Monday, April 25, 2016

Day 2 Show 1 Jazz Fest

New Orleans Jazz Fest 
It's an 'in and out' gig a bit regrettably as New Orleans is always a fun adventure of sights, sounds and delicious food.‎ I did arrive in time to hang with the Pearl Jam crew for a bit as our load in overlapped their out. It's been a while such a great camp.

It's not often I see a stage so clean, notice anything missing? 

Like the entire lighting system. New Orleans version of Warped tour, daytime shows, sunlit and work lights. Ha! In the ongoing battle with Scott the Lampi, we can rock a fun show with no lights, wonder how a lit show with no sound would go over.

Starting up a new tour cycle has its challenges. In my mind, I envision the sound setup just progressing from where it left off some two or so years ago. In reality the multitude of small and large changes converge into clusters of variables and unknowns. Plus me being rusty and the abrupt change of focus from 'at my house' to 'front of house' has me relearing all those nuances that had become second nature.

Not only was this the first show but also first time mixing on a Clair Cohesion PA as well. A variable I would have rather done without as I much prefer a familiar system, especially on the front end of a tour. The crew was good, pretty straight forward and everything functioned as it should, Ran stereo mains and stereo subs on an aux. The show was fun, especially cool ‎was the jam finale with 3 of The Meters.

Sunday, April 24, 2016

New Peppers tour show day 1

So here we go again, in New Orleans with Chili Peppers playing Jazz Fest. Trying to get my head around shifting gears from home to travel world. Rolling over the mental lists of how to approach tuning systems and all the bits not to forget to keep in my rolly bag.

4 days of rehearsals went well. I have a pretty similar setup to last tour with a few changes so far. Most exciting is a brand new console. Well not exactly but close. We had a Midas H3000 at the shop which we pulled from an installation and has lived in a theater for 15 years. Oh my those smooth slidey faders!

Also I have a pair of the new Rat Sound SuperWedges I used for my rehearsal PA. Hope to carry them as reference wedges for as much of the tour as possible.

For rehearsals I had the SuperWedges in 4-Way mode. Input 1 on the amp drives them full range 4-way with one of the 12"s 40hz-80hz and the other 12" 45hz to 300hz. This cleans up the mids and extends to lows a bit over the 3-way setting.

What is really cool is that input 2 on the amp just drives the 12" I a using a a sub and input 3 on the amp drives the other 12" plus the 10" and the 2". So I had them hooked up as stereo triamp mains plus stereo subs on an aux to recreate my real world show setup.

Well alright, off to wander about the festival an contemplate my first show mixing on the Clair Cohesion 12 system.

Monday, January 11, 2016

Subwwofer Setup for Bassnectar NYE 360 degree

In my last post I outlined the goals of the sound system design for Bassnectar's New Year Eve 360 sound setup and covered the main flown system decision and configuration (goals #1, 2 and 3). In this post I will cover the subwoofer side of things

The goals of the system design were:

  1. The sound system must be optimized for 360 degree arena coverage
  2. The system should not block sight lines or distract from the visuals in any way
  3. The system must cover the entire arena as smoothly and uniformly as possible
  4. The sub woofer must be powerful and immersive to a very low frequency
  5. The sub woofers and main system must not reproduce excessive low frequencies in the center of the room where the artist is located. (This has been a significant issue in the previous years of doing 360 degree shows before I was involved)
Achieving smooth loud low frequencies covering a large area can be quite challenging. Time alignment issues causing cancellations and huge audible holes in the coverage are quite common in all but the most well thought out configurations. To cover the venue evenly, a ring of subwoofers around the stage optimum. Unfortunately, the subwoofer sound will be the loudest at the any point that is equidistant from the most sources. With a 360 degree coverage subwoofer ring, the equidistant point is dead center and exactly where the artist is located. In past 360 coverage shows, the low frequency volume levels in the center were so loud that vision was blurred and the control equipment needed to be strapped down to prevent it from rattling, falling and there were issues with hard drive malfunctions.

Here is a coverage map of a ring of subwoofers 38 feet in diameter. The grid lines are spaced at 50 feet. In the prediction below with a single ring of 8 clusters of 5 subs, 40 total, we are able to get 103 db at 300 feet away where I marked the level. The prediction specs are listed on the left side of the image measured 20 to 80hz. The actual venue is much smaller so the actual levels were much higher for even the farthest audience member.

But, now lets look at the level in the center where Lorin will be DJ'ing from::

Yikes! 134 db is crazy loud and over 30 db louder than the sound 300 feet away. So, the challenge is to reduce the level in the middle significantly and also if we can get more level far away, that would great. Additionally the solution should look cool and be physically feasible to achieve without disrupting the super smooth coverage we already show.

So to do this I added an inner ring of subs that were also facing outward. the inner sub has a diameter 14 feet smaller and is 8 clusters of 3 subs totaling 24. 

The reason clusters of 3 were chosen rather than more or less was that an inner ring of 24 generated a volume level dead center that most closely matched the volume level that the outer ring generated dead center. The idea is to have both cluster create as close to identical signals dead center as possible. 

The reason a spacing of 7 feet was chosen is that 7 feet is 1/4 wavelength at 40 hz, which is the center frequency between the 20 and 80 hz.and the frequency I wanted to optimize for. For more info on setting up sub arrays I have 3 youtube videos on sub setups:

Ok, so since the most critical purpose of this sub setup is to drastically reduce the level in the center I used a polarity reversed cardioid setup. Once the volume levels are matched as close as possible measuring from room center, then the arrival times of from both the inner and outer subs are matched as well. For this setup at 25 degree C and a spacing of 7 feet, it required the inner ring to be delayed 6.2 ms for maximum summation room center. Then I inverted the polarity of the inner rings and rather than maximum summation, maximum cancellation was achieved. Here are the predictions with the inner ring:

Ok, that's good, we gained a few db at 300 feet, the prediction still shows smooth coverage all the way around so lets look at the level in the middle.

Awesome! 93 db in the middle and  over 10 db quieter than the 105+ db level at 300 feet away. Super cool and exactly what I was looking for. Of course there was a lot of messing around to get to this point. Paul F at Rat helped me with some skills using soundvision software, which I am not overly well versed at. Also Jason Brandt not only assisted in refining the predictions, he also was invaluable in implementing the setup and getting it to perform as predicted. 

And an up close

The real world outcome was quite interesting. The subs covered quite well throughout. No significant holes, low end naturally drops with distance but we were able to get a pretty good level to the rafters. When walking to the center, the low end became oddly decentralized between the rings and when you got up into the central booth, you could feel low end and hear the rotating structure rattling but the it sounded distant and there was an almost surreal drop in level.

If all that info is not enough for you or you are versed in Soundvision software, here a link to download the file with all the info:

And here a link to download Soundvision, though you probably will need a training course to use it.

Cool cool, hope this is interesting stuff, hit me up with comments on stuff you like or want more of.  Gonna try and get back into the rhythm of posting and sharing.


Thursday, January 7, 2016

Designing a 360 sound setup for Bassnectar

Over the past year I have been working on and off with Bassnectar as a sound consultant. My position is multifaceted and in general I work to solve some technical challenges so Lorin (Bassnectar) can achieve the audio connection with the audience he is looking for. My focus has been on improving the audio impact of the show when there are overly restrictive sound limitations, occasionally I fill in as the sound engineer if Jason Decter is not available and I also work with Jason and production on the design of the sound system when Bassnectar is bringing in full production.

I really enjoy working with Lorin, Jason and the full production team. Not unlike working with Chili Peppers, Lorin and the whole team really care about all aspects of his shows. For this past New Years Eve show I was brought in to design a sound system with some unique and fun challenges.

The first step was outline the goals:
  1. The sound system must be optimized for 360 degree arena coverage
  2. The system should not block sight lines or distract from the visuals in any way
  3. The system must cover the entire arena as smoothly and uniformly as possible
  4. The sub woofer must be powerful and immersive to a very low frequency
  5. The sub woofers and main system must not reproduce excessive low frequencies in the center of the room where the artist is located. (This has been a significant issue in the previous years of doing 360 degree shows before I was involved)
Achieving 360 degree coverage from a conventional line array system is not overly challenging if one is willing to hang 5 or more clusters. The problem is that one can not physically put two line array hangs next to each other without a space between them if they are not both pointed in the same direction.due to the "J" shape of a conventional line array.

Additionally, placing J shaped line arrays in close proximity will cause undesirable interference if the same signal is sent to to both arrays. To deal with the interference, the arrays need to be physically separated.

But regardless of whether they are closely placed or separated, the amount of sight line blockage of video screens can be an issue.

For this particulate show, the video screens in the arena scoreboard were incorporated as a central video source which meant that if I could place sound arrays at the 4 corners of the square scoreboard, I could minimize sight line blockage, yet to cover the venue sound wise each of the 4 sound arrays would need a relatively wide coverage and would need to be flown in a relatively limited vertical space.

To solve this challenge analyzed and compared coverage, volume levels and sight lines using a conventional J shaped Line array versus using an EAW ANYA system. The EAW ANYA system offers some unique advantages for this application in that the arrays hang in a straight line rather than a J shape. Additionally 2 or more arrays can be connected together side by side, increasing the horizontal coverage while minimizing blocking the video screens and lighting. Additionally, since the vertical coverage of the ANYA system is controlled electronically, the trim height of the sound system could be adjusted to an optimal height without compromising coverage. Here is the ANYA system layout with the goal of exceed 105 A weighted throughout the venue

And here is the system in the actual show during setup

And a closer pic of one of the arrays

And tweeted pic of the full show

In this application, it is all about sound being heard and not seen and an enjoyable challenge working with video, lights, riggers and all of production to merge everything together.

And as predicted, the system was able to meet meet the first 3 goals. In my next post I will discuss how goals #4 and #5 which involved the subwoofers challenges, were addressed.

Cool cool, and never forget to have fun making it loud!


Saturday, May 9, 2015

Happiness and Fun Toys

So its been a while since I have blogged, been busy with some cool projects that I am having fun with. Oh, and hey, Kim and I got married and it is truly awesome! Who woulda knew? I like to take the important things slow and do them right. We have not had the party yet but will let ya know when we do.

**** warning extended sound nerdery ahead ****

Ok, so on another note about things that make me happy, the new wedge design I have been working on is coming along.and ready for some road testing

This is no ordinary stage monitor. In designing them I combined the cool stuff I learned from building the Rat L-Wedge, the MicroWedge and the double hung pa into a single product.

Which was that sonic advantages in clarity and volume can be gained with a 3-way triamped wedge design With conventional high quality biamped wedges, it is fairly easy to get an adequate level when testing the vocals by themselves but after kick, snare, bass and guitar are added, the vocal can become less clear and difficult to get on top of the mix. By using a triamped design that has separate LF speakers for the lows and the 10"/2" for the vocal region, much of the IM distortion issue is reduced, plus the vocals come from a small area in the center of the enclosure.

The MicroWedge series addresses those same IM distortion issues in a different way.  Rather than separating the the signal by frequency ranges, the compact size allows multiple mixes to be in close proximity. For high volume and demanding situations, a pair of MicroWedges can be set to reproduce vocals and an additional MicroWedge or two can be dedicated to reproducing instruments.  This totally eliminates issues of instruments blurring the vocals while adding the advantage of having the instruments radiate from a different monitor completely, further enhancing intelligibility.

With the double hung PA concept I was able to implement and demonstrate that having instruments and vocals coming from separate sources is not only an advantage for stage monitors but can be applied on a grand scale. Also, since I could move any instrument to either the outer or inner PA in real time, I became very aware of the important advantages gained in using separately located sources. With monitors, I would find out after the show if separate sourcing worked, with the double hung main system, I was in the listening position personally (along with 20,000 of my best friends) and could hear the immediate and direct effect.

The SuperWedge Series


Combining all the advantages and pushing things even further resulted in the SDW22 and several similar offshoot designs. The SDW22 is a dual 12" with a 10"/2" coaxial mid high component.All four loudspeakers are separately powered, have high grade neodymium magnets and 4" voice coils. Yes, a 4' voice coil 10" with a 4" voicecoil beryllium compression driver coaxially mounted. I believe this is the first of its kind. Each 12" is separately chambered, ported to the floor and the monitor is about the same weight and size as the premium dual 12" two way wedges currently on the market. Additionally, what really makes it unique is that the SDW22 has the ability to operate in multiple different modes.

  • Mode 1 - Full Range Triamp. In this mode it is purely a single input high fidelity wedge that gets really loud, basically a modern hot rodded version of the L-Wedge
  • Mode 2 - Full Range Vocal Optimized. This mode rolls off the upper frequencies of one of the 12"s reducing the low mid buildup caused by both 12"s reproducing the 100hz to 200hz range while also extending the low frequency response.
  • Mode 3 - Full Range plus Guitar. One thing that PA speakers never do well is reproduce a guitar sound . This setting uses the one 12" and the 10"/2" as a full range triamp monitor and a separate input on the amplifier powers the second 12". Rather than mic the guitar cabinet, using a Palmer or similar DI box to capture the guitar sound after the amp and send it to the second 12", not only allows the guitar signal to be reproduced bypassing the microphone, but also reproduces the guitar from a separate dedicated speaker. Plus, for even more discerning musicians, one of the 12"s can be physically removed, replaced with a Celestion 12 and powered from a guitar tube amp. This means the guitar player actually gets his or her exact sound coming from a the wedge.
  • Mode 4 - Vocals plus Bass.  The same concept as Mode 2 except with the 10"2" operated full range like a high power MicroWedge 10 and both 12"s are dedicated to a separate bass guitar signal.
  • Mode 5 - Subs on an Aux. The 12'/10"/2" operates full range and the second 12" is driven as a sub on an aux.  A pair of SDW22s on a drummer in stereo plus subs on an aux for a powerful and versatile drumfill
  • Mode 6 - Dual 12" subs on an aux. The SDS22 is powered by a Powersoft X4 amplifier capable of 1600 watts per speaker x 4.or 6400 watts per wedge and can be used as a high power sidefill with or without a separate subwoofer. Full Range to the 10"/2" and 12's on a separate subwoofer send
  • Mode 7 - Multi-way multi-source. Full range to the 10"/2" and bass guitar to one 12" and guitar to the other 12"
  • Mode 8 - Dual Biamp. Full range to one 12" and the 2" plus full range to the other 12" and the 10". This is for applications where extended frequency response and power handling is needed from the secondary send.
  • Mode 9 - Conventional Biamp. If the sound of a dual 12"/2" is preferred for the specific application, the 10" can be bypassed and the SDW22 can be operated as a conventional dual 12"/2" wedge. That said, try finding anyone else making a dual 12"/2" wedge with all 4" voice coils and a full sized, 2" throat beryllium compression driver.
So far the reactions have been ranging from, "that's crazy, why would you need that?" to "Oh shit, that is the best idea I have ever heard, why hasn't anyone done this before?" These wedges are not for the faint hearted or easy to please, these are designed to deal with the top level, most discerning, most temperamental, most demanding and most deaf of the artists and applications where the highest of fidelity, maximum volume or utmost in versatility is required

The next stage for this adventure is to put powered pairs of these out on the road with select musicians and engineers. I will try and stay on top of posting progress reports and if these look like a solution you have been seeking for your application, give me a shout.

Next up in the audio adventure, the SDS30, a high power sub that is the size of one but replaces 3 dual 18 boxes....


Thursday, September 11, 2014

Perception and Failed Illusions

Perception and Failed Illusions

Does a muffled band in a rehearsal room down the street sound more 'live' to you than a high def recording played through high quality stereo? Or have you listened to a recording and thought "whoa shit, I thought that was band, but it was just a recording played through speakers?"  Is it just live music that defies realistic reproduction or do these same perceptions apply to voices, fireworks and just about everything else we try and recreate through loudspeakers?

It seems there is something about a live band playing, even muffled and far away that divulges its aliveness. A certain rawness, dynamics, dispersion from the sources, perhaps multiple source locations. If these observations are taken to be correct or at least in the realm of close, what is especially interesting is that frequency response appears to have little to do with whether we perceive something to be real-time live. Comparing the muffled band a block away versus direct exposure to Hi-Fi wherein clearly the Hi-Fi has a distinct advantage in presenting a wider and less altered frequency response, yet somehow the live band sounds more real.

Quite puzzling indeed and perhaps this perspective lends some credibility to why so many audio people have such an affinity for audio gear that exhibits less than flat response and less that technically ideal sonic characteristics. Perhaps, just perhaps we are focusing on the wrong aspects as a starting point and that is why sonic realism is so illusive.

Oh, and just a thought on making sound reproduction more real. What if rather than focusing on frequency response and accuracy of the reproducer we instead focus on eliminating introducing aspects that identically alter all the instruments? For example; we can significantly compress a single instrument without undesirable side effects yet even minor compression on the whole mix is readily audible. Think FM radio versus the CD or when the PA vendor puts a left/limiter on the PA. Looking at the dispersion of instrument, cymbals have a 360 degree radiation pattern whereas a kick drum has more of a figure 8 radiation pattern.  Guitar rigs can be figure 8 or somewhat cardioid pointed forward. Each of these instruments have vastly differing and unrelated frequency responses that can be readily altered  by choosing a differing cymbal manufacturer, switching to a felt kick beater changing the guitar cab type, yet none of those changes alter their "liveness".

Frequency response can be altered before or after the sound reproduction process so it is important for things sounding desirable but has little to do with things sound real or live.

So based on this I am thinking I can add the concept:

"Nowhere in nature do multiple unrelated sound sources offer identical dispersion patterns, yet in pro audio we do it all the time"

to the two other fundamental concepts I have been distilling, which are:

"Nowhere in nature do multiple unrelated sounds radiate from a single point in space, yet in audio reproduction we do it all the time."


"Nowhere in nature does the exact same sound radiate from multiple points in space but in audio reproduction we do it all the time."

With the underlying idea being that the more we stray from what occurs naturally, the more illusive realism will be.

Ok and on another note, I have been putting together a small playback studio with some spare and older bits of gear from Rat.  I have a lot of old multitrack DA88 tapes from various past tours and am looking to do some multi-channel mix downs for use in sound seminars and demos and such. The tapes have all been backed up to ProTools but rather than buy or tie up one of Rat's Pro Tools rigs and since we have 5 DA98/88/38 series machines laying around, I figured why not bring them home and use them.

What I quickly found is that they were very hungry and had a overwhelming urge to eat tapes. I cleaned the heads and ran the error rate option and all 5 machines were all over the place so I opened them up to see what I could find. What was happening was the tape tension seemed to be low and excess loose tape was building up in front of the pinch roller. For some reason they lacked tape tension.

After a bit poking around and found some good info here that helped a bit and got me in the right area

And thought I would share what I found was the exact same issue with all 5 machines. The tape tension arm shown below was no longer moving freely

When you press play, the arm should wing to be on the tape as shown here. but instead was barely moving

So, with a very small tweezers and exacto knife, I removed the two plastic split washers

Which are very small, do not drop them in the machine!

Removed the tension spring

Removed the tension arm by gently rotating back and forth with a needle nose pliers. I snapped a wood q-tip in half and soaked it in some WD40 and used it to clean out the pivot hole. Then used alcohol on a q-tip to clean the pivot shaft. Then put a drop of some multi purpose ultra lube on the pivot shaft. Dont put any lube on the tension shaft that contact the tape.

 And then reassembled it all back together and everything worked perfectly and all the error rates dropped to zero. 

And since there is more to life than pure audio. a few adventure pics to lighten the load. There was a most wonderful week of amazing waves that came to visit our southern California shores

but not without consequences for the unprepared and when the waves get big enough to break things

It can become a spectator sport as well

But when it looks so good I just can not resist


Sunday, August 24, 2014

Building New Toys

So Peppers tour has ended and  walking into the production office after the last show at Isle of Wight I could not resist taking a photo. Three years of on and off travels and another chapter comes to a bittersweet end. I will miss seeing all my friends on world adventures till next time and oh the thought of being home for a while is very very wonderful.

It is a shame those set lists did not go to fans but some things ya just got to let go. It has been a while since I have blogged.  Partially due to recovery from my bike crash, partially due to focusing on dedicating time to finishing Peppers tour, partially from immersing in the business side of Rat Sound and also because I have been working on some new speaker designs and concepts.

As far as bike crash recovery, I am mostly back up to speed with only the odd lump from my broken collar bone, a slight bit of shoulder rotator motion loss and most oddly, I seem to have an altered sense of smell. Some things I just can not smell at all and other things I am quite sensitive to. My sense of taste seems fine though. Ha, maybe light losing sight improves hearing, maybe losing smell will help hearing too.  Lucky me.

Here is a blog post I started a while back and never posted:

Comb filtering is a description of the cancellations created when a signal is re-summed with a time shifted version of itself.  The 're-summing' can be electronic or acoustic.  

If you wish to eliminate comb filtering you need to either reduce the number of source such that only one source can be heard at the listening positions. not allow time shifted versions of the same signal to sum electronically or alter the signals so they are sufficiently dissimilar.

In real world reinforcement applications, comb filtering typically is not solved, it is mitigated. Where it gets interesting is that the humanly configuration of our bodies and location of our ears is such that undesirable effects of comb filtering occurring in the horizontal domain is actually minimized when the sound sources are sufficiently far apart from each other and we are located somewhere between those sources which is why we prefer stereo instead of mono home stereos even when the sound radiated from both speakers is identical or similar.

I personally strive to minimize sending the exact same signal to multiple horizontally spaced speaker arrays. I want the guitar mic sent to the left PA stack to be a different signal than the guitar signal sent to the right.  I want them both to sound good, but not to be identical.  Same with bass, and as many other instruments as possible. This reduces comb filtering and minimizes creating power alley.

And for some newer stuff, last week I did a Dave Rat Seminar for Disney sound technicians. Super cool and I felt quite proud that I have shoveled enough knowledge into my sandbox that I am asked to interact with such a highly respected organization.

Doing the Dave Rat Seminars has helped me clarify some basic fundamental concepts. One of those concepts is:

"One of the driving reasons that humans gather in groups is to experience lasting memories."

We attend rock shows, sporting events, houses of worship, theme parks or political rally's in order to create a memory for ourselves and for others.Those memories are created by connecting the people that have something to say with the people whom desire to listen, watch or interact. The more of our senses immersed in the experience, the more powerful the memory. 

As sound reinforcement professionals, our specialty is the audio spectrum and to work with the visual, and other specialists to create the most powerful connections we can. If we keep our grand purpose in focus we greatly increase the probability of a desirable outcome. 

Sooo, on another note

As far as projects, I am currently working on designing what I believe to be the best sounding, loudest, clearest and most versatile stage monitor ever created. With the assistance of (in no particular order) Mario DiCola, Eighteen Sound, Jefferey Cox, Powersoft, EAW and the key people at Rat Sound, we are creating a stage monitor so clear and powerful, using only the most premium components, that no other stage monitor even comes close to its capabilities.

oooh, powersoft visit

Taking everything learned from building the Rat Sound dual 15"/10"/2" L-Wedge and everything learned from designing the EAW MicroWedge series of monitors and creating a stage monitor that is about the same size as the leading high power wedges and exceeds the capabilities of the L-Wedge and MicroWedge combined. I would very much like to share more as we have a working prototype that literally makes the top wedges currently available sound like they are broken when put side by side. Soon Rat will have 4 pairs of wedges with power that we will put out with some key clients and I will give more details.

Here is a photo of Mario, this is not the wedge but rather an early stage of component testing. 

Working with Mario and Eighteen sound has given us access to fine tuning every aspect of the custom loudspeaker design from voice coil material, voice coil length, cone type, weight, magnet type, strength and material and more. I wanted components for this wedge that have never before existed. Here is a laser testing parameters of one of the custom components.

My long standing relationship with EAW is the foundation for the cabinet construction, testing, specs and processor settings. The developing relationship with Powersoft will optimize the amplification and aspects while us at Rat have developed the actual design look, features and capabilities.

Can't have a new design without napkin drawings

Another project I am excited about is I am building a super compact portable sound system that is 8 inputs, 8 processing channels, 8 outputs at 50 watts per channel and the whole ting fits in a suitcase. I intend on using this as a demo system for future seminars to show the differences between mono, stereo and multi-source audio reproduction as well as use it to test some concepts I hope to apply on a larger scale for future arena tours.

As you can see, the small cabinets have mini pole mounts so you can build erector set type structures.

And now for the serious stuff:

Proof that beer and sound go together

That Leonardo guy was a sharp cookie

Oh, Another project was building a head mounted iPhone steady cam for Josh. I love power projects where you just make something useful from stuff laying around the garage

And finally, a video from Thailand at a little zoo on the beach of little otter with something to say.