Do ohms matter? Speaker Impedance

[@DeXx_The_Reaper]

I have two questions: If my speaker has 4Ω resistance and my amp has 8Ω, is it gonna damage the amp or just the speaker? If I use my amp at low volumes is it gonna burn the speaker slower?

[@guerrillastudiosmanchester]

Possibly both, there's a few variables that effect the results. If the resistance of the circuit connected to the amp is too low then more current than the speakers can handle will be drawn from the amp and the speaker coils will overheat and become melted and stuck. If the amp in question is a transistor amplifier then the current flowing from it will be fairly consistent regardless of volume. If it is a valve amp then the level and the input will both effect the current but it'll still be too much for the speakers and they will fail in short order either way. Also components in the amp may overheat. Best to adjust the wiring in the cabinet to match the amp. Speakers can be wired in series or parallel which will change the resistance of the circuit. For example connecting two 8ohm speakers in parallel results in a 4ohm load, while connecting them in series results in a 16ohm load. Some amps and cabs have separate connections or switches to achieve this but if not you can rearrange the wiring and check it with a multimeter. Put simply though if you want your speakers and amplifier to last make sure they match.

[@musicmason]

@dexx7620 As long as the resistance of your speaker(s) is equal to or higher than your amp, no damage will occur to your amp. When you run speakers at a resistance lower than the amp is stable to, you risk burning up the output transformer. This applies to tube and solid state (as both use essentially the same type of transformer). For example, if the lowest resistance your amp can handle is 8 ohms, then don't run a final resistance of your speaker(s) lower than 8 ohms. You can absolutely run a 16 ohm speaker on that same amp without risking damage to anything (because of inductance, you may notice the 16 ohm speaker to sound "brighter"). You will not damage speakers because of mismatched resistance. If you are wiring 2 or more speakers, there are three ways to do it. Series, parallel and series-parallel. In series, you simply add all of the resistances (8 ohms + 8 ohms = 16 ohms). In parallel you divide the product of all resistances by the sum of all resistances (8 ohms x 8 ohms ÷ 8 ohms + 8 ohms, or 64 ohms ÷ 16 ohms = 4 ohms). In your case having an amp stable to 8 ohms and running a speaker at 4 ohms can damage your amp, even if only playing at low volume. I would advise against this. If you can get a second speaker at 4 or 8 ohms, wire the second speaker in series with your 4 ohm speaker and you will end up with a final resistance of 8 or 12 ohms respectively (both of which are perfectly safe to run if your amp is stable at 8 ohms).

[@DeXx_The_Reaper]

Thank you guys