PA's - quick and dirty

[Tom M]

I know nothing about PA's. I'd love to be educated. Example situation:

3 piece band that doesn't have one. 2204 Halfstack + the second coming of Bonzo + high powered, full range bass stack is its competition. The instruments are not being PA'ed, but the vocals are. How much wattage, what sort of speaker arrangements, etc? Just tell me anything and everything there is to know.

Thanks a bunch guys.

 

[Tothaurun]

Re: PA's - quick and dirty

I know nothing about PA's. I'd love to be educated. Example situation:.....

How much wattage, what sort of speaker arrangements, etc? Just tell me anything and everything there is to know.

Thanks a bunch guys.

Whoa!

Hold your horses cat! There is lot to consider here.
First: What size venues are you playing?
Second: Are they going to get larger soon, or stay the same for some time?
Third: Since you obviously are new to this, it can't be complex.
Fourth: What kind of music are you playing?(contrary to popular belief it is somewhat important)
Fifth and Sixth: What kind of sound do you want and can you afford it?

As the old hotrodder maxim goes, speed costs; how fast do you want to go...

Not to mention your going to have to learn some basics about sound.
For instance: Most everyone can't really hear it below about 35-40Hz. At that range you just feel it. At about 120Hz or less(give or take) sound becomes hard to tell which direction its coming from(that's how a small subwoofer hidden under an end table can seem to fill a room). And at about 16-20kHz and above you just plain can't hear it or feel it. Low frequencies travel a long way and aren't picky about speaker placement, highs on the other hand have very defined sound field patterns, ergo the tweeters must be placed to saturate the audience as best they can. Feedback can be eliminated by using a sound analyzer to indicate the offending frequency(after flattening the room prior to the show with a noise generator and a calibrated mic) and then drop the corresponding eq slider just enough to squelch the noise. Since you are new though try something like the dbx Feedback Eliminator. It will do this for you, though I prefer the 'old school' method as it is rock solid, easy to learn, and detracts less from the sound(all of these new feedback reduction units use filters, sometimes many and can cut the sweet spot out of your sound{you get what you pay for here}). Alternatively you can get a new equalizer with this built-in.(prior caveat still holds)Mic placement, monitor placement, amp placement you can learn by trial and error. Try placing the bass player to the drummers left so he can easily hear the hi-hats. As to wattage.... No less than the speakers demand and no more than they need...that simple. I've seen over the years more amps and cabs ruined by under-powering the system than overpowering one. Match the ohms rating of the amp with the cab and power appropriately. Better the question how big a cab do you need to fill the room? Huge? Long throw cabinets(these are usually folded cab designs).
Small? These will typically be direct firing units. Oh, another note on eq's:
set them and forget them. Don't be constantly tinkering with them after you flatten a room. Eq's are the most easily abused/misunderstood part of a PA system. Sweeten at the board. Ah, the board. Simple recommendation: a used Peavey MKIII board. They are simple, quiet, easy to use/learn, come built into a flight case from the factory and are nearly indestructable. Don't EVER, repeat EVER let anyone drink or place a drink near the board. I nearly de-testicled a roadie in Memphis over spilling a beer in the master section of a 16 channel board in '88. Lucky we had another. Did I mention the MkIII's are cheap used? Awesome deals are to be had my man. Another thing, CS800 Peavey amps were the industry workhorse for years for a reason.
They sound nice, are super reliable, mostly idiot proof(learn the back patches and don't let anyone touch them), and are built like a M-1 Abrams tank! The effects rack is complicated topic. Tired now. If you like this and want more(like your head isn't busy enough now)reply to the thread and I'll launch into effects for PA.

Good Luck,
Tothaurun

 

[Tom M]

Re: PA's - quick and dirty

Woah thanks. That's way more than I needed to know.

We aren't concerned about effects at all. We'll probably never need them. I'd actually have to be to my drummer's right (I'm the bassist)... he's a lefty. :22: We're playing mostly small places. Our practice space is the biggest area we play in. There may be a couple outdoor shows, but those will be backyards. Our style is "alternative", I guess. For now, all I see is having 2 vocal mics.

Based on what I know about speakers and the way sound works, 15's are too big. They're too boomy, and the sound doesn't form well until it's pretty far away. Would 12's work better, or smaller still? Thanks a lot for your help.

As for sound, we just want loud and clear. As I mentioned before, our main obstacle is a 100 watt Marshall halfstack. We'd like it to be as inexpensive as possible though.

 

[RushOfBlood]

Re: PA's - quick and dirty

yeah i'd get one of those behringer mixers, they're cheap, good, and reliable. that's the only thing i can recommend out of experience.

wait no, QSC amps are good too. probably the best consumer-level (arguable)

and i have a pair of 15" cabs that i LOVE the sound of. they're sort of old, they're peaveys and have black widow speakers.
i haven't found them to be boomy at all, and i almost always use them at close range (as sort of a supplemental onstage p.a. at gigs)

 

[Tothaurun]

Re: PA's - quick and dirty

Seminar Resuming...

First, 'effects rack' is a catch-all for where you're going to put things like eq's, so its a bit of a misnomer, and yeah you want one even if its tiny.
I personally like a tri-amped low/mid/high set-up(though you can cheat and bi-amp a 3-way system). Fifteens aren't too big either. The real beauty of larger speakers is their ability to reproduce low frequencies at lower volumes and amperages. An 'old school' workhorse set was a Peavey
FH-1/MB-2/MF1X horn. That's a 15/12/BIG horn. You might try a Peavey SP-1(15/horn). The SP-1 should be(typically)elevated about a foot above ground level for better high frequency dispersal. Two SP-1's would do you fine. Note: make sure they are left/right just forward of your mics, unless of course you like feedback. Next thing you should be aware of is that doing outdoor gigs is sort of like pissing in the Grand Canyon. You just can't fill it up. Having the cabs up close to the audience is a MUST. You'd be surprised at how little distance it takes to drop even 12,000 watts of power to little more than a whisper.
Onward and upward! First thing you want to do is get a couple of passive direct boxes and, after effects and preamp, send the signal of your guitar to the board. Yes that's right, the board. You can stop the amp/stack competition instantly. Use your amps as your personal monitors.
Turn them down low, the preamps hot. Now you're up to four channels. Next, mic the kick and hi-hat/snare. Six channels. That's about all you need. See if you can find an old Peavey 701R rackmount mixer. It's just a tiny MKIII in a rackmount config. Till you move up to bigger venues put the board by the stage, behind a cab. You want a snake when you move up to real club gigs, though. Nothing can replace having the board at the back of the room center of the rear of the sound field. You hear things differently back there and thats important. When your making tweeks in the sound you will want to go to that position to hear what the audience hears. This is slow and cumbersome without a snake and having the board back there, but there really isn't another way(without using wakie-talkies and a 2nd person).
You'll also want a small(about 100-300watts)amp to send a signal to a monitor for the singer, because now he can't hear himself properly. 300 watts is plenty to run three small monitors so the singer and everyone else can hear whats going on. Note: monitor mixes are run dry of any effects!
Ah, yes! Effects. You said you didn't need any. Let's see. You'll want a double 27/31 band eq. Minimum. If you don't you'll be chasing feedback the whole gig. Ignore this at your peril. Board reverb mostly just sucks. Yeah, I know the Behringer boards can be had with effects, but frankly, they aren't up to snuff for durability. Period. I've trucked all over the country with more damn gear than you can imagine and let me tell you something: **** happens. Try being up for 36 plus hours straight and not getting a little hamsfisted with the equipment. People get drunk or careless, people get rowdy and bounce into cabs and boards. Trust me, when money is on the line get real gear. Used good gear is cheap and it is out there and plentiful.
One good 2-channel effects unit can do reverb and can do something very useful. Stereo PA's sound nice but are power consumptive to be loud. Cheap and loud is mono, but loud isn't enough. Mono can be eq'd and then run thru a multi-effects unit(Lexicon is excellent) to perform a 'psycho-acoustic shift'. What this does is run a 3-6millisecond delay on top of a slight wave modulation that tricks human ears. Poor man's stereo PA. These new units have reverb too and are cheap. Our old Lexicon PCM42 and PCM60 units were over 1K$ when they first came out(the new units are even cheaper used :burnout: ).

 

[Tothaurun]

Re: PA's - quick and dirty

Sorry, ran out of room on the last post...to continue....

Now all this can be put together relatively cheaply and do the job nicely. Your real challenge is yourselves. Turn the stacks down guys. Let the PA do it's job. And get a friend you can train to run the sound, and then LET HIM DO HIS JOB! I used to keep a flyswatter by the board in the early days to shoo off guitarists, not flies. Eveyone is SURE they aren't loud enough in the mix. (We're all stars aren't we?)
Well, there you go. That rig will get you moving in the right direction and only need about 800-1200watts total(not counting monitors). This doesn't cover how to use the system, but should get you started. A couple of last tips. Use a receptacle tester to assure a good ground(and to make sure it's wired right). Don't put lights and amps/boards on the same breaker.
Restrained use of acoustic processers(BBE/Aphex)can make a small system sound like pure gold. Don't over do it on the mic gain, it ain't a guitar. Turn down amps before powering up and shutting down. Run spike protection on sensitve gear(boards/processers/eqs). Use good cables, wrap them neatly, and wipe them down after every gig(or the next day, just easier before things get, well, sticky). Run the amps wide open and control from the board. That last may be controversial, but I assure you it increases the headroom. Use a crossover to bi-amp a 3-way system(cheaper than tri-amping, still sounds good). Well, that about covers it. I'll check back later.
Let me know how it goes.

Rock On!

Tothaurun