Hi-fi Speaker ratings.

[kia cat]

We have several older speakers, from previous music systems. Do they all need to be rated similarly if we want to use more than one pair around the house? Have a speaker switching box, so what [simply, please] does the Ω rating mean? and I'm guessing here, the wattage rating is how much they'll consume from the amp? Thanks

[rojash]

The omega stands for Ohms and indicates the impedance of the speaker. The wattage is not how much power they consume, but how much they can withstand before damage.

Assuming that you mean "use one pair at a time" around the house, then each pair would ideally be rated the same, but all of the pairs don't need to be.

The most important factors are:

Do not use a lower impedance than that recommended for the amplifier (the lower the impedance, the more current will be drawn - this obviously can overload the amplifier).

The power rating should be at least as high as that of the amp.

Connecting speakers in series is never a good idea

Connecting speakers in parallel will produce a lower impedance, and draw more pwer from the amp - e.g two 8 Ohm speakers in parallel will have a combined impedance of 4 Ohms. The formula is 1/R = 1/r1+1/2+1/rn

[Matheous]

I'm not expert on this at all - but, I know that the 'Ω ' symbol refers to speaker resistance in ohms. Generally, older systems with big 10" or 12" woofers (bass) were rated at 15 or 16 Ω . Newer systems 8Ω -In my experience if mixed up they still work- but don't sound as good and I'm unsure if damage can be inflicted on the amp so I would avoid mixing 8 and 15 ohms. Wattage refers to power output with various ratings eg. RMS etc.
It used to be -many, many years ago that a 30watt or 50watt amplifier would virtually blow your walls out!
Now the talk in the region of 200+ watts- in the car! (different ratings) Hope I've been of some help....Please forgive any inaccuracies.

[kia cat]

Thanks guys, that's a bit clearer now. Cheers!