Sound Reinforcement (PA) - A Guide to Making Live Sound Work For You

Discussion in 'Bad Dog Cafe' started by simoncroft, Aug 2, 2019.

  1. strat a various

    strat a various Friend of Leo's

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    I had a friend in the 60s and 70s who played and recorded with a very big name, but had his own combo on the side. When I went to see him at his gig, he had a trio w a female singer. Trio was nylon string guitar (miked only), drums, and upright bass through a small bass amp. (Ampeg flip top).

    This combo played a very crowded lounge that would seat 80 but usually was standing room only, so well over 100 patrons squeezed in at all times. They did the Pop music of the day: Jose Feliciano, Beatles, 5th Dimension, Motown hits, Oldies, filmscore tunes. All great players. Their "Sound Reinforcement" system? A Shure Vocalmaster tube PA with the tall columns. They played LOUD.

    So, as I got older, I really was impressed by the beautiful sound they got in that crowded cocktail lounge with just a tube head and two column speaker cabs. The handmade nylon string was mic'd by a Shure SM58 type mic, and it was really loud and clear. The vocals sounded like a record, just pristine.

    How did they do it? Skill. The band leader very carefully oriented the columns, and artfully adjusted the primitive PA system to get feedback-free volume for his guitar, and rich, well EQ'd tone for their vocals (two mikes).

    Good ears ... experience ... skill.

    I came to realize if they could fill the dance floor doing Pop Rock and Soul music with that instrumentation and that sound system, then I could learn to work practically any system I encountered thereafter. That's what inspired me to make gear work, no matter what.
     
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  2. OldCAT

    OldCAT TDPRI Member

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    "With my hands hidden from view, flat on the desk without touching anything, I'd look down and act like I was moving something for a second or two, then look back up and ask "how is that now?" Nine times out of ten I nailed it on the first try and the fussy one was fussy no more."

    I used this for 38 years of doing live sound, wish I had known it for the first 2 years of learning to do sound.
     
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  3. OldCAT

    OldCAT TDPRI Member

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    This is great, well done. I started on a TAPCO 6 channel. Ended in the Digital console and IEM world. Retired from live mixing a year and a half ago. I still want to go and "FIX" the mix at some shows I'm at but life moves on.
     
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  4. beagle

    beagle Friend of Leo's

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    When he was still active as the monkey behind the desk, and in real life, he goes by the name of Beagle. Check my name on my emails ;)
     
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  5. uriah1

    uriah1 Telefied Gold Supporter

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    I remember back in the day having tri Amps. One for bass Bins one for mid And one for horn . Now with acoustic small stuff problems are hollow stage risers getting feedback in monitors under control.
     
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  6. Musekatcher

    Musekatcher Friend of Leo's

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    Besides the one big contributor, the room acoustics, the two primary challenges I see, are MI equipment, and excessive volumes for room sizes. I'd say those are 80-90% of the contributors we can control, successfully or unsuccessfully. And I'd say half or more of all bar-weekend bands are making the same mistake(s).

    EQ, balance, speaker placement, too many speakers/phase, and a few other small things may only be 10-20% of the control. Many folks struggle in vain by trying to tweak the 10-20%. We might call it "turning the small knobs". You can't override the big fundamentals like mediocre equipment, and trained expectations (getting used to LOUD vs balanced, dynamic, and pleasant). But, it helps sell a lot of equipment, and creates lots of discussion ;)

    I'd say outdoor challenges are usually insufficient equipment (MI again).

    Because of the limitations of MI, and the tendency to go excessively loud in small rooms, smearing all balance and value into a ringy mush, I think folks get trained to live there, and like has been said already in this thread, no longer recognize bad sound support.

    How much MI contributes to bad habits and lost ability to recognize bad sound, is probably a worthy subject.
     
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  7. Ronkirn

    Ronkirn Doctor of Teleocity

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    I know the feeling... often when at some place with a combo cranking in the corner.. my friends have to physically restrain me to keep me from approaching them and offering a bit of help... sometimes the sound just plain hurts...

    r
     
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  8. cyclopean

    cyclopean Poster Extraordinaire

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    i have never heard the speakers that aren't instrument amps referred to as anything other than a PA.
     
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  9. cyclopean

    cyclopean Poster Extraordinaire

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    you are the sound guy i hate. i only ever ask for any change if it's actually impeding my ability to play.
     
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  10. Mjark

    Mjark Doctor of Teleocity Silver Supporter

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    Ha! last night they couldn't figure out why the self powered monitors weren't working so I turned them on.
     
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  11. Chud

    Chud Poster Extraordinaire

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    And you’re (probably) not the fussy guy. [emoji23]


    Sent from my iPhone using Tapatalk
     
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  12. David Barnett

    David Barnett Doctor of Teleocity

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    The "fussy guy" who used to frustrate me was usually a secondary musician, like say the cellist/glockenspiel player in a "scene kids" screamo band who wants a full band mix in his wedge, and starts asking for things like a little more hihat and floor tom...
     
    Last edited: Aug 3, 2019
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  13. Ronkirn

    Ronkirn Doctor of Teleocity

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    Kinda like the very successful "City Slicker" that decided to "feel the country" . . . so he buys a small spread. He needs to clear a few acres, so he heads to Home Depot and buys a world class Stihl Chain Saw....

    a few weeks later he throws the thing in the trunk of his Mercedes AMG... storms back to Home Depot, griping that this overpriced POS isn't worth squat.... the Salesman takes it.. wondering why such a great product isn't functioning, gives the rope a yank.. and Brrrrrrappp, brapp, brapp, brapp, brapp, brrrrrrrrrr..

    The slicker says, what's that noise? :rolleyes:

    Point being, success in one aspect does not make one an authority in all peripheral aspects... Many years ago I was taping an interview with Wernher VonBraun .. he said one of the most difficult and exasperating things, in working with the hyper educated, is reminding them that they do not know everything, and, that which they do not know is vastly more comprehensive than that which they do.

    If "you" think you know something and are in the presence of someone highly regarded, competent, and successful in that field.. show 'I'm how intelligent "you" are, keep quiet and listen... :p

    r
     
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  14. simoncroft

    simoncroft Tele-Meister

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    Doh! I really should have worked that one out.:rolleyes:
     
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  15. Mjark

    Mjark Doctor of Teleocity Silver Supporter

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    To be fair to my band mates I don't think that's an apt comparison, they just didn't think for a moment. There were a lot cables and cords everywhere it was hard to tell they were self powered.
     
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  16. simoncroft

    simoncroft Tele-Meister

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    OK, I hear you. It's what most people in bands would call it in Europe too. Rather than risk alienating anyone on this thread, let's just agree that for the purposes of this thread, the two terms are interchangeable. I've put (PA) in the title in acknowlegement of this point.

    Oh yes, the dangers of overlooking the obvious! The parallel peril is turning up all the gains then discovering the one switch that routs the audio... I used to tell my sales guys that if they blew up any speakers falling foul of that one, they could buy them at trade. :D

    Sussing out how somone else's rig is configured is not easy under pressure of time. Rehearsal rooms seem to specialize in routing outboard into the weirdest place possible of the board, leaving me with the indignity of looking like a clown while the band waits for a little reverb!

    In our household, anyone who makes too much fuss about too little is called the "bongo player" after a real character on a real tour who was more trouble than the rest of the band put together. And yeas, all he did was play bongos, believe it or not. :confused:
     
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  17. simoncroft

    simoncroft Tele-Meister

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    Screen Shot 2019-08-03 at 16.28.31.png In HiFi systems, crossovers are nearly always passive, comprising a bunch of unpowered capacitors and coils that sit on a circuit board inside the speaker cabinet. In many ways, they are an evolution of the tone control in a guitar, which uses a capacitor to progressively bleed high frequencies to ground as the tone pot is rolled forwards.

    (That makes it a ‘low pass filter’, which is exactly what you need to feed a woofer with nothing but low frequencies. To create a 'high pass filter' to feed a tweeter, you need a coil.)

    Unfortunately, there is a downside to passive crossovers: they absorb a fair amount of power. While this isn’t a big deal in a HiFi, about the last thing you want in a Sound Reinforcement rig is a component that converts power intended to drive the speakers into heat!

    Active crossover units sit in the signal chain between the output of the mixing desk and the power amplifiers. Diagram C shows a three-way active system compared to a passive system. The active system would be considered as ‘tri-amped’. In a real-life rig, the three components I've shown in one cabinet are likely to be multiple bass bins and multiple mid-range boxes, possibly with the high frequency units housed in a third type of enclosure.
     
  18. simoncroft

    simoncroft Tele-Meister

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    In medium-sized systems suitable for music in clubs, a combination of design approaches is often used. The large sub-woofer speaker enclosure is also used to house the amp for the sub, plus a second amp that feeds the companion mid/high unit that sits on a pole above it. Usually, there is an intelligent DSP-based controller in the sub that acts as an electronic crossover, as well as providing EQ presets suitable for a variety of musical styles. Because the power levels required to drive the mid and high frequency units is a lot lower than the sub-bass, a passive crossover is used inside the mid/high cabinet.

    More recently, compact system have started to appear that are genuinely tri-amped. This is largely because Class D amplification can be sufficiently light-weight and compact to design active mid/high cabinets that are still suitable for pole mounting the HK Audio L5 Power Pack is an example of a compact, active three-way system. https://hkaudio.com/produkt/l5-power-pack/#1508491584677-623ce8b4-e2cf

    In recent years, speaker system design has become much smarter. Thanks in part to the revolution that was started with the ‘line array’ concept we are now seeing almost impossibly small speakers delivering high quality sound to very carefully defined areas within the venue. And new materials technologies are making the speaker drivers lighter and more powerful.

    Before we climb those heady heights though, we should continue our exploration of the Sound Reinforcement rig as it has evolved. Next post(s) from me will be about The Evolution of the Mixing Console.
     
  19. David Barnett

    David Barnett Doctor of Teleocity

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    I hope this will include some insight into how the Brits came to dominate the mixing console industry?
     
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  20. simoncroft

    simoncroft Tele-Meister

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    Nothing quite that divisive. :twisted: Depending where you start, it's somewhat 'chicken and egg', in that you could say what kick-started the British live console industry was partly Yes coming back from touring with Iron Butterfly, having discovered the power of cascading several Altec 5 channel mixers into one acting as the sub-group mixer.

    Graham Blythe of Soundcraft was among the first to say:" We could put all of this into one mixing desk..."

    The rest, as they say, is history. I used to know Graham quite well and we could have some very long conversations about mixing consoles, always at my request, I should add. He greatly admired the Claire Brothers' CBA 32 live console, which he described as an "audacious design", because what was good about it for the mix engineer made life difficult for the design engineer.

    One would be foolish to leave Yamaha out of this history, starting with the 1978 PM2000, so there are at least three countries who have been successful and influential in the field of live mixing consoles.

    If you wanted to make me feel very old, you could remind me that when I first started in pro audio sales, we still had a SoundCraft Series 1 in stock. That was 1979. Dear Lord!

    To be honest, I wasn't going to go too far down this road, because someone will inevitably say: "How could you not mention Midas?" Or whatever brand they feel should be on the list.

    EDIT: I don't like stealing other people's pictures, so check this out if you want to know more about the CBA 32 https://soundgirls.org/consoles-to-surfaces/
     
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