Metal vs Plastic Cartridge Bodies: Which Is Better?

What the cartridge body does

A phono cartridge generates an electrical signal from the motion of a stylus in the record groove. The body of the cartridge holds the generator components (magnets and coils) and anchors them to the tonearm. The body must be rigid enough to keep these parts from vibrating independently of the stylus, because any unwanted vibration becomes a coloration in the sound. The material of the body influences that rigidity, as well as the total weight the tonearm has to carry.

Cartridge bodies are typically made from metal (aluminum, magnesium, or sometimes brass) or from engineered plastics. Each has trade-offs in stiffness, weight, and cost. Understanding these trade-offs helps you match a cartridge to your tonearm and your listening priorities.

Resonance and vibration control

Metal bodies are inherently stiffer than most plastics. A stiffer structure has a higher resonant frequency, which is less likely to be excited by the low-frequency energy of record grooves and tonearm motion. This means metal cartridges tend to have a cleaner, more neutral presentation, especially in the bass and midrange. Plastic bodies are more flexible and can resonate at audible frequencies, adding a subtle coloration. However, modern plastic compounds are often filled with damping materials, and some plastic-bodied cartridges sound excellent. The key is not the material alone, but how well the body controls internal resonances.

The Library of Congress emphasizes careful playback to preserve records, which involves proper tracking force and alignment. A well-damped cartridge body reduces the risk of mistracking, but the stylus shape and cantilever materials play a larger role. If you are upgrading your cartridge, consider the whole assembly, not just the body material.

• Metal: high stiffness, high resonant frequency, low self-noise.
• Plastic: lower stiffness, potential resonant peaks, but can be engineered with damping.
• Some expensive plastic bodies use filled or layered composites to mimic metal's stiffness.

Weight and tonearm matching

The weight of the cartridge body directly affects the effective mass of the tonearm system. A heavier cartridge (typically metal) adds mass to the tonearm, which lowers the resonance frequency of the arm/cartridge combination. A lighter cartridge (typically plastic) makes the system behave as a lower-mass arm. Which is correct depends on the compliance of the cartridge's suspension. Low-compliance cartridges (usually moving coils) pair well with higher-mass tonearms, while high-compliance cartridges (many moving magnets) prefer lower mass. Mismatching can cause a resonant peak in the audible range, muddying the bass.

If you have a tonearm with adjustable counterweight and a comfortable headshell, you can use either body type, but a heavy metal body can sometimes prove too much for a low-mass arm. Conversely, a light plastic body may not provide enough mass for a high-compliance cartridge on a heavy arm. Read our guide on cartridge compliance and tonearm effective mass to find the right match.

Electrical shielding

The tiny voltage generated by a phono cartridge is easily contaminated by electromagnetic interference from motors, transformers, and wiring. A metal cartridge body can act as a shield, blocking stray EMI from reaching the coils. This matters more for moving coil cartridges, which produce much lower output than moving magnets and are more susceptible to hum and noise. Plastic bodies provide no shielding, so MC cartridges with plastic bodies usually include an internal mu-metal shield or rely on an external shield in the tonearm wiring.

If your turntable includes Bluetooth or a built-in preamp, the circuitry is a potential source of interference. A metal-bodied cartridge can help maintain a quiet signal, but proper grounding and cable routing are equally important. For more on connectivity, see our article on turntable connectivity options.

Moving magnet vs moving coil

Moving magnet (MM) cartridges generate a higher output voltage and are less sensitive to EMI, which is why many are housed in plastic bodies without concern. Moving coil (MC) cartridges output much lower voltage and often use metal bodies or metal shields to protect the delicate coils. However, this is a design choice, not a rule. Some high-end MM cartridges use machined metal bodies for resonance damping, and some budget MC cartridges use plastic with internal shielding.

When choosing between MM and MC, the body material is secondary to the generator type and stylus. MC cartridges generally offer finer detail but require a step-up transformer or a phono stage with high gain. Plastic-bodied MCs can still sound excellent, but metal bodies add a layer of physical and electrical isolation. See our detailed comparison of moving magnet vs moving coil for more.

Which cartridge body should you choose?

For most listeners, a plastic-bodied cartridge is perfectly adequate, especially with a quality stylus and careful alignment. Plastic bodies are lighter, which makes them ideal for lower-mass tonearms, and they are often more affordable. If you are using a moving coil cartridge, or if you have a tonearm on the heavier side, a metal body can provide extra rigidity and shielding. The decision also depends on your budget and the overall quality of your turntable.

Ultimately, the cartridge body material contributes to the final sound, but it is one factor among many. Stylus shape, cantilever, compliance, and phono stage quality have a larger influence. If you are upgrading from a stock cartridge, focus on those aspects first, then consider body material. Our buying guides can help you find a complete turntable with a cartridge that suits your needs.

What to pick for your use

Questions

Does cartridge body material affect sound?

Yes, but indirectly. Metal bodies damp resonances better and provide electrical shielding, which can produce a cleaner sound, especially in the bass. Plastic bodies may introduce subtle colorations if they resonate. However, the stylus shape, cantilever, and alignment have a greater impact on overall sound quality.

Are metal cartridges always better than plastic?

Not necessarily. A metal body adds mass, which can be a drawback on low-mass tonearms. Plastic bodies can be engineered to be very rigid and damping. The best choice depends on your tonearm's effective mass and the cartridge's compliance, not just the material.

Can I use a plastic cartridge on a high-end turntable?

Yes, many high-end turntables come with plastic-bodied cartridges, especially moving magnet models. Plastic bodies are light and can offer excellent performance when paired with a well-matched tonearm. The key is proper setup and cartridge alignment.

How can I tell if my cartridge has a metal or plastic body?

Visual inspection often reveals the material: metal bodies have a cold, dense feel and a metallic sheen, while plastic bodies are lighter and often have a matte finish. You can also check the manufacturer's specifications online. If you are unsure, gently tap the body (with the stylus protected) to hear its resonance; metal will ring higher and shorter.

Is metal necessary for moving coil cartridges?

It is common but not essential. Many MC cartridges use metal bodies for shielding and rigidity, but some models use plastic with internal shielding. The low output of MC cartridges makes them more vulnerable to interference, so some form of shielding is beneficial, whether from the body or the tonearm wiring.