Your cart
Contact us
Close contact box
Connect ID #
986 206 773 4
Connect ID #
986 206 773 4
Don't wait on hold. We'll call you back when it's your turn to talk with the next available .
Please enter your name  
Please enter your phone number  
Please enter a message  

Calls may be recorded for training and quality control purposes.

We are located in Virginia USA.

MB Quart GMR-3

Marine digital media receiver with built-in Bluetooth®

Item # 049GMR3

MB Quart's GMR-3 marine digital media receiver isn't big (it fits in a standard gauge opening), but it gives you...

MB Quart's GMR-3 marine digital media receiver isn't big (it fits in a standard gauge opening), but it gives you...

California customers:
Please click here for your Proposition 65 warning.

Discontinued item
5 questions - 11 answers

Item # 049GMR3

Hands-on research

We double check the details on each item.

60-day returns

If you don't love it, send it back.

Need an expert?

Our Advisors know their stuff and love to help.

About the MB Quart GMR-3

Jon Paul

Round rockin'

MB Quart's GMR-3 marine digital media receiver isn't big (it fits in a standard gauge opening), but it gives you big-time performance and tons of connectivity options. This rugged multimedia receiver packs a ton of features into a compact design that's made for the outdoors. Built-in Bluetooth makes music streaming easy and awesome.

Round rockin'

MB Quart's GMR-3 marine digital media receiver isn't big (it fits in a standard gauge opening), but it gives you big-time performance and tons of connectivity options. This rugged multimedia receiver packs a ton of features into a compact design that's made for the outdoors. Built-in Bluetooth makes music streaming easy and awesome.

Apple® control and more

You can tune in to AM/FM radio, of course, but the big deal is built-in Bluetooth® that lets you stream music from your smartphone or other Bluetooth-enabled device. The GMR-3 is Apple-ready too, so you can access the iTunes collection on your iPhone®, iPod®, or iPad®. You can also use the rear aux input for your music player, or plug a thumb drive into the rear USB port to enjoy your favorite music.

Expand your system

The GMR-3 also includes a pair of rear-mounted preamp outputs, making it easier to add on an MB Quart marine amp. The LED display gives you the info you need, while the watertight, UV-resistant face and big, easy-to-use buttons will stand up to the rigors of marine use. The carbon fiber-look face will bring some extra style to your boat, too. You can also add up to two MB Quart wired marine remotes and control your music from anywhere.

Bluetooth note: Use of this receiver's Bluetooth features will depend upon your phone's Bluetooth capabilities. Learn more in our article explaining Bluetooth profiles.

iPod/smartphone note: If you're going to use your iPod or smartphone with this receiver, be sure to check "Details" for compatibility information.


Product highlights:

  • AM/FM marine digital media receiver (does not play CDs)
  • built-in amp (20 watts x 4 RMS/40 peak x 4 channels)
  • built-in Bluetooth® for music streaming
  • marine-rated watertight face
  • large, easy-to-use buttons
  • backlit LCD display
  • inputs: rear USB input, rear aux input
  • outputs: 2-channel preamp outputs
  • fits into a standard tachometer opening
  • large, backlit control buttons
  • waterproof, dustproof, and shockproof
  • required cutout: 3" (diameter) x 3-3/4" (depth)
  • works with MB Quart wired remotes (sold separately)
  • warranty: 1 year
  • Our 60-day money-back guarantee
  • MFR # GMR-3

What's in the box:

  • Marine digital media receiver
  • Wiring harness
  • Mounting bracket
  • 2 Screws
  • 2 Nuts
  • 2 Lock-washers
  • Operators Guide

Featured video:

Customer reviews

Loading reviews...

MB Quart GMR-3 reviews

Average review:

23 reviews

Thanks for submitting your review

Filter by rating

Customer photos

Customer provided image, click to load a larger version.
Customer provided image, click to load a larger version.

Sort reviews

Sort by:
Items per page:
View page:

Verified customer (What's this?)
Verified employee review (What's this?)

Reviewed on

This review was collected as part of a promotion



Crutchfield response
Customer provided image, click to load a larger version.

<< >>

More details on the MB Quart GMR-3

Stacey B.

Features & specs

AUX Input RCA (rear)
Audio/video Input ---
USB Input Rear
USB Port Power 0.5A
Backup Camera Input No
Second Camera Input No
CarPlay No
Android Auto No
Siri Control No
Alexa Voice Control N
Android Control Yes
Memory Card Slot USB memory
Bluetooth Compatible Built-in
Satellite Radio Ready No
HD Radio No
Navigation ---
iPod Compatibility
Full size Classic
Nano 5Gen and newer
Touch 3Gen and newer
iPhone 3GS and newer
RMS Power (CTA-2006) N/A
RMS Power (Manufacturer) 20 watts
Peak Output 40 watts
RMS Power Bandwidth Not givenHz
Preamp Outputs 4-channel
Sub Preamp Outputs No
Switchable Rear Preamp Outputs No
Video Screen No
Navigation App Compatible (iOS)
Navigation App Compatible (Android)
Preamp Voltage 4 volts
Screen Size 0
Screen Type N/A
Display Color Bluish white
Key Button Color Bluish white
EQ Bands None
Wireless Remote No
Steering Wheel Control Compatible No
Parts Warranty 1 Year
Labor Warranty 1 Year
FM Sensitivity ---
European Tuning Yes
Seek/Scan Seek
Radio Data System No
File Playback
Music File Playback MP3
High-res Playback N
The MB Quart GMR-3 replaces these items:

Product Research


Marine Grade Protection: The MB Quart Nautic GMR-3 meets or exceeds the American Boat and Yacht Council (ABYC) marine electronics standards and the American Society for Testing and Materials (ASTM). It has been designed and tested against the elements and built to handle the outdoors. Its waterproof, dust proof, snow proof, and shock proof.

Splash Proof LCD & Large Buttons: The marine source unit's splash proof LCD features a bluish white backlight. The front-panel LCD indicates Source input, AM/FM station, and Volume level (it does not display song/artist information). Large waterproof buttons provide Play/Pause, Tracks Forward/Back, Volume Up/Down and Power On/Off functions. Their size and space also makes them easy to operate with gloves on.

Audio Section: The marine source unit is equipped with a 20W (RMS)/40W (Peak) x 4ch amplifier. The marine source unit is also fitted with two pair of 4V RCA outputs to connect an external amplifier or powered subwoofer. The GMR-3 offers 5 preset EQ modes - Flat, Classic, Pop, Rock, or Off. The source unit also offers independent Bass & Treble control; plus Balance & Fade adjustment. When listening to music at low volume levels, the Loudness feature will boost the bass & treble response. Every time a button is pressed the unit output a beep tone (this can be turned off).

AM/FM Tuner: The MB Quart Nautic GMR-3 features a built-in AM/FM tuner with manual & seek tuning. You can select either US or European tuning. The unit does not offer preset tuning.

Bluetooth Audio Streaming: The MB Quart Nautic GMR-3 supports wireless audio playback (AD2P) and control (AVRCP) of a Bluetooth-enabled device. The GMR-3 supports playback of stored music and music apps on your Bluetooth device. The unit will be able to control basic playback functions, such as Play/Pause & Skip Next/Previous. Advanced music control of your music apps will still need be done via your Bluetooth-enabled smartphone. The unit offers quick and easy wireless connection to your Bluetooth enabled device. When the unit powers up, it immediately connects to the last device connected.

Note: This unit does not display song/artist information. This unit does not support Bluetooth hands-free communication for making and answering phone calls.

USB Port: The MB Quart Nautic GMR-3 is equipped with a rear-panel USB (type-A) port attached to the chassis by a 7" pigtail and comes with a 40" USB extension cable. The USB port allows you to connect a USB MSC (mass storage class) device, like a USB thumbdrive or portable digital audio player. The unit supports audio playback & control of MP3 audio files stored on a compatible USB thumbdrive or MSC device. The unit offers Play/Pause & Previous/Next Track playback functions. This unit does not display song/artist information. The unit also charges your connected USB device (up to 0.5A).

Note: The unit's USB port does not support Android smartphones or tablets.

iPhone Direct Connect: The unit's rear-panel USB port can be used to connect your Lightning-connector or 30-pin dock connector iPod/iPhone with the cable that came with your Apple device. The GMR-3 supports audio playback, basic control (Play/Pause & Previous Next Track), and charging of your compatible Apple device. You will continue to use your iPod/iPhone for advanced music browsing and to view song/artist information. The GMR-3 is "Made for iPod/iPhone" compatible and supports the following iPod/iPhone model features (as of 4/25/2019:

Apple Device Generation Tested Version Media Type Control Type Display Type Bluetooth Charge
Audio Video Head Unit iPod/iPhone Artist/Song Text Track Info Phone Audio
3GS 6.1.6 Y N Y Y N N N Y Y
4 7.1.2 Y N Y Y N N N Y Y
4S 9.3.5 Y N Y Y N N N Y Y
5/5C 10.3.3 Y N Y Y N N N Y Y
5S/SE 12.2 Y N Y Y N N N Y Y
6+/6/6S/6S+ 12.2 Y N Y Y N N N Y Y
7/7+/8/8+ 12.2 Y N Y Y N N N Y Y
XS-Max/XS/XR/X 12.2 Y N Y Y N N N Y Y
3rd 5.1.1 Y N Y Y N N N Y Y
4th 6.1.6 Y N Y Y N N N Y Y
5th 9.3.5 Y N Y Y N N N Y Y
6th 12.2 Y N Y Y N N N Y Y
5th 1.0.2 Y N Y Y N N N N Y
6th 1.2 PC Y N Y Y N N N N Y
7th 1.02PC Y N Y Y N N N Y Y
classic 80GB 1.1.2 Y N Y Y N N N N Y
120GB 2.0.1 Y N Y Y N N N N Y
160GB 2.0.4 Y N Y Y N N N N Y
Note: Apple iPod/iPhone software updates may change functionality results. If you download a newer software version, you may need to reset the unit and your iPod/iPhone to regain functionality. If this doesn't work, you may need to wait until a newer software update is available.

Aux Input: This unit features a rear mounted, stereo RCA auxiliary input on a 5" pigtail so you can connect an external audio source. An RCA-to-Minijack cable (sold separately) will be required for the connection of a portable audio player with a headphone jack output.

Optional Wired Remote: The Nautic GMR-3 supports MB Quart's GMRWREM marine wired remote control (049GMRWREM, sold separately). The MB Quart Nautic GMRWREM comes with a 19.5' DIN-cable to connect the wired remote to the GMR-3 source unit. Up to two GMRWREM wired remotes can be used to control one GMR-3 source unit.

Mounting Options: The marine source unit requires a round cutout in the bulkhead or dash for inserting the chassis. The integrated protective gasket, supplied U-bracket, and included hardware secure the unit in place against the mounting surface.

  • Chassis: 2.9375" (diameter) x 2.875" (depth)
  • Face-Plate: 4.125" (diameter x 0.875" (depth)
  • Cutout: 3.0" (diameter) x 3.25" (depth)
Note: The GMR-3 features a round design and does not include a mounting sleeve or ISO-mount screw holes to accommodate standard automotive installation.

Loading accessories...

Customer Q&A

5 questions already asked

Can the display brightness be adjusted?
[ Stephen  Jul 25, 2022 ]
1 answer
Display brightness cannot be adjusted sadly, Stephen.
[ Bo  Jul 25, 2022 ]  Staff
If i hook up an after marker sirius xm tuner to rear inputs, will it display properly on the head unit itself?
[ ROBERT  Apr 09, 2021 ]
2 answers
It is possible to use the aux input to connect a SiriusXM tuner. This input can only take in the audio from an external SiriusXM tuner. However, some receivers will work with a direct-connect hideaway tuner which will fully integrate satellite radio including the display of the song and station information. I recommend contacting an advisor by calling 1-800-324-9695 to check on current options
[ JASON  May 08, 2021 ]  Staff
I can't say for sure, but I doubt that it would. I just use the app on my phone and connect with bluetooth.
[ RICK  May 03, 2021 ]
does this product require an amplifier for use?
[ Jovani  Oct 21, 2020 ]
6 answers
No, but would benefit from one.
[ WILLIAM  Oct 21, 2020 ]
No, it will work fine as it is. Speaker size, and number of speakers will have an effect on available power. I run 2 6x9's , and 2 6.5's with no issues. Hope this helps.
[ JIMMY  Oct 21, 2020 ]
I do use it with an amp. If I turn the amp off it will still work but with 6 speakers it is much less volume obviously. If you only had 2 speakers it might be just fine
[ gary  Oct 21, 2020 ]
I have installed this in my pontoon boat. The boat has front and rear speakers, I do NOT have an amplifier installed on the boat the sound is good. The factory speaks on the boat couldn't really handle an amplifier anyway. But if you have premium speakers or wake tower w/speakers, an amplifier would give you the super loud sound, but definitely not needed for use with this radio.
[ JOHN  Oct 21, 2020 ]
I don't know if it's required, but I recommend it, I added a $93 amp, and this blows away much more expensive systems.
[ RICK  Oct 21, 2020 ]
No it doesn't.
[ DAVID  Oct 21, 2020 ]
Will it fit in a single DIN opening?
[ MICHAEL  May 18, 2020 ]
1 answer
I'm not sure what you mean by DIN opening? I replaced the factory installed radio in my Pontoon boat. It was direct replacement with no altering hole size.
[ JOHN  May 18, 2020 ]
[ MICHAEL  May 18, 2020 ]
1 answer
Chassis: 2.9375" diameter x 2.875" deep Face-Plate: 4.125" diameter x 0.875" thick Cutout: 3.0" (diameter) with at least 3.25" for depth
[ JASON  Jun 02, 2020 ]  Staff

Loading articles...

Compare the sound