Everything you need to know about upgrading your Skyline OS audio system

If you own a 2023.5 or newer Harley-Davidson with the Skyline OS infotainment system, you've probably discovered something frustrating: upgrading your audio isn't as simple as it used to be.

Gone are the days of tapping into speaker wires and adding an amplifier. Harley's new A2B (Automotive Audio Bus) digital technology changed everything.

But here's the good news: Once you understand A2B, you'll have MORE options than ever before - and better sound quality to boot.

In this guide, we'll break down exactly what A2B is, why Harley made the switch, and the three proven paths to upgrading your audio system.

What is A2B Technology?

A2B stands for Automotive Audio Bus - a digital audio protocol that sends pristine digital signals from your Skyline OS radio directly to amplifiers.

The Old Way vs. The New Way

Pre-2023.5 Harleys:
Radio → Analog audio signal → Speaker wires → Amplifier → Speakers

2023.5+ Harleys with Skyline OS:
Radio → Digital A2B signal → A2B-compatible device → Amplifier → Speakers

Why the Change?

Harley didn't make this switch to frustrate riders. A2B brings real benefits:

• Better sound quality - Digital signals don't degrade like analog
• More data bandwidth - Can send multiple channels plus control data simultaneously
• Future-proofing - Enables software updates and advanced features
• Cleaner installation - Fewer wires, less electrical interference

The catch? You can't just wire in a traditional amplifier anymore. You need an A2B-compatible solution.

Your Three Upgrade Paths

When it comes to upgrading audio on your 2023.5+ Harley, you have three distinct options. Let's break down each one:

PATH #1: Built-In A2B Amplifiers

What it is: Premium amplifiers with integrated A2B digital input that connect directly to your Skyline OS system.

Example: Rockford Fosgate TMA-1000X4i

• 1,000 watts dynamic power
• Built-in DSP (Digital Signal Processor)
• RF Connect app control via Bluetooth
• IPX4 weather resistance
• Direct A2B integration - no additional interface needed

Pros:

• ✅ Cleanest, most integrated solution
• ✅ No additional interface boxes needed
• ✅ Premium features (app control, DSP)
• ✅ Professional-grade build quality
• ✅ Easiest installation

Cons:

• ❌ Higher price point ($799+)
• ❌ Locked into one amplifier brand
• ❌ Limited model selection currently available

Best for: Riders who want a premium, turnkey solution and don't mind paying for top-tier integration.

Estimated Cost: $950-1,200 (amp + installation kit)

PATH #2: Universal A2B Interface (The Game Changer)

What it is: A standalone module that converts A2B digital signals to standard RCA outputs, allowing you to use ANY aftermarket amplifier.

Example: Volunter Audio Universal HD-A2B Interface

• 5-channel RCA outputs (Front, Rear, Subwoofer)
• 4V RMS output voltage
• 32-bit DSP resolution
• 112 dB signal-to-noise ratio
• Works with ALL amplifier brands

How It Works:

The interface sits between your Skyline OS and your choice of aftermarket amplifier, giving you unlimited amplifier options.

Skyline OS → A2B Interface → RCA Outputs → Your Amplifier(s) → Speakers

Pros:

• ✅ Use ANY amplifier brand (Cicada, SounDigital, Diamond, Hertz, etc.)
• ✅ More cost-effective than built-in A2B amps
• ✅ Flexibility to upgrade amplifiers later
• ✅ Can pair with external DSP for ultimate control
• ✅ Maintains full Skyline OS functionality
• ✅ Reuse amplifiers from previous bikes

Cons:

• ❌ Requires additional installation step
• ❌ One more component in the system
• ❌ Need to select compatible amplifier separately

Best for: Custom builders, riders who want flexibility, anyone with a preferred amplifier brand, budget-conscious upgraders who want maximum power.

Estimated Cost: $1,650-2,500 (interface + amplifier + wiring)

PATH #3: Complete Plug-and-Play Kits

What it is: Pre-configured packages with speakers, amplifier, A2B interface (if needed), and model-specific hardware - everything matched and ready to install.

Examples:

• Harley Davidson Plug and Play Fairing Kit (Road Glide) 23.5-current
• Harley Davidson Plug and Play Fairing Kit (Street Glide) 23.5-current
• Various amplifier options (FLX1000, SD800, etc.)

Pros:

• ✅ Zero guesswork - everything is matched
• ✅ Model-specific mounting hardware included
• ✅ Pre-wired harnesses
• ✅ Guaranteed compatibility
• ✅ Fastest installation
• ✅ Complete system upgrade in one purchase

Cons:

• ❌ Highest total cost
• ❌ Less flexibility for customization
• ❌ May include components you don't need

Best for: Riders who want a complete solution without piecing together components, those who value convenience over customization.

Estimated Cost: $2,500-3,500 (complete system)

Side-by-Side Comparison

Factor	Built-In A2B Amp	Universal Interface	Plug-and-Play Kit
Price Range	$950-1,200	$1,650-2,500	$2,500-3,500
Amplifier Choice	Limited (1 brand)	Unlimited	Pre-selected
Installation Difficulty	Easy	Moderate	Easiest
Customization	Low	High	Medium
Component Count	1 device	2+ devices	Complete system
Future Flexibility	Low	High	Medium
Includes Speakers	No	No	Yes

Real-World Scenarios: What We Recommend

Scenario 1: "I want the best sound possible and I'm willing to pay for it"

→ Universal A2B Interface + Cicada FLX2000.4 + Cicada DSP88V2

Why: Maximum power (542W x 4 channels), full DSP control via phone app, ultimate flexibility for future upgrades.

Total Investment: ~$2,200

Scenario 2: "I want premium quality without the complexity"

→ Rockford Fosgate TMA-1000X4i (Built-in A2B)

Why: All-in-one solution, app control, proven performance, easiest installation.

Total Investment: ~$950

Scenario 3: "I want a complete upgrade but don't want to research components"

→ Plug-and-Play Kit for your specific model

Why: Everything matched and ready, guaranteed fitment, includes speakers and all hardware.

Total Investment: ~$2,500-3,500

Scenario 4: "I already own a great amplifier from my previous bike"

→ Universal A2B Interface

Why: Reuse your existing amp, save money, maintain flexibility.

Total Investment: ~$450-600

Scenario 5: "I want to future-proof my build"

→ Universal A2B Interface

Why: Swap amplifiers anytime without replacing the interface, upgrade speakers independently, add DSP later.

Total Investment: Starting at ~$1,650

Common Questions Answered

Q: Can I just bypass the A2B system entirely?

A: Not recommended. You'd lose all radio integration and control. The A2B interface maintains everything while giving you upgrade options.

Q: Will aftermarket audio void my Harley warranty?

A: Audio upgrades typically don't affect your motorcycle warranty, but always check with your dealer. Professional installation is recommended.

Q: Do I need to flash my radio?

A: With A2B interfaces, no radio flashing is required. This is a major advantage over older methods used on 2014-2023 models.

Q: Can I add a subwoofer?

A: Absolutely! The Universal A2B Interface has dedicated subwoofer RCA outputs. Pair with saddlebag subwoofers or trunk-mounted subs for serious bass.

Q: What about speaker upgrades?

A: A2B only affects the signal path from the radio to the amplifier. You can upgrade speakers independently - just make sure your amplifier has enough power for them.

Q: Will I lose steering wheel controls?

A: No. All A2B solutions maintain full Skyline OS integration including steering wheel controls, volume, source selection, fade/balance - everything works exactly as factory.

Q: Can I use multiple amplifiers?

A: Yes! The Universal A2B Interface has 5-channel RCA outputs. Many riders use one amp for front speakers, another for rear/sub. This gives you maximum flexibility and power distribution.

Installation Tips from the Pros

1. Plan Your Power Distribution

• Use proper gauge wire (4 AWG minimum for high-power amps)
• Fuse at the battery (120A+ for big systems)
• Keep ground wires short and connect to clean, bare metal
• Route power wires away from signal cables

2. Consider Adding a DSP

The Cicada DSP88V2 pairs perfectly with the Universal A2B Interface and gives you:

• 8-channel processing
• Time alignment (critical for motorcycle audio)
• 31-band EQ per channel
• Phone/tablet app control
• Crossover control

Cost: $379.99

3. Don't Skimp on Speakers

Your amplifier is only as good as your speakers. Consider:

• Component speakers for front fairing (separate tweeters and woofers)
• Marine-grade construction for weather resistance
• Proper impedance matching to your amplifier specs
• Power handling that matches your amp output

4. Test Before Final Assembly

• Connect everything and test BEFORE buttoning up fairings
• Check for noise, distortion, balance issues
• Adjust gains properly (use a multimeter or test tones)
• Verify all speakers are working and in-phase

The Bottom Line

A2B technology isn't a limitation - it's an opportunity for better sound quality and more upgrade options than ever before.

Our Recommendation for Most Riders:

Start with the Volunter Audio Universal HD-A2B Interface.

Why?

• Maximum flexibility - works with any amplifier
• Better value than built-in A2B amps
• Same sound quality as premium solutions
• Future-proof your investment
• Reuse quality amps you already own

Pair it with your choice of amplifier (we love the Cicada FLX series for baggers), add a DSP if you want ultimate control, and you'll have a system that rivals $5,000+ factory upgrades - for half the cost.

Ready to Upgrade Your Audio?

We're here to help. Call us at (864) 334-6131 and we'll walk you through your specific build.

Our team will:

• Answer your questions about A2B compatibility
• Help you select the right components for your bike
• Provide installation guidance
• Ensure you get it right the first time

We're riders too - we get it.

Questions? Comments? Share your A2B upgrade experience in the comments below!