# Building a Backstage Monitoring System



## Herr_Sprecker (May 24, 2016)

Good day all. Apologies if this subject has already been covered in another thread that I just didn't come across.

I'm speccing out a system for backstage monitoring. The theatre I am at has just built a new building attached to the performance space, so we have brand new dressing rooms, costume shop, and huge rehearsal space. I'm trying to piece together a system that can originate at the racks near our sound console and be spread to the dressing rooms and other areas.

As I understand them, it seems like a 70v system would be preferable, as I would anticipate 100' to 150' worth of wire run to get to any individual speaker. Never having built a system, and only having a tiny bit of working experience with an existing system, I'm trying to solicit two things:
1. Gear I need to get
2. Things I need to know about such systems

The ideal world is for the distribution amplifier at the sound system to have at least two inputs, one for program feed and one for paging. Most of the amplifiers I've looked at seem to accommodate this easily. I do not foresee the need for the system to expand beyond this, so a TOA system with multiple potential inputs is probably more than we need.

In an ideal world, we'd be looking at each dressing room and the costume shop having 2 ceiling speakers, connected to a single wall attenuator for volume control. In total, 6 ceiling speakers and 3 wall controls.

As I understand it, the 70v system is preferred particularly to accommodate the longer cable runs, yes? And the speakers I would select would need a 70v transformer? Or would most any ceiling speaker work as long as the load is within the tolerances of the amp? 

Any help and advice would be greatly appreciated. Thank you!


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## garyvp (May 24, 2016)

Been there, done that...after years of aggravation and bad information, I replaced our house mike and intercom system (70v) (very clunkly and very problematic) with a PA amplifier, an impedance matching speaker distribution switch ($50) and ran from there to six locations - where I installed a separate good remote speaker volume controller ($25 each), all items from Pyle. I also ran new 18 awg 2 conductor stranded Carole Comm speaker cable. Speaker size and impedance varied a lot. I've had no problems since. In your situation you would run three 4-conductor cables but you still only need one volume controller per room (they are made for stereo set ups). Note that the distribution switch is also meant for stereo.


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## Herr_Sprecker (May 25, 2016)

Would you have some suggestions for a particular PA amplifier? I'd need one with at least 2 inputs, one of which would be a feed from our sound console and/or an area pickup microphone.

Thanks!


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## RonHebbard (May 25, 2016)

Herr_Sprecker said:


> Good day all. Apologies if this subject has already been covered in another thread that I just didn't come across.
> 
> I'm speccing out a system for backstage monitoring. The theatre I am at has just built a new building attached to the performance space, so we have brand new dressing rooms, costume shop, and huge rehearsal space. I'm trying to piece together a system that can originate at the racks near our sound console and be spread to the dressing rooms and other areas.
> 
> ...


If you're going with a 70 volt system, and with future expansion in mind you may want to, you may choose to consider detented (stepped) 70 volt autotransformer style mono attenuators c/w internal bypass relays configured such that artists can turn down the monitor level if/when desired but they can NOT alter the level of pages as the attenuator's setting is bypassed for the duration of any / all pages. Budget priced attenuators of this type cost even more money with units worthy of installing costing even more again. Lowell could be one of several manufacturers to consider but these could easily be beyond the scope of your budget.
Toodleoo!
Ron Hebbard.


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## microstar (May 25, 2016)

Have you considered installing a video monitoring system? A security-type camera, 2-channel audio mixer, and an RF modulator would send video and monitor mic/paging audio to standard TV sets at the various locations. Or do two separate systems..... performance monitoring thru the TV set and paging thru ceiling speakers and separate amp. Here's an inexpensive but good-performing camera I've used at a community theatre:
http://www.mcmelectronics.com/product/82-18285


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## firewater88 (May 25, 2016)

I installed a 4 ch Crown 70v amp in our stage manager rack and feed it a program feed off the main system and a feed out of the com base unit for paging. The other 2 ch are in a patch panel for tour shows to plug into the system. All go to 70v speakers in each room, on both floors. Be sure you match the transformer output at the speaker to not overload the amp. I did not put a volume control in each room because I didn't want the kids to turn it all the way off and then miss an announcement. 
As a side note, we also have a tv in each room that is modulated throughout the building and takes a feed from the house hanging mics. We had the infrastructure already in the building for distributed CATV, so we just piggybacked on that. Works great. But the 70v speakers are mostly used for dressing room page for the most part.


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## RonHebbard (May 25, 2016)

firewater88 said:


> I did not put a volume control in each room because I didn't want the kids to turn it all the way off and then miss an announcement.


 This is exactly why I mentioned the possibility of utilizing 70 volt stepped / detented mono attenuators equipped by their manufacturers with internal bypass relays permitting end users to conveniently adjust the monitor sound to any setting, including completely off, yet effectively bypassing the attenuator to full level (zero attenuation) for the duration of any / all pages. All of the bypassed attenuators cost appreciably more money but, as with virtually all products, the economy models have a comparatively short service life while the pricier units will often survive ten years, or more, of severe usage. "Severe" in the sense of 8 performances per week, year after year, plus many weeks of rehearsals between productions and the dreaded dance and body builder rental experiences. Possibly attenuators of this type are beyond the scope / budget of many posters' needs.
Moderators: Why does Control Booth's spelling checker consider "detented" to be an incorrectly spelled word?
Toodleoo!
Ron Hebbard.


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## garyvp (May 26, 2016)

Herr_Sprecker said:


> Would you have some suggestions for a particular PA amplifier? I'd need one with at least 2 inputs, one of which would be a feed from our sound console and/or an area pickup microphone.


Keep in mind that our house mike system is very crude but does the job. Our amp is a five year old 125w Pyle with several mic inputs. We have two onstage mics (Radio Shack - nothing special) hanging from from the ceiling for performance pick up, and we can add a third mic for announcements from the booth. The amp allows for additional audio inputs but we don't use them. One issues is the distance from the mics to the performers is always several feet, so the gain is quite high on the amp, and therefore we have some background noise. it just gets the job done as long as no one messes with it.


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## microstar (May 26, 2016)

Herr_Sprecker said:


> Would you have some suggestions for a particular PA amplifier? I'd need one with at least 2 inputs, one of which would be a feed from our sound console and/or an area pickup microphone.
> 
> Thanks!


I'm partial to the TOA brand of mixer-amplifiers. Although they are expensive new, you can get great deals on used ones on Ebay. I've found them to be bullet-proof; they will run 24/7/365. One neat input option module is a chime module, very useful for signaling the audience into the auditorium before the show and after intermission if you have lobby speakers.


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