Outboard Mixer to Control Hearing Impaired, Monitors, etc

[Les]

So my facility runs a 48 channel A&H board, and the staff is all volunteer. I oversee the technical side of things, and one of my biggest headaches is keeping important (permanent) things patched in to the correct Auxiliaries.

For example, we have an induction loop system as well as several 70v amps that feed devices such as backstage/scene shop monitors, lobby speakers, audience recall chime, etc. Some of them have been unpatched since the theatre got a new console, and I'm just now getting my head around how to get it all back online. The problem is, designers also come in and repatch the board to their liking and it is difficult to enforce or oversee what all they do. In addition, inexperienced ops may not know what is what, and how to do much other than ride a fader. So when the SM says "more greenroom!", there may be some head scratching as well as my thinking the sound board op shouldn't have to be responsible for that to begin with.

So I had this idea and you guys tell me if I'm crazy.

We have a large rack next to the console which contains things such as Clearcom, effects processor, hearing impaired amp, etc. There is also a patch panel at the bottom. My thinking is to add an additional outboard mixer such as the Alesis Studio 12r, and connect all these devices to that.

Then there is one of two ways I could interface it with the board.

1). Take the Alesis' main outputs and patch it in to a clearly-marked Post-fade Aux with a clearly marked cable. Then there's one connection, one control, one headache.

2). Since the patch panel at the rack contains the main I/O for the house speakers, I could just wye the signal off of that (preferably behind the patch bay) so these devices always get the house mix - which doesn't seem like a problem unless I'm missing something. Levels can still be controlled locally at the devices as well as the fader on the outboard mixer, and the beauty would be that there is nothing on the console that can be messed with.

What do you think? Is this a viable solution or am I going down the wrong path?

 

[techieman33]

My venue uses a more complex version of option 2 and it seems to work well for us. We have two mixers in our amp room so we don't have to worry about people messing with them. One for the backstage areas, dressing rooms, green room, shop, front office, etc. And the other for public areas like the lobby. Then at FOH everything is just a bank of switches. You can send the main mix or the theater monitor mic if there are parts of the show that aren't mic'd. We have also have two additional lines at the patch bay where we can send a specific mic, or a line level to those mixers. The backstage speakers all have their own volume control so that mixer hasn't been touched in years. We don't have a volume control in the lobby so that gets tweaked a few times a year if there is an event out in the lobby and we want a little more volume out there.

 

[Les]

Thanks for the reply! That tells me that I'm on the right track, and it sounds very similar to our setup. We also have multiple PA amps around -- three in the booth's rack, which is built in to the wall, and another two backstage at the SM console (one is for backstage monitors and the other is actually an assembly amp). I need to track down where they end up since they've been un-patched for years, which irks me as one amp handles the Emergency Announce System which I believe plays a message over the house system when the fire alarm goes off.

Well hopefully getting all this tied in to a separate mixer can streamline things once and for all, and mitigate future problems.

Part of this upgrade is to also extend 70v speakers to the greenroom and dressing rooms. For whatever reason, the 70v backstage monitor system ends at the scene shop, and the current "solution" has DJ-like speakers daisy-chained from a single amp channel and controlled from the console. Probably an impedance nightmare and it is quite unwieldy. As for the new 70v speakers, I'm leaning towards not putting a volume knob in every room and instead have it globally controlled from the amp at the SM console. I've found that when you give someone a volume knob, they'll invariably turn it to zero and begin to complain that there is no sound.

 

[RonHebbard]

Thanks for the reply! That tells me that I'm on the right track, and it sounds very similar to our setup. We also have multiple PA amps around -- three in the booth's rack, which is built in to the wall, and another two backstage at the SM console (one is for backstage monitors and the other is actually an assembly amp). I need to track down where they end up since they've been un-patched for years, which irks me as one amp handles the Emergency Announce System which I believe plays a message over the house system when the fire alarm goes off.

Well hopefully getting all this tied in to a separate mixer can streamline things once and for all, and mitigate future problems.

Part of this upgrade is to also extend 70v speakers to the greenroom and dressing rooms. For whatever reason, the 70v backstage monitor system ends at the scene shop, and the current "solution" has DJ-like speakers daisy-chained from a single amp channel and controlled from the console. Probably an impedance nightmare and it is quite unwieldy. As for the new 70v speakers, I'm leaning towards not putting a volume knob in every room and instead have it globally controlled from the amp at the SM console. I've found that when you give someone a volume knob, they'll invariably turn it to zero and begin to complain that there is no sound.

@Les In the world of 70 volt stepped attenuators there are a couple of things to know:
1; As with most things, you tend to get what you pay for with name brand attenuators commonly working for 20 years without servicing and cheap plastic attenuators being a servicing nightmare that NEVER ends.
2; This point addresses your worry about users turning the attenuators off and missing pages. Look for attenuators manufactured with built-in bypass relays. The relays are designed to leave the attenuator in circuit other than during a page when the relays activate effectively by passing (removing) the attenuation for the duration of the page. Typically you wire the system with four conductor, dual twisted paired cable using one pair for the 70 (or 25) volt amplifier output and a second pair applying 24VDC to the by-pass relay's coil for the duration of the page. Install a PTT (Push To Talk) mic. Normally the PTT switch's normally closed contact mutes (shorts) the dynamic mic's voice coil output when not activated and its normally open contact applies the low voltage DC to the by-pass relays for the duration of pages.
Name brands such as Lowell manufacture attenuators worth installing. Bogen's attenuators used to be good when they were manufactured in New Jersey. Avoid the plastic attenuators. A fellow I used to install for bought a case quantity of the cheapos and we found an appreciable quantity didn't work out of the box and quite a number worked until you bolted on the single gang cover plate. Literally; You could test them and they'd be working fine. Bolt on the cover and they'd quit. Remove the cover and they'd be working again. Simply mounting the cover would flex the plastic enough that the attenuator's internal contacts would fail.
ALWAYS purchase stepped attenutors based upon actual rotary switches. Never purchase non-stepped L or T pads OR L or T pads with stepping detents added to fool the unwary. They're essentially junque and not worth your time to install.
Attenuators with by-pass relays are very common in installations where you want to allow the talent the ability to turn the show monitor audio down, or off, yet want pages to boom out loud and clear.
Toodleoo!
Ron Hebbard.

 

[Les]

Oh come on, @RonHebbard . You know I'm too lazy and cheap for that!

Actually, it sounds like a great system and I will give it due consideration. The only hiccup is that our theatre doesn't really Page dressing rooms, unless you count running around yelling "Places!" (though that could change with a better system in place). Most of it is just hearing the show.

One thing I did just realize was that the Assembly and the Emergency Announce Systems should really be pre-fade, so that they can still be sounded when the main faders are down. Luckily they are on the same amp, but I will have to navigate that. Perhaps patching them in to the Mains signal chain isn't the best plan.

Here is a picture of the amps at the SM console. I believe the bottom amp runs the 70v speakers and can be post-fade. Though ideally the Audience Recall Chime would be on the other amp. I guess I could move it and redo the labels.

 

[RonHebbard]

Oh come on, @RonHebbard . You know I'm too lazy and cheap for that!

Actually, it sounds like a great system and I will give it due consideration. The only hiccup is that our theatre doesn't really Page dressing rooms, unless you count running around yelling "Places!" (though that could change with a better system in place). Most of it is just hearing the show.

One thing I did just realize was that the Assembly and the Emergency Announce Systems should really be pre-fade, so that they can still be sounded when the main faders are down. Luckily they are on the same amp, but I will have to navigate that. Perhaps patching them in to the Mains signal chain isn't the best plan.

Here is a picture of the amps at the SM console. I believe the bottom amp runs the 70v speakers and can be post-fade. Though ideally the Audience Recall Chime would be on the other amp.
View attachment 15604

@Les Here's a link to the first attenuator Google dredged up. It's a 100 Watt unit but you ought to be able to find lower wattage quality units in the five to ten watt area https://www.lowellmfg.com/product/100lvc-pa-rm-mono-attenuator-100w/
A couple more comments for you.
I found it useful to have two amplifiers for the backstage monitor / page system.
One amp supplied monitor only sans pages for places such as FOH booths where you don't want the pages leaking into the audience area. The second amp provided two functions: Its basic function was monitor audio which muted during pages. It's second function was delivering pages only, sans monitoring, to spaces which wanted to hear all pages but not have to listen to the show for the third month in a row. We had both amplifiers located USR at the "Book ASM's" desk where every 70 volt zone had a four position lever switch selecting between:
1; Monitor with no interruptions.
2; Monitor with page override.
3; Pages only with zero monitoring.
4; Totally off.
Toodleoo!
Ron Hebbard.

 

[Les]

Thanks for the info, @RonHebbard

One thing I did just realize was that the Assembly and the Emergency Announce Systems should really be pre-fade, so that they can still be sounded when the main faders are down. Luckily they are on the same amp, but I will have to navigate that. Perhaps patching them in to the Mains signal chain isn't the best plan.

Here is a picture of the amps at the SM console. I believe the bottom amp runs the 70v speakers and can be post-fade. Though ideally the Audience Recall Chime would be on the other amp. I guess I could move it and redo the labels.

Yes, I am quoting myself. I think I overthought this. The Audience Recall, Assembly, and Emergency Announce signals are generated from sources other than the sound console. So the position of the Main faders should not matter here. Carry on.

 

[teqniqal]

". . . you guys tell me if I'm crazy.

Done. You're crazy. Its an occupational hazard.

As to the wiring of the original system to know where / how it's all connected, I suggest reaching-out to the original installing contractor for the as-installed (as-built) documents (I can get you that info if you don't have it, just contact me off-line).

Some things to consider on these various audio feeds:

• Assistive Listening Systems (ALS) typically need a limited bandwidth (particularly the bass cut-out) as this contributes little to speech intelligibility. This also applies to the ClearCom Intercom program feed, and somewhat less to the Lobby and Backstage zone speaker feeds.
• Assistive Listening Systems (ALS) typically can benefit from a short program signal delay so the sound coming out of the receiver Headsets / Earbuds / Induction Loop accessory is synchronized (aligned in time) with the arrival of sound from the stage (mid stage, or wherever the dominant acting space is) so the listener is not further confused by multiple sound arrivals. Setting this time offset to align to the 'average' or middle seat in the house is usually best.
• Lobby feeds and Backstage feeds can typically can benefit from a short program signal delay so the sound coming out of the Lobby speaker is synchronized (aligned in time) with the arrival of sound from the auditorium (this may vary depending upon the acoustic path from the auditorium seating chamber through any vestibules and corridors that interconnect them). This minimizes any echo effect that might be distracting. If there are video monitors in these areas, consideration for synchronizing the audio to the video (lip-sync) may also be a consideration. For large facilities with long audio delay paths, it may be necessary to insert a video delay, too.
  
• Adding a compressor / limiter to the signal chain (post EQ for the zone mix) can increase intelligibility and protect the system from overload (clipping) as live show feeds are much more dynamic than is necessary for the listeners in these special zones. Set limiters to prevent clipping, set compression to make it a little more "AM Radio"-ish.
  
• The audio mix for the Assistive Listening Systems (ALS) may need the music and sound FX portion of the mix strongly compressed / limited so as to not drown-out the speech intelligibility.
• The audio mix for a Simultaneous Interpretation System (SIS) interpreter's headset feed should not have any music or sound FX.
  
• The audio mix for the Lobby can generally follow the main PA feed mix.
• The audio mix for the Intercom program feed probably does not need the music mix.
• The audio mix for the Backstage zones may, or may not, need the music and sound FX mix - some performers relate to music cues better than script cues.
• If you have over stage microphones for general stage activity monitoring, they should be carefully mixed or substituted for the direct mix from the board that comes from on-stage or body mics. Choose whichever is more clear. If you are running a show with only some performers mic'ed, then the floor mics or overhead mics may be better for over-all consistency - remember that the sub-mix feed from these can be highly compressed without concern for feedback as they are not going through the main PA speakers.

With some digital mixing consoles it may be possible to control all these sub-mixes via a separate computer / tablet interface so as to not distract the main board operator. If possible, just set it all up like a virtual onstage monitor mixer so the mixes are completely independent of the house mix and each-other.

 

[Jay Ashworth]

Something worth thinking about:

Lots of mixers take OSC control input these days; it's possible, and probably practical, to use this to "hardwire" some of your auxouts, so that they always go where you want, no matter where a road engineer tries to point them. It will take an offboard computer, and some software, but it may be the best answer.

 

[Les]

@teqniqal - thank you for the suggestions and offer! I do have some drawings, but you know my venue. So many things were changed last-minute so I'm not sure if they are as-built or the original dream system. I'll take a look and see what I can find out.

A few questions about your post:

• How does one go about adding a delay to these?

• The ALS is an induction loop - Williams Sound - and it may have a delay feature built in to the amp that I can try adjusting. Otherwise, I'm not sure about that one either.

I will probably end up just needing to take the main LR feed from the console. I would love to do a more elaborate setup, but I'm barely squeaking by as it is in terms of finding/funding the equipment and attempting to do this on my own with limited knowledge in sound.
I have also considered overhead stage microphones, but apparently that has been tried before and it sounded like a fishbowl. I'm not sure what equipment they were working with though. Is this a common trap, and is there a more elegant and better-sounding way to do that which the other people missed?

Referencing my original post... Either I was thinking about things backwards, I'm over-thinking it now, or I had a stroke of genius that now eludes me. My original plan of taking the LR output from the mixer/patch panel and feeding a mixer that has everything else connected to it (ALS, Monitor Amps, etc doesn't seem like it would work. I need one input and several line-level outputs. The mixer I referred to, like most all other mixers, is about the opposite. Can someone help me get back on track?

 

[Jay Ashworth]

No, you're right: What you're doing is akin to a monitor mix (lots of outs for each in), not a main mix.

Which Allen do you have?

Cause if it speaks OSC, you might be able to digitally wire down the stuff you care about.

 

[Les]

@Jay Ashworth - it is an A&H GL2800.

In looking at the system closer, it appears that a lot of the mixing is already done by a TOA system. All I really should need is a good Line Out for Program (to the TOA Backstage Monitoring system) and to the induction loop. I wonder if I can split it off the rear of the patch panel?

 

[TimMc]

@Jay Ashworth - it is an A&H GL2800.

In looking at the system closer, it appears that a lot of the mixing is already done by a TOA system. All I really should need is a good Line Out for Program (to the TOA Backstage Monitoring system) and to the induction loop. I wonder if I can split it off the rear of the patch panel?

Probably. Or install a little distribution amp (RDL - Radio Design Labs - is a common and affordable choice) and use it to drive the various other devices that need a program feed.

www.rdlnet.com

 

[Les]

@TimMc - Thank you for the link! That little EZ-ADA4 might be perfect, and it's small enough that I can tuck it in the cabinet somewhere.

I also see some cool solutions for video distribution, which might be one of my upcoming projects.

 

[FMEng]

RDL makes decent stuff, but their video components are obsolete. The ship has sailed and sunk on NTSC and VGA.

 

[TimMc]

RDL makes decent stuff, but their video components are obsolete. The ship has sailed and sunk on NTSC and VGA.

Technically you're absolutely right. From a practical standpoint there is still a lot of NTSC and VGA out there but it's obsoleting faster rather than slower.

 

[RonHebbard]

RDL makes decent stuff, but their video components are obsolete. The ship has sailed and sunk on NTSC and VGA.

@FMEng @BillConnerFASTC @MNicolai @Amiers @dvsDave @TimMc
Perhaps it's time to refresh everyone's memories of these folks while they're crossing my mind:
https://horita.com/video-audio-test-and-production-equipment
Toodleoo!
Ron Hebbard.

 

[BillConnerFASTC]

I avoid sound systems so don't call on me.

 

[RonHebbard]

I avoid sound systems so don't call on me.

@BillConnerFASTC Noted. Horita's product range is primarily video rather than audio, that's why I thought you MAY find some of their gear useful to you and yours.
Toodleoo!
Ron Hebbard.

 

[MNicolai]

The RDL widgets are cool but they easily eat up money if you need more than one or two.

Before you go too far down the rabbit hole financially, I would recommend evaluating what it would cost to replace your TOA's with a proper DSP rather than buying into replacements and extending the current functionality with other widgets and parts and pieces. $2500 for a Q-Sys Core 110f and you can replace and update a lot of the functionality you have, and make improvements upon what you can control and how well you can tune each of the zones.

Typically what I see for a DSP in this kind of space is some variation on this:

Inputs:
Left
Center
Right
House Mic Mid (because usually I spec a Shure VP88)
House Mic Side
Quick Mix 1,2,3,x
Page Mic 1,2,x
Aux Subs
Aux FF
Aux ALS
Aux Front of House 70V
Aux Back of House 70V
Booth Monitors (unless handled internal to console -- processing through DSP allows tuning these to behave as an extension of the main PA, and allows page mic's and house mic to feed into these whenever the console does not have something solo'd)
Stage Mon A, B, C, D (if semi-permanent, idiot-proof tuning is required, or if the console is analog and does not have EQ-per-output)

The DSP does all of the system tuning, handles the mixing for a console-free Quick Mix setup for a talking head style event, gives you all of the delays and EQ and ducking you could want, and derives each of the individual mixes you're looking for.

Usually that would be something to the effect of having a program mix derived from LR/LCR console feed and Quick Mix inputs. Then breaks out into individual processing/paging for each of the subsystems. Absent the derived program feed from the console, each subsystem follows the house mic. If the subsystem gets an Aux feed from the console, it ducks the program mix and emphasizes the aux feed. This is usually because you are riding the vocals on top of music. Hearing impaired and back of house systems want a touch of music and ambiance, but they need speech intelligibility first and foremost.

Similarly, subs/front fills/delays all take the derived program mix from LR/LCR unless you switch them into Aux-only mode. This way whenever you turn on the system, all of your different systems are broadcasting by default and you don't need to set up a discrete feed on the console for them every time. If you do drive a dedicated Aux feed, it only improves what those subsystems are doing.

Sets you up for being able to drive your system over Dante/AES67, and gives you the ability to run events without the console if it's just a talking head at one or two mic's.

Assistive-listening wise, it also means if you have an unamplified event you at least have some degree of ALS feed for hearing impaired coming in from your house mic.