Got a question for you electronics/stereo people

[phx]

I just bought a new mini stereo system. it has output jacks for surround sound which are labeled rated 8 to 16 ohms. i've got some old stereo speakers rated 4 ohms and i plugged them into the surround sound jacks. the problem is, sometimes they work, sometimes they don't. Is there a way to make the speakers work all the time or are they jsut not compatible?

[camaro]

I'm more in car audio, but the same should appply. Let's say you got an amp that can do 100W into 4ohm load and 200W into 2ohm load. It is not stable when connected into 1ohm load cause it can't deliver the current fast enough. It will go into thermal protection(if it is a good amp) or just burn out(if it is a cheap amp). You're asking too much of that amp. It is shutting down to prevent any damage to itself.

[phx]

so with ohms as you decrease the number the load increases?

i can follow schematics and stuff like that the but individual words are what confuse me

[Graham]

phx,
As camaro says, you may be drawing too much from the amp. If they are still flakey at low volumes, I would suspect the speakers themselves. They are normally very reliable, just physical damage (fingers?) and too much power do them in. You say they are 4ohm impedance, but you don't quote their power rating. If the amp has a simple surround sound setup, and you have a mono signal (e.g. speech), you may not hear anything from them.
Post some more details, system type, power ratings (and if they are music power, rms or whatever), and details of the surround speakers.

G

[Graham]

phx,
Simply put, yes, as the resistance decreases, the power drawn increases. With amps, the output impedance comes into play too, but I dont think this is your problem.

G

[Roy]

4 ohm speakers usually work on outputs labeled for higher impedances. Why yours don't is unclear. The actual output impedance of the amp could be on the order of one or two ohms. Camaro may be correct regarding a protection circuit turning them off. However, that should not happen except at higher volumes.

You don't explain the condidions of when they do and do not work. Try this ~ run at a very low volume and see if they stay on for a long time. If they do, turn it up and watch the clock to see if they switch off after a while. Let things cool down for an hour or so and try again. If the same thing happens, look for some different speakers to try.

[phx]

ok, i plugged both of the speakers into the normal speaker jacks and they both work fine. on the back of the old speakers it says

impedence: 4 ohms
power nominal 5w
max 8w

there's nothing mentioned in the stereo manual about the wattage of the surround sound jacks.