What's the difference between marine and car amplifiers?

[firecap797]

Dumb question, but what is the difference between marine grade amplifiers and car amplifiers?

If you aren't in an area with salt exposure, can you use a car amp?

 

[Speedling]

Marine amps will have extra protection on the circutry from moisture.
In fact, i have car amps and let me tell you what happens!
I trailer 99% of the time. My boat does sit outside, however, with a cover. Several times i have gotten on the boat after i DID have it in a slip and one of my amps would turn on the protection mode. Any moisture from towels, toys, etc underneath the cover or in the cuddy was now droplets all over the amps. I had to have the door open and drive for a few minites before they would turn on. Probably started screwing up the circutry as well.
Lesson learned! Either be ready to air out your amps and possibly buy new ones every few years or just get a marine one!

 

[Mainah]

Marine amps have what is known as a conformal coating on the circuit board. The conformal coating is waterproof/resistant depending in how good a job is done. The better marine amps also have sealed knobs and switches. The downside to waterproofing is that it makes heat transfer more difficult. This is where JL audio shines. They have great moisture resistant chassis that dissipate heat well on top of their great electronic components.

I have made some budget recommendations in the past but will no longer do so unless I have tested them myself. I will only use JL audio amps therefore they are the only ones I can recommend.

 

[Jgorm]

I've had car amps in boats for years without issue. I got over 10 years on a pos Jensen amp on a boat docked in salt water. 10+ years of a Sony amp in salt too. My friend has a Sony amp in his river boat for well over 15 years. Don't get them wet and you'll be fine.

 

[Mainah]

Car amps will work but for how long is the question. Some people have great luck with them lasting in a boat. The key to them lasting in the boat is mounting location. If the compartment sees a lot of moisture from wet towels, humidity, or other sources it will get trapped in the compartment and may condense on a metal object like an amp. If you have a spot that stays dry and free from moisture then it is more likely that a car amp will work out. Some car amps even have conformal coated boards these days. I think some brands may be making one amp design and marketing it as both a car amp and marine amp with different model numbers and graphics (I don't know this for a fact but it is my guess).

When I mounted my amp in front of an area that has other electrical components I made sure there was a suitable gap at the top and bottom of the mounting board. I did this to ensure that air would flow in the area allowing moisture and heat to dissipate.

Long story short there are two issues with water/moisture. One is bridging contacts which can be instantly catastrophic. The other is corrosion over time from moisture which is more rapid when electricity is applied due to electrolysis. That said far more important than the amp is the wiring. Don't use CCA wire, make sure it is thick enough to carry the load, and properly fuse it close to the source.

Perhaps @David Analog can chime in with his years of experience. He is much more of an expert on audio gear application and theory where I am more just an electronics hobbyist.

 

[David Analog]

I tend to agree with the comments from Mainah.
Jensen, Boss, Pyle, and to a degree some, not all, of the Sony amplifiers are disposable (cheaper to replace than to repair). If you are buying those products you take your chances knowing that getting long term service is a real roll of the dice, that the lower cost might warrant the risk, and that sonic performance is known to be poor out of the gate. I can't argue with anyone's budget or buying priorities. However, I do have decades of experience with hundreds of samples rather than 3 or 4 samples and the those statistical fluctuations, and that I can dispute.
Just because an amplifier continues to work doesn't mean that it hasn't suffered from sonic degradation, such as corrosion build-up or extreme heat damage.
Some cheaper marine amplifiers are no more than a white chassis and have no real additional protection. In contrast, you have JL Audio which has a sealed chassis, a sealed lid over the pots/switches/controls, conformal coating, special/extra filtering related to common marine/boat noise sources (namely switching transients).
It's true that many use automotive amplifiers in fresh water with good results. That becomes a calculated risk which you can reconcile against the cost. NO WAY is this acceptable in coastal or highly brackish areas.
If an amplifier has an open or vented chassis, or is fan-cooled, or has exposed pots & switches, I do not consider it a marine amplifier despite any label to the contrary. As the big off-shore OEM supplier, JL Audio changed their products based on their long term experiences, and Wetsounds has also followed suit more recently. The size of the sample matters.

 

[Jgorm]

@David Analog sounds like you may be the owner of a stereo shop. Is that correct? What is you experience with actual failed car amps in boats vs cars as a percentage? I won't deny that a marine amp may hold up better in a boat, but between me and my friends that grew up with boat docks in salt water, all who own boats now, I've never seen one fail. The amp in my car failed. I've had a jl car amp in my jeep for over 6 years now. It's under the driver's seat. I've been rained on with the top off a few times, and have had inches of water on the floor multiple times. Not a huge N, but 100% success across at least 15 amps, over 20 years in salt water, it's hard to justify spending more.

 

[David Analog]

@David Analog sounds like you may be the owner of a stereo shop. Is that correct? What is you experience with actual failed car amps in boats vs cars as a percentage? I won't deny that a marine amp may hold up better in a boat, but between me and my friends that grew up with boat docks in salt water, all who own boats now, I've never seen one fail. The amp in my car failed. I've had a jl car amp in my jeep for over 6 years now. It's under the driver's seat. I've been rained on with the top off a few times, and have had inches of water on the floor multiple times. Not a huge N, but 100% success across at least 15 amps, over 20 years in salt water, it's hard to justify spending more.

As just a kid, I began installing 8-tracks in '60s Century's (not Centurion). And that's when my boating experience begins. Not an owner, nor employee, nor associate of any company at this time. Started a car audio company in 1980 (Earmark is still going strong today thanks to Odin, Joe and their excellent teams). Began a dedicated marine audio division in 1998 (Earmark Marine). Sold and retired nearly 4 years ago. I have no horse in the race. Still love the audio category and subject.
The better audio companies did not add a marine electronics category just to add more revenue. Marine electronics are completely warranted.
What I might or might not do and risk in my own craft may be a little different from the advice that I give to others, so I'm not reconciling any decision that I have personally made, and I take the responsibility of making those recommendations to others very seriously. I've laid out the risks in some detail. It's your hard earned money.

 

[firecap797]

Thanks for all the replies. A good lesson for me. JL (Or WS) seems to be what everyone is happy with and I haven't heard anything negative feedback on either brand. I would rather spend a few extra bucks and not have to worry about things down the road.