My little blue-ray home theater 5.1 blew up and I bought a new home theater receiver thinking I could re-use the old speakers and sub-woofer.
The specs on the receiver says that it supports speakers in the “Normal 6-16 ohm impedance range”. I checked the old speakers and they say 3 ohms impedance.
Do I need to get new speakers?
3 ohms is pretty low.
You could add a 3 ohm resistor in series with each speaker, and that would protect your amp, but it would cut your maximum volume by half.
I’d probably buy new speakers.
it would also change the frequency response of the speakers since you’ve set up a voltage divider and the speaker’s impedance is not flat across the frequency spectrum. adding too much resistance in series will make the amplifier look like a current source, and the speaker’s frequency response will be influenced by its impedance curve.
you probably should. most A/V receivers are built and rated for “8 ohm” speakers.
A nominal impedance of 3 Ω is pretty low for a speaker. Most speakers are 6 Ω to 8 Ω. Speakers that have a nominal impedance ≤4 Ω tend to be “high-end” (i.e. expensive). Am curious what type of speakers you have.
I know you’ve already purchased a new amp. But if your speakers are indeed high-end/expensive, I would get an amp that can safely drive these speakers (i.e. an amp that can drive speakers with an impedance of 2 Ω). After all, the performance of the speakers are what determine the overall performance of your system, not the amp.
How sure are you that the “3” ohms you read off the tiny embossed black print on the back of the black plastic speaker by flashlight light while teetering on a ladder isn’t actually “8” ohms?
those “Home Theater in a Box” (HTiaB) systems are known to use Class-D amplifiers and have lower impedance speakers so they can have a higher power rating without needing a big and expensive power supply inside the amplifier.