Amp heats up

[mgabsa]

The amp I just installed heats up so much I cannot put my hand on it. Initially I had it in the starboard storage right behind the head unit. It's a Kicker DX600.5 (not a marine amp). I called the mfg. and they told it is not recommended to run a 13' ground wire and try to move the amp closer to the battery. I moved the amp back to the battery compartment and ran a 2' (8 ga.) power and ground wire. The amp still runs so hot I can't keep my hand on it.

Any ideas on how to solve this or is this natural?

 

[redthumper9]

What speaker set up is it running?

 

[jcyamaharider]

Space it out away from the board you are mounting it too. I had this same issue , put in half inch spacers and it hasn't done it since.

 

[brockhals]

Bigger gauge wire may help too. 8ga isn't much coming in or going out. I'd do 4 ga power and ground

 

[tdonoughue]

I doubt that bigger wire will help heating of the amp itself (though I do agree that 4 ga is likely a better wire selection). Spacing as suggested should provide big benefit. Also, what orientation do you have on it? That can matter, too.

 

[David Analog]

It's Class AB on the four satellite channels so it will run hot.
It will run hotter as the supply voltage decreases. So monitor the voltage and make sure you are always maintaining at least 12.0 volts.
Resistance is accumulative so a short two feet run of 8-gauge +/- might be fine. But I would normally use nothing less than 4-gauge. The quality of terminations can also be a major factor.
Spacing the amplifier up off the mounting surface will help to a degree.
A cooling fan is somewhat helpful without a shroud but ten times more effective with a shroud. However, if you are saturating the heatsink I would initially be more concerned with the source of the heat rather that dissipating the heat in consideration of the long term reliability.
So I probably would not run all four satellite channels at a 2-ohm load (two speakers in parallel per channel). The amplifier will run much less efficiently creating far more heat with lower impedance loads.
I consider that amplifier to be adequate to run a sub and four to six in-boat coaxials. The demand when running tower speakers is extreme so I would not consider that single chassis adequate to run both in-boat and tower zones.
If you are using any amplifier bass boost, defeat it. Any other form of equalization/tone boost is also wasting power.
If you are not running all speakers highpass (except the sub) then remedy that immediately.
Keep the amplifier out of clipping. Trust what you hear while at rest and apply that limitation while underway by adhering to that volume control numeric value.
All of these will make an incremental improvement.

 

[mgabsa]

@jcyamaharider where do you have your amp mounted?

On my next opportunity, I'm going to move the amp back to the starboard/helm storage and space it out about 1"-2" from the mounting board. I'm going to run the 4 AWG power and ground wires. This will allow me to open the door to the storage and help maintain air flow to the amp.

This is a 5 channel amp. The 4 channels are Class A/B which I run to the front and rear RCAs and then splice into the speaker wires coming out of the back of the HU. The other channel is Class D which goes to the 10" JL MXIB3 sub.

Overall, I was not totally impressed with the sound improvements. The sub sounds good-I will probably buy a second (same exact one that I have) and run it parallel. I make sure to pay close attention to the positive/negative sides of the RCAs and speaker wires. I followed the amp setting instructions for gain/crossover frequency and think I have them set very close if not spot on. I expected the speakers to to be so loud I could not get close to maxing the volume and at times I had the HU at max volume.

Any ideas of what else I should check to to make sure I am getting the max performance from this amp?

 

[jcyamaharider]

I have 2 amps mounted behind the helm starboard side just like you described. I spaced mine out the 1/2 and I have a electric fan just in case I need to increase air flow but have not had to use it yet.

 

[Bob27]

There are lots of small 12V computer fans that you can use for cooling. Cam.

 

[David Analog]

Quote, "The sub sounds good - I will probably buy a second (same exact one that I have) and run it parallel."
I would strongly suggest you don't if you are already running into heat issues. The lower the impedance load the lower the amplifier operating efficiency and the more of the consumed power is transformed into heat rather than audio.

Quote, "I expected the speakers to be so loud I could not get close to maxing the volume and at times I had the HU at max volume."
It's not a surprise you are having thermal issues. Some source units can play to full volume clean while others are beginning to clip at 85%. Also, if you drive your amplifier into compression it is going to get extremely hot. It is like an over-sized drill bit on an under-sized drill motor. When you push the drill to the point the rpms are slowing down significantly it will eventually burn your hand and/or the breaker pops.

The system needs to be properly tuned (probably by a pro). Whatever numeric volume value you end up with on the display as maximum once tuned is the number that you do not exceed, even if you are at full speed, even if it has been a long day, even if your auditory system is fatigued, traumatized, masking, and loud doesn't sound loud anymore, stay within the systems pre-clipping capacity.

In this day and age there are two kinds of Class AB amplifiers. First, is the very limited and highly esoteric and expensive amplifiers from the JL Audio Slash series and Audison. Second, is entry level where Class AB is still less expensive to produce. You have the second. So perhaps you have got to alter your expectations.

 

[Bob27]

Analog is right. I takes high $$ equipment to run clean sound at max volume without overheating. I set my systems up with a tone CD and an osciloscope. With that you can see any clipping. It is surprising how many "good" HU clip at a lower level than expected. Once you find that clipping level you never (never) exceed it (I stay 5% under). Anything more just damages the sound equipment. I will sometime put an unobtrusive label on the HU to remind me what max is. Keep tweeking and you will get to where you want to go. Cam.

ps I just repaired a sub where the inner leads had melted off. Thats excessive power. Suprisingly the sub was still ok.

 

[David Analog]

Along these lines, some will find this information helpful when they are ready to do an audio system for their jet boat.
Odin with Earmark Marine will supply (a free lease) those who purchase their full system from him a test tone CD and a Distortion Detector so that you can achieve unity gain (maximum non-clipped signal) on ALL audio components (source unit, processor if applicable, and amplification). This will serve to lower the noise floor and maximize the dynamic range.
Also, Odin is an amazing sound engineer and can instruct you on system tuning methods that you'll find no where else. I consider him to be THE authority on gain structure and getting the most from your equipment. Good tuning also means getting the most efficient operation from your system with less current draw from a very modest jet boat charging system.