Expert Service 1-877-289-7664 [Hours]

2nd Annual Warehouse Sale!

MB Quart NAU 660

540W Max, Nautic Series 6-Channel Marine Amplifier (NAU660)

Discontinued
|

We apologize

This item has been discontinued

  • Nautic Series 6-Channel Class A/B Marine Amplifier
  • RMS Power Rating:
    • 4 ohms: 60 watts x 6 chan.
    • 2 ohms: 90 watts x 6 chan.
    • Bridged, 4 ohms: 180 watts x 3 chan.
  • Max power output: 360 watts
  • MOSFET PWM power supply
  • UV and salt water resistant paint, silk screen and heat sink enclosure
  • Marine-grade conformal coated circuit boards resist corrosion from salt spray and moisture
  • Non-corrosive brushed aluminum casing
  • Conforms to the American Boat and Yacht Council (ABYC) marine electronic standards
  • LED power and protect indicators
  • Bass Boost (0-6 dB bass boost at 45 Hz)
  • 2/1 channel operation
  • Full range line outputs
  • 4-Way system protection circuitry (DC, short, thermal, overload)
  • Heavy duty aluminum alloy heatsink
  • Gold-plated RCA level inputs
  • Gold-plated screw terminals
  • Variable high-pass filter (40-250 Hz)
  • Variable low-pass filter (40-250 Hz)
  • Variable frequency: 40-250 Hz
  • Variable input level control (0.2V-6V)
  • Damping Factor: 180
  • Dimensions: 18-3/4"L x 9-1/2"W x 2-1/8"H
  • 4-gauge power and ground wiring is required for installation. Contact us for information regarding a discount on select amplifier kits when purchased together with this amplifier.
  • 1-year SonicElectronix.com warranty

Power Specifications - Full Range Channels

RMS Power @ 4 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 4 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

60 watts x 6 channels
RMS Power @ 2 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 2 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

90 watts x 6 channels
RMS Power @ 1 ohm

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 1 ohm, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

180 watts x 3 channels

Amplifier Specifications

Marine Certified
Marine certified means that the unit has been designed and manufactured with a marine use in mind. It will withstand the harsh conditions that come from marine use. Generally, they are treated against UV rays and treated with special protective coatings.
Yes
Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.

AB
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
6
Total Peak Power Output
The total peak power output is measured as the wattage per channel multiplied by the number of channels, and is calculated at the lowest level of operating impedance.

It is measured during a brief musical burst, such as a sudden drum accent. Some manufacturers display peak power ratings on the face of their products to increase the appeal.

The RMS power rating is more accurate, and we recommend using it for product comparison.

540 watts
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.

540 watts
Maximum Input Gauge Size
This is the largest gauge wire that will fit into the power and ground terminals of this device. The lower the gauge number, the thicker the wire is. For example, a 4 gauge wire is thicker than an 8 gauge wire and thus has higher current carrying capacity. Always do your best to get this size wire to reduce the risk of damage to your components.
4 AWG
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
2 ohms
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
4 ohms
THD at Rated RMS Power
The amount of change in harmonic content of the signal as it is amplified. A lower figure indicates less change and a more accurate amp. THD below 0.10% is inaudible.
.05%
Speaker Level Inputs
Speaker level inputs are commonly referred to as high-level inputs and vice versa. This input type allows you to get your audio signal directly from the speaker wire in your vehicle, instead of using RCA cables. The advantage of this is factory integration, as most stock radios do not have RCA outputs to run amplifiers.
No
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
No
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Low-pass (LP)
High-pass (HP)
Full (AP)
High-Pass Crossover Frequency
The high-pass crossover frequency can be a fixed crossover point or a variable crossover range. A variable high-pass crossover allows you to select a specific crossover point which allows frequencies above the set crossover point to pass, while making frequencies below the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

40 - 250 Hz
Low-Pass Crossover Frequency
The low-pass crossover frequency is typically used for subwoofers. It can be a fixed crossover point or a variable crossover range. A variable low-pass crossover allows you to select a specific crossover point which allows frequencies below the set crossover point to pass, while making frequencies above the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

40 - 250 Hz
Signal-to-Noise Ratio
This spec compares the strength of the signal to the level of background noise. A higher value indicates less background noise.
93 dB
Channel Separation
Also referred to as crosstalk. The amount of interference on one stereo channel caused by the leaking of the other stereo channel. The higher the rating in decibels (dB), the better the Channel Separation.
80 dB
Bass Boost
The objective of the bass boost is to get more kick out of your subwoofer. It is a circuit that emphasizes the lower frequencies at a given point. The bass boost should always be set first before setting the gain. This feature is known for destroying subwoofers and is commonly used incorrectly, so be cautious.
0 - 6 dB
Bass/Gain Remote
If the amp comes with a bass/gain remote you will be able to control the level of your bass from your dashboard. Typically bass remotes also include a 16-20 ft. wire for installation.
No
Fan Cooled
A great feature to have if an amp generates a large amount of heat. Cooling fans can help regulate the temperature to prevent the amp from overheating (burning).
No
Fuse Rating
The amperage and the number of fuse(s) an amp requires.
70A x 1 
CEA-2006 Compliant
Amplifiers that have been tested to meet specific standards. When a car amplifier meets these standards, you can be sure that it will be able to produce the amount of power specified by the official CEA-2006 rating. Usually, these rating consist of the following items:
  • RMS Power
  • Signal-to-Noise Ratio

This rating applies to both external car amplifiers, as well as the amplifiers inside of in-dash stereos.

No

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
64%
4 Star
36%
3 Star
0%
2 Star
0%
1 Star
0%

Average Attribution Rating

Durability
4.6
Value
4.9
Features
4.8
Design
4.5
Usability
4.9

Jonathan

Garner, NC

Overall
Durability
Value
Features
Design
Usability

Damn near waterproof!

February 10, 2013

I use this on my 20' bowrider for wakeboarding. This powers my kicker speakers nicely after bridging four of the six channels. It does get hot, only after blasting for a while...but still hot. But not a problem when you consider its never shut off on me, its an amazing value, and the thing keeps kicking even after taking some sharp cuts taking water in through the vents and directly onto the amp. After the ride I opened the engine bay to find this thing with water all over the top and around the amp, but it was still playing fine. Great value, and MB Quart is a good product!

0 of 0 found this helpful

Help our customers find the most helpful reviews

Taylor

Pinellas Park, Fl

Overall
Durability
Value
Features
Design
Usability

Quality

January 20, 2013

I've had this amp for about a year. This thing is just enormous. It's roughly the size of a full-sized computer keyboard. I have mine powering 6 infinity in-cab 2-way speakers. 4 6x9's and 2 3 1/2's. It sounds great but I did notice when trying to tune more mid bass into the door speakers while trying to get more "highs" from the dash speakers if adding just a bit more gain to either channel seems to fall off a perpetual cliff. And seems to cut bass completely from the 2nd channel. If I back off on either gain level its fine. This could also be an issue with my electrical system. Because I use this amp exclusively for my in cab speakers, my sub is driven by a separate amp. This amp actually draws 10 more amps of current than my sub amp and as a result of that extra draw could be the reason the amp ceases to push bass at higher gain/volume levels. Nothing I stated above should have any negative impact on anyone's decision to purchase this monster. Its heavy, its big but best of all it is impressive. I love the way I can tune 6 channels, that is why I purchased it. My car only had 4 speakers and I wanted to add 2 more and not have them pushed by the stereo and have to have bass blockers. I went the more technical and difficult route just to custom tune each channels behavior. This amp is also as reliable as a watch, it just works. I live in Fl and it can get blazing hot and this thing no matter where its mounted will keep going. It does get warm even being in a dynamatted trunk in the middle of summer but it keeps going. Lets see, other than the aforementioned details for what you get, it is an absolute steal. Get one!

0 of 0 found this helpful

Help our customers find the most helpful reviews

Spdfreak

Canada

Overall
Durability
Value
Features
Design
Usability

Good value for the money

January 11, 2013

I bought this amp as a low cost way to power my kmt6's. I was pleasently surprised, it works very well and I've had no issues with the unit. I currently am running it bridged to 3 channel with plans to add a sub next year. I would recommend this to someone on a budget looking to build a decent marine system

0 of 0 found this helpful

Help our customers find the most helpful reviews

Rick

Buffalo, NY

Overall
Durability
Value
Features
Design
Usability

Great Amp

August 5, 2012

I bought this amp based upon the reviews that I read here, and around the internet. EXCELLENT unit. I'm running 4 MB Quart Nautic NKF-692's and an MB Quart RLP-254 10" Sub and it sounds truly amazing. I'm not one for super loud music or thumping, vibrate-your-boat-apart bass, but wanted more of a quality sound at high volume so as to hear it better over my boat's engine. The cons are: Labeling. Everything could stand to be a bit larger, but that could be my own eyes failing me! Also be cognizant of the fact that the + & - are staggered on speaker connection side, meaning that all the + are not on the bottom with the "-" on top, etc. The unit is big and heavy, but I didn't have any issues installing it. It didn't get as hot as I thought it would, which is another plus.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Ron

Ponca City, OK

Overall
Durability
Value
Features
Design
Usability

Great Product

June 3, 2012

I was hesitant to buy this product as well as the NAU 460 that I bought at the same time. I knew MB Quart was a solid speaker company, but was not familiar with their amps. I bought these two amps to drive 10 seperate Polk Audio speakers in my boat (six in the boat, 4 on wakeboard tower), driven by an Alpine head deck. All I can say is WOW! I can run my system at Volume level 31 out of 35 with no detectable distortion and solid quality sound. I have had my boat out probably 20-25 times since the install, and have not gone easy on the amps, and so far they are still performing perfectly. The only issue I had on the install, was the speaker connection configuration is different between the 460 and 660, so if you happen to get one of each pay extra attention to the wiring diagram. I am one very pleased customer, and already have recommmended these amps to friends who love the way my system sounds.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Mittchy Shotta

Anguilla

Overall
Durability
Value
Features
Design
Usability

The Amaizin MB Quart NAU 660

March 25, 2012

What should I say, Maxxsonics has impressed me with their amplifiers. I bought the MB Quart Q4.150 in December for my car and it has been so impressive!! It plays so clean and brings out the little details that a lot of amps leave out. I can say the same about the MB Quart NAU 660 that I bought for my boat. The surround sound is so full I would say that this amp has been under rated. When it comes to amps those that are CEA Compliant are great quality from Maxxsonics. I would recommend this amp and any other amp from Maxxsonics to anyone.

0 of 0 found this helpful

Help our customers find the most helpful reviews

mrfixit

miami ,fl

Overall
Durability
Value
Features
Design
Usability

good app

April 9, 2011

This app runs really good it is a great value or the money

0 of 0 found this helpful

Help our customers find the most helpful reviews

Peter

Canada

Overall
Durability
Value
Features
Design
Usability

Great Amp

September 24, 2010

I have used the amp for 4 months now. Plenty of power to drive 4 full range and a sub no matter what the volume. Also i found Sonic great to deal with.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Big Bite

SLC , UTB

Overall
Durability
Value
Features
Design
Usability

Quality Amp

December 4, 2009

Nice Amp, well designed flexible worth the money and dose a good job powering six 6.5's and a tube sub. 2-45rms 4-35rms 75rms sub

0 of 0 found this helpful

Help our customers find the most helpful reviews

Trenton

Inez, TX

Overall
Durability
Value
Features
Design
Usability

awesome

November 3, 2009

Real good quality amp makes them speakers in the boat scream.

0 of 0 found this helpful

Help our customers find the most helpful reviews

lanchon

Puerto Rico

Overall
Durability
Value
Features
Design
Usability

nau 660

April 8, 2009

works great but is too heavy .

0 of 0 found this helpful

Help our customers find the most helpful reviews

Accessory Tools and Products

Accessories added

NVX XKIT42

Complete 4 Gauge Amp Wiring Kit with RCA Interconnect Cables and Speaker Wire!

Your Price $89.99

The InstallBay AK4 by Metra

4 Gauge Amplifier Installation Kit with RCA Interconnect Cable

Your Price $22.99

StreetWires ZN1K-04

4 Gauge (AWG) ZN1 Series Single Amplifier Installation Kit for Systems up to 1000 Watts

Your Price $44.95

Stinger SI4617 4000 Series Interconnect Cable

17 ft. 6-Channel 4000 Series Audio Interconnect Cable

Your Price $41.99

StreetWires SCP1215BL - 12 AWG Speaker Wire

12 Gauge Wire - 15 ft. of Speaker Cable with Twisted Construction

Your Price $24.95

StreetWires FB4

4 AWG / 4 Gauge Firewall Bushing

Your Price $6.95

Car/Marine Audio Installation Kit

Includes Test Light, Crimp/Splice Tool, Multi-bit Screwdriver and more.

Your Price $12.99

Product Summary

Manufacturer

Model Number

NAU660

UPC

806576215868

Weight

14.00lbs

Internal SKU

nau660

Internal Product ID

17760

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: MB Quart NAU 660