SR/Live Sun, November 23, 2008

Back in 1974, the Grateful Dead put together what was easily the most unique, experimental and perhaps complex sound system ever configured for live sound reinforcement in that era. This system was named the “Wall of Sound” and was a complete divergence from conventional sound reinforcement thinking. There were two key concepts combined together resulting in a very interesting outcome:

1) Because PA systems of the day were stacked on either side of the stage and often blocked audience sight lines, they designed a sound system that was placed behind the band and acted as both the PA system, their instrument amps and as their monitor system (way for the band to hear themselves).

2) They found that when all the various instruments and vocals were mixed together into the PA speakers the sound was less clear than when each instrument was amplified separately. To deal with this, they actually designed and used a separate sound system for each instrument and another sound system for the vocals totaling six PA systems!

While a giant step in forward thinking was made, it was not without issues. Having the sound system directly behind that band meant the speakers are pointed straight into the microphones.

Also, the sheer complexity and magnitude of the setup greatly limited the venues that it could be implemented and the fact that the sound system became the entire stage backdrop relegated it to become a niche concept that possibly could only be used by its creators and equally unique Grateful Dead.

And as you can see in the photo above at right, it did not make for the cleanest stage set, while to provide some contrast, the photo below at right is a cool old picture of The Rolling Stones stage setup with the PA located behind the lips scrim.

Even with it’s awkwardness, the concept of the Wall of Sound was so intriguing that I had to try it and understand it.

I finally got that opportunity in 1986 while touring with Black Flag when, after some persuading, Davo and I talked the band into letting us set up the Rat PA in a mini Wall of Sound configuration. Since I had designed and Rat Sound had built Black Flag’s guitar and bass cabinets exactly the same dimensions as the Rat PA, the system fit together really well. (That system is pictured left.)

On the upside the system was incredibly clear sounding while on the downside, it sounded a bit distant and the sound bleeding into the mics was cumbersome enough not to continue with that setup. The most important thing is that I learned enough to set my sights on someday resolving the issues.

Twenty years later, through a roundabout way I have come full circle. My testing in designing the MicroWedge Series has clarified my understanding and goals. The evolution of sound systems from giant globs of speakers to finesse full narrow line-arrays created the opportunity to cover large venues with multiple systems utilizing minimal space.

The entire Wall of Sound was 26,000 watts, current systems run at ten times that power and are a fraction of the size. Plus we now have the capability of effectively predicting the sonic coverage in a venue based on room dimensions.

What this means is that with today’s sound system technology, multiple sound systems can be hung conventionally to either side of the band rather than stacked behind them without blocking sight lines creating an inconspicuous yet effective implementation of the concept. (The photo at right shows the “dual-PA” system approach that Rat Sound has developed for The Red Hot Chili Peppers.)

Initially I considered proposing a triple system rather than the dual system the Peppers are currently touring with. The triple would have been three separate stereo sound systems, one for guitar, one for bass and one for vocals with drums interspersed into the three.

To test the concept, I purchased three small home hi-fi systems and roadie Ethan and I built a small simulator in my living room. With a ProTools system and live Peppers multi track recordings from last tour, I was able to try out different combinations and test the effectiveness of the setup. I found that the most noticeable improvement occurred when going from one system to two and adding the third was more subtle.

So here we are today, and I smile as long ago dreams have become real. A refined and usable version of what the Grateful Dead had started, a grand scale application of what I learned from so many years.

Dave Rat is the owner of Rat Sound Systems, a leading sound company based in Southern California. He’s also an accomplished audio technology and product developer, noted in particular for the MicroWedge Series, and posts the fascinating “Roadies In The Midst” blog that relays his experiences in the world of professional sound and a wide range of other topics. Click here to check it out.