A quick guide to audio resistors
Resistors are an important but often overlooked component in any speaker, they restrict all frequenies that pass through them.
- The higher the value of a resistor, the higher the resistance to the signal passing through.
- They come in a variety of forms and materials, each with their benefits and drawbacks.
- Ideally, they should be non-reactive and do as “little harm” as possible
Common varieties include:
- Ceramic (aka “Sand-caste”)
- Metal Oxide
- Wire/foil wound
Ceramic “Sand-Caste” Resistors
These are by far the cheapest, and most common resistors on the market, and the most likely variety of resistor to be found in the vast majority of commercial speaker crossovers. often using steel caps and may use steel leads as well.
They are often add a noisy or gritty texture to the sound, reducing clarity. (Think of the film-grain type noise found in older movies or photographs)
We highly recommend replacing them with pretty much any better quality resistors.
Metal-Oxide “MOX” Resistors
MOX resistors offer a step up in clarity without the gritty nature, while still remaining quite affordable.
They are our standard for budget resistors, and will offer cleaner performance, especially when swapping out cheaper ceramic resistors.
Wire-wound resistors are often among the best resistors available, with the goal of doing as little harm to the signal as possible. They are made using one or more strands of thin wire wrapped around a ceramic core or encased inside a heat-resistant epoxy, both of which are used to dissipate heat.
Some are reasonably affordable ($2-5), like the Dayton DPR resistor (right), with other premium resistors easily reaching into the $20-30 range, or more, per resistor.
Often wire or foil wound, and occasionally made using high-quality or unique materials, these resistors tend to offer the best performance, but be prepared to pay a lot more more for them.
Among the more budget-friendly options, Mills was our go-to resistor for many years and wont break the bank. ($8-12 each)
At the very high-end, you will see unique options from Path Audio and Duelund and others.
- Path Resistors enclose their resistors inside of a copper tube to absorb external RFI & EFI. (~$30 each)
- Duelund offers graphite resistors as an alternative to traditional wire-wound resistors in both a standard & resin-cast version. ($30-55 each)
Placement & Orientation:
Resistors are non-polarized, though we recommend following the same advice as capacitors when putting them into the crossovers.
“Input” is before the text, “output” is after the text, but It won’t hurt anything if a resistor is placed backwards.
All resistors have a “wattage” rating, most are listed on the resistor with a “W”
Most resistors will be rated at 10W, but it’s not uncommon to see 5W and 20W resistors as well, depending on their application in a circuit.
- If the original resistor is 5W, it’s okay to use a 10W resistor in it’s place.
- If the original resistor is 10W or 20W, it must be replaced with the same wattage rating (or higher)
- Do not replace a high wattage resistor with a lower wattage rating, as you will risk burning up the new resistor.
- Two 10W resistors in parallel will match a 20W rating, but the value of both resistors will also need to be 2x higher than the original value.
- Example: 20W 2 ohm
- Replace with: 2x 10W 4 ohm resistors in parallel.
Reading a Resistor:
Some resistors aren’t marked as clearly as others when it relates to the stated value of a resistor.
For example, a Lynk resistor may read as follows: “LYNK 10W 12R5 J TWN”
Here’s how to read it:
Resistance: 12R5 = 12.5 ohm
Tolerance: J = +/-5%
County: TWN = Taiwan