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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => HistoryOfConcertSound.org => Topic started by: Art Welter on August 27, 2013, 05:22:52 PM

Title: 1975 Line Array
Post by: Art Welter on August 27, 2013, 05:22:52 PM
In the summer of 1975 Rocking Horse played at the Donnybrooke Speedway, now the Brainerd International Raceway in northern Minnesota.
Rocking Horse was a great band at the time with lead vocalist  Tom Baden, David Kurowski guitar & vox, Mark Schramm bass & vox, Ricky Peterson keyboards & vox, and Dale Waracz drums & vox.

We used portions of our PA and rented and borrowed other gear to make a vertical array.
While in high school I had previously built most of the cabinets which had been sold to other bands, the stack was a combination of three PA systems.
Set up had to go quickly, as we were not allowed to place our equipment until after the race ended and the track area was opened to the race fans.

All the cabinets were sealed straight Hyppo and Domino horns (Steve Hall designs), from the bottom there were two Guass 18", an EV SRO 15", a Gauss 12", two JBL 2420 on Recchi fiberglass radial horns, two EV 1823M on EV 8HD horns, and an RCA driver on a University H-600 horn.
The stack was about 10 foot tall.

The "processing" consisted of a Wingo (Mark Winger designed) 1000 Hz 12 dB per octave active crossover, all the cone drivers below 1000 Hz, all the compression drivers above 1000 Hz, and possibly a PAiA  kit-built octave equalizer.
A variety of amps were used, the only one I am sure of was the Sunn 200S tube bass amp which I owned was used for a pair of stage monitors. There may have been a Crown DC 150 for highs and a couple Phase Linear 400 for the lows.

Mixers were a pair of Tapco 6000R cascaded for 12 channels: 5 vocals, guitar, bass, keyboard mix, Leslie high and low, kick and snare.

After a day at the races most of the crowd cleared out pretty quickly to head home, I remember the PA sounded good way further back than any of the audience was  ;D.

Art
Title: Re: 1975 Line Array
Post by: Ivan Beaver on August 27, 2013, 08:52:44 PM
Yeah that is how we did it.

Here is a photo of a neighborhood 4th of July gig I did back in '83 (I think).

The FOH rack consists of the following:
On top of the rack an Ibenez analog delay

The white unit with the knobs is a custom EQ I built.  The top row of knobs was unusual as the upper and lower freq (on the outsides) were 1 octave apart-while the ones in the middle were 1/2 octave apart-so a "kind of graphic-without the graph-if you will".  The lower row of knobs was a 4 ban d full parametric eq that was in series with the "graphic" or fixed eq.

Below that was a fixed 1KHz crossover for the mids/highs and a 200Hz fixed xover for the lows/mids.

Below that was a "home stereo" dual 10band eq for the monitors and of course a cassette playback deck.

All the amps were 100 watt/channel units that I build.  It was a couple of quad 100 watt amps with old stop signs as heat sinks.  I have a photo at work of me building one-I need to post.

You can barely make out the "tweeterbank" on the very top-which is a pair of piezo 2x6" horns (back when they were good) that are angled inwards (copied the idea from Bob Heil)-passively hooked up.

The bass cabs were single scoops with JBL woofers and the mid was a 4560 copy-all of the cabinets I built.

Title: Re: 1975 Line Array
Post by: Ivan Beaver on August 27, 2013, 09:05:23 PM
Found the photo of one of the amps.

The side with the filter caps and transformer is the front-I just don't have the front rack panel on in the photo.

Notice the "high tech" old kit scope-----Hey it worked and did what I needed it to do.  It lasted much longer than the Techtronics one I bought did :(

My heathkit tube signal generator is behind my head
Title: Re: 1975 Line Array
Post by: Tim McCulloch on August 27, 2013, 09:22:09 PM
What, no love for the BiAmp 1621?  We have a 1221 at the PAC...

Yeah that is how we did it.

Here is a photo of a neighborhood 4th of July gig I did back in '83 (I think).

The FOH rack consists of the following:
On top of the rack an Ibenez analog delay

The white unit with the knobs is a custom EQ I built.  The top row of knobs was unusual as the upper and lower freq (on the outsides) were 1 octave apart-while the ones in the middle were 1/2 octave apart-so a "kind of graphic-without the graph-if you will".  The lower row of knobs was a 4 ban d full parametric eq that was in series with the "graphic" or fixed eq.

Below that was a fixed 1KHz crossover for the mids/highs and a 200Hz fixed xover for the lows/mids.

Below that was a "home stereo" dual 10band eq for the monitors and of course a cassette playback deck.

All the amps were 100 watt/channel units that I build.  It was a couple of quad 100 watt amps with old stop signs as heat sinks.  I have a photo at work of me building one-I need to post.

You can barely make out the "tweeterbank" on the very top-which is a pair of piezo 2x6" horns (back when they were good) that are angled inwards (copied the idea from Bob Heil)-passively hooked up.

The bass cabs were single scoops with JBL woofers and the mid was a 4560 copy-all of the cabinets I built.
Title: Re: 1975 Line Array
Post by: Ivan Beaver on August 27, 2013, 09:28:03 PM
What, no love for the BiAmp 1621?  We have a 1221 at the PAC...
I thought that was kinda obvious. :)

That was my first commercial mixer.  Everything before that, I hand built-down to drawing out the traces on the circuit boards and etching the boards in the bathtub.

I really liked that console-REAL easy to get a mix on. :)  I used it for many years and never had an issue with it.  Many a punk and metal band played through it up in DC.
Title: Re: 1975 Line Array
Post by: Steve M Smith on August 28, 2013, 01:37:04 AM
Yeah that is how we did it.

Same here.  Between 1985 and 1991 our system was lots of JBL4560s and Martin folded horns with various horn loaded mid and top cabinets too.

I'm thinking about building some horn loaded cabs just for something to do (as if I didn't have enough projects at the moment!).


Steve.