Back in the day, Crown created a startling audio development with their pressure zone boundary microphone design. The PZM-30D was brand-new on the market. I had seen them in use at South Street Seaport–12 of them on Plexiglass plates in front of a choir standing on risers! My God, the sound was crystal clear, uncolored and beautiful! I had to have a pair for hanging on our stage. No more dangling microphones over the heads of actors! This was going to be the best! I purchased a pair of PZM-30Ds. Carefully following the directions, I built two Masonite plates to mount the mics on. With mics and plates C-clamped to the first electric pipe, I was prepared to make sonic history in the auditorium at drama club rehearsal. Fortunately, no one was around to witness what really happened that day as I fired off those new microphones!
For Front of House speakers, I was using a pair of Kustom model 302 columns. Yup, those tried and true tuck-and-roll Naughtierpleated beauties that had served me so well throughout the rockin' '70s. A brand-new Carvin D-800 stereo amplifier, bridged into mono mode, fed the speakers with signals from a Carvin 1204 mixer at the rear of the house, some 125 feet away.
The Carvin mixers of the day had no phantom power. Electrit-Condenser microphones were just coming on the market and need for phantom power was in its infancy. I had purchased a pair of Crown phantom power supplies for use with the PZMs. Each box held two 9-volt batteries to power the mics and had an on/off/phantom switch. These I proudly placed at the mixer, 150 feet from the microphones –my first bad mistake!
I powered up the mixer first. I was always very careful not to get cone damaging pops and clicks kicking out of the speakers at boot up and knock down. "Mixer on first followed by power amps, power amps off first followed by mixer!" My second bad mistake occurred, as I left the mixer position for backstage to power up the amp–in my haste, I left the PZM faders and FOH master up!
I switched on the power amp and started walking back to the mix position, anxious to hear my new PZMs. About 75 feet back, horrors–feedback started ringing! Should I run 50 feet up the stairs to the mix position or should I sprint backstage and kill the mains???? As the system really started screaming, I blew past a Kustom 302 onto the backstage. As I reached down to kill the switch, the amp–clip lights glowing–blew itself out! Oh crap! I sat down in silence. Two hours to rehearsal. I began to think of what power amp I could use to substitute for the blown D-800 when something smelled funny.
Smoke! Something was burning! What the hell? Not the amp I observed! I stepped through the stage door to face a Kustom 302 fully in FLAMES! Smoke and fire emanating from the rear vents! The front polyester grill cloth melting upward on the column! The cones and windings I had so carefully protected from pops and clicks were being consumed inside their metal baskets! Smoke was heading upward toward the ceiling! I had to act fast.
I pulled the speaker cable, laid the column on its side and grabbed it by one handle. Still flaming, I ran with the inferno 75 feet to the exit door and outside into the pouring rain. Throwing the speaker down– face up, the rain put out the fire! What had I done? I almost burned the school down. The speaker was ruined. The amp was blown. Rehearsal started in less than two hours. Last but not least, I was sure to be fired!
Once the fire was out, I dragged the carcass down to my office and buried it in the store room. We'd deal with it on Monday! I got into my truck and ran home to pick up one of my personal 302s and another power amp. Arriving back at school, I swapped the amps and placed the borrowed Kustom column into the setup. RTFMing (reading the effing manual) told me the Crown phantom power supplies shouldn't be more that 5 feet from the mic capsule–they were high impedance on the input side of the box and low impedance from the output! Quick–up on the "A" frame ladder–gaff the Crown power supplies to the electric pipe. Replug the mics and get off the stage–15 minutes to spare!
This time, I pushed the damn faders down to "0" on everything. Powered up the mixer, powered up the amp, no smoke or flame this time–just sweet, sweet audio from those lovely PZMs. The director raved, and the principal never knew it could sound so good without those "ugly" mics hanging overhead! The kids loved the sound, and I was a hero!
Twenty-five years later, no one is any wiser. The principal retired and the director moved onto another school. I still have those old PZM 30Ds, and they still work just fine. The Kustom 302 and its sister column received all-new speakers during the next fiscal year along with new matching grill cloth. Still using them for outdoor field days and at "speech only" events. And–I haven't gotten FIREd–yet!
Don Fisher, Audio Visual Technician
Southold Union Free School District
Owner, Sound Productions
Southold, NY
