@Dionysus
How Freudian your last statement in light of where you're employed.
You've taken me back to New Years Eve December 31st 1982 / New Years Day January 1st 1983; the night / morning I first walked through your Grand's sound booth with Peter Roberts (within days of his vacating Stratford to follow Robin Phillips to the Grand as their new
Production Manager), Dave (David P.) Long from your London, Ontario IA local was the gentleman who'd recorded and operated SFX while simultaneously mixing live reinforcement of the cast, chorus and pit
orchestra of the Grand's Christmas / New Years musical.
Peter had borrowed me from Stratford for an overnight visit in search of a hum, a hum varying in
intensity, frequency and
harmonics with the optimistic goal of my finding, snaring, capturing and EXORCISING your Grand's hum; the hum they'd acquired less than a year before when they reopened after a full building upgrade: Heating, cooling,
HVAC, make up air, electrical, water supply, drainage and venting, new lighting
console, dimmers, hard-patch and load
circuit distribution throughout.
Imagine your Board Of Directors' disappointment post their years of fundraising, corporate and private donations, total building remodeling only to be embarrassingly plagued by an OBVIOUS and
ANNOYING mysterious combination of NEW hums they'd never had prior to their total upheaval and installation of all their wondrously marvelous, NEW and EXPENSIVE equipment and systems.
To move this along, here're my recollections of my 1st walk through New Years Eve, listed in
point form in the order I noticed them:
-
Walk in sound booth.
- 44 RU rack.
- Loaded 'helter skelter with an "interesting" variety of equipment.
- Four or five rows of decent quality, telco / broadcast style, long frame jacks.
- Patched with an eclectic assortment of standard 1/4"
mono, stereo, shielded and non,
instrument and
SPEAKER cables.
- A 1/4" 1/4
track STEREO Revox A77 rack mounted immediately below the aforementioned four or five rows of telco jacks,
- Portions of the lower three rows of jacks BLOCKED by the two 10.5" reels when attempting to record or
play tapes on the STEREO A77,
- A second
portable, suitcase style, A77 sitting on a spent case of 24 of someone's preferred alcoholic beverage. This second Revox was borrowed from your studio
venue in order to have a recorder / player capable of spinning 10.5" reels while still accessing the lower rows of the
jack field.
- Layers and strips of every adhesive tape imaginable to route cables
clear of the 5" reels fitted on the rack mounted Revox in order to have two machines available simultaneously.
- Both Revox's were 1/4", both were stereo BUT one was factory equipped with 2
track 1/2
track heads
while the other was fitted with 2
track 1/4
track heads.
Hmmm?? Why wouldn't you have two machines with identical head stacks to permit copying / dubbing from machine to machine?
- Read poorly labelled
jack fields:
- Find jacks for channels 1 & 2 of the stereo 1/2
track Revox.
- Find jacks labelled for channels 1, 2, 3 and 4 of the STEREO 2
TRACK 1/4" 1/4
track rack mounted Revox.
Two problems:
1; Someone, (Read the consultant /
system designer) thought one Revox was a four
track simultaneous QUAD recorder player, it would rack mount in 6 RU and its 4 unbalanced inputs and 4 unbalanced outputs would interconnect wondrously via his rows of long frame , Telco style
RTS jacks.
2; By reading the consultant's paper work, he was suggesting the installers should install the the "QUAD' recorder player in the main
stage rack and he was including the
portable STEREO recorder / player as a token loss leader for the future upgrade to your McManus Studio
venue, the upgrade he was certain would be coming his way when everyone heard and saw his
WONDROUS new installation in your Grands's main
stage .
Apparently when someone realized neither Revox would mount in 6 RU, let alone BOTH of them, one of the Revox's was subbed from a rack mount to a
portable.
- Notice
mic level,
line level, low
impedance AND 70 volt
speaker levels all being terminated and patched via the same telco style "tree blocks" within the rear of the rack enclosed by its hinged rear door, the door you can barely see, let alone OPEN, since it's backed solidly against the rear wall of the booth.
- The "tree blocks" were of course wired to their respective Telco style jacks via unshielded twisted pairs within an overall vinyl /
PVC outer
jacket.
- Four RADICALLY different signal levels tightly bound together
in one overall outer
jacket!
- Add intercom, a couple of 60
watt incandescent clip-on lights (also secured by the variety of ever popular adhesive back tapes) intertwine the clip ons unshielded 120 VAC
power cables, add a home style 600
watt dual
SCR dimmer to tame the two 60
watt clip ons down to performance
level, season and adjust
dimmer to "taste", and you wonder why it hums?
And then it got worse: How do all of the field terminations (
mic level,
line level, balanced, unbalanced, low
impedance effects speakers, 70 volt paging, green room, crew and dressing room speakers intercom and 120 volt
power circuits) route from their various distant locations to our "interesting" 44 RU rack?
Out the top of the rack, an assortment of 90 degree bends in
conduit along with 90 degree turns in pull and junction boxes, across the booth ceiling to the windowed wall separating the booths from the attic ceiling, through the wall, another 90 degree turn via another assortment of bent
conduit and pull boxes, onto Uni-Strut across the attic on the attic side of the booth wall to the SR / HL side wall of the attic.
Along the way, said Uni-Strut picked up a number of booth circuits carrying the outputs from
Strand's Telco style lighting hard patch.
As the conduits on their Uni-Strut continued their journey towards the
stage via the HL / SR wall of the attic, they were joined by ALL of the
stage lighting circuits of the rear
FOH lighting
cove.
The ~36" length of Uni-Strut suspended from the attic ceiling via all-thread rods was now jammed end to end (side to side if you think of it that way) thus a second ~36" length of Uni-Strut was added below the first to accommodate ALL of the
stage lighting circuits from the front
FOH lighting
cove.
Through the prosc' wall at attic
level where additional
stage lighting circuits were added for wall mounted
stage lighting circuits in wall boxes away down there ~ 18" above
stage level.
Continuing on their way to the USR corner of your building, our dutiful pair of Uni-Struts supported one immediately above one another were joined by ALL
stage lighting circuits for the 1st LX, then the 2nd LX, then the 3rd LX then all of the wall mounted boxes across the US wall away down at ~18" above
stage level.
And then it got even worse.
In the USR corner of your building ALL of the
stage lighting circuits, 20 amp AND 50 amp
stage lighting circuits, turned 90 degrees straight down into the top of
Strand's telco style hard patch where every
stage lighting
circuit in your building's main
stage patched into the outputs of 80 or a 100 SIX KW
Strand dual
SCR stage lighting dimmers in the
dimmer room in the basement at
trap level below your main
stage's
stage.
Sure, the previous consultant had specified all audio circuits would be installed in separate conduits segregated by signal
level, and he was even willing to accept many of his different levels making 90 degree turns
in one 2' x 2' pull box
BUT
He'd NEVER intended them to be ALL racked up together cheek by jowl on the same 36" length of Uni-Strut with a second length of similar Uni-Strut packed every
bit as snuggly by every
FOH stage lighting
circuit in your main
stage's
FOH ceiling then through the prosc' and joined by every
stage lighting
circuit behind the prosc' wall before turning 90 degrees straight down, through Strands telco -style hard patch and then ALL the way down to below
stage level.
And they wondered why it hummed.
And they wondered why the sound,
pitch,
intensity,
level and harmonic content of the hum changed as a function of their lighting cues???
The better query'd be: How could they expect it NOT to HUMMM?
When I summarized my thoughts and your
theatre's management called their consultant, his position was he'd specified separate
conduit systems, pipes, pull and junction boxes; it was the electrical PEng and electrical contractor's faults for not maintaining their conduits and
conduit systems well away from his audio conduits and systems.
I don't need to tell you where they felt the failure to communicate occurred.
I suspect
@TimMc and others will NEVER have witnessed this sort of failure to communicate.
@Dionysus If you've ever noticed; this would explain the installation of ALL new
conduit systems, conduits, pull and junction boxes along with bonus systems added to your studio space largely comprised of equipment removed from your main
stage's
system.
To pour a little more salt on their wounds:
Your entire London Ontario Grand complex closed and relocated to rented facilities for a full year in 1981 or 82 only to have more and worse HUMs than they'd ever had then have some
nut case from Stratford walk through on New Year's Eve and tell them. Two things:
1; You've a collection of less than desirable gear. Nothing wrong with a TEAC Tascam model 3 but they were not known for their fabulous RF and electromagnetic noise rejection, or their Model 5. I beleive the Model 5 ended up in your space and the Model 3 became part of Sheila McCarthy's choreography and warm up little rolling rack housing the Model 3 facing up on top of a rolling rack containing two consumer grade cassette decks and either a butch stereo amp, or two butch
mono amps in the bottom of the rack for
ballast and stability while rolling and to
power two JBL 4310's removed from some where in the upgrade from only one or two years earlier.
2; Interfaced in a totally incorrect / not feasibly corrected manner.
Net result: All new equipment interconnected by TOTALLY new conduits, boxes and cables.
Pretty much everything removed was handed down to your McManus Studio space and a
portable / rolling
system for the choreographer / warm up people.
Toodleoo!
Ron Hebbard