Velocity OverDrive 4 Channel Ultimate Harley Road Glide Amplifier and Speaker Bundle with RTA SKU: C-OverDrive-4RG



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Full System - Amplified 4 Channel with DSP and 4 component speakers - Plug & Play with all wire harnesses

  • Best Speakers
  • Best amplifier
  • Best DSP
  • Factory Fit & Finish
  • Plug & Play
  • Computerized Tuning Kit Rental Included

We Tune Your Bike for You

All Live-Tune enabled systems can be remotely tuned via the internet by one of our professionals. We can tune your bike from anywhere in the world. Why settle for anything less than the best? Our techs set these systems up every day and have tuned thousands of bike audio systems over the years.

Read More About The Live Tune Option Here

Product Description

This is the most well thought out and capable Harley Road Glide audio system ever produced. The OverDrive-4RG is a top of the line 4 channel complete plug and play Harley Road Glide stereo system upgrade. The Velocity OverDrive plug and play kits are the only computerized self tuning Harley audio systems in the world. A fully calibrated acoustic analyzer with laboratory grade microphone is included with the kit as a rental for you to use when tuning. This guarantees a perfect result every time. This is the kit to get for a no compromise crushing system. These kits stand way out from the crowd for many reasons.

  • Top level competition grade pro audio speakers sound far better than any other pro audio type speakers
  • Insanely loud
  • Best sounding amplifier ever put on a bike
  • Very best DSP software
  • Built-in radio analyzer and radio equalizer
  • Built-in speaker analyzer and 10 speaker equalizers
  • Augmented Bass Enhancer
  • Stage Enhancer
  • Fully Plug & Play to both the bike as well as the speakers
  • All electronics are located in the fairing and speakers fit factory locations
  • Bags are left open and free for luggage or even more insane upgrades
  • Very expandable and capable

Lid Speaker Mounting Options

This kit is available with four different mounting options for the lid speakers. Please choose before adding to cart.

  1. Standard 6x9 for aftermarket 6x9 speaker lids
  2. Loaded Velocity Premium 6x9 lids (paint ready)
  3. 5x7 to 6x9 for factory Harley speaker lids 
  4. 6x9 cut-in kit for standard factory non-speaker lids

Computerized Tuning Kit Rental Included!

Simply plug the microphone into the USB port of your PC running the included PC-Tool software while the MFour amplifier is also connected to the PC and the analyzer will be available on-screen. You can then see exactly what your bike's audio system is doing. Making the perfect equalizer corrections at that point is easy and very accurate.

Live Remote Tuning Session Included

We want you up and running fast. This rental includes 30 minutes of one on one tuning time with one of our very experienced techs. We remotely log into your PC using TeamViewer and we can then see the software and analyzer on screen and remotely control your entire bike system and make adjustments for you or show you how to make any adjustment yourself. TeamViewer is a safe and secure way to remotely connect to your PC and once our session is over we will no longer have access to your computer.

Rental Details

  • Rental term is 5 business days (Monday through Friday)
  • Rental amount $125 FREE
  • Fully Refundable $200 deposit
  • Free return shipping included
  • $50 store credit if returned early (see contract for details)
  • Live remote tuning session with our tech team included
  • $50 per day after the 5 day term
  • Tuning Kit Not For Sale


This kit is plug and play with all factory wire harnesses, speaker and amplifier fitment requires light modifications to the bike which are all well documented in the links below. A radio flash is not required for a perfect frequency response but is always recommended to ensure that you get the best features your radio has to offer such as 4 speaker fader and Apple CarPlay. 


  • Helix components 2 years
  • American Hard Bag components 5 years
  • Velocity components 2 years with an additional year (3 total) if installed by an authorized Velocity dealer


Water Resistant

Extreme Level Performance

Road Glide

What's Included

  • (1) Helix MFour DSP Amplifier/Sound Processor

  • Helix Professional Acoustic Tuning Kit (Rental)

  • (1) OFC 8 Gauge Amplifier Power Harness

  • (2) Amplifier Mounting Pads

  • (1) Plug & Play Harley Radio and Speaker Interface Harness

  • (1 pair) Velocity OverDrive Steel Speaker Grills with Horn Mounting Kit

  • (2 pair) Velocity OverDrive RZ75H Compression Horns

  • (1 pair) Velocity OverDrive Plug & Play Crossovers for RZ75H

  • (1 pair) Diamond Audio MSPRO65 6.5” Pro Audio Mid-Woofers

  • (1) Plug & Play Rear Speaker Harness for Lid Speakers

  • (1 pair) Velocity R690 6x9 Woofers

  • (1 pair) 6x9 Speaker Service Disconnect

  • (1 pair) Velocity OverDrive 6x9 Speaker Lid Adapters (Cut-in for non speaker lids, 5x7 to 6x9 for 5x7 lids, or OverDrive horn mount for aftermarket 6x9 lids.)

M Four DSP Amplifier

Product Overview

The Brand New Helix M FOUR DSP is a powerful 4-channel amplifier with a fully-integrated digital sound processor manufactured in Germany that brings a continuous output of 135 Watts per channel, both at 4 Ohms and 2 Ohms. This game-changing control center runs cool, is compact, extremely practical, and up for any challenge in your Harley system.

Perfect for integration with factory Harley radios, the M Four amplifier/DSP has a number of features that make it totally different and better than anything else ever made.

Technical Specifications

  • Power RMS: @ 4 Ohms: 4 x 135 W; @ 2 Ohms: 4 x 135 W; Bridged @ 4 Ohms: 2 x 270 W
  • Inputs: 6x RCA, 6x High-level speaker, 1x Optical SPDIF, 1x Remote In
  • Input impedance high-level: 9-33 Ohms
  • Outputs: 4x Speaker, 6x RCA, 2x Remote Out
  • Output voltage RCA: 6 Volts RMS
  • Frequency response: 20 Hz-22,000 Hz
  • DSP resolution: 64 Bit
  • DSP power: 295 MHz
  • Dimensions (H x W x D): 2.0” x 9.06” x 6.06”

Velocity RZ75H Horn Compression Tweeters

Product Overview

The all new magic compression horms from Velocity Speaker Design.

Technical Specifications

  • Sensitivity: 105 db 1W/1M
  • Frequency Response: 2.5 Khz - 20 Khz
  • Nominal Impedance: 4 Ohm
  • RMS/Max (pair) 100W/200W
  • FS: 1710 Hz


Product Overview

Perfect for use with compression horn tweeters. We engineered the Velocity R690 6x9" woofer to work better in a saddlebag than any other 6x9. They play louder, deeper, and have a much higher output for every watt you feed them. Traditional 6x9 car audio type speakers do not work well in Harley saddlebags for a number of reasons. So we went a very different route and made speakers that work spectacularly in bags. We purposely engineered a pronounced bass response on the bottom end. This required a total redesign of the voice coil. We made it longer and we made the woofers suspension with more throw as well. We did this while keeping the moving mass low and the efficiency high (which wasn't easy to do). The end result was a speaker that has the high SPL output and bass response that we need on a bike in real-world situations. 

Technical Specifications

  • Max power 300 Watts Pair
  • Nominal power 150 Watts Pair
  • Impedance 2 Ω
  • Freq. Response 60 Hz - 20 KHz
  • Sensitivity (2,83V/1m) 93 dB
  • Magnet Ferrite Magnet size Ø x h 85 x 17 mm 3,35“x 0,67“
  • Total driver displacement 0,3 l 0,011 cf
  • Weight of one component 2,315 lb
  • Voice coil Ø 25 mm 0,984“
  • Voice coil height 11 mm 0,433“


Product Overview

Loud and Clear! The MSPRO65 woofers have a very distinct low frequency (mid-bass) response that is much more aggressive than other speakers of this variety. Designed specifically for Harley applications, these speakers are designed to perform both in open fairings and lids as well as fairing speaker pods.

Technical Specifications

  • Power Rating: 200 W RMS/ 400 MAX
  • Sensitivity: 97dB 1W/1M
  • Frequency Response: 110Hz-10k Hz+/-3dB
  • Nominal Impedance: 4 Ohms
  • Mounting Depth: 2.375"
  • Cut-out Diameter: 5.625"
  • Overall Diameter: 6.5"
  • Overall Height: 2.5625"