Dave Rat Blog

Saturday, September 29, 2012

Dave Rat Blog - Up Down and Side to Side

San Antonio Texas and a cool hotel on the Riverwalk. Show day of the 4th gig of the tour leg. San Diego, Glendale AZ, and Denver so far with Dallas and New Orleans still ahead.

I continue to ponder the deficiencies in the methods typically used to setup and measure the implementation of live audio systems and question whether a truly accurate and useful method even exists. Primarily the aspect I am focused on has to do with the inability of measurement systems to adequately differentiate between comb-filtering issues occurring in the horizontal versus the vertical domains.

With two horizontally spaced sources, like our home stereo or a typical live sound system setup, the comb filtering that results is not really a negative issue to our ears yet common measurement methods will typically indicate the interaction from the output of the two sources as undesirable, not flat and a series of summations and cancellations known as comb-filtering.

With identical vertically spaced sources conventional measurement methods will measure the same issues from any single point as with the horizontal sources mentioned above, yet sonically perception-wise to our ears, the sound is far from the same. Horizontally spaced sources covering the same area sound 'stereo' and so desirable that we strive set up sound systems this way, comb-filtering and all. With vertically spaced sources covering the same area we do not enjoy the perceptual benefits of that 'stereo' sound so all we are left with is determining whether the resulting comb-filtering is an issue or not.

Is vertical comb-filtering less important to our ears than horizontal comb filtering? Is that why variable angle line arrays are always vertical? Is horizontal comb-filtering desirable from spaced sources (stereo) and an issue from horizontal sources in close proximity? Yet with vertical sources in in close proximity, are our ears less likely to here the issues associated with the multiple sources reproducing the same signal? If any or all of the above are true, then differing amounts of relevance would need to be attributed to comb-filtering issues depending on whether the sources are horizontally spaced or vertically spaced and also one the spacing distances as well.

Does the method you use to measure, calibrate and EQ a live sound system have the ability to tell you effectively "OK, these horizontal issues are no big deal and these horizontal issues are a big deal where as these same vertical issues are no big deal and these vertical issues are a concern."?

And on to sharing a few pics:

This blog is focused on the audio and adventure side of tour but a bit of love and recognition for my friends and the band who has me join them on these worldly adventures.

My view from FOH

It was great to see the band OFF! opening for Peppers in Los Angeles. Long history with old friends, yay!

And where I left off last blog was in Beirut, we then headed to Istambul and WOW! What and absolutely amazing city. Truly magic and I can not recommend enough a visit there added to your adventuring dream list.

And doing Dave Rat seminars in cool places is so darn cool! Another group of wonderful sound nerds. Thank you for hanging out with me and being such gracious hosts!

Here is the Istambul gig

This was the last show with us for Ulf whom came to join us and assist with the stadium sized Peppers show. A true pleasure and honor working with you and see you soon I hope.

Finally, to sign off with a bit of curiosity, here is a pic I snapped out the van window as we drove into Tel Aviv

Oh my

OK, more to come and off to do a show in San Antonio, rocking!

Tuesday, September 18, 2012

Dave Rat Blog - Believing Illusions

So coming up on the last show of this leg of tour I start this post 45 minutes before lobby call in Istambul. Beirut show was three days ago and we're heading to Tel Aviv this afternoon. It is truly amazing and intriguing to visit these ancient and historical cities and yet find the common ground of happy and enthusiastic humans gathering to enjoy music. More so than any other travel trip I have done, this tour has highlighted the vast discrepancy between the impression that corporate news media presents and the reality of what to see and expect. So naturally the unfamiliar is blown out of proportion illogical fear levels. Just as Nebraskans can watch aghast with fear over the how unbearable it must be for Californians to live in constant fear of earthquakes, while yet another swirl of tornadoes roll past ripping through local houses and corn fields.

People die of gangland shootings in Los Angeles so common that the news stories rate lower than a traffic jam on the freeway while just a mere mention of visiting Beirut, Tel Aviv or Istambul is met with wide eyes aghast,"is it safe, those places are all over the news." There was a guy, killed and kidnapped there just yesterday!" I hear someone say. "Really? someone died in a city that is not the city I am going but it is in the same country?, wow!" And what comes to mind is the simple minded logic in reverse. that I occasionally hear "Wow, you are from Los Angeles? Hey, my sister's husband's brother is from Los Angeles, do you know a guy named Joe Smith?" And with the same odds and probability that I know Joe Smith, I will embrace those irrational fear levels as I travel the earth.

Now that is not to say that having an alertness to one's environment whether in the forest, the desert, south central Los Angeles or any other place on the planet earth is not a wise.mindset. And just like going on a camping trip where I neither got lost, died or ran out of water but saw some amazing and interesting things, I get to share a few pictures and memories.

So Lets start with Beirut, oooh look!

And as far away as places seem to be, the simple familiarity of being able to live off of plastic cards holds strong

Loading up the crew bus at the airport to head to the hotel

Our bags are very safe right now

Yay Tour bus!

Ooooh, cool UN vehicles!

Our bags are even safer when we unload at the hotel

Hey look a special conveyer belt to help move the bags a 5 feet closer and save us hauling them a bit plus a walk through metal detector too.

Yummy amazing meals

This was the view out our hotel room window. Did a bit of asking around and it is the Holiday Inn from the "Battle of the Hotels http://en.wikipedia.org/wiki/Battle_of_the_Hotels

Plus I did a mini Seminar there as well

The Gig

And some wandering

And back to the airport

Next stop Istambul.

and thought of the day:

So wandering around the local Best Buy and Fry's looking at electronics and such as I occasionally like to to do. I notice the growing popularity of "sound bars"

https://www.google.com/search?q=sound+bar&sugexp=chrome,mod=17&sourceid=chrome&ie=UTF-8

And with these horizontal steerable sound systems each seems to be all about simulating surround sound. I guess not so much surround actually but rather trying to create an enhanced stereo image. In essence inferring that the stereo image is inadequate in the recordings or that there are improvements to be made? Could they be trying to make the instruments sound like they are coming from different places? Meanwhile, the bulk of live engineers, we have total control and yet most engineers mix on huge complex sound systems what is almost always very close to mono. Hmmmm

In real life, next stop San Francisco. In Blog life, next stop Istambul. Meanwhile, 6 days home and 5 days of surfing, huge piles of pretending I am a business man and no where near enough time with my daughters. But hey, it can always be worse and upload it goes without a proof read or edit.

Good night

Wednesday, September 5, 2012

Dave Rat Blog - Perception and more

It was very cool to be able to get to do sound seminars in Prague, Bucharest, Sofia and today in Athens as well. Meeting sound humans in each city is super cool.

My latest ponder is back on to the deficiencies of the equipment we use to measure audio. It is so tempting to look at frequency response and believe it is an accurate picture of what we are hearing. Yes, I do very much rely on frequency response and tonal balance as a primary factor of the sound being presented. I also try my best to be aware of the fact that frequency response is just a small part of the bigger auditory picture.

Can any measurement gear tell you who manufactured the system you are listening to?

For example, what if I were to EQ an L-Acoustic K1, JBL Vertec and a D&B J rig to look exactly the same on my measurement system? Will they sound the same? What if I space two speakers 4 feet apart horizontally in cube shaped room and measured the sound. Then I move the speakers to be vertically spaced in the same room, the same distances from the floor and ceiling as they were from the walls before. The same mic position as well. Acoustically the exact same sound would be created and measured, the exact same frequency response. Yet if we listened to the two scenarios would they sound the same? Would we be able to hear that the speakers are placed horizontally versus vertically? If we can not hear the difference then we can start placing our home Hi-Fi speakers vertically spaced and it would sound the same, Right?

So if the measurement system we rely on can not easily differentiate between drastically different speaker positions and systems types, something so easy for us to hear as vertical versus horizontal speaker placement, what other valuable information is it denying us? Now move those same speakers very close together and compare the sound of horizontal versus vertical placements, can we still hear the difference? Is there comb-filtering?

The theory of line arrays relies somewhat on placing all the issues of speaker interaction vertically where our ears are less likely to hear them. No major manufacturer or any manufacturer that I know of makes a horizontal line array wherein overlapping coverage between adjoining boxes is utilized to increase coverage distance. Horizontal arrays are typically splayed at fixed angles that minimize overlap between boxes.

OK, some adventure pics. Say hey to the Bucharest Romania seminar crew.