Best Marine Amplifiers

There’s no denying that installing a new marine receiver and upgraded marine speakers in your boat will give you an immediate upgrade in sound quality. But if you want your boat speakers to really come into their own, a marine grade amplifier is definitely part of the picture.

A good marine amplifier will bring more to your boat than just decibels – you’ll also hear details and musical notes that would usually be lost to the wind, splashing water, and engine noise.

All in all, choosing the best marine amplifier will allow you to hear your favorite songs the way you know they’re supposed to sound.

Why add an amplifier to your boat?

You know the drill. Your boat sound system sounds great when the boat is parked at the shore, but start cruising through ocean waves and it leaves a lot to be desired. The overall volume drops, the highs get muddy, and the bass disappears. You can turn it up to compensate, but as soon as you’re running through open water at full throttle, it just gets worse — so you’re forced to crank it up some more. But unfortunately, you get nothing but a lot of distortion.

The culprit is likely the underpowered, built-in amp. The power-handling characteristics of your speakers also come into play, but a good marine amp can do wonders even in a stock setup.

If you’re adding powerful aftermarket marine speakers to your system, it’s highly likely that they’ll need more power than your stock receiver can provide. If you’re adding a marine subwoofer, you’ll definitely need a lot more power. If you’re a serious basshead who’s into big bass, a separate amp isn’t just a good idea, it’s an absolute necessity.

Best Marine Amplifiers — Reviews

1. Rockford Fosgate TM400X4AD

Rockford Fosgate TM400X4AD

• 4-channel marine amplifier
• Conformal-coated circuit board and UV-resistant finish
• Variable high- and low-pass filters
• Variable bass boost
• Three auto-turn on modes
• Preamp-level inputs and outputs

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Rockford Fosgate is one of the most trusted and well-regarded names in the car audio industry. It’s been around for over four decades and makes a wide range of upper-end audio gear and their TM400X4AD is a powerful marine amplifier with an emphasis on quality and performance.

With this 4 channel beast, you can power systems with front and rear speakers, drive a pair of subs, or switch the amp to 3-channel mode to power a system with a pair of speakers and a subwoofer.

This rockford Fosgate amp is built to stand up to harsh marine elements, with conformal-coated circuitry that withstands moisture, heat, and humidity and marine-grade stainless steel hardware that won’t succumb to corrosion.

For long lasting performance and reliability, this amp sports a 3-stage thermal lock extrusion, twin cooling fans, and real-time thermal sensing. That said, you won’t have to worry about overheating this amp no matter how hard you push it or even when it’s tucked into a tight space.

The TM400X4ad features high- and low-pass filters tailor the amp to the job at hand, whether it’s driving a powerful set of component speakers or a couple of marine subs. This amp will provide outstanding power and versatility in a variety of vehicles on land and sea.

The best thing with this amp is the fact that it uses Fosgate’s CLEAN (Calibrated Level Eliminates Audible Noise) level setting technology with LED input/output indicators, which allows you to match your headunit’s output to the amp’s gain, and optimize the amp’s output. So there’s no more guesswork while setting your gain levels.

2. Rockford Fosgate M400-4D

If you’re looking to scale down from the TM400X4AD (mentioned above), Rockford Fosgate has plenty of other choices available. One of the more popular options available is the M400-4D.

The M400-4D is one of the best marine amp that Rockford Fosgate has to offer at this price range. This compact 4 channel amp sports a conformal-coated circuit board and UV-resistant finish. It uses highly efficient class D circuitry to deliver high output levels whilst keeping the footprint small.

Rockford Fosgate M400-4D is a marine certified amp designed to meet tough UV and salt-fog protection standards. So you ca mount it with confidence in your boat, whether you’re blasting across inland waterways, or cruising out to your favorite salt-water fishing grounds.

This 4 channel amp can drive two pairs of full-range speakers in your boat, feeding 75 watts continuous power to each speaker. You can also switch the amp to 2-channel mode to drive a pair of subs, sending 200 watts to each subwoofer — plenty of power juice if you want some serious bass on board.

The amplifier comes with preamp-level inputs and outputs. It’s featured with a variable bass boost and variable frequency filters to adjust the amp’s output to your system, whether you’re running full-range speakers or subs.

Thanks to its compact design, this little beast will easily fit in a small storage locker or other tight spot.

3. Kenwood KAC-M1824BT

Kenwood KAC-M1824BT

• Wireless Bluetooth connection via wired remote controller
• USB port for charging your portable device
• Conformal-coated circuit board
• MOSFET power supply and Class D amp technology
• Preamp and speaker-level inputs
• Preamp outputs
• Signal-sensing turn-on

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If you’ve ever taken any interest in any sort of car audio systems, Kenwood is a brand you likely recognize, and for good reason. It’s a legacy component maker that makes a range of a wide selection of sound products for different applications.

The KAC-M1824BT is one of Kenwood’s best marine amplifiers. This super-compact 4 channel amp will fit in a lot of places when space is tight. It can deliver up to 45 watts RMS per channel — that’s more than twice the power of most car stereos.

Kenwood KAC-M1824BT is built to withstand harsh outdoor elements, making it a good fit for any kind of vehicle on land or water. This little beast comes equipped with plastic plugs that protect its power and speaker connections. It’s also featured with a conformal coated circuit board that keeps out elements such as moisture and salt, so the party won’t stop just because of a little wetness.

The biggest thing with the Kenwood KAC-M1824BT is it’s Bluetooth connectivity, which allows you to play music stored on your phone or other portable device without the need to install a receiver.

The included wired remote controls the volume and track selection, while the USB port on the amp lets you recharge your device, so you won’t miss a beat of the fun.

That’s not to say that this won’t work with a receiver. Quite honestly, this amp comes with RCA connections so you can hook it up with an aftermarket receiver. It can handle speaker-level signals as well, so you can still get input from a radio without RCA outputs.

The amp is also featured with signal-sensing turn-on on speaker-level inputs which eliminates the need to install a separate remote turn-on wire.

4. JBL MA704

JBL MA704

• 4-channel marine amplifier
• Class D amp technology
• Variable high- and low-pass filters
• Conformal-coated circuit board
• Preamp and speaker-level inputs
• Preamp outputs

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Within the audio space, JBL is one of the oldest and trusted names. The company has been around since 1946, and you could say they know a thing or two about sound.

JBL released everything from headphones portable speakers and maintained a level of quality throughout. The same goes for its selection of amplifiers.

JBL MA704 is a very well-engineered marine amplifier. It’s going to be the most expensive pick of the lot by far. Is it worth the extra money? Let find out…

Let’s start out by stating the JBL MA704 is a 4-channel amplifier rated at 70 watts RMS per channel. The amp could also be switched to 3-channel mode to drive a pair of speakers and a subwoofer. Furthermore, you could bridge the amp to 2-channel mode and power a couple power-hungry speakers with 200 watts RMS each.

This beast uses class D technology for maximum amp efficiency. It’s fitted with a coated circuit board and comes equipped with stainless steel connectors to ensure that it’ll rock for many seasons to come.

Unlike most amplifiers out there, JBL MA704 is featured with both preamp and speaker-level inputs so you can hook it up to almost any system, even if you’re keeping your boat’s factory radio. The variable high- and low-pass filters on front and rear channels will help you maximize the performance of your speakers and subs.

5. Kenwood KAC-M3001

Kenwood KAC-M3001

• Mono subwoofer amplifier
• Class D amp technology
• Conformal-coated circuit board
• Variable low-pass filter
• Preamp and speaker-level inputs

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Yes, Kenwood makes a second appearance on this list, because they make great amps.

So you’re a basshead looking for separate amp for your subwoofer? Well, we can’t think of a better option than the Kenwood KAC-M3001, especially if your have a space-challenged boat, motorcycle, or ATV.

Kenwood KAC-M3001 is an ultra-compact little powerhouse that will fit almost anywhere. It’s fitted with conformal coating which protects the internal circuits from water and dirt, so the party will always go on, even through the roughest conditions.

This mono channel amp will power the bass in your vehicle with up to 300 watts RMS. It comes with variable low-pass filter, preamp and speaker-level inputs so it’ll work with almost any system. The subwoofer output terminal features a plastic-covered plug that provides further protection for the connection.

6. Skar Audio RP-75.4ABM

Skar Audio RP-75.4ABM

• Class A/B 4-Channel Amplifier
• 4 Way Protection Circuitry: Thermal, Voltage, Speaker, DC
• Stainless Steel Hardware
• High Speed MOSFET Power Supply
• Soft Turn on Circuit
• 8 Gauge Power and Ground Terminals
• High- and Low-pass filters

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While Skar Audio might be one of the younger companies in the car audio industry, its reputation is on the rise. The company has been able to carve out a place for itself as a viable competitor.

The RP-75.4ABM is one of Skar Audio’s top rated marine amplifier. It’s built to bring the speakers on your boat to life with unrivaled power output and sound clarity.

Speaking of power, the Skar Audio RP-75.4ABM is rated at 125 watts RMS per channel, which is more than enough to make your aftermarket speakers come into their own.

This 4-channel amp is 2-ohm stable and it’s incorporated with high-grade components, such as high speed MOSFET power supply as well as an advanced marine grade PCB board layout with special marine coating, so the the amp can withstand the harshest conditions for long lasting use.

On one side of the amp you’ll find a fully adjustable built-in user control panel, while on the other side you’ll find a variety of adjustable controls for gain, high pass filter, low pass filter, a crossover switch, and more. In other words, this amp offers a full control over your listening experience.

Additionally, this amp features four-way protection circuitry, which will give your the peace of mind knowing it’s protected against damage to the amplifier for various reasons – including electrical shortage, overheating, low voltage, and more.

7. JL Audio M700/5

JL Audio has been in the audio electronics since 1975, and you could say they know a thing or two about sound.

JL Audio is well-known for creating quality products on the high end of the price and power scale, and the M700/5 amp at hand is no exception.

JL Audio M700/5 sports a small-footprint chassis measuring less than 11″ wide. Despite its compact chassis, this amp can deliver up to 100 watts from each of its front and rear channels, plus up to 300 watts from the subwoofer channel. It owes these impressive specs to JL Audio’s NexD ultra-high speed switching technology, which improves upon the traditional class D technology to deliver outstanding performance, excellent efficiency, and very low distortion levels.

This 5 channel amp can drive a complete marine audio system, running two sets of high-performance coaxial or wakeboard tower speakers, and feeding up a sub at the same time with fifth channel.

The special powder-coat finishes, the gasketed control cover, and the stainless-steel hardware together chalk up to protect this amp against the harsh marine elements.

This JL Audio marine amplifier is featured with built-in variable frequency filters which offer high- or low-pass modes depending on the channels, letting you quickly fine-tune the output to meet your system’s needs and musical preferences.

This amp is also available in 6 channel configuration.

8. Rockville RXM-F4

Rockville RXM-F4

• MOSFET power supply
• Auto start smart turn-on
• RCA preamp line output
• Status Mode LED Indicator
• 2 CH / 4 Channel input mode selector

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Rockville isn’t as well-known as some brands but they know how to build solid amps. Its RXM-F4 4 channel marine amp features a cool, modern look and most importantly, 400 Watts (100 Watts RMS per channel) at 4 ohms and up to 600 Watts (150 RMS Watts per channel) at 2 ohms. You can also bridge the amplifier and get 300 watts per channel at 4 ohms.

As with most marine grade amps, the RXM-F4 is fully marine-rated from start to finish. It has a conformal coated circuit board that protects it against harsh marine elements such as moisture, humidity, heat…etc.

This amp is also featured with high-grade components such MOSFET power supply, beefy capacitors, studio-grade bipolar output stage transistors…etc, which chalk up together to deliver consistent performance. There’s also a professional peak limiter circuitry which ensures distortion-free musical playback at all levels.

Additionally, the RXM-F4 has an auto-start smart turn-on feature which automatically turns on the amplifier without the need no need for a remote turn-on wire.

The RXM-F4 is a universal marine amp. It comes with RCA and and high level speaker inputs so you can connect it to almost any marine system.

9. Pyle PLMRA400

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Pyle PLMRA400

• 4-channel amp system
• Dual MOSFET power supply
• Dual high level speaker input connectors
• Dual RCA input connector jacks
• Gold-plated speaker output terminal connectors
• Adjustable input gain level control
• Anti-thump delay circuitry
• Built-in thermal, overload & speaker short protection
• Heavy duty aluminum alloy heatsink

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Some of the amps on this list cost hundreds of dollars, and they’re worth it. But if you’re on a budget and looking for an affordable marine amplifier that can get the job done without tearing a hole in your wallet, the Pyle Hydra PLMRA400 Marine amplifier is where price and performance meet.

With 100 watts of power per channel, it’s more designed to breath life into your speakers than make your vessel rattle. It also features adjustable input gain level control, and will accept both RCA line-level input and speaker wires for easy integration into your setup.

This little amp uses class A/B circuitry design and heavy duty aluminum alloy heatsink for solid and consistent performance. It’s also incorporated with anti-thump delay circuitry, built-in thermal, and overload and speaker short protection for more reliability.

How to choose a good marine amp

To find the right marine amplifier for your boat, you need to take a few key specs into consideration. How much power do aftermarket speakers need? How many channels should my amp have? How much power do I need for a subwoofer? Asking these questions will help you narrow down your choices and make the right decision.

How much power do aftermarket speakers need?

Well, it depends. Not all aftermarket speakers are created equal. Some aftermarket speakers are power hungry and require more power than others. Therefore, it’s important to make sure that your boat speakers are getting the power they need to perform at their best.

When you’re looking over the specifications of a set of speakers, you’ll see the RMS power handling, which refers to the amount of power these speakers can handle on continuous basis. The RMS is usually expressed as a range — “5-60 watts RMS power range” for example. The higher number represents maximum power the speakers can handle; at which the speakers will sound their best, according to the manufacturer.

For your speakers, use an amplifier whose top RMS output per channel is around the RMS rating of your speakers.

For your amplifier, get speakers with top RMS ratings that are equal to or slightly higher than each amp channel’s top RMS output.

How many amplifier channels do I need?

First it’s worth mentioning that each “channel” of an amp is a discrete source of power, intended to drive one speaker. How many channels you need depends on how many speakers and subs your sound system consist of.

If you have a small boat, or just don’t want a massive sound system, a 2-channel amplifier is a practical solution if you only want to power a single pair of speakers. But if you’re considering adding another pair of speakers (wakeboard tower speakers for example) to your system down the road, get a 4-channel amp now, so you’ll be ready when the time comes.

If you’re thinking about adding a marine subwoofer, there are some other amp configurations you need to take into account. A 3-channel amp for example can take care of a single pair of speakers plus a sub quite effectively.

Multi-channel amplifiers offer ample system-building flexibility. A 4-channel amp for example can be used to run a pair of speakers and a sub, with two channels to drive the speakers and the other two bridged to power the subwoofer.

With this set-up, you can make the amp drive four speakers and use a separate amp to drive your power-hungry subwoofer when you decide to expand your system.

Of course, you may want to consider a 5-channel amplifier or 6-channel amplifier that can power your entire sound system from one convenient package.

A bridgeable 6-channel amplifier for instance can be employed to run three pairs of speakers, or two pairs of speakers plus a subwoofer, with two channels bridged to run the sub and the other four to drive the speakers.

These multi-channel amps can be configured to run almost any speaker combination — from multiple speakers and wakeboard tower set-ups to high-powered subwoofers. If you don’t want to invest in multiple amps, and would rather get an all-one-solution, this is what you need.

How to plan your marine audio system

Asking yourself “how big do I want my boat system to be?” will help your narrow down your choices of amp(s). The speakers in your boat and their power handling characteristics is going to determine how powerful your amp should be.

Generally speaking, marine audio systems don’t necessarily need a ton of power to get loud when you’re moored in a creek or tied up at the marina, but having the right amount of power makes a night and day difference when you’re underway at full speed.

On a smaller boat, a compact marine amp rated at 50 watts RMS per channel can probably make a big difference in your overall sound. For such an amp, look for speakers with at least 50 watts RMS rating to got along with it. The bigger your boat, the higher the speakers’ RMS rating should be.

If you have a bigger boat, or just like to crank it up, you should look for an amp rated at 75-100 watts RMS per channel at least. A small difference of 5-10 watts either way won’t matter much, but somewhere in that range is the sweet spot. Your new boat speakers will each need to have a max RMS rating of 75-100 watts RMS or slightly more.

If you add multiple sets (on a tower, for example), make sure you have enough amps for all of them. And if your boat has a loud and high-performance engine, plan to build a system that’s powerful enough to be heard over it.

Boost your boat’s bass with a subwoofer

We can all agree that everyone will appreciate strong bass in their lives. It’s hard to live without it if you’re used to a thumpin’ car or home stereo. Luckily for you, there are numerous powerful marine subwoofer amplifiers out there dedicated solely to reproducing thumping bass. These mono channel amps are designed for subwoofer duty, so they work with a variety of impedances and have tone controls and filters designed to maximize bass.

If you’re going to add a hard-hitting subwoofer to your boat, it’s highly recommended that you opt for a dedicated amplifier. Sure you can use a multi-channel amp, bridge two of its channel to power your subwoofer, but it’s worth mentioning that these amps can’t handle the sub’s low impedance, so they overheat or go into protect mode. Therefore, a dedicated mono channel amp is essential if you like to hear low-end thump at high volume. What you want is bass that blends into your overall sound instead of overwhelming it.

Matching your sub and amp is mandatory before you order either one. You don’t want to buy an amplifier to find out that it’s not adequate to drive your subwoofer, or that the later is capable of handling more than what the amp can pump out.

Additionally, it must be noted that if you’re adding a subwoofer to a factory system; get an amp with speaker-level inputs, so it can get be paired up to your stock headhunt, because otherwise, you’ll need to buy a line output converter which converts speaker-level output signals into RCA preamp-level signals (low level signals); those that you can actually feed an amplifier with.

Bottom Line

A good marine amplifier will make a night and day difference in terms of sound quality.

In this guide, we’ve evaluated the best marine amplifiers that will make your marine audio system rock. We included everything from cheap marine amps all the way to high-end models and a few in-between to cater for different needs, and budgets.

We hope that our list was of help to you in choosing the right marine amp for your setup.