BOSS MCBK420B Review

The experience often becomes boring on long rides, especially when there are no sounds that boost your mood. Our beloved engine sound becomes familiar to our hearing throughout the ride. It is still better if there are tunes with various low, mid, and high beats and rhythms.

For motorcycles with a pre-installed audio system, there are times that we are not satisfied with its output. All you need is the new audio system to give more satisfaction to your experience for the length of time you stay on the road.

This post is our in-depth review on the BOSS MCBK420B to help you decide if this speaker system is suitable for your motorcycle enough to replace that built-in audio system of your bike.

The BOSS Style

With MCBK420B you can listen to all the music produced by your smart devices or portable music players due to its Bluetooth capability.

Its speakers are black or chrome and look sleek. The style will add the right or suitable flavor and edge to your bike. Because of this, you can enjoy your favorite tunes more.

Sometimes you don’t even notice that there are motorcycle speakers that come with an amplifier. Some are just limited to radio, nothing’s wrong with that; however, your experience while on the road will be at a different level with the features that MCBK420B provides.

Four speakers setup

As mentioned, MCBK420B comes with an amplifier included. One cool thing about it is you can choose whether to have two or four speakers. For most riders and general consumers, we can say that they will choose four without a doubt. Your listening experience is at a different level with two speakers; however, you can level up even more with four speakers.

This speaker system setup is suitable for motorcycles and golf carts, ATVs, boats, and snowboards.

This setup can handle any elements and shocks so that you can expect a quality and reliable unit in the outdoor dweller like your motorcycle.


If you look at the MCBK420B, you can quickly notice its speakers; you can even say that it’s all about the speakers. Its speakers are marine-grade, waterproof, and weatherproof. It includes 3 inch matte black full-range speakers that are suitable to use anywhere. As mentioned as well, you can choose from matte black or chrome.


Wattage is essential if we want to know how powerful this speaker system is. Its included amplifier is straightforward to install and use. Its peak power is 600 watts, and compared to others, it produces intense sound.

It has 80 Hz to 15 kHz, and its total harmonic distortion is less than 0.01% which gives a good sound.

Sources of input

The MCBK420B has a 12V power source and includes a 12V power cable to plug into the bike adapter. It has RCA inputs and 3.5 mm AUX inputs. These inputs are typical for home audio systems, and good thing they are available on motorcycles. For more freedom and to put the amplifier anywhere, you prefer its volume control to be on the amplifier and not on the speakers.

Now for wireless connectivity that is now common to modern speaker systems, the MCBK420B has Bluetooth connectivity that is easy to connect and supports apps such as Spotify, Pandora, Apple Music, and more.

Don’t worry about skips for every bump because it is shockproof, and the Bluetooth connectivity of this unit is much more stable than previous versions. Same with its AUX input, shocks can’t do anything to interrupt your music.


When it comes to its design, it is weatherproof and waterproof. Compared to other weatherproof speaker systems, the MCBK420B is more realistic when it comes to its weatherproofing capability. Its shock resistance is also included in its proofing capability so expect continuous music while on the road.

Being weatherproof and waterproof doesn’t mean it can dip or submerge in water. Its proofing is designed only to protect the speakers from unintended water and other weather conditions.

Options for mounting

The MCBK420B kit includes everything you need to mount the speakers on your bike in any part of it, including various sizes of clamps and brackets for the handlebars for 3/4 inch to 1 1/4 inches. With these sizes, there will be no problem no matter what the size of the handlebar of your motorcycle. You can easily install this speaker’s system.

Mounting plays a significant part in making your ears more exposed to the sound output of the speaker system. So we suggest that you mount the speakers on handlebars, especially for those speaker systems designed for handlebars.

How’s the sound?

The MCBK420B speakers are full-range, high-definition, and 3-inch. Its speakers provide the broadest range of sound, which is very pleasant to listen to. Due to its quality, you can hear the details of the music more clearly even at high engine sound or speed, including external noises.

The MCBK420B amplifier is class A/B type 2 and is a high-quality amplifier for motorcycles. More efficient compared to other amplifiers available today in the market.


When it comes to price, it is around 100 dollars for its high-quality speaker system. It is the unit if you are particular with your budget. You can buy this for 103 dollars on Amazon, and relatively wallet-friendly compared to other speaker systems with the same quality output.


The MCBK420B has 3-inch matte black full-range speakers. Its adjustable brackets will fit handlebars ranging from .75 “to 1.25”.

This unit weighs 4.4 pounds, and its dimensions are 3.5 x 3 x 1.5 inches. And its depth is 1 inch.


The MCBK420B is very similar to the MCBK470B when it comes to features. If the MCBK420B has a class A/B type 2 amplifier, the MCBK470B has a class D amplifier. When it comes to weight, the MCBK420B is 4.4 pounds, while the MCBK470B is 6 pounds. The MCBK470B has dimensions of 9 x 6 x 1.2 inches while the MCBK420B has 3.5 x 3 x 1.5 inches. The wattage of the MCBK470B is 1000 compared to the 600 watts of the MCBK420B.

MCBK420B and MC420B are reflective because they are almost similar, including their weight and dimensions. However, MC420B is slightly heavier than MCBK420B. An in-depth MCBK420 is 1 inch while MC420B is 0 inches.

MCBK420B’s speakers are 1 inch smaller than GoHawk TJ4-R. The GoHawk TJ4 response frequency is 20Hz-20KHz compared to 80 Hz to 15 kHz. When it comes to price GoHawk TJ4-R is almost half cheaper than MCBK420B. However, GoHawk TJ4-R is only 100 watts compared to the 600 watts of the MCBK420B.

If you prefer a class D amplifier, you can go to MCBK470B, but if class A/B is enough for you, then the MCBK420B is fitting. If you want a lighter speaker system go for MCBK420B than MCBK420B, and for lighter, you can choose GoHawk TJ4-R.

When it comes to frequency, MCBK420B and MCBK470B are distinct from the GoHawk TJ4-R. And if you prefer a much louder speaker system, your first option will be MCBK470B, next is MCBK420B, then GoHawk TJ4-R.

MCBK420B comes with:

  • One Pair High-Performance Black Weatherproof Speakers
  • Two Speaker Handlebar Mounts
  • Amplifier
  • In-Line Remote Volume Control
  • 12V Power Cable
  • Mounting Hardware
  • Owner’s Manual

Honest Response

When it comes to the music quality of the MCBK420B, no doubt it is loud and clear. Some users responded that after six months of use in rain, shine, and dirt, its sound output performance is still the same. Although its speakers are small, you can expect rich, correct, and decent bass. The bass is not that much, but you can make adjustments using its amplifier. This speaker system is also loud with no distortion. However, this audio quality is as-is when you found the right place to install it and how you install or set up the amplifier/receiver. At 70 mph on any bike, you can still hear its sound if the speakers are in good condition. So you always need to make sure or check that the speakers are in good condition and there are no broken parts. The only thing that will bother the rider is the beep when you turn the bike on, and it is not ideal for riders who often travel early in the morning.

The MCBK420B has low power requirements. If you install LED strips, the unit can supply enough power even with speakers streaming Bluetooth audio at enough loud volume for 10 to 12 hrs before it requires a charge.

Its wire is very thin and difficult to solder. And that makes it hard to put together as well. But its length is enough.

The control of this unit is decent. However, the volume control is backward, so you need to turn it anti-clockwise to turn the volume up.

The MCBK420B has the quality for its price. There are much lesser quality or equal quality that are more expensive than this, and if you are someone who is one to save some budget, then this is a good option and unit for you. Its mounting brackets are not that impressive, and maybe it has something to do with its price. But not everyone cares about that since most are looking for sound quality or overall quality in general.

It has no On/Off switch. It also has no way to turn off Bluetooth if you want to use the cable. If you don’t want to use it while riding, it will stay active if there is no On/Off switch. One way to fix this is to splice and get your own switch.

This speaker system is louder than JBL 400 watts and is a truly waterproof, pre-wired plug and play connector.

The brackets that come with the speaker unit are rubber strips to adjust the diameter of the bar. There are two thicknesses of strips 1 / 16 and 1 / 14. The thin strips do not allow the clamps to hold the speaker in position. The thick strips are very compact and do not allow the mounting stud to stick out to reach the nut. The wires coming out of the speakers have plugs mounted at their ends. If you want to use clamps, you need to cut the connection to pass the cables to the clamps and then replace the plug. The leads of the speakers are not that long to reach the amplifier after it has been placed where it should be.

The lead for the volume control is long enough to mount it virtually anywhere you want. The volume control does not include brackets, so you will need to provide your own. It has a threaded shaft with two nuts, so mounting is easy.

Additional Information

  • Although MCBK420B has four speakers, even two speakers are decent, clean, and have lots of volume.
  • MCBK420B will fit 300 cc touring scooters.
  • This speaker system will work for Honda Rebel 250 if it uses a battery and has a place to hide the amplifier and if the handlebars are average size.
  • To prevent noises, make sure the auxiliary cord does not stick to anything that will cause noise in the amplifier.
  • When the amplifier is close to the engine, battery, or any part of the motorcycle that emits feedback, it picks up noises.
  • You can control the volume with your phone, but it is difficult to do while riding, peculiarly when the sun is upright, then the glare is hitting the screen.
  • This speaker system does not come with a remote but a volume knob. The knob is approximately 24″ long, and the speaker wire is roughly 4″.
  • If you turn the volume knob all the way down it won’t turn off the speakers but rather stays on.
  • On the highway running about 70 mph, you can still hear it. You can also use earplugs on the highway to cut out wind noise. Try it and you can easily hear the music.
  • MCBK420B will also work on a 2011 Mule since it can accommodate any 12-volt application.
  • This unit will also work with golf carts; it simply has a place to mount and the cart’s batteries are strong and sufficient with an audio source to connect to the Bluetooth.
  • The RMS max wattage for its speakers is 75 watts.
  • It needs 12 volts of power to operate. You can hook it up to the ignition wire or to the battery. If you hook it up to the battery remember to put a cut-off switch.
  • If you want to use it to 110 volts AC to 12 volts, use a 110 volts AC to 12 volts DC converter to the amplifier with a 30 Amp fuse.
  • There is no way to get rid of the loud “bong” sound when connecting to Bluetooth.
  • The speakers are 4 inches in circumference and 6 inches in the front top to bottom of the threads on the bolt at 4 1/2 inches front to back.
  • Our recommendation is to connect the power source 12 V red wire to the MCBK420B to a switched power source. We do not recommend connecting it straight to the battery because the amplifier will stay on and will drain the battery even when the bike is not in use.
  • Place a line level before the amp. Placing the preamp before the amp will only result in distortion.
  • To prevent the battery from being drained, put a toggle switch.
  • The amplifier of this speaker system is waterproof.
  • The RMS for the amp is 4 ohms.
  • The speakers are 8 ohms.
  • To link to a fuse for the type of wire connection of this unit, use an inline fuse
  • To fit this speaker system with the Kawasaki Vulcan 900 classic with 18 inches bar on them, the best option is to just install two speakers.
  • There is no woofer add-on to this unit.
  • Its mounting bolt size is 1/2 “
  • The unit includes a bolt but is poorly made.
  • You can add two more small speakers even if the amp is only rated for 1,000 watts and the speakers are 250 watts each.
  • You can put the speaker system on a grom, it goes on 7/8 to 11/4 bars or you can drill a hole and mount it.

Our take on MCBK420B

MCBK420B has a lot of good things about it, especially in terms of sound quality. If you are looking for a quality speaker system that is budget-friendly this is the best option.

This post is our honest in-depth review including the pros and cons scattered in the contents. Aside from discussing each feature which is essential, we intend not to be biased as much as possible to our take. If there are good things we emphasize and vice versa. We hope that through this review you will have enough knowledge about MCBK420B and help you decide if it is suitable for your bike. You can also check our review for BOSS MCBK470B here   and for BOSS MCBK425BA here.

If you want a further guide or reference to help you choose a suitable speaker system available on the market today for your motorcycle you can check our buying guide here. Or you can check our top picks here depending on the category you prefer.

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About Our Blog

We at Ridersbeat are bike lovers at our core. We like it big and loud. Through our thorough research and long-time experience in riding bikes, we aim to share information to help you choose the best motorcycle speakers for you.

As riders, we have an understanding of how a motorcycle works and other related stuff about it. However, our focus is on motorcycle speakers because we like to add sounds to our bikes to add a more exciting experience during every ride.

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