Only 3 left!

Plug & Play Musway M4+ Four Channel Amplifier with 8 Channel DSP Harley Package

$1,099.98 $979.99

This True plug-and-play amplifier/DSP package includes an unprecedented level of pre-configured equipment. We have included a Techno Research radio flash module with this kit. Now you will be able to flash your bike for any configuration you want any time you want! The flash module also will enable Apple CarPlay for free without the need for any special parts. The module will be VIN locked to your bike. 

What's in the Box 

  • Radio Flash Module ('14 through '20 or '21 and later)
  • Harley Radio T Harness (plug & play for all '14 and up bikes)
  • Harley Specific Plug & Play Accessory Power Harness 
  • USB Thumb Drive with Speaker Settings, Installation Articles, Test Track, and Software.
  • 4 x 100/135 Watts RMS of Onboard Power
  • 8 Channels of DSP (4 internal & 4 RCA outputs)
  • Amplifier Mounting Pad

Possibly the Perfect Amplifier for Harley Applications

The M4+ has everything you need for a truly elegant audio system whether you are going basic or going huge. This amplifier integrates flawlessly with the factory Harley Davidson radios and has plenty of onboard power to drive most any speaker system. No clicks, pops, or distortion problems. The M4+ has a built-in system that loads your factory radio's outputs so that your radio performs as if the factory speakers were still in play. This dramatically improves sound quality and eliminates unwanted noises and distortion in the audio.

  • Retains Factory Fader, Hand Controls, and Intercom
  • Harley Charging System Friendly 
  • Properly Loads Factory Radio Outputs

    Powerful and Versatile 

    The onboard amplifier is a very capable 4 x 100 Watts at 4 ohms. We have found this amplifier to be much more capable than other 100 Watt per channel amplifiers. Not all 100 Watt amplifiers are equal! The Musway M4+ has a superior design that allows the amplifier to push the limits of performance under less than ideal conditions where other amplifiers would fall on their face. When it comes to real-world performance, this amplifier just can not be compared to other amplifiers that claim the same numbers. 

    4 Rca Outputs With Dedicated Dsp Lets You Add More Amplifiers

    The M4+ is a lot more than a 4 channel amplifier. It is the perfect centerpiece to build a large-scale system around. With 4 channels of 6 volt RCA output, you can go wild with multi amplifier systems. 

    • Intelligent high level input with EPS (Error Protection System)
    • Soft clipping in 2 Ω operation
    • Signal-to-noise ratio ≥90dB, frequency response 15 Hz - 22 kHz (-3dB)
    • Total harmonic distortion ≤0.1% (1 kHz, 4Ω, 90% power)
    • Separately adjustable input sensitivity (channels 1-6, AUX), clipping LED
    • Dual 32bit, 330 MIPS DSP technology controllable via PC software or APP
    • External Bluetooth® USB dongle ( BTS & BTA ) for audio streaming & app control (optional)

    Built-In Dual 32 Bit DSP

    We are in love with the Musway sound processor software. It is beautifully laid out and easy to use. Musway did a fantastic job with including all of the right bells and whistles but still keeping the interface and learning curve simple. The DSP can be accessed by connecting the included USB cable to your PC or by using the optional Bluetooth adapter (available late September) to connect to your smartphone (Android or Apple).


    4 x 100/135 watts RMS @ 4/2 Ω or

    2 x 270 watts RMS @ 4 Ω bridged

    6 x high level input

    6 x RCA low level input *

    2 x AUX / RCA inputs

    1 x input optical / stereo

    4 x amplified loudspeaker output

    4 x preamplifier output / RCA (configurable via DSP)

    Dimensions: 150 x 44 x 220 mm

    Musway M4+ Manual Download Download User Manual


    Fits all '14 and up Street Glide, Electra Glide, and Ultra models. Compatible with CVO and screamin' Eagle models. Amplifier bypass plugs are required for factory amplified systems. 

    Fits all '15 and up Road Glides with a simple modification to the upper headlight and headlight bracket (needs to be widened between brackets by 1/4").

    Not compatible with 2013 and earlier bikes. This package is specifically designed for the 2014 and newer bikes. 

    Flash Module Notes 

    The radio flash module comes in two flavors. Either 2014 through 2020, or 2021 and newer. The software and module are the same but the cable that comes with the module to connect to your bike is for one year range or the other. If you decide that you want to use your module to flash a second bike, you can call TechnoResearch and purchase a second license for $50 and if you need the cable for the other year range, you can purchase that as well. Flash as many bikes as you like by simply purchasing a license for each bike as you go. 

    Shipping This Item Ships to The United States 

    Items built to order have a build time of up to two weeks before shipping. Items that are not built to order (e.g. amplifiers, speakers, .etc) typically ship in 2 - 3 business days. Many of our speaker kits feature machined special parts and customized wire harnesses that are built to order. We process and build orders in the order that we receive them. This allows our experts to go over every order and check that your particular order is correct for your particular bike. This means sometimes you have to wait a little longer to get your order but it's always worth it! 

    Once You Order Does Ship

    You will receive an automated email with tracking information as soon as our shipping department creates a shipping label for your package.  


    There are many more speakers, amplifiers, and kits to choose from than what you see here.

    [powr-form-builder id=1f43a15c_1475460501]

    Please allow 10 business days for your order to arrive if it is an item that is built to order. Items that are not built to order (e.g. amplifiers, speakers, .etc) typically ship the next business day.We process and build orders in the order that we receive them. This allows our experts to go over every order and check that your particular order is correct for your particular bike. This means sometimes you have to wait a little longer to get your order but it's always worth it! 

    Returns are easy, simply contact us for a returns number and send your item to our returns centre for fast processing. We'll get you a replacement or refund in a snap! You can find our refund policy here.

    Here are 5 great reasons to buy from us:



    Easy Returns

    Returns are easy, simply contact us for a return Authorization number and send your item to our returns center for fast processing. We'll get you a replacement or refund in a snap! You can find our refund policy here.



    Your part is guaranteed to fit. We test fit every part we sell on actual bikes in order to verify fitment on each model, generation, and in each possible location. You can be sure that if we have stated that a part fits your bike, that it will, or your money back. You will find model, year, and location fitment details on most product pages.

    Secure Ordering


    Ordering from American Hard Bag is 100% safe and secure so you can rest easy. Your personal details are never shared, sold or rented to anyone either.



    We Thoroughly Test Every Part We Sell on a Real Bike. There are a lot of parts out there that we refuse to sell. If it’s not up to our high standards, it never makes it to this website. We have parts that fit various budgets and levels of insanity, but all parts we carry are exceptional performers.



    Because We Are Fully Authorized Retailers for All Brands We Sell, Manufacturers Warranties Are 100% Valid. There are only a select few authorized online retailers for the brands that we sell. Most all online retailers (even the really big ones) are not authorized at all! And the manufacturer's warranty is void before you even get your items.

    Easy as 1 - 2 - 3!

    We have 3 great financing options for you. Snap Financing, Installment Payments, and Split Pay. Learn more below.

    No Credit Financing

    12-18 months

    4 Payments

    Did you know - you can check your eligibility with all 3 options without negatively impacting your credit?


    Questions? Call us at 888-311-0016

    Financing with Snap!

    Get Approved

    Could get approved for a lease purchase agreement of up to $3,000

    *minimum finance $450

    Instant Access

    Get instant ACCESS to your financing upon approval


    Get shopping! Snap lease-to-own financing lets you get what you need, when you need it.

    • 100 days same as cash - $0 in fees if paid off within 100 days
    • No hidden fees
    • No interest
    • No application fee
    • No credit needed and no hard credit inquiry - Bad credit/No credit OK!
    • High credit limits
    • 80% approval rate - All you need is a job making $1200 or more, be 18+ years old, and have an active checking account.
    • Snap doesn't offer traditional loans. Instead, we offer a consumer lease that allows you to finance the merchandise over 12-18 months of convenient payments. We also offer a 100-Day payment option, the best terms around. Need new tires for your car? Or new furniture for your growing family? Don't let bad credit stand in your way. Snap is your partner for fast and easy lease-purchase financing.
    • No Credit Needed refers to Snap’s lease-purchase financing that considers more than just credit reports to determine approvals or denials. In fact, applications for Snap’s lease-purchase financing aren’t even reported to TransUnion, Equifax, or Experian. Our proprietary decisioning process allows us to look beyond bad credit, no credit, and bankruptcy to approve more applicants.

    See what you qualify for without impacting your credit.


    Questions? Call us at 888-311-0016

    Financing with Bread

    Shop Online
    Select Pay Over Time with Bread at checkout

    Choose your plan - Easy Installments or Split Pay with your card of choice

    Get your item now and pay over time!
    It's that easy!

    1. Simple transparent terms. No prepayment penalties. No deferred interest.
    2. Applying is easy. All we need is a few pieces of information and you get a decision in seconds.
    3. Sign up for automatic payments and have the flexibility to change your due date if needed.
    4. Always know how much you’ll pay. Easy equal installments. No surprises.
    1. U.S. residents over the age of 18 (or over 19 for Alabama or Nebraska residents) are eligible, provided your identity can be verified.

    2. Checking your rate does not affect your credit score as only a soft pull is completed to check your eligibility. If you choose to finance your purchase with Bread after your pre-approval, we will not perform a hard inquiry with any of the three major credit reporting agencies. Once you have taken out a loan, Bread may report repayment information about your account to the consumer reporting agencies, which may impact your credit score. We may also obtain your credit profile from smaller credit reporting agencies.

    3. You will not be able to adjust your loan terms after you have checked out.

    4. You can apply via the website of any participating online store. When you’re ready to buy, click on Bread’s® financing button to get your rate in seconds. If you pre-qualify, you will be presented with the financing terms offered and sample payment amounts. Add the item to the retailer’s shopping cart and choose Bread® or “Pay Over Time” as your preferred method of payment when you check out.

    Got Questions? 

    Call American Hard Bag and we can help to see if Snap or Bread Finance is right for you!
    1(888) 311-0016