Sign In:     

Forum: General Discussion

Topic: Amp overheating...gig coming up. HELP! - Page: 1

This part of topic is old and might contain outdated or incorrect information

Hey guys, I'm having a HUGE problem, and I'm spinning at my cousins engagement party this Saturday night. I need to resolve this by then. I'm a self proclaimed rookie at all of this, so bear with me.

I'm having a bit of a problem with my amp. It's getting too hot, and it shuts itself down in order to protect the hardware, but it's absolutely KILLING my rep. I just got this setup, and so far I've done a few house parties for my friends, and one block party with about 150 people in attendance. The setup would be running fine for about an hour non-stop with no problems, then suddenly the music shuts off, and the Peak LED's are blaring red on the amp. This has happened twice, and neither times were the gain controls on the amp turned all the way up, they might have been a little over half way up. I operate in stereo parallel mode, so it's not from being in bridge-mono. It seems the amp overheats, though it has an internal fan that kicks in when things get too hot. Both times I had to shut down the amp for at least a full minute (enough time to clear out the dancefloor and for me to really hear it from the crowd), then turn it's back on and it'll fire right up with music playing fine. I placed an oscillating house fan in front of the amp to push colder air through it, and that helped.

My setup is as follows.

Hardware:
Phonic MAX 1600 amplifier
Hercules RMX DJ Console
Kustom KPC-215h cabinets x 2
Speakon to 1/4" cables going to cabinets
1/4" audio cables from RMX to amplifier inputs 1 and 2.
Rockford Fosgate PUNCH Series 10" subwoofers in a carpeted, sealed box x2
regular speaker wires going from amp outputs to subs
Dell Inspiron 1721 laptop

Software:
VirtualDJ 5 with MixLab skin

Music:
Usually house or trance with some hip hop and oldies mixed in. I play it pretty loud too.

The amp sits on a carpeted wooden board held up by 2 legs, about 5 ft off the ground, next to my laptop, with the RMX sitting on top of the amp. The carpeted board has a cloth over it that amp sits on. Should it be overheating this easily, especially in stereo parallel mode? Does it have to do with where the amp is placed, i.e. surfaces, heat retention, etc? Or do I simply just need to turn down the levels on my RMX and on VDJ, and turn up the gain on the amp channels? The first time was indoors, which would make more sense because it was substantially warmer inside, but the block party was outside, and it still overheated? Is there anything I can do to keep it from overheating and shutting down on me?

Thanks for the help guys...I have 3 gigs coming up this weekend, and I'd hate for this to happen again.

-Matt (DJ Persia)
 
Posted Tue 14 Sep 10 @ 4:39 am
Seems you only have one amp and a pair of dual 15's plus your 10's, could use another amp for your 10's unless the 10's are powered of course.

Never run your amp much further than half way, if your maxed or even at 75% then you need a larger amp. What you've described is a classic example of an under powered amp.

Try Hercules console panel, make sure your turned up to the max in there.

OMG, I just realised you don't have an external mixer!!!!!!!!!!!!!!!
 
I could be wrong and someone else can chime in on this as well, but it seems to me that you have a Ohm overload going on.
You should have seperate amps for your subs and your 215s and either be going from the RMX with a left and right signal in to a crossover then out of the crossover with your lows going to the subs and your mid/highs going to the 215s.

I'm not exactly sure of your set up but it seems your 215s would push more bottom end than the 10" subs would so you would want to use the 215s to their full range potential. If your subs have a internal crossover than maybe just run two stereo outs from your RMX to two seperate amps then to your 215s and then your subs. If you cant spare the cash for another amp just remove the subs from your set up until you can.

Always Check your Ohm and wattage specs on your cabnets VS your Amps.

Hope this helps.
 
The amp should have its own fans, are they coming on?

I have a Yamaha p7000 that was doing this and the fans were not coming on due to a board sensor that cycles the fan speed.
Sent it back and it was the last time it happened.
 
If it is an older amp, it might just need cleaning. Those vents around the fan can get clogged up with dirt and such.
 
Dual 15's @ 4 ohm + Subs @ 4 ohm (Usually) = 2 ohms, the amp will just be working to hard.

Get another amp for your sub's and sell the RMX and get a VMS4 or use an external mixer with the RMX.
 
Let us know how you are connecting all of this together. If it's connected how I think you have it connected there are many problems. In your 2x15 cabinets there is a crossover for the for the 2x speakers in each. With using just these cabs your amp should be pushing 4 ohms per channel. Now you are also pushing to 2x subs. This brings the ohms to 2 per channel your amp should be pushing. Looking at the specs for the amp it can only go down to 4 ohms per channel. That is a big problem that will overheat at eventually kill your amp and cabs. Your cabs have a for ohm load each and your amp will be fine. There will not be much headroom with this amp for your cabs though. A goo rule of thumb that I have been told over the years is have at least 50% more power per channel on your amp than the cabs will handle. This allows you to run cabs at there best performance with plenty to spare on the amp to prevent clipping and overheating. Your amp is most likely clipping out and has internal protection that kicks in (hence the red lights). Remember Green means go, amber watch out, and red STOP. Your cabs are 600W RMS and the amp is only 450W perchannel at 4 ohms. Personnally I like powered subs and passive speakers. Cuts a lot of guesswork out from the system/amp set up.

Suggestions:

1. Drop the subs for now. Until you can get another amp for mains and use current amp for subs.
2. If you have the cash now get an 1800W amp with 900W per channel at 4 ohms. This is a little bit less but a great amp
http://pro-audio.musiciansfriend.com/product/QSC-RMX-2450-Power-Amp?sku=481565
3. Get an external mixer. Your RMX is mainly a software controller and soundcard.
4. If you need the system now, like I said, drop the subs and you current amp for cabs. Try that and let me know how it goes.

One final thought - running your current system as is WILL blow speaker coils and amp.

Gary
 
Yep, got to agree from reading, get rid of the subs for now and I think your problems will be much reduced, if not completely gone.

Also, you said soemthing like"the red clip LEDs blarring away". The red clip LEDs should never come on, but you can probably get away with like once every 10 minutes at the most. Even if your amp is "only turned half way up" and the clip lights are on, then you need to turn the amp down until the clip lights go off. The only reason they dials make it so loud is incase you have a very quiet sound music source.

The technical answer is to get all the specs for your speakers and see what the impedance they all are. Let us know and I'm sure people will let you know what's what.

Hope that helps.
 
Because I don't know the brand and type of the subs I've been googling around: They're caraudio-subs...
10", 200-400 W RMS/peak.... They will NEVER be able to keep up with the Kustoms. Besides that: The Kustoms have 2x15" and will produce more low than a single 10" can ever do.
So I do agree with Gary and Andy: Get rid of them, but not for now. For the next gig only use the Kustoms and save for some PA-subs and their own amp. To give you an idea: normally a sub has 1,5 to 2 times the power the tops can push. This will give you more balance and reserve. The subs should have bigger chassis so I would go for single or double 18". Otherwise they only will give you more power, but their frequency-range could be equal to the tops (without the high-drivers).
 
There's a simple old school solution to do this if you cant resolve the issue in time, buy a cheap desk fan (the vortex ones are good) and position it so that the stream of air enters the vents wherever they are located. It should keep the overall temperature of the amp low.
 
He is already using a fan to cool the amp and it still over heats lol
 
wow lots of great info, and so prompt!

so basically, I was using the rmx as a makeshift mixer, but now I know I'll need a real one. like I said, I'm brand new to all of this stuff, so I appreciate you guys being so patient with me.

the 15s in my cabs realy don't put out too much bass, which is why I added the subs. I'm going to get a sub in the future, and another amp to run it. I don't need too much bass for my next few gigs, so I'll drop thee subs and see how that goes.

this amp came with the cabs, so I figured musicians friend.com knew what they were doing when they sold them as a package.

I'm replying from my cell phone, so I'll chine in later with more questions.
 
Charlie Wilson wrote :
He is already using a fan to cool the amp and it still over heats lol


If it's a sealed unit and he's placing it at the front that won't work, the fan has to be placed near the vents so cooler air can penetrate inside. The fan he's using probably isn't powerful enough hence why he should use a "turbo" style desk fan or double up with another.

Worked for me back in the 90's in the days of big heat sinks and thermonuclear transformers...

Strictly temporary measures of course....lol
 
Yeah those subs I new straight away that they were car subs by the make and size, however I have seen people using there car audio to DJ from before although it sounded crap.
 
Dear Mattin:
Your best bet would be to buy a More powerful amplifier that is matched with your setup, nix the subs they only throw 2 feet, sure they will kick in a car but not for a larger room. If buying an amp is not feasible , then go to your local music store and rent a qsc/crown/makie/peavey/ yorkville/yamaha .....( im sure i missed a few) amp and maybe a powered subwoofer. Good luck.... the Amp you have now is not really made for anything below 4 ohms.... its rated at only 450 watts per channel at 4 ohms and thats at 1khz , id bet it only trly puts out half that at full range... Good LUCK and ask in the forums about equipment , im sure you will get mixed info but im sure that most will be leading in the right Direction. , also try used , look in cragslist....... etc

JAMM
 
The best advice someone ever gave me...

If your going to expect to be paid like a professional you better play on reliable professional equipment.

Phonic??? Sorry I never dis other DJ's equipment but dude hit the pawn shop. QSC, Crown, Crest etc.

Better yet Drop me a private message. I can help you out.
 
Haha trust me, I'm getting paid like an amateur, which is why this is my first setup ever. Some background info: I'm a 20 year old kid working 45 hours a week, a full time student, with two recently laid-off parents who can barely afford to keep our home...this was the best I could afford, plus, all my gig cash goes towards the family and supporting myself completely so they don't have to. It's not professional equipment, I know, but it gets the job done for now, when it doesn't overheat.

Okay, so I'm getting the basic consensus of everyones posts. I don't have the cash right now to buy a better amp, so I'll just sacrifice by buying a powerful fan and direct it into the vents in the front of the amp. I'm ditching the subs, because I don't need that much bass anytime soon...I'll keep the volume lower so it wont clip, and try to save for a mixer.

Thanks for being so helpful guys. I'd be lost without your knowledge of this stuff.

-Matt (DJ Persia)
 
Matt,

you can probably keep the money you want to spent on the fan. Running your set without the subs means you're within the maximum load of your amp. This should not give you any problems. (if the internal fans work...)
About the max. volume: clipping is (if it occurs) detected between the pre-amp and the powerstage in your amp. By turning the volume down on the amp you're ignoring the real problem: Your input signal is too loud. Better turn down the output signal on your RMX until the clipping indicators stop lighting up. (using the main fader on your RMX)
Better be safe: Open your amp and vacuum out the dust. Clean out the air intake filters and remove the clutters of dust that build up on the heatsinks) (something you should do at least once a year, more if you're using your amp more often)If the amp is brand new, you can skip this part ;)
Finally: There's really no need to keep the volumeknobs on the amp at 0,5 or max. 0,75 of the maximum. Amps can run on full power, just as long as you make sure not to overdrive them (clipping). It's clipping that kill speakers. ( think the idea of keeping the volume knobs at 0,5 of the max is something from the old days, where pushing your amp caused trouble because the powersupply in the amp couldn't keep up. Every amp you buy nowaday have overpowered powersupplies. It won't happen that you get clipping from a underpowered PS)

Enjoy your gig!
Martin.
 
From having owned lot's of different amp's and active cab's over the years I have come to the conclusion that the best way to run your gear is with the amp backed off to half or no more than 75%

In any case, having all that head room at the mixer from having your amp maxed out is just crazy, what happens if some dick walk’s up and turns the volume knob up on the mixer to the maximum? or you do it by accident ? bang!! goes the speakers

Amp will flash red easier if turned right up sooner than if turned down a bit with the source turned up a little more to compensate, anyway, like with all rigs you have to find the right settings/balance.

1600w is enough for his 4ohm dual 15's, it's the fact that there's no mixer so the amp is working un-necessarily hard, he just needs any old mixer to plug hix RMX into and to forget about the subwoofers until he can afford a separate amp to run them.
 
Hi, Charlie,
It's becoming an off-topic story, but I will try to explane:
Like most DJ's I have my gains set up this way that I can throw my faders to the max while working. 1 Simple reason: you will not spend any time on moving your fader to a 0 dB-position because it takes too much time. This means that most of the faders are already on max. The moron who tries to touch my mixer has lost some fingers before he can...... But even if he does, he has to open the gain of the deck that is playing at that moment. That's one out of 30 knobs. Low chance on that.
In my setup there's ALWAYS a limiter. I can make a mistake, someone else can, but it ends on 0 dB (with a soft-knee limit). And they cost just a part of a blown speaker..;) If things go too loud, my amps will shortly clip, but the limiter will set things back, so no harm done. I'll always advice to buy one. Since the limiter I've never blown a speaker again.

On the 50%: Common advice is to buy an amp that has at least the same RMS-output power as the peak of the speakers. At least... A speaker normally stands about twice the RMS-power what it's designed for (Not for the whole gig, but it will stand for a long time) . For example: My speakers are 300W RMS and my amp 550W RMS. In 4 years no driver has send me smoke signals. You just don't blow speakers that easily. But if you keep pushing your amp above the clipping-point, now THAT destroys speakers (clipping produces sharp edges in the sinusses, which your speakers can't follow.). A momentarily peak like you described won't.

If you combine an amp with speakers according to the "common advice" but following your advice about the 50%, you'll have to buy an amp with 3x the power your speakers can handle. Now that's tricky.... ;)
Besides that: You'll have to buy everything double-sized to handle venues that someone else will do with half of your equipment. To me that's a waste of money. (But you do have a lot of reserve if needed :D )

Regards,
Martin.
 
69%