The Blackforge
Obsidian Kit
Featuring Hertz Drivers & Infinity Amplification
Performance Sweet Spot
The Blackforge Obsidian Kit steps up to higher wattage and dedicated motorcycle-specific engineering. This is the system for the rider who wants to hear their music clearly at 80+ MPH without overtaxing their bike's charging system.
80+ MPH Clarity
Highway-rated punch that cuts through wind noise. Hear your music clearly at speed.
75W RMS Per Channel
50% more power than the Iron Series. Significantly more volume and headroom at cruising speed.
92dB Sensitivity
Hertz Cento delivers massive efficiency for a 4" speaker. Requires half the power to hit the same volume as standard speakers.
Efficient Class D
Infinity's high-efficiency power supply draws less from your bike's charging system while delivering more watts.
Blackforge Acoustic Lining
Proprietary internal acoustic dampening material absorbs cabinet resonance and road vibration, giving you tighter bass and clearer mids at highway speeds.
Technical Details
What Drives the Obsidian
Amplifier
The Brain of the System
- Model
- Infinity Kappa Perfect KP5004
- Power
- 75W RMS x 4 @ 4Ω
- Topology
- Ultra-Compact Class D
- Efficiency
- High-efficiency PSU
- Form Factor
- Motorcycle-specific chassis
- Water Rating
- IP67
Speakers
What You Actually Hear
- Model
- Hertz Cento CX 100
- Size
- 4" Coaxial
- Power
- 40W Continuous / 120W Peak
- Sensitivity
- 92dB @ 1W / 1m
- Design
- Marine-ready UV Cone
- Impedance
- 4Ω
Why These Parts
Sensitivity That
Punches Above Its Size.
The Blackforge Obsidian Kit is built around the Infinity Kappa Perfect KP5004 — engineered with an ultra-compact Class D chassis designed specifically for the tight spaces inside motorcycle fairings and bags. But more importantly, its high-efficiency power supply delivers 75W per channel without overtaxing smaller motorcycle charging systems.
The Hertz Cento CX 100 brings something rare to a 4" speaker: 92dB sensitivity. That means it requires roughly half the power of a standard speaker to reach the same volume. Paired with the 75W Infinity Kappa amp, you get massive headroom. The amp never pushes into clipping territory, which means the audio stays crystal-clear even at highway speeds with wind noise competing for your ears.
Universal Engineering
Perfectly Paired
92dB Sensitivity
The Hertz Cento CX 100 delivers 92dB at 1W. On a motorcycle, every 3dB increase is like doubling your power. These speakers are designed to be loud without needing a nuclear reactor to drive them.
Low Noise Floor
The Infinity Kappa Perfect KP5004 maintains a 75dB+ SNR ref 1W. When the bike is idling, you won't hear that annoying hiss common in cheap motorcycle amps.
4-Channel Future-Proof
Because the Infinity is a 4-channel amp, adding Secondary Strike kits — bag lid speakers or lower fairing pods — is a simple plug-in upgrade. You're buying the brain for a 4-speaker system today, even if you start with two.
Blackforge Obsidian Strike
Add a second pair of Hertz Cento CX 100 speakers in your bag lids or lower fairing pods. Your Infinity amp already has two unused channels with 75W each waiting. Pre-wired, waterproof connectors — just plug in and double your sound.
The Blackforge 5-Year Promise
Integrity Guarantee. Performance Guarantee. And our "Rider's Policy" — if a part is discontinued, we upgrade you. Every Iron, Obsidian, and Damascus system ships with our industry-leading warranty. No fine print.
Read Full WarrantyReady for Highway Sound?
The Blackforge Obsidian Kit. MSRP: $1,499.00. The sweet spot between power, clarity, and value. No fairing required.
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