Can I hook a PA speaker to my stereo?

Question

Can I hook a PA speaker to my stereo?

Answer 1

It depends. If it's a full-range speaker system, then there will never be a problem. (I've never heard of 2 ohm full range speakers, unless  they are very large.)

If the "PA speaker" you are referring to is a horn, then it can be a problem. Older PA systems used separate woofers, mid-range horns and tweeters, powered by separate power amplifiers. If you have a mid-range horn or tweeter, then you can damage it by attempting to play full-range sound through it. You can use these as long as there is a capacitor wired to it. This would remove the low frequency sound that would damage these speakers. The sound from these will not have any lows. You can always play full-range sound through a woofer or sub. While this will not damage the speaker, it will just not produce any of the high-frequency sound very well.

Speakers generally come in 2 to 16 ohm impedance's. Multiple individual drivers inside a cabinet may be wired in parallel to give you an impedance as low as 2 ohms, but it is rare. Home amplifiers are generally rated for 4 to 16 ohms. Many professional amplifiers will also drive the lower 2 ohm load, but that is generally done with multiple speaker cabinets wired in parallel.

Answer 2

Most the time, YES.

Most home speakers are rated at 8 ohms.  Home stereos are usually built to handle 8 ohm speakers, but can usually also handle a 4 ohm load.

Look at the impedance rating on the PA speaker.  It will usually be either 8 ohms or 4 ohms.  If you have the manual for your stereo, check to see what kind of speakers it can handle.  

I really wouldn't worry about it too much unless the PA speakers are rated at 2 ohms or less.  In that case, there is a danger of damaging your amplifier.