Resonator Buyer's Guide
A resonator is an exhaust component designed to refine the sound of your exhaust. While a muffler reduces overall volume, a resonator targets specific frequencies, smoothing out harsh tones and eliminating drone. Most exhaust systems use both a resonator and a muffler, with the resonator positioned before the muffler. This guide covers how resonators work, when to add one, whether a resonator delete makes sense, and what to look for when shopping.
How Resonators Work
Exhaust systems produce sound across a range of frequencies. Some are desirable, such as the low rumble at idle or the aggressive tones produced at wide open throttle. Others are not, such as the sustained drone that occurs while cruising at highway speeds, typically in the 1500 to 3000 RPM range.
A resonator is tuned to target these unwanted frequencies. As sound waves enter the resonator's chamber, they reflect off its internal surfaces, and opposing waves cancel each other out through a phenomenon called destructive interference. This prevents sound waves of certain frequencies from exiting the chamber and causing drone. Because the resonator is tuned to a narrow frequency range, it removes the targeted frequencies while leaving the rest of the exhaust note largely intact.
Types of Resonators
Resonators come in two main designs:
-
Straight-Through: These resonators feature a perforated center tube, often surrounded by sound-absorbing material. The most common choice for performance applications due to their minimal restriction of exhaust flow.
-
Chambered: These resonators feature internal chambers and baffles that reflect sound waves. Chambered resonators are more common in factory vehicles because they allow for better fine-tuning of exhaust noise. They are usually avoided for performance application because they create more backpressure compared to straight-through designs.
When to Add a Resonator
The most common reason to add a resonator is exhaust drone. This hum at highway speeds is one of the most frequent complaints with aftermarket exhaust systems missing a resonator. If your car has drone at highway speeds, adding a resonator is the most effective fix. A resonator can also be used to fine-tune the sound character of your exhaust.
Resonator Delete
A resonator delete removes the factory resonator and replaces it with a straight pipe. Unlike a muffler, a resonator creates minimal flow restriction, so removing it provides no meaningful power gain. A resonator delete will however make your vehicle slightly louder.
For most, a resonator delete is not recommended because it will only increase drone and make your vehicle less driveable. If you are looking to change your vehicle's sound, modifying your muffler is the most effective solution. Check out our muffler buyer's guide for more information.
Choosing the Right Resonator
Diameter
Match the resonator's inlet and outlet diameter to your existing exhaust piping. A diameter mismatch complicates installation and disrupts flow, so this is the most important specification to get right.
Material
Stainless steel is the right choice for longevity, as it resists corrosion that would otherwise rust out a mild steel or aluminized steel unit. 304 stainless offers the best corrosion resistance.
Length
Resonators come in a range of lengths. Confirm the resonator fits your intended location by measuring your existing unit or the space available, accounting for room to weld or clamp it in.
Installation
Resonators are typically welded or clamped into the midpipe section. Welding provides the most secure, leak-free joint, while clamping is more accessible for DIY installation and easier to service later.
Conclusion
A resonator is the most effective way to reduce drone and refine your exhaust note. Match the inlet and outlet diameter to your existing exhaust, choose 304 stainless for longevity, and select a straight-through design if maintaining flow is a priority. You can find all the parts you need and plan your build on RideBuilder.
Additional Resources
