Sub Amp fading out issue ?

I have an issue with my stereo system, not sure how to overcome it. I'm running 2 amps, 1 amp for highs and 1 amp for sub. Both amps run on there own dedicated battery with a battery share switch. Other battery runs the boat. Did this so I can play my stereo while swimming and not worry about draining my starting battery. Now, what is happening is after we sit for a while, the amps are getting hot from cranking it up. I had no choice but to put the amps in the rear engine compartment and I think that's my issue. The engine is getting these amps pretty warm, plus jamming them out. Once they get hot, when the sub hits, the stereo starts fading out. If I turn the gain down on the sub amp, everything is fine. The sub amp seems to be the hottest. Is there a good way to cool these amps or do I need to try and relocate the sub amp under the dash on sub box perhaps ?

Is the WHOLE Stereo fading or Just the SUB amp?

If the Whole stereo is Fading...its not your Hot Subs amp..
If just the SUBs...then, your Sub amp is protecting itself...mine will do than too ....

When the sub hits, seems everything fads out. If I turn the gain down on sub, the problem goes away. I can drive around for an hour on the lake and never have the issue. Its only after I sit jamming music does it do this.

Are you shore charging your stereo battery when your not on the lake.

No, I kill both batteries with the blue sea switch when not in use. Cant recall the system, but it has a charging amp for both batteries.

Both AMPs - HI and LOW may be doing the Same thing as they get Hot...
What kind are they?
Does you head until provide any Power to speakers? ....On some Like FUSION you can turn the internal amp OFF if you are just using Pre amp out... Saves Heat and Power

Found it, Im using the Blue Sea Add-A-Battery System with ACR and Battery Switch

Sub amp is the Rockford M12001D Marine Amplifier and for the highs Im running a 4 channel JBL JBLMA6004 marine
My Sony Head unit just runs RCAs, no speaker power

Would a air exit fan help pushing air out the rear vents ? Possibly the air just cant get out. I have good air flow coming in with a small 7" radiator fan, but just a 5" air exit vent towards the back of the compartment. Maybe I mount a 5" computer fan on the air exit pushing air out.

Sounds like low voltage to me. Next time you go out on the water check the battery's resting voltage.

But wouldn't starting the boat and running it for a bit charge the battery back up ? In this case I still have the issue even after driving around, and the amp is super hot to touch. The amp for highs works fine as long as I turn the bass down. If it was a voltage drop issue, would a capacitor fix it ?

When amps get hot they become less efficient and put a taxing on your voltage. A couple small computer fans wired in will help. Also make sure your wiring is up to par. I would run 1/0 for the sub amp and 4 gauge for the 4 channel. Resistance equals heat!

Brad Morring

Nope to running the boat around to charge it. If the battery is drained really low the alternator can't keep up it can only maintain. I've been there done that you need to charged the batteries each time after you go to the lake. Especially if your floating and playing the stereo hard.

I'm no expert but I have learned the hard way. Somebody that knows more than me will chime in.

Blair hit it first. You're battery voltage is low. Get over the HOT issue, and look at voltage. An alternator is not a charger. It will never recharge a battery, just maintain voltage while the boat is running.

What a capacitor help the situation ? I don't have a outlet for a charger in my boat storage. I would have to bring the boat home every time.

Oh, I am running 2 gauge on both amps for power. I think I'm OK there.

Capacitor will not help. You'll need to charge the stereo bank batteries with a dedicated charger. Low voltage will kill amps in hurry.

Even if I charge the batteries, playing the stereo for a couple of hours after there full charged will still heat up the amps and create the issue. Could I run a larger alternator to help ?

So they don't get hot when the batteries are charged, but only after a couple hours? What is resting voltage of stereo battery then? Usually adding more capacity to your battery bank is much more cost effective than getting a super high output marine alternator.... assuming you have the ability to recharge the batteries with a shore charger.

I would check your batteries,You might a bad battery that's not holding charge.

I can take the boat out first part of the day and cruise around jamming the stereo full for a few hours. The issue only happens when I sit and jam the stereo in 90-100 degree weather. I may get an hour out of it before the sub starts making everything fade out. I can reach in there and feel the sub amp is really hot. I have opened the compartment and let it air out for a while before and turned everything back on and it works fine. I feel my issue is heat and not correct air circulation. Both batteries are brand new Die Hard Gold Marine batteries I bought a few months ago.

do you charge the batteries with a shore charger after a day at the lake?

No, I never have

So what Im getting from all this is I need to be charging my batteries up to full after each trip to the lake ? Maybe just the stereo battery ? I think I will still make some airflow changes as well to the area. Also going to put some stand off spacers behind the amps to get air flow behind them. Right now there are flat on the carpet wall.

1) would verify that the house bank is receiving alternator feed through the ACR when the engine is running. If you are parking the boat with a low battery, then you are starting the next trip in the hole, with little chance of recovering before dropping anchor again.

2) I would look to relocate the amps from the engine bay, thats no place for electrical equipment like amps.

All those here that are pointing at low voltage are really helping you.
If the battery(s) are low enough and you continue to play the system hard, the Blue Sea voltage sensing relay can resist closing and stay open which means that the stereo battery may not always be on line with the alternator when underway. A VSR/ACR can actually increase your dependency on AC shore charging.
You do not want to deplete your batteries below 11.8 volts....ever.
Take voltage measurements at key times in order to profile your voltage situation throughout the normal usage day. If needed, make sure you remedy the voltage situation first because there are many additional implications to low voltage, and they're all negative. Once the voltage issue is confirmed good then turn your focus to thermal if you still have a problem.
Fans & fan shrouds certainly can help thermal issues. But my concern is that you are attempting to fix the symptom and not the cause when the amplifier is saturating and over-driving the heatsinks ability to dissipate. There are any number of reasons that an amplifier can run much hotter than intended, such as usage, impedance load, system tuning, subwoofer location, equalization, just for starters.

Originally Posted by chpthril

1) would verify that the house bank is receiving alternator feed through the ACR when the engine is running. If you are parking the boat with a low battery, then you are starting the next trip in the hole, with little chance of recovering before dropping anchor again.

2) I would look to relocate the amps from the engine bay, thats no place for electrical equipment like amps.

^^^ Yes, relocate the amplifiers. What if when cleaning spray gets through the exterior engine compartment vents? The vent acts like a nozzle and water goes everywhere.

I learned last year if you want a system in your boat you have to charge your batteries. It's just part of it, I had all kinds of electrical problems last year because it was the first year I had a three amp system and I didn't realize how much you need to charge those batteries after every trip. With my perko on 1&2 it would start pulling down my starting battery while I was jamming during a set if I started in the hole with a low stereo battery. Then perfect pass would start cutting out and that's not good on the marriage LOL!!!!!!


At least charge the stereo battery

Thanks everyone for the help. Ive got to find a way to charge either after or before I head out. Im also going to move at least the sub amp up under the drivers side console and see what happens.

Originally Posted by gapple12

Thanks everyone for the help. Ive got to find a way to charge either after or before I head out. Im also going to move at least the sub amp up under the drivers side console and see what happens.

You should charge a depleted bank immediately after an outing....rather than just before going out the following weekend or two. Your battery life will be impacted for the better or worse depending on when you shore charge.

^^ What if your boat is in a slip all summer with no way to get power to it? Is there another option? not trying to be a smartass, but for people like myself, I cant pull it everyday and charge the batteries. I only run 2 amps, 1 for sub and 1 for in boat speakers.

My guess is a bigger alternator that charges your stereo battery's ? I guess i figured wrong running the batteries separate with the blue sea system, one battery strictly for boat, one for stereo. I thought the Blue Sea would evenly charge them both back up while driving.

Originally Posted by gapple12

My guess is a bigger alternator that charges your stereo battery's ? I guess i figured wrong running the batteries separate with the blue sea system, one battery strictly for boat, one for stereo. I thought the Blue Sea would evenly charge them both back up while driving.

Whether or not you have the Blue Sea you can have a recharging issue. Example. After a long period at rest, you burn a little gas (maybe 20 minutes) back to the marina or ramp. You go thru a no-wake zone at low rpm. You idle at the ramp behind several boats while a guy and his girlfriend argue on the ramp.
It's probably going to take just as long to bulk recharge the batteries as it did to discharge them. That's a lot of gas. An alternator is a dumb blunt charger so it is not going to condition the batteries like a smart three stage shore charger will.

Originally Posted by masongardner

^^ What if your boat is in a slip all summer with no way to get power to it? Is there another option? not trying to be a smartass, but for people like myself, I cant pull it everyday and charge the batteries. I only run 2 amps, 1 for sub and 1 for in boat speakers.

It is what is it. If you don't have access to AC while in storage it may negatively effect your weekend to weekend battery performance and the lifespan of your batteries.
Before assuming anything, measure the voltage of your batteries right after you return with enough time for the elevated alternator voltage to fully dissipate. You'll know with certainty whether you have a concern or not.

Originally Posted by gapple12

My guess is a bigger alternator that charges your stereo battery's ? I guess i figured wrong running the batteries separate with the blue sea system, one battery strictly for boat, one for stereo. I thought the Blue Sea would evenly charge them both back up while driving.

The alternator is still the only source of output and the blue sea is not a charge on demand, device. As JonyB stated above, alternators make for poor battery chargers. If you run a battery down deep, a short 15-20 minute ride back to the dock wont cut it, regardless of what switch or ACR system one has.

"What if I don't live close to a gas station, can't I just run on fumes?"

^Same question as OP.

Recharge batteries with a device called a battery charger. If you're dock doesn't have power, it's worth a couple batteries per month to find one that does have power. As David eluded to 11.8V, if the batteries dip below that and you don't recharge, it doesn't matter how old you're batteries are, they're done.

Of course, the same standard answer as seen throughout the audio world - "it's never been a problem for me"

Congratulations then.

The last three people on here, know what their talking about. It will save you a lot of trouble in the long run if you try what they are talking about.

Looks like somebody pulled a ninja edit between my posts

sure did, not worth an argument on an internet forum. I told you my experience, thought it may not be technically correct, guess I have just been lucky.

I have a good Charger I can use from home. I just spoke with the lady that runs my storage complex and she said I can put an outlet in if Id like. There is a light and switch so I can tie it into that. Is there a safe trickle charger I can leave plugged in at the storage and is small and wont consume a lot of power and it can stay plugged in all the time ?

look at something like a promariner prosport 20. It mounts in the boat and stays permanently connect to your batteries. All you do is plug in when you get to the power outlet and voila, done.

Is it safe to leave plugged in all the time ?

Never mind, I just read the manual. Looks like this is what I need, just plug it in and leave it. I'm curious if there is a smaller one, less amps that would still work for my needs ?

they make an 8, a 12, a 20, and a three bank 20. the cost savings for stepping down to a weaker charger really isn't there IMHO ($106 for two bank 12 vs 136 for two bank 20), but that's your call.

Makes sense to get the 20 for sure, was just curious. Thanks !!

I've used the Pro-Mariner as well. What Shawn recommends is a great option. Nothing beats just plugging in a cord and being done. Not having to monkey around with clips on the end of a charger.

There's also a surface mount port that you can install on the transom to just plug a cord straight in to, then plug the extension cord in to it.

Jonyb

I'm guessing the surface mount has to be above the water line. I would put one on my supra if I could hide it better under the plate form.

Originally Posted by jonyb

I've used the Pro-Mariner as well. What Shawn recommends is a great option. Nothing beats just plugging in a cord and being done. Not having to monkey around with clips on the end of a charger.

There's also a surface mount port that you can install on the transom to just plug a cord straight in to, then plug the extension cord in to it.

Haha, I would've suggested that too 'cept the OP seems like he's got a pretty serious case of the "cheaps."

This is the one I use: http://www.amazon.com/NOCO-Genius-GC...xgy_200_text_z

"oh I don't want anything crazy"

I completely agree Shawn. I'm amazed at the way people cheap out on small things with their installs - not necessarily aiming that comment at this thread or the OP.

Originally Posted by jonblarc7

Jonyb

I'm guessing the surface mount has to be above the water line. I would put one on my supra if I could hide it better under the plate form.

Absolutely. No way can it go underwater, even if it's not plugged in.

I was looking at the back of the boat and I think I'll buy one and just center it above the heap bar on the transom

I think most people (?) would mount them inside a locker. I don't think I would install it exposed on an exterior surface of the boat. This is how mine is done:

I just route my charging cord along the starboard side just up under the gunnel. When I get home I just reach up underneath and plug in. It stays out of sight, doesn't cost you more money for a port mount, can be removed, and is just as easy to deal with.