How to blow up PA system

So i just had a job interview at a local sound rental/events company and the boss liked me so she said i'll probably come in for a test to set up a basic sound system. I'm not worried about it but she did say another guy blew up the speakers.

How did he do that? Anything I should look out for when i set it up? Did he just have the gain way too high?

Basically, i just want to know what NOT to do when i set it up.

She did say she would give me all the necessary equipment

Turn it up as loud as possible, if it starts making funny noises hit it with a hammer.

Yep, keep the gain in check. Basically if the amp sends more wattage to the speakers than they're capable of handling, they're liable to blow up.

give everything a good wash before you start

  On 5/16/2014 at 7:54 PM, Bob Dobalina said:

Yep, keep the gain in check. Basically if the amp sends more wattage to the speakers than they're capable of handling, they're liable to blow up.

And if nothing's clipping I'm pretty much good?

High gain microphone hooked up to mixer with the level's up to '11'

slap with bell end

call it ambient music

You may want to learn about ohmage if you're going to be matching speaker cabinets to amps. You're at risk of destroying an amp if you use it with a speaker cabinet with a higher ohmage. Presumably the systems you'll be renting out in most cases already have speakers paired to an amp, but if you have to suggest a custom setup to a customer you risk giving them a bad combination.

For example: You should know if it's okay to plug a 4 ohm amplifier into a 2 ohm cabinet (it isn't) or whether you can plug an 4 ohm amplifier into an 8 ohm cabinet (acceptable, but may diminish the potential for maximum wattage).

  On 5/16/2014 at 8:43 PM, Wall Bird said:

You may want to learn about ohmage if you're going to be matching speaker cabinets to amps. You're at risk of destroying an amp if you use it with a speaker cabinet with a higher ohmage. Presumably the systems you'll be renting out in most cases already have speakers paired to an amp, but if you have to suggest a custom setup to a customer you risk giving them a bad combination.

 

For example: You should know if it's okay to plug a 4 ohm amplifier into a 2 ohm cabinet (it isn't) or whether you can plug an 4 ohm amplifier into an 8 ohm cabinet (acceptable, but may diminish the potential for maximum wattage).

Okay that makes sense. But if she gave that other guy the correct amp and necessary materials to set everything up, how could he have fucked up that badly?

  On 5/16/2014 at 10:09 PM, Danny O Flannagin said:

 

  On 5/16/2014 at 8:43 PM, Wall Bird said:

 

You may want to learn about ohmage if you're going to be matching speaker cabinets to amps. You're at risk of destroying an amp if you use it with a speaker cabinet with a higher ohmage. Presumably the systems you'll be renting out in most cases already have speakers paired to an amp, but if you have to suggest a custom setup to a customer you risk giving them a bad combination.

 

For example: You should know if it's okay to plug a 4 ohm amplifier into a 2 ohm cabinet (it isn't) or whether you can plug an 4 ohm amplifier into an 8 ohm cabinet (acceptable, but may diminish the potential for maximum wattage).

Okay that makes sense. But if she gave that other guy the correct amp and necessary materials to set everything up, how could he have fucked up that badly?

He never had a hammer.

  On 5/17/2014 at 12:25 AM, calx said:

 

  On 5/16/2014 at 10:09 PM, Danny O Flannagin said:

 

  On 5/16/2014 at 8:43 PM, Wall Bird said:

You may want to learn about ohmage if you're going to be matching speaker cabinets to amps. You're at risk of destroying an amp if you use it with a speaker cabinet with a higher ohmage. Presumably the systems you'll be renting out in most cases already have speakers paired to an amp, but if you have to suggest a custom setup to a customer you risk giving them a bad combination.

 

For example: You should know if it's okay to plug a 4 ohm amplifier into a 2 ohm cabinet (it isn't) or whether you can plug an 4 ohm amplifier into an 8 ohm cabinet (acceptable, but may diminish the potential for maximum wattage).

Okay that makes sense. But if she gave that other guy the correct amp and necessary materials to set everything up, how could he have fucked up that badly?

He never had a hammer.

 

Lol

What's to say she gave the other guy the right matchings? Maybe read up beforehand and check before you go setting it up.

Maybe it wasn't a good idea to accept a job setting up speakers if you don't know how to do it.

  On 5/17/2014 at 11:18 AM, zkreso said:

Maybe it wasn't a good idea to accept a job setting up speakers if you don't know how to do it.

fake it till you make it

Make sure all faders and volume controls are turned way down before switching everything on and off again.

A few key things to consider:

1. Speakers

2. Mixer

3. Sound Source

Make sure your speakers are on, but not turned all the way up. Depending on the speakers, they may have a volume attenuator (ie, volume knob) on the back.

Make sure your mixer is on, the main mix is set to 0dB (unity gain), but your faders are all the way down and muted.

When testing your sound source, make sure it's plugged in and it's something consistent, like someone talking into a mic or music playing.

One good technique is to leave your channel muted, but turn up the gain slowly, and watch for the green light to flicker (the light that lets you know that sound is coming to the channel). When you see it consistently flicker, unmute the channel and slowly raise the fader. If you still don't hear anything, check your signal path.