AUDIO ORIGAMI BLOG
It ain't heavy...
Effective tonearm mass explained.
For decades, audio enthusiasts sought out tonearms with a low effective mass to get the best performance from high-compliance cartridges. However, most modern cartridges have a low-compliance and perform best when paired with a tonearm that has a higher effective mass.
Confused? Yes, it's complicated, but this guide will explain the relationship between a tonearm's effective mass and a cartridge's compliance in simple terms.
What is Effective Tonearm Mass?
Effective tonearm mass is a measure of how much the tonearm resists movement (its inertia) at the stylus tip. It's a crucial factor in determining the resonance frequency of the cartridge and tonearm system, which affects sound quality. A well-matched tonearm and cartridge system, with appropriate effective mass and compliance, will minimise unwanted resonances and ensure optimal tracking of the record groove.
Key points about effective tonearm mass:
Not just weight: Effective mass isn't simply the total weight of the tonearm. It's a calculation that considers the weight of various components (headshell, counterweight, etc.) and their distance from the pivot point.
Influence on resonance: The effective mass, combined with the cartridge's compliance, determines the resonant frequency of the tonearm-cartridge system.
Matching for optimal performance: Matching a tonearm's effective mass with the cartridge's compliance is essential for good sound quality. Generally, a lower effective mass is better for high-compliance cartridges, and a higher effective mass is better for low-compliance cartridges.
In simpler terms: Imagine the difference between pushing a light object and a heavy one. The heavy object offers more resistance to being moved, which is analogous to effective mass. A tonearm with high effective mass is more resistant to movement than one with low effective mass.
When the tonearm and cartridge resonate at a frequency that is either too high or too low, it can cause sound to become distorted or "muddy." By properly matching the tonearm's effective mass with the cartridge's compliance, you can ensure the stylus accurately follows the record's grooves, resulting in the best possible sound quality.
What is cartridge compliance?
Cartridge compliance refers to the flexibility of a phono cartridge's stylus suspension system, indicating how easily it can move within the record groove. It's a crucial factor in determining how well a cartridge tracks records and is essential for achieving optimal audio reproduction.
Key aspects of cartridge compliance:
Stylus Suspension: Compliance is determined by the stiffness or softness of the stylus suspension, which supports the cantilever and stylus.
High vs. Low Compliance: High-compliance means a soft suspension, allowing for easy movement, while low-compliance indicates a stiff suspension, requiring more force to move.
Tracking Ability: High-compliance cartridges are better suited for low tracking forces and can accurately follow groove undulations, while low-compliance cartridges may require higher tracking forces.
In essence, compliance is a measure of how well a cartridge's stylus can follow the complex movements within a record groove, and matching it with the tonearm is crucial for accurate and enjoyable playback.
Matching Effective Mass to Cartridge Compliance
Cartridge compliance should be matched with the tonearm's effective mass for optimal performance. Compliance, along with tonearm mass, influences the resonance frequency of the cartridge/tonearm system, which should ideally fall within a specific range (e.g., 8-12 Hz) for good tracking and sound quality. Mismatches can lead to poor tracking, distortion, and even damage to the stylus or records.
Today, the majority of cartridges on the market are low compliance. A phono cartridge with a compliance of 5 to 15 µm/mN is considered to be low-compliance. These cartridges are best paired with moderate-mass tonearms.
Audio Origami tonearms have a moderate mass, making them a great match for low-compliance cartridges. We can also increase each tonearm's effective mass to suit your specific cartridge by adding weight to the end of the arm tube.
For fine-tuning, all of our tonearms come with oversized brass and stainless steel cartridge thumbscrews, which let you adjust the effective mass to within a single gram and make it very easy to align your cartridge.