PDA

View Full Version : Amp Getting Hot & Turning Off



THSEADOO
06-14-2010, 03:07 PM
I have 2 Kicker amps installed in storage area under glove box on passenger side. They are both mounted on the back wall 1 above the other with about 3" between them. The fins are mounted in the correct position. The 4 channel powering sub and 2 tower speakers keeps turning off and then when cools down will come back on. Does anyone have any suggestions on how to stop this problem? Thanks

philwsailz
06-14-2010, 03:23 PM
SEADOO-

Hey, Phil here....

Is this a factory install or one done by someoe else?

What are the EQ settings you are using on the head unit? Do you have the bass control maxed out? Also, have you tweaked any of the control settingson the amps? Where is the bass boost set?

Don't take it the wrong way, I am trying to find out if any of your friends have gone in and adjusted things. I have this guy who is always messing with my amp.... He thinks he is a joker, but really it is just a pain.

Anyway, having the setings outside of what we consider normal, with bass heavy setting in particular will cause the amp to work harder than it needs to.

For the tower section of the amp, you waht teh crossover switch set to hi-pass. If you have a crossoiver frequency control knob on the face of the amp, you want it set to 80 Hz, or even up to 100 or 120 Hz. You do not want it set lower. With the hi-pass crossover turned on, you want to make sure any bass boost control is turned totally off...

Then for the sub section of the amp, you want low-pass crossover, with the crossover frequency set to roughly 80HZ to 100 Hz. Bass boost should not be turned up mich, I really do not like bass boost past about 30%; any more and you are just working your amp too hard...


Any amp, I don't care what brand, will get hot and shut down peridically when it is run hard hard hard. Are you jamming with the thing maxed out or is it at a lower level? ALSO, are you sitting with the moto off jammming in party cove when this happens? Low voltage from a battery running out of steam will cause an amp to pull more current to make power. Low battteries are a very common reason for amps shutting down from heat.....


Let's hear back from ya on the questions I posted, and let's see if we can figure out how to get it running good for ya.


Phil
Kicker

THSEADOO
06-15-2010, 12:38 PM
Hey Phil thanks for the help, this is not the amp that came with the boat I added it. please see below for responses to your questions:

1) HU set to "user" Bass 0, Treble -2, Mid 0
2) Bass control knob wired with sub at Mid position, bass knob on amp at mid position
3) I set the amp up myself, very knowledgeable about home stuff but not so with car/marine. Set the volume at 75% on HU and then backed off until no distortion for the gain.
4) The amp works fine in providing tunes for everyone while sitting still. I think it is just getting too hot pushing the 12" sub and the 2 8" towers. I didn't know if i could find a 12 volt fan to try to cool or something.

Do I want the towers set to high-pass as they are 8" woofers? I will use the settings you suggested and see what happens. Thanks again for your help!

mutau052
06-15-2010, 01:01 PM
A bildge fan makes a great amp fan, you can even install it to push or pull air from inside the storage area. With a couple hoses you can actally aim the air on the spots your wanting cooled.

I don't think it would cause any electrical shielding problems if hooked up correctly.

philwsailz
06-15-2010, 01:19 PM
Hey Phil thanks for the help, this is not the amp that came with the boat I added it. please see below for responses to your questions:

1) HU set to "user" Bass 0, Treble -2, Mid 0
2) Bass control knob wired with sub at Mid position, bass knob on amp at mid position
3) I set the amp up myself, very knowledgeable about home stuff but not so with car/marine. Set the volume at 75% on HU and then backed off until no distortion for the gain.
4) The amp works fine in providing tunes for everyone while sitting still. I think it is just getting too hot pushing the 12" sub and the 2 8" towers. I didn't know if i could find a 12 volt fan to try to cool or something.

Do I want the towers set to high-pass as they are 8" woofers? I will use the settings you suggested and see what happens. Thanks again for your help!

Yeah, I would turn the hi-pass crossovers on, even for the 8's. If even you set teh crossovers as low as 50 to 70, you still will remove fully one or two octaves of information that the amp will try to create, that you likely cannot hear out of the 8's anyway, especially at the end of a rope.

A fan will help, especially if you take the great pains of setting the fan up so that it can pull cool air from outside the compartment over the amps. Another trick is to install the amp on spacers so it is stading off of the mounting surface so air can get all around it. In some installs, juat the installation of spacers has had a huge benefit to keeping the amp running.

Let me ask you a fw other things. What is the woofer, is it a dual-voice-coil sub? How is it wired to the amp? Then, which amp are you having trouble with, what model specifically? Finally what power wire do you have run to it?

I know of multiple examples where an amp wired with power wire that is too small will get hot much quicker than one wired with the recommended wire size. Let me know the answers on the woofer, the amp, and the wiring, and we will see what else to suggest to make sure your system rocks solid without cycling.

Phil
Kicker

morgan040
06-15-2010, 05:32 PM
I will bet you are running your sub at 2 ohms and the amp isnt rated to handle a 2 ohm load when the 2 channels are bridged for the sub.

1. What type of sub is it?
2. Are the Voice coils 2 or 4 ohms?
3. Are they wired parallel or Series?

THSEADOO
06-15-2010, 07:31 PM
The amp I have is the 08ZX6504. The woofer is an MTX Marine TM1204, 12" 4 ohm. It is wired with 14 gauge speaker wire directly to the amp. The hot and ground wire are direct to battery with 4 gauge wire. The sub is bridged the towers are not. Thanks again for the help.

Phil can you tell me what material should be used for the spacers?

BRANDNIRON8971
06-15-2010, 11:03 PM
SEADOO. I went down to Ace Hardware and got some rubber foot pads and loger screws to put under mine.

THSEADOO
06-16-2010, 08:24 AM
Thanks I will get some of those and try them before the blower.

EarmarkMarine
06-16-2010, 10:38 AM
Its particularly hard on a single amplifier when its shouldering the two most demanding sections ; the sub and tower. when possible its a good practice to try and more evenly distribute the load.
Have to echo all that Phil has advised. I've had most tower speakers on an RTA. Many start rolling off at 200 HZ and even the largest ones are totally done below 80 HZ. Keep in mind they're all in tiny pods which seriously elevate the resonance. So highpass 'em. Otherwise you're over-taxing the amplifier for zero audible gain.
Cut the bass boost all together. You're trading EQ for output and thermal stability. Choose one or the other. Raise the lowpass crossover a little which will significantly increase the perceived output and allow you to gain the amp down a little. There's alot more natural amplitude at 80 HZ than at 50 HZ. Remember You're already running half power at your crossover point.
Taking steps to increase system efficiency can produce the same or greater output with half the current draw.
The type of sub box and location may also be contributing factors in how hard
the amplifier is working.
David
Earmark Marine

philwsailz
06-16-2010, 10:51 AM
Sounds like you are wired properly, so I would do the spacers, check your crossovers to make sure they are on, and check the bass boost to see how much you can turn it down on the sub. You say you have it half-way up on the amp, and to me that is really too much.

Bass boost can be a real killer, a heat generator. Basically it pushes the sub harder in a narrow range of frequencies to try to make up for lack of respose from the sub. Extreme use of bass boost really points to problems elsewhere with the subwoofer part of your system, a need for a different woofer, need for an enclosure, need for more woofers etc...

Try to grasp this analogy: Bass boost is like nitrous on a little motor. When used sparingly, you can get performance exceeding design, briefly, but if you run nitrous hard, or all the time, you will blow something up. You can get the same performance by swapping out your little nitrous-shot motor with a big-block V8 that will perform like the little motor, but do so all the time, all day.... Think of the motor in this analogy as the woofer, AND maybe an enclosure. Something might need to change with your woofer and/or woofer installation so that it works more like the big-block V8.

You may be looking for performance from the woofer that exceeds its designed capabilities. You might want to look into a different woofer while adding an enclosure. You also might look at your current installation to see if it can be improved on. Are there are any paths for the sound from the backside of the woofer to get out into the listening area? The MTX woofer you are using is a "free-air" woofer, so I assume you have it mounted on a baffle somewhere. Does that baffle or board go totally to all walls next to it, or are there openings? Any hole, or baffle board that is not totally sealed around the edges will let the sound from the back of the woofer mix with the front. Taking care to ensure a proper installation, whether it be "free-air" or ina sealed or vented box will go a long way towrds creating a subwoofer setup that requires NO bass boost......

I know, it seems funny I am talking about the subwoofer and bass boost when you have amp heating issues, but trust me, if you can get the performance you are looking for, with the bass boost lower or even off, you will have an amp that runs a lot cooler and will shut down way less, or not at all. Tell us about the sub install, how it is mounted, where, holes, etc...

Phil
Kicker

THSEADOO
06-16-2010, 02:51 PM
Thanks for all of the replies. The sub is mounted in an enclosure under the area in front of drivers seat. The problem is it takes a lot of bass to give you the real bass feel in an open area such as a boat to be turning down the bass significantly. The MTX sub will shake the boat if you will let it. Does the bass boost control knob wired to the amp come into play on this also? Or just the controls that are actually on the amp itself?

EarmarkMarine
06-16-2010, 07:52 PM
Yes, if the level control is a boost/cut for the bass EQ then turn down the EQ, raise the crossover point and reset the amplifier input gain to the desired output level. I know it doesn't appear to be much of a distinction, but, in effect what you're doing is broadening the sub's bandwidth to create more output with less current consumption, higher system operating efficiency, with an easier workload for both the amplifier and subwoofer. This way you're truely impacting the thermal stability rather than using a fan as a band-aid. Then add a fan if necessary.

David
Earmark Marine

philwsailz
06-17-2010, 11:08 AM
Thanks for all of the replies. The sub is mounted in an enclosure under the area in front of drivers seat. The problem is it takes a lot of bass to give you the real bass feel in an open area such as a boat to be turning down the bass significantly. The MTX sub will shake the boat if you will let it. Does the bass boost control knob wired to the amp come into play on this also? Or just the controls that are actually on the amp itself?

The remote bass controller on that amp is a gain or level control device. It turns the sub's overall volume up and down. The knob on the amp is an EQ-modifying boost, specifically around a narrow band of frequencies centerd at 45 Hz. The BASS BOOST knob on he amp is the thing we are asking you to turn down.

David at Earmark is right. If you open the subwoofer section crossover, specifically to a higher frequency, and turn the boost knob, (on the amp) down you will be asking less of the amp thermally. You will still get a lot of bass sound, just not that enegery-wasting 45Hz material...


Phil
Kicker

THSEADOO
06-22-2010, 04:14 PM
Thanks for all the help on this. This past weekend I put in 1.5" spacers and turned the cross-over up and bass control on the amp down. I think this helped as it did not cut off any. I would like to test another weekend although as we were not able to get out as much. Thanks again for the help.

EarmarkMarine
06-22-2010, 05:10 PM
Seadoo,
It would appear those things did make a difference. Hopefully its enough to be a permanent fix.
Consider this: The few adjustments that wil dramatically alter the thermal stability have also increased system efficiency resulting in more dynamic headroom (contrast and clarity). What would the system sound like if your system selection and execution focused on maximizing efficiency every step of the way ?

David
Earmark Marine