencies. Higher frequencies with short wavelengths only need a small vertical dimension while lower frequencies need an array of a much longer dimension. This is one of the fundamental reasons for the K1 sub. It allows the lower frequencies to have a longer line array length and and help match the coverage/throw of the lows to the mids and highs. Though this concept is natural and logical to line array design, it has been overlooked completely by all the line array emulations. But if the future follows the past, not for long as I am sure other companies will be soon to scramble to follow as it works way to amazingly well to ignore.

In fact the 'low throw' worked so well that we are rethinking the way we implement delay clusters. The natural absorption of HF by the air means sound will get duller with distance and so far, this means that for huge gigs the need to put up delay cluster is un avoidable, but since the K1 has the ability to present a clean tight controlled low end over much longer distances, the demand upon the delay clusters is reduced to only needing HF and perhaps a bit of mids. Running smaller, less obtrusive delays is a very cool thing cause we all know that setting up delay clusters is a pain, screws with sight lines and running low end into delays gets messy because it is so hard to control directivity. There is also another application for K1 subs as well but that will have to wait for a another day.

In the Sahara dance tent we set up mini sub cannons for the 2 side clusters and 2 rear clusters to get cardioid control and reduce bleed to other stages. This was the first year that we had no complaints about Sahara's sound stepping on the other stages. These are 1/4 wavelength at 50 hz spacing and time aligned for forward projection. Plus there is the added benefit of becoming a wonderful stacking surface for the V-Dosc. Say hey to Ronnie!

Not only was this the largest outlay of K1, ever in the world to this point in time, I also think it was the worlds largest outlay of EAW MicroWedge's with at least 50 or so. MicroWedge's did 4 of the 5 stages flawlessly!

So fun and more to come!

 

Dave Rat

There are several non-human things with which my life, as I have chosen it, I consistently depend. My laptop, my cell phone, my car (not so much lately) and to some degree, my camera. Avoiding losing these things provides a constant and often humorous challenge and yes, I do lose my car in just about every parking lot. Additionally, since my world of motion is so inter-woven with these items, it brings me great pleasure to assure that the ones with which I chose to interact are optimized for my particular desires. So with that argument built up as a self justification, I set out out and purchased the new sexy Blackberry 8800. Ooooh! Smaller, built in GPS, plays videos and holds a micro SD card so I can send pics from my camera. I may even figure out a way to blog from it now that I can get my camera pics into it. Excited about my new acquisition, I show Dave Lee who immediately invokes a durability test

It is an on going roadie joke that when anyone gets something new and fragile that we try and politely "take a look" followed by pretending to bite, step on, twist, disassemble and in any way possible, cause dismay to the owner. Dave Lee did very well, pay back is a bitch and I deserved every second.

So we are at the airport terminal and take a shuttle to the lounge that is like a mile away in trailer that requires the shuttle bus to traverse several runways. Fortunately for the plane riders, a wise man has placed this useful notice assisting a safer journey for all.

To the plane and yumm! Read this menu,

wow, does that not sound delicious or at least interesting? Well, being the adventurous eater I am, I am all good with giving it a shot. I under estimated the potential. Oh my, and then I remember that I have already learned this last and perhaps every time I fly to Japan.

I love sushi, I love clean simple healthy foods. I do not love slimy gelatinous and rubbery items of unknown origin. I do not love fish goo, and though the pic does not represent it's full glory, I do not understand why such great lengths of complication would be taken to transform what was at one point, perfectly good food into complex fish flavored jelly.

Simple clean healthy foods, how hard can it be?

**** Sound Nerd Speak ****

The realization that I have been ignoring my fellow and fellowess sound nerds struck me and brought a sad feeling to my heart so I pondered a bit and came up with this to share.

One of the big issues with subwoofer arrays is that they provide significant sound in front of the stage and considerably reduced sound levels off to the sides. Early in the blog days I describe the method we use on this Pepper's tour to increase side sub coverage and made up the name "Sub Cannons" for them. Well, not ever tour or show has the flexibility to build the stage as part of the sub woofer array sooo.....

Here is a simple method of increasing that horizontal dispersion of sub woofer coverage utilizing the side firing sub cannon method with all the subs are stacked in a straight line. This setup is useful both indoors and out and allows you to easily alter the amount of low frequency energy you provide off axis to the people on the sides. The main subs on send 1 are facing forward and have zero time offset. The side firing subs are pointed outwards at 90 degrees and delayed incrementally such that their acoustic focus is 90 degrees off axis. The delay times listed on the drawing are based on a 2 foot deep subwoofer and a 1 foot spacing between the subs.

In order to envision how the setup works, think of the main subs including the first (non spaced) side firing sub as one system which I have circled in red. Think of the spaced side facing subs as a second system. The main subs form the typical forward facing sub array that is quite common and tends to lack adequate side coverage. The fact that the zero time delay sub on the end is pointed sideways is of little or no consequence. Now think of the the +3 feet delayed subs as waiting for the sound from the subs behind it before it radiates it's sound. Then the +6 feet delayed sub waits for the sound of the combined zero delay and +3 delayed subs before it radiates and finally, the +9 delayed sub waits before radiating as well.

This incremental addition increases the volume for the listeners off to the sides while having a relatively minimal effect on the listeners in front. The setup works quite well and is easily adapted to various venue types. If you increase the side firing sub spacing, increase the delay times accordingly. The delay time in feet of each increment is (cabinet depth in feet) + (spacing in feet). So, if your subs are 2 1/2 feet deep and you space them 18", then you would use 4 feet of delay per increment.

You can alter the ratio of the quantities of forward firing to side firing subs as well as the quantity of side firing spaced stacks to achieve different coverage's and volume levels as well. The real beauty of the setup is that it does not require any complex measurements, it transfers well from venue to venue, you can keep all your settings intact as long as you keep your spacing's on the side firing subs the same and if the sides of the venue need more sub you just turn up sub send #2.

Cool cool, if ya give it try, don't forget to let me know what ya think and how it works for you.

**** End Sound Nerd Speak ****

The not afraid to nerd it up,

Dave Rat

Tonight we will ride the bus overnight to a day off in Prague.

It got a bit hectic during load out for me. The word came through that a hard drive with the Lyon, France show needs to ship to Los Angeles, ASAP! First I capture the Pro Tools rig before it is buried in the truck. I set it aside and go seek out a Euro to US power transformer only to find the Pro Tools rig hijacked towards the truck. I set down the heavy transformer, chase down the PT rig, come back and oh no, the transformer is gone. Argh. Mark gave me a hand, we located the transformer, an outlet, set up the PT rig and sat there for 25 minutes while the show copied onto another drive, packed it all up and got it onto a truck without screwing things up too much.

Found a tower near the hotel with a pretty bird on top

**** Sound Nerd Speak ****

Subwoofers and Sub Cannons

I have settled on three variations on a basic sub layout. The goal it to achieve adequate side coverage in arenas out to 135 degrees off of center. In order to achieve this in the limited space available while also present a functional layout, I am implementing a 'shotgun' configuration utilizing time delayed, spaced sub blocks that also double as stage wings. The stage is 5.5 feet high and the stacked subs are 5 feet, so with two 4 foot by 8 foot risers strapped to the side subs, the subs effectively add stable stage width.

Configuration "Narrow" has what we call the "sub canons" facing forward and they are delayed to form a cardiod pattern that then combines with the front line subs.

Configuration "Wide" rotates the cardiod cannons 90 degrees to face the sides of the venue increasing the potential output to the sides.

Configuration "Medium" has the canons facing forward like Narrow with the difference being that the outside subs are delayed 4 feet. The distance of the delay is based on the acoustic centers of the enclosure to the next forward facing row in. This creates a moderate increase in side level over the Narrow setup.

By altering the levels of the various sub clusters, we are able to optimize the low frequency coverage to the venue. All this looks good on paper but the reality is that sub woofer coverage inside complex enclosed venues is only partially predictable. The reality is that we gain more control than a conventional setup it is far from a perfect science and wandering and listening and adjusting is the only way to dial it in. It is still a work in progress but so far we have exceeded the coverage consistency that I have seen other large scale tours achieve.

 

Dave Rat

IWBLBISYILML!