What do watts and ohms ratings of amps and speakers mean, and how can you match them properly?
Thanks to Chris Cox, a listener who wrote in with some questions about this topic.
What’s the ratings of your favorite, most-used amp?
- Dave: 350W into 8ohms or 500W into 4ohms
- Paul: 500W into 8ohms, 800W into 4ohms
What do these numbers mean?
- Need to talk about ohm’s law
- Need to talk about wattage
Matching cabs with an amp — do you mix and match?
- I have – can be tricky especially when going used and there isn’t much information available
- Cheat sheet on daisy chaining: (Ohms x Ohms) / (Ohms + Ohms)
- The easy one to remember: two cabinets of the same impedance make half that impedance
- Running two 4ohm cabinets is almost never a good idea and will roast your amp, unless specifically designed for it
Some good rules of thumb
- Go by the manufacturers recommended ohm capabilities/limits
- Try not to blow up your amp, especially if it’s a tube amp
- Great point… tube amps respond way worse to this scenario than solid state
- Speaker wattage rating — matching to amps
- If they’re close, don’t worry about it
- Riskier to hook up a very high wattage speaker to a low wattage amp