Let's see...tin cans, a cardboard box, and a suitcase...

[soundlight]

I went to a John McCutcheon concert last night at the ArtsCenter, a very small venue in Carrboro, NC. I went up to talk to the sound guy (as always) and he was actually glad to share some of his knowledge with me. After the show, we were discussing the mic techniques used on stage. Now the drum kit for this show is no ordinary drum kit. This was, as stated on stage, the "Drumship Enterprise." There's two regular cymbals, a hi-hat, a snare, a cardboard box, some tin and aluminum cans, and a suitcase. So the sound guy says "So they show up with this drum kit and I'm thinkin' 'how do I mic a cardboard box, some tin cans, and a SUITCASE?' So I stuck a D6 on the suitcase, and a 57 on the box an the cans." And then we laughed for a minute or two at the hilarity of this randomness!

The way that John's setup was run was very interesting. He plays about 8 or 9 instruments throughout the show, almost all of which plug in to his wireless beltpack. After they go through the reciever, they come back to the pedalboard in front of the mic stand for transformation, and then go back to be run through a Soundcraft Compact 4 mixer (along with the signal from the hammer dulcimer) and then the whole thing goes out throgh a DI. The vocal mic is also apparently taken care of by a DI, as it is a wireless mic and is also sent through the mixer, and out through a different route. I thought that this system was very intriguing. Also, I now want to get a Compact 10 mixer froms Soundcraft, for just a utilty mixer, because of the wealth of I/O provided in such a small form factor. The thing's also built 'like a tank' and is soundcraft quality. What else needs to be said?

About half the show was DI'd, and the other half was straight mic'd. The two keyboards were DI'd, but the fiddle and all of the vocals were mic'd. I don't know exactly what happened with the accordion. The Drumship Enterprise also had a PRO-37 over it to pic up the cymbals and the hi-hat (the snare was mic'd top and bottom with phase reverse on one of them).

I just thought that I would share this random montage of techniques used for the show.

 

[Andy_Leviss]

Actually, the bottom mic on the snare was polarity reversed, not phase reversed. This is a common mistake, and one that the labels on most consoles actually get wrong. Swapping the polarity does effectively produce the same end result as putting signal 180 degrees out of phase, but that switch is actually just doing the former; phase has to do with the timing of the waveform, something not as simply done.

 

[soundlight]

Just a question...since it's a polarity reverse, then why the heck do a large majority of the console manufacturers call it a phase reverse? Just wondering. It seems that since it is a polairty reverse, the console manufacturers (of all people) would name it properly.

 

[Chris15]

Just a question...since it's a polarity reverse, then why the heck do a large majority of the console manufacturers call it a phase reverse? Just wondering. It seems that since it is a polairty reverse, the console manufacturers (of all people) would name it properly.

Probably has to do with the fact that reversing the polarity has the same effect as being 180 degrees out of phase.

 

[soundlight]

I still think that if it's a polarity reverse, they should label it that, and not mislead people.

 

[Inaki2]

Not to discredit you Andy, in any way, but phase is actually measured in degrees, not seconds, we use timing to correct it because of the nature of sound. I have corrected phase issues with amplitude as well (it was in Cuba...don't ask).

But phase comes from a radial background. The difference in timing between 2 signals will produce a phase offset of so many degrees. So 180 degrees out of phase is not entirely wrong. Although you are correct, all consoles out there do actually flip the polarity upside down.

 

[Andy_Leviss]

True, Inaki...I did say it was measured in degrees, but drastically oversimplified the explanation Was more going for the clarification of the way too common misnomer than for an in-depth discussion of phase. Phase is one of those subjects that still makes my head spin sometimes, lol (of course, that's in part because by the time I get my paws on systems, phase has usually already been dealt with by somebody else, but one of these days I'm going to sit down and really understand it all, rather than just the basics)

 

[RelativeMischief]

Best way to understand phase is grab a system thats got a good stack of bass bins (half on the left, half on the right) and put on a cd thats heavy on the bass end. Walk from one side of the room to the other listening to the bass. If you can't hear the acoustic phase shift (canellation/summation) then all the math in the world won't help

 

[Andy_Leviss]

Oh, I very much understand it in that sense. It's more the advanced stuff like choosing crossover slopes and frequencies and aligning multiple drivers in a cabinet, that sort of thing, that I don't have an entirely solid handle on. I know enough to understand what's going on and why it needs to be done, but I'm not one of those guys who can sit down with my Smaart rig and design a preset for the XTA or Lake to drive a 3-way cab from the ground up.

But as far as the bigger multi-box things such as the "power alley" that you're noting, that I'm down with. The nice thing on the last tour I was out with was that it was an arena show with portable decking, so I could get my subs at center and avoid that issue altogether...the drastic difference when you get the subs coupling properly and aligned with the main clusters is amazing compared to the nasty nulls and knock-you-on-your-back sums with split subs. Sadly, in theatrical situations that's often not a viable solution.

 

[RelativeMischief]

Being a concert tech myself, rather than a theatre tech, I can appreciate what you're saying about having your subs clustered in the center. I might even go so far as to say thats a wet dream of mine. I've never had an opportunity to implement that idea myself, but one of these days I'll try it.

As far as the advanced phase calculations we were talking about, I leave that to the guys who passed math. I figure that I have more than enough to keep in my head already, the physics required to build line array boxes is unnecessary and more than likely wasted drive space in my head.

Give me a laptop to input the array stats and a clear head for tuning and I'm set. I tend not to spend more than 30 mins with smaart tops.

 

[Andy_Leviss]

Yeah, it was nice to have that option, even though the implementation wasn't 100% optimal. We were touring with our own ramp and thrust stage ("ego ramp"), but using house deck, as is often the case. Since the house deck varied in whether I could fit the subs under it or not (depending on height, cross braces, etc.), I had to put the subs under the ramp instead. Except that the only place I could put it without screwing up the carps was under the thrust stage, which put it some ways in front of the main clusters.

The solution I ended up with was to delay the subs (what?!) to reach a suitable compromise where the subs were in line for most of the house, but not so far out of whack for the people seated around the thrust stage (ie, in between the subs and the mains, not to mention the most expensive seats in the house). Not a perfect solution, but workable, and in my view a far superior solution than splitting the subs and having massive power alley issues. I'll happily trade great low end over the majority of the house and okay but slightly "off" imaging in a tiny portion of the house for inconsistent sub coverage everywhere.

Anyway, this is drifting wayyyyyyyyyy off topic now, so I'll stop

As for phase, I hear ya with the wanting to keep the math out of your head, although I will admit to not only being one of the guys who passed math, but one of those guys who came within spitting distance of an 800 on the math SATs back in the day, LOL (although that's more a test of how well you take a standardized math test than how good you are at math!).

 

[RelativeMischief]

Even with the subs split L/R and stacked under the array I still usually end up delaying them a few ms anyway, occasionally I try shading them as well but thats another subject.

800 on the SAT, If I knew what that meant I geuss I'd be impressed

 

[Andy_Leviss]

LOL, the SATs, or Scholastic Aptitude Test, is a standardized test that many of our U.S. based members either recently took or will take in the next couple of years as a precursor to applying to colleges. Colleges use the scores on them, in addition to grade averages, letters of recommendations, admissions essays, and other factors to decide who they accept for admission.

In theory, they test a student's abilities in various basic subjects, while in reality, they test how well a student takes standardized tests, for the most part. Back when I took them in the late 90s, there were two sections, one for Verbal, one for Math, each scored with a perfect score on the section equalling 800, for a total of 1600. I know significant changes in subject matter have happened since then, although I doubt they do entirely much to make them more relevant. But that's a whole 'nother discussion entirely!

--A

 

[soundlight]

Just to continue with the off-topic nature of this, the SAT's now have three sections. A math section, a verbal/reading section, and a writing section. The math is just about the same stuff, the verbal/reading is all of the critical reading and that kind of stuff, and the writing is writing an essay and scentence completions and other technical stuff 'bout writing. I got a 2000 overall, can't remember my individual scores. The new total score is 2400, each section still worth 800 points.