Tuesday, March 6, 2012

Dave Rat Blog - Flying Power and Wires

Well alright, break time is nearly over and Peppers tour will be hitting the road again soon.  We were all slated to head out late January but we had a little set back and in the bigger picture it is good news that Anthony's foot is healing well from a painful injury that he had fixed up early Jan. Rehearsals start next week and by month's end we'll be finessing gear into a venue in Tampa Florida.

As I mentioned in the last blog post, I want to make a few changes to the Chili Peppers' touring sound system setup. Whilst I am exceedingly happy with the sound the L-Acoustics K1 system setup has been giving me, I feel we can do better and I am betting that the weakest link in the current chain is the long speaker cables we are running, 150 feet, is possibly causing an audible degradation to the sound. This may or may not seem obvious and while there is no doubt that the recommended shorter cables lengths are better, my true concern is "how audible is the difference in real world venues" and most importantly, I want to hear it for myself and not make assumptions or take someone else's word on it, especially if they have not actually tried it and heard it.

If you are not exposed to larger scale concert touring you may be wondering "why in the heck do you need 150 foot speaker cables?" Well, typically amp racks need to be tucked under the stage, cable then travels upstage to a point clear of sight-lines 30 to 40 feet, then upward 40 to 50 feet and then back toward the main clusters 30 to 40 feet.  Add in swag, slack and some length for venue to venue variation combined with prioritizing 'identical everyday' over 'short as possible' and the 150 foot runs are just what they need to be.

What started me on this push was doing a few back-to-back shows on a Vertec rig supplied by the same sound vendor in two different cities during the Peppers South America run. One Vertec rig was smaller, sounded tight, cleaner and had impact.  The next show we had a much larger Vertec system and it was nothing but mush. Tonally it was what I expected but for the life of me I could not get a solid impact out of the kick and it just had a overall blah sound. "Where have I heard that sound before?" It kept eating at me "what was the difference between the rigs?" Same amps, same vendor, same speakers, and I was bypassing all the system processor EQ and used the exact same preset, doing all the control on my side with gear I am carrying. Then it hit me, 70 volt systems! That's that sound, that soft mush. Tonality can be EQ'ed but it is like there is a big squishy compressor on everything. Could it be related? The larger Vertec setup was massive and the cable lengths would have had to be excessively long. Is it possible that the long cable lengths were introducing a bit of that soft squishy sound similar to the sound of 70 volt systems? Yes, I know the whole premise behind the 70 volt wiring is to run high voltage and minimize power loss and all but lets face it, constant voltage systems sound like the speaker is controlled by the amp about as well as a balloon can be controlled by a 50 foot string.

Once my ears had focused on it I then started to think I was hearing a similar, though way less drastic, version with the K1 system we had on the European dates. Perhaps a psycho-acoustic illusion, perhaps not and only one way I know to find out. And I sure as heck don't want to listen to the morons that make/buy audiophile ac and audio cables, as they will tell me that changing the AC wall outlet on the end of 100 miles of power company cable will make a 30 watt tube amp stereo sound better.

Oh, and while we are at it, I may as well take advantage of the AES digital inputs on the L-Acoustic LA-8 amps. Since the amp racks will be up in the air and less accessible, having a redundant digital and analog return line systems seems prudent anyway.

Ok, pretty simple, right? Add a few motors, some amp rack fly bumpers, throw some AES lines on the return snakes and all good. Hmmm, also need AC feeder up to the amp racks, longer return lines. But wait, we have a 330 foot main snake plus now we are adding another 150 feet to get up to the near-side clusters and 100 foot cross stage and then 150 feet to the far-stage cluster totaling nearly 600 feet on the far run. Oh my, so I loose 100 feet of speaker cable dropping to 50 footers while adding 150 feet to the signal wires. Plus yikes, we need about 4 AES lines per side, so maybe 4500 feet in AES cable and AES does not really like super long runs.

OK, enough of the blah blah about hoop jumping, what we settled on doing after considering fiber, AES repeaters and numerous other systems out there is to give the Riedel RockNet system a try.  We will convert to AES/EBU at FOH via an Apogee AD-16X we already own, hit a Riedel RN335DI and have an RN332DO in the flying amp world on each stage side.

So, if all goes well on this adventure, I will have 50 foot or shorter speaker cable runs from the flown amps, convert the return lines to digital at FOH and stay digital all the way into the processed amps and have analog return lines as well that convert to digital in the amps.  The audio signal will only convert from analog to digital one time regardless of whether I use the analog og digital return lines and I will be able to compare in near real time the sound differential between the two. Then to test the audibility of cable length I can have an additional 100 foot length of speaker cable added in on one side of the PA and pan between left and right to do a real world comparison between the sound of 150 feet of speaker cable to 50 feet on an arena sized K1 rig.

Oooh, fun! And thank you Jon Monson, Jim Lockyer and the other Rats for doing a all the research and work and making this adventure happen!

Alright, now that I have shovelled a big pile of nerdy audio overload out there, may as well look at some pictures.

Kurt Metzler, Kenton Forsythe and Paul Hugo rocking Rat hoodies my new office at the super cool new Rat Sound headquarters in Camarillo. 

So the day starts out all good. Heading to some head high waves with Gene.

I had so much fun on my first day out riding an old beat up Yater I had just finished patching up the night before

The leash breaks, board gets mashed on the rocks, I swim to rescue it, I get mashed on the rocks and now the board is dead, I was banged up pretty good, end of story.

My one and only gig during the break was mixing the Transplants at the Roxy, all good, so fun!

And I got to see the results of Tyler the Creator's temper tantrum at the Roxy and I actually used those group modules that he custom modified with his foot as seen below

And ha! Say hey to Sammy

And Madeline, so absolutely wonderfully smart, sarcastic and all around awesome!

And finally my fierce attack dog, Bones

Dave Rat


  1. Hi Dave Rat, my name is Hans and I'm running a venue(The Star Performing Arts Centre) in Singapore with the first set of K1s in the country. I had serious issues with my venue's speaker cable length when I realise the speaker cable from my amplifier rack room to my K1s was more than 200ft. I had to relocate my amplifiers up at the catwalk nearer to my K1s and KARA to reduce my speaker cable length by more than 60%. I did not use the Riedel Rocknet but I did use the Nexus system as my signal routing via fibre for the AES signals. You should check out the Nexus system cos they are really good stuffs!

  2. Very cool and will take a look. Yes, shorter speaker cable is a very important and surprisingly overlooked way to noticeably improve sound quality of a system.

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