JBL MA6004 4-Channel Full-Range Marine Amplifier

I purchased this bad boy to power my Igloo cooler stereo that I built for floating the local rivers and getting the parties started out in the sticks. I paired it with two JBL Marine 6x9s (bridged), and all I can say is that this thing is VERY loud and crystal clear with absolutely no distortion at high volumes. In fact, I think I may have gone a little overboard on my project - we brought the cooler out disperse camping the other weekend and it sounded like we were having a rave in the forest. Anyway, I digress. Back to the amp...I've seen a lot of reviews on here about overheating issues. Let me tell you, I ran this amp sitting inside of my cooler in the beating sun here in Sacramento with outside temps of over 95 degrees playing music at loud levels for hours with absolutely no issues whatsoever. Granted, the cooler may be insulating the amp a little bit from the temps, but still, I have no fans or other cooling devices inside.I haven't had a chance to test the marinized circuit board (and, quite frankly, I hope I don't run into a scenario where I'd need to, because that would mean my cooler was sinking), but the build quality on the amp is superb. It definitely looks like it could stand up the the harsh marine elements in a semi-exposed environment.This amp provides all of your typical adjustment knobs on the back: input gain, bass boost, high pass/low pass filter and frequency adjustment for both channels. The bass boost function works great, and really seems to add a lot of extra "umph" to my 6x9s.I've seen a few people posting general concerns about plugging a phone or other audio device directly into this amp using a 3.5mm headphone to RCA adapter (to avoid installing a deck). I can attest that you'll have absolutely no problem doing this with this amp; you will not need a pre-amp. The amp gets plenty loud using only the adapter cable. For those wanting to bridge 6x9s or other speakers, simply plug an extra RCA cable into the AUX output and then to the Rear input and plug your 3.5mm headphone to RCA adapter into the Front Input. A lot of you probably already know how to do this, but I figured I'd mention it for any newbies out there (like I was!)So, if you're looking for a LOUD, crisp, sexy looking amp that will keep your boat or other water toys rocking, this is the one for you. I've had it for a couple months now and it has performed flawlessly.Side note: This amp has three bright, blue power lights directly under the JBL logo. Something to consider if minor aesthetics are to be taken into account during your system build.UPDATE: June 2016After two years, this amp is still kicking just fine. I've taken it out camping and floating over 20 times now and it sounds the same it did the day I bought it, and I've definitely put it through some abuse. All is not perfect, however. Some of the overheating issues that other buyers have mentioned have come to fruition. These overheating episodes only happen on very hot days when the amp is blasting at very high volumes. Since my amp is in an enclosed cooler, overheating is almost inevitable. I'm not going to knock any stars off my review; this is still an excellent buy and the sound quality cannot be beat. I plan on installing a pair of computer fans in the cooler to help cool this thing down when I really crank the volume on hot summer days.

I bought this amplifier to build a portable 2.1 system. The bridging features, crossovers, and independent gain controls are awesome and make a multichannel setup a breeze to hook up. Do note that if the front and rear channels are to receive the same signal, RCA jumpers from the pass through must be connected to the b channels externally. The three blue lights on the top are very bright. For size constrained projects, you might consider another product, so name sure you review the dimensions. Because I had the amp running off a small 12 volt agm sla battery, I was originally concerned with power consumption, and the amplifier gets quite warm. Although I originally attributed most of this to an inefficient design, the length of time the amp can run on such a small battery (18ah) has convinced me to look elsewhere for at least part of the heat build up. After thinking about it, I think that the fanless design, important for the marine grade build, may explain the issues some people have described. Most amplifiers with decent power output at least have vents, many with fans. This is a SEALED amplifier. It will get hot. Ensure proper and this amp works great. The features are nice, the price is right at ~ $100, and pungent l plenty of juice for most systems. I'm satisfied with this product, 4 stars because it won't work for everybody. Edit: lost a star because screw terminal stripped out way too easily

I've been using this amp in my boat to drive four 4 ohm polk audio speakers with no issue. I bought it in July 2013. I've never seen the protection light. I do remove the amp from my boat during winter storage. I have it wired right to the battery with a separately purchased 8 gauge wiring kit. The amp is installed under my gunwale where it is moderately protected from splashing and rain. The unit does get a splash of water on it here and there and it hasn't went poof yet. I do wish there was a way to turn the blue lights off at night since it makes the back seats glow but other than that I am super happy with my purchase.

This is my second one of these (only reason I am giving it 4 stars). The first one died due to water damage after 2 seasons. In the manufacturers defense I do have it in a very harsh application (personal watercraft sound system). The unit is extremely energy efficient if you do not have a monster electrical system, and the built in crossovers minimize the need for external components. At this price, even if I had to replace it every two years, it would be worth it. The only gotcha with this unit it does overheat easily under high volume, when it does, the audio cuts out and when it cools, it automatically resumes operation. The secret is to find the sweet spot for the correct volume level (not maximum power) to keep unit operating cool and efficiently.

Amp worked for less than 24 hours on my boat. I was running 2 Sony 6.5" bridged on 3/4 amp input level (>100watts each) quality was okay then got worse then completely stopped working. I've been installing stereo equipment for 15 years in all of my toys. I knew the price was too good to be true. It's worth buying the higher end stuff, stick with: JL, Clarion, Kicker, etc...... Pyle, Rockford, JBL, and others alike will eventually fail and coat you more money in the long run.

I'm by no means an expert on amps. I've only owned probably a half dozen of them over the years. This one seems to be a great amp for the money. I pushes four 7" marine speakers easily. Very loud and clear sound. No buzzing or engine noise. I've had some cheap marine amps that always had a slight buzz in the background. Better grounds, ground loop isolators, you name it wouldn't fix it. Not a problem with this one. No ground loop isolators, No super high end cables trying to get clean sound. Just hooked it up with some decent twisted RCA's to the head. Made sure it had a good ground and the proper sized hot wire for the length of the run. Sounds great.