Members james on bass Posted February 12, 2008 Members Share Posted February 12, 2008 My band's PA has a problem. We continually blow the horns out of our mains and it's costing a lot of money and time. I don't know much about PAs so I'm asking for some help here from the experts (that'd be you guys in case you were wondering). We have 2 Peavey SP4 mains (2x15 + horn) on top of 2 18" subs. The mains, subs and monitors each have their own power amps. Do you think it's a matter of the way we EQ, or could it have something to do with the settings of the crossover? Any help would be appreciated. The guys are looking to buy a new PA system because of the problem and I want to rule out something simple first. Link to comment Share on other sites More sharing options...
Members bnyswonger Posted February 12, 2008 Members Share Posted February 12, 2008 Are you powering it up and down right? Maybe you need to run a limiter across your mains. Link to comment Share on other sites More sharing options...
Members burdizzos Posted February 12, 2008 Members Share Posted February 12, 2008 They should have sound guard tweeter protection built in such that a bulb blows before the horn does. It's possible that someone has jumped out the bulb, it happens. Those bulbs also dissipate excess power going to the horns to further protect the drivers. I'd check the circuitry and make sure that crossover is right. Link to comment Share on other sites More sharing options...
Members james on bass Posted February 12, 2008 Author Members Share Posted February 12, 2008 I'm not sure about how it gets powered up and down. They do have the bulb type fuse. I've seen them glowing. Link to comment Share on other sites More sharing options...
Members burdizzos Posted February 12, 2008 Members Share Posted February 12, 2008 I'm not sure about how it gets powered up and down. They do have the bulb type fuse. I've seen them glowing. So the horns are blowing, but the bulbs are not? Strange. Also, if those are glowing, it's because you're pushing the speakers too hard. Link to comment Share on other sites More sharing options...
Members burdizzos Posted February 12, 2008 Members Share Posted February 12, 2008 have your local Authorized Peavey Dealer verify that the bulbs in the crossover are the Peavey Units. I suppose it's possible that someone could have blown them and the replaced them with an automotive bulb that is the wrong size. Link to comment Share on other sites More sharing options...
Members bnyswonger Posted February 12, 2008 Members Share Posted February 12, 2008 Powering up - board and all periperals on first. amps last, and pot them up slowly. Powering down - pot amps down, turn them off, wait a minute THEN turn off board and peripherals. The reason you do it this way is that turning your board or peripherals on or off while your amps are powered up can send a DC thump through the system and fry your drivers. Link to comment Share on other sites More sharing options...
Members gspointer Posted February 12, 2008 Members Share Posted February 12, 2008 If you are consistantly lighting up the protection bulb, you either need to turn down, or get new mains. Link to comment Share on other sites More sharing options...
Members georgestrings Posted February 12, 2008 Members Share Posted February 12, 2008 Powering up - board and all periperals on first. amps last, and pot them up slowly. Powering down - pot amps down, turn them off, wait a minute THEN turn off board and peripherals. The reason you do it this way is that turning your board or peripherals on or off while your amps are powered up can send a DC thump through the system and fry your drivers. Agreed on all counts... - georgestrings Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted February 12, 2008 CMS Author Share Posted February 12, 2008 It would really help to know what amps are being used here, and how they're connected (bridged-mono, two speakers on one amp, etc). And are any of the amps' clip lights coming on at all? If you're clipping anywhere in the system, the HF drivers are the most likely to suffer. Clipping produces harmonics that can be well above the power level the drivers can handle, and the bulb protection won't always help here.....as you're seeing. This could be something as seemingly innocent and unrelated as a kick mic channel clipping because the gain is too high. But first let's get the amp specs and start there. Link to comment Share on other sites More sharing options...
Members rpsands Posted February 12, 2008 Members Share Posted February 12, 2008 With a rig this size, maybe you should use an active crossover for the horns? I've heard that most cabinet passive crossovers are inadequate for high power PA rigs. At least, all of the sound gurus I've ever talked to swear by 3-way crossovers. My knowledge of the subject is cursory at best, but I've heard numbers like 5khz for high freq is better than typical cabinet settings of 3khz or 3.5khz. (Edit: I thought about this, and I am not sure I am not mixing up my horn frequencies with those for a bass rig, so it might not be xover frequencies that are the problem so much as what the dude below me here posted about not having enough horns.). I'm just parroting the sound guy gibberish I've heard so I might be off base. Link to comment Share on other sites More sharing options...
Members bnyswonger Posted February 12, 2008 Members Share Posted February 12, 2008 You've got 3 low frequency drivers per side vs. 1 horn that probably has to cover everything over 1.5k . In order to balance out against all that low information, you might be asking more of your drivers than they can deliver. The answer would be beefier drivers or additional hornage. I just checked the specs - the internal crossover is 1.8k. If it's not the powering up issue, have a pro look at it. There has to be a reason for blowing drivers. Link to comment Share on other sites More sharing options...
Members chugheshc2 Posted February 12, 2008 Members Share Posted February 12, 2008 2 X 15 PA speakers have a reputation (on the sound reinforcement forum) for being muddy - and you have subs to boot. Also sounds like you play loud.1) turn down. 2) ditch the 2X15 and get 1X15 3) get another horn unit to supplement these.fwiw - I have heard one pair of PV 2 X15 PA cabs and yes, I thought they were lacking in high end. cheersC Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted February 12, 2008 CMS Author Share Posted February 12, 2008 There are a lot of assumptions being made here. Let's get the facts on what is powering the speakers and how, and take it from there. Link to comment Share on other sites More sharing options...
Members Robin Posted February 12, 2008 Members Share Posted February 12, 2008 There are a lot of assumptions being made here. Let's get the facts on what is powering the speakers and how, and take it from there. That's a good start! Link to comment Share on other sites More sharing options...
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