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Mobile Live Sound Rig (half rack space unit)

Starting in January, I am going to be going into schools with one other guy and putting on presentations. We need a small, portable system to drag around with us that is easy to set up and strike. We need two inputs for each of our headsets, two more for each of our guitars, one for playing music, and one for miscellaneous. Here is my idea. I want to use a unit like this:
(Dead Link Removed)

Except instead of super deep, full rack mounts, I want to take build a gatorcase with a small, 4mic preamp soundboard and a 6U HALF RACK space beneath it. In the six rack spaces:
-2 wireless headset receivers
-2 wireless guitar pack receivers
-A half rack EQ unit for EQing the school gyms (hopefully I can find a half rack unit that's stereo... Do you guys know of any?)
-A half rack power conditioner. This will probably be the hardest thing to find. I might have to get it custom made. I have never seen a half rack power conditioner. Have you guys? I know some guys on this forum will tell me I don't need a power conditioner, but being in a different school gyms every day next year with no familiarity with the electricity situation of each location, I feel that its necessary; but its up for discussion.

We're probably going to go with two 750watt powered Yorkville speakers and one small powered monitor. The idea is to leave the 4 wireless receivers plugged into the board at all times, and the soundboard and all of the rack mounted units plugged into the power conditioner. So all we have to do for set up is plugin the power conditioner with an extension cord and set up the speakers.

Can you guys think of anything else I need, or have any other ideas I should toss around? It will be hard to find the half rack stereo EQ and power conditioner, and someone that can make the casing for me. If you guys have any pointers, please pass them on. I just thought of this idea earlier today, and have been mulling it around. It's unconventional, but I think it would be really slick, and small enough to check as baggage on a plane, which will be a huge bonus for us.

Pax Caritas et lol,


audiokid Wed, 09/11/2013 - 08:27
That looks like a really nice start to a rig however, I don't think there is much improvement in the final product between spending $15,000 and upward or spending $2,500 on something that will do it all with very comparable results. I have two mobile rigs. One that cost thousands and the other is recommended below this paragraph. There is no in between for me anymore. Either you spend big bucks for serious pro gear or be smart and don't get caught up in dated concepts buying a bunch of cheap products that are more hype than sound quality.

You should also consider a studiolive 16.4.2 that comes with Capture and the basic Studio One and forget about a modular set-up. Its all you need for mass processing, 16 pre's and FW AD conversion that also comes with one of the best DAW's on the market.
It will blown you away on what this very affordable system will do. Don't get me wrong, I'm big on high end modular mobile recording but for what you are talking about.... look at this before you settle on anything.

dvdhawk Wed, 09/11/2013 - 10:27
The Gator case that pops up with your pic link is a standard width GRC-STUDIO4GO-W laptop compartment over 4U rack. I wonder if you've looked at the compact [=""]SKB 10U over 6U[/]="http://www.skbcases…"]SKB 10U over 6U[/]. For certain gigs and rentals, I have two of the [[url=http://="http://www.skbcases…"]SKB Mini Gig-Rig[/]="http://www.skbcases…"]SKB Mini Gig-Rig[/] and was surprised by how heavy they are even empty (33 lbs). Add a Soundcraft FX-16 mixer on top, and the 6U below containing a good 1U Furman power conditioner, a 1U dbx 166XL, a mercifully lightweight 2U Crown XTI-2000 and 2U dbx 2031 EQ - and it will give you that warm-fuzzy feeling in your lower back if you grab it by yourself.

The smaller power conditioners like the Furman AC-215, or Sanus ELM205 are essentially half-rack size - but you would have to add your own custom rackmount ears, or use a rackmount tray. Another issue you will have with the smaller conditioners is they're generally designed to be used behind flatpanel TVs, so they only have 2 or 3 receptacles, and are only rated at 10A.

And in my opinion, there aren't enough EQs in the world to tame a school gym. But any single 31-band / dual 31-band / or dual 15-band EQ worth buying will take 2U or 3U minimum (standard 19" width). I know there are manufacturers making cheap 1U (standard 19" width) single 31-band / dual 15-band EQs. I've never heard one that I'd want in my signal chain.

If I were traveling and playing a lot of modest volume venues I'd also consider the [=""]Yamaha EMX-512[/]="http://usa.yamaha.c…"]Yamaha EMX-512[/] powered mixer and use passive speakers instead. That EMX is ridiculously lightweight and still sounds very good, complete with 1-knob compressor on 4 channels and 2 little 7-band EQs for mains / monitors and a very respectable reverb/FX unit. One IEC power cable, two or three SpeakOn cables and you're set-up. There's a rackmount kit available for it if you want to protect it with a rack and facilitate keeping the wireless stuff all pre-wired. I also own the smaller Yamaha EMX and it never fails to impress me with how good it sounds vs. how little it weighs. I have a nice little Calzone case that holds it along with all the necessary power and speaker cables for a quick PA system.

By the time I factor in the extra electrical distribution I need when using a system with powered cabinets, it offsets much of the perceived streamlining you might expect when using powered speakers. How many added heavy-duty extension cables and long XLR cables, and case(s) to carry them in - does it take to equal the weight of any of the lighter power amps available today? Pulling more cables and making more connections takes time and greatly increases the chance of failure.

I'd be inclined to put the wireless gear in a soft-sided rack like the Gator GRB-4 that way if you're jumping on a plane, and you're going to a venue that has the PA provided you're ready to grab your personal wireless stuff and go. Pre-wire the power, and snake 4 XLRs together and you should be able to patch your wireless into your PA, or someone else's, in under minute.

Custom cases aren't that hard to build if you have a modest set of tools and know where to buy the hardware. - [[url=http://="http://www.tchweb.c…"]TCH[/]="http://www.tchweb.c…"]TCH[/] and [[url=http://[/URL]="http://www.penn-elc…"]Penn-Elcom[/]="http://www.penn-elc…"]Penn-Elcom[/] are both very good and are easily accessible in Canada.

Personally, I like audiokid's idea, if your goal is to record these gigs and you can afford it. Even the 16.0.2 is worth a look.

All just food for thought....

ClarkJaman Wed, 09/11/2013 - 13:07
dvdhawk, post: 407277 wrote: Personally, I like audiokid's idea, if your goal is to record these gigs and you can afford it. Even the 16.0.2 is worth a look.

To clear things up, I'm not recording these gigs. This is just a live sound rig. I guess I should have posted this thread in a different forum. :/

dvdhawk, post: 407277 wrote: The smaller power conditioners like the Furman AC-215, or Sanus ELM205 . . . are only rated at 10A.

I'm glad you brought those ones to my attention. I wasn't aware of them. But to someone who's electronically illiterate, what kind of problems will the 10A issue cause?

For the EQ, I wasn't planning on getting a 31 band. I was going to look more at something like the Boss Pro GE-21 or else try and find a stereo parametric EQ. I know that EQing a gym is a nightmare, but all I want to do is make it significantly more bearable.

As far as getting a powered board, are there small powered boards (4 mic pres) that sound good out there? If none of this half rack business works out, I will probably go with a larger board and a full rack unit with a powered board.


audiokid Wed, 09/11/2013 - 15:20
Recording with the StudioLive console is a bonus ( and a really good bonus) . Its a live digital console with very nice analog pre's. The console is on 30v rails, better specs than most consoles trying to rival this. Nothing comes close to this at this price.
You still need preamps, EQ's comps, gates, effects, an interface and a DAW to track to. This has it all in one clean console. Super slick and stable.

StudioLive and a good laptop with FW and you are sailing.
Take a second and watch a few Video's on this.

dvdhawk Wed, 09/11/2013 - 16:00
I noticed the original post didn't include anything specific about recording, but since it was under this heading I thought it was worth mentioning. The PreSonus audiokid recommended is just as viable for live sound, even if you're not recording.

Although they probably would not run at their theoretical limit, 2 x 750w = 1500watts. [and those calculations are based on the Yorkville's being 100% efficient - which is impossible] Then add an additional powered monitor of several hundred watts and whatever other miscellaneous you want racked into the same power-supply, and you should be prepared to supply up to 20-amps for everything.

The Furman for instance can supply 10A @ 120V = 1200watts max. So you would theoretically run the risk of blowing the breaker if you were hitting it hard and went beyond the 1200watts. Most rackmount power conditioners are 15A (1800w max.), or 20A (2400w max.) Please note: Here in North America, a true 20A power conditioner will have [[url=http://[/URL]="http://images.lowes…"]a different plug with one blade turned 90˚from norma[/]="http://images.lowes…"]a different plug with one blade turned 90˚from norma[/]l - that may, or may not, fit into any of your available receptacles.


Again, most things rarely, if ever, approach their absolute maximum power consumption. But to my way of thinking, anyone who cares enough to condition the power, would care enough to not short-change your entire system with a 10A power supply and run the risk of blowing the breaker mid-crescendo.

FYI: I think the Boss is designed for guitar signal level, which would have very mis-matched levels/impedances to be used as a PA system equalizer.
Attached files

ClarkJaman Wed, 09/11/2013 - 16:24
Thanks for your help, dvdhawk.

dvdhawk, post: 407280 wrote: FYI: I think the Boss is designed for guitar signal level, which would have very mis-matched levels/impedances to be used as a PA system equalizer.

I think you're right. :o I'm sure I can find an alternative though. I just suggested that one off the top of my head because I knew it was half rack.

dvdhawk, post: 407280 wrote: Here in North America, a true 20A power conditioner will have [[url=http://[/URL]="http://images.lowes…"]a different plug with one blade turned 90˚from norma[/]="http://images.lowes…"]a different plug with one blade turned 90˚from norma[/]l - that may, or may not, fit into any of your available receptacles.

Is that the plugin that powers the unit? I have a Furman conditioner, and it doesn't have that. Does that mean that it's not truly 20A?

dvdhawk Wed, 09/11/2013 - 22:24
Glad to be of help.

Furmans generally have a breaker on them, that's all you need to look at to determine what amperage you have.

If it's a normal molded plastic plug, you probably have a 15A unit, or if it is not molded it's very possible someone has replaced the connector on a 20A model to the more universal 15A.

The folks at Furman say in the manual for their 20A power conditioners, that you can either buy an adapter cable (which they sell) - OR it would be perfectly safe and legal for you, the end-user, to change the plug to one designated as 15A. However, they cannot sell them with anything but the 20A plug due to safety regulations. Despite the fact that having a novice re-wire their own electrical plug might be like handing them a loaded gun.

As I understand it, the Canadian codes and laws governing electrical safety are even more strict than ours. So I'd be surprised if Furman could ship a 20A unit to Canada with a plug designated for 15A use.

dvdhawk Tue, 09/17/2013 - 08:37
ClarkJaman, post: 407340 wrote: So that should mean that the 10 amp should be able to run my 2000 watts system, right?

It will work beautifully.... right up until the breaker blows, (BIG) IF you're ever in a large enough venue that you have to push the system. Until then, it will be just fine.

Case in point, your 3000 Watt system apparently never ran more than 1800 Watts, or the Furman would have shut it down based solely on electrical consumption.

I have a 20-Amp Furman conditioner in each of my amplifier racks. Even though, if you added up the theoretical maximum wattage (both output watts and power consumption watts) of the amplifiers in each rack, they would each total more than 2400 Watts (20 Amps). Touring companies who have to go flat-out with high-power amplifiers require massive power distro racks and hundreds of pounds of big heavy mains cables. Littler guys like us, have to consider the typical venues only have a few circuits on stage @ 20-Amps each.

You've probably noticed the relationship between Watts and Amperes and figured out the equation is pretty simple: Watts / Volts = Amperes

Canada and the US run 120V, so for the purposes relevant to this thread at Canadian and US Voltages ONLY (120V). 1200 Watts = 10 Amps. 1800 Watts = 15 Amps. 2000 Watts = 16.66 Amps. 2400 Watts = 20 Amps. **(these numbers do not apply for others reading outside of North America, but the equation above still applies at different voltages)**

Audio output specs are largely BS, but the electricity specifications on the supply side are pretty strict.

Like I said before, a typical amplifier rarely (if ever) runs at full bore requiring every single watt/amp of electricity to produce the maximum output listed on the audio spec sheet. Just like a 1000 Watt amp rarely gets anywhere near 1000w. And if it does, it's usually just for a tiny fraction of a second. Just as most mid-grade, and below, speakers rated at 1000w couldn't take a true 1000w signal for very long. Audio performance specs are just that, the manufacturer's best foot forward. The really good audio companies tell you exactly how they derived those specs, and all the conditions involved. But in the end they're all trying to inflate the output wattage, because that's the number the average consumer will use to compare them. But if you think about it, buying speakers and amplifiers based solely on watts is a lot like buying a vacuum cleaner based on how many amps the motor uses. Just going by that one spec completely ignores how efficiently the device converts the power it consumes into tangible real-world results ..... but I digress.

You'll notice that the better amplifier companies, provide electrical consumption specs now that include: idling power, 1/8th power, 1/3rd power, and maximum power - basically acknowledging that the range between 1/8 and 1/3 is pretty typical for normal operation. They still have the headroom to provide that short spike for the kick drum or other loud transient, but typically aren't running anywhere near maximum output. Which in turn means, they're also nowhere near their maximum power consumption. So when you see an amplifier listed at 2000 Watts per channel (4000 Watts in all), and account for the fact that no electrical device is 100% efficient, and then see it has a standard IEC power cord with a standard 15 Amp Edison plug on the end - you know somebody is exaggerating to the tune of a couple thousand watts.

So, if you understand that, and you're confident the actual demand of your 2000 Watt system won't exceed 1200 Watts - it's perfectly safe to use the 10A conditioner. Worst-case scenario, it will just shut off. [Amplifiers hate that, by the way. And if the amplifier purges that hate into the speaker - it can truly be a worst-case scenario]

dvdhawk Tue, 09/17/2013 - 15:23
The breaker on the weakest link would blow if you went nuts and really pushed the system hard, in this case that's the Furman. If your demand exceeded what the Furman could supply, it would trip the breaker in the Furman and the 'house breaker' would keep on working. You would then reset the Furman and try again. Once any breaker reaches the brink, it tends to get warm and trip more easily until it has a chance to cool down. So you should go a little easier on the volume for a while until it gets back to a normal operating temperature.

Most commercial buildings here would have 20A breakers in their panel providing power to the receptacle your Furman would be plugged into. So on the supply side, you have a 20A limit.

But what you won't know is, how many other receptacles are on the same circuit. Hopefully someone at the venue knows. If they have live entertainment very often, someone will know how many circuits there are, and which receptacles are on what circuits. If you get to a point your needs go beyond 20A a basic understanding of electrical panels and a volt meter you can help to determine which receptacles are on different legs of the panel feed, without ever seeing the panel or resorting to randomly flipping breakers. If it's on the other leg, then you're assured they are also on separate circuits if your electrical needs require more than 20A, this is a good thing to know how to do. Not terribly complicated, and only slightly dangerous.

Will you be using any lights or projector(s) in your presentations? If so, that's a completely different animal. Incandescent lightbulb wattages are real and constant when the light is full-on, which would include projectors.

ClarkJaman Tue, 09/17/2013 - 15:38
Cool. Makes sense.

dvdhawk, post: 407364 wrote: Will you be using any lights or projector(s) in your presentations? If so, that's a completely different animal. Incandescent lightbulb wattages are real and constant when the light is full-on, which would include projectors.

We will be using one projector, two LED light trees and two LED pot lamps. I wasn't planning on plugging them in through the conditioner. Should I?