My Dad just found these "car speakers" in the loft and asked if I wanted them - I've been wanting some new speakers for ages but not really got round to buying them.
Speakers are these:
Apparently they are 300w and 8 ohm.
Can they be used in my car? It's a totally standard Wira with a Kenwood KDC-3041 headunit.
Hes jelous cause he rides a bike Awwww it's ok Jamie, just make your own like i used to, no-one can hear you in your helmet, atleast thats what i thought :P
The problem you will have is that 99% of car stereos are designed to run speakers that have an impedance of 4 ohms, which means that you will be feeding the speakers with only 4 ohms, which is half of the current that the 8 ohm speakers you posted are designed to take.
They will still work, but you will not be able to get as much volume from the speakers as they will be being fed with only half of the current that they are meant for.
It won't damage the speakers or stereo, it just won't be as loud as it would be with proper car speakers.
Just as a reference i bought these a few months back and they can take pretty much anything my sony head unit can throw at them.
As ole Dannyboy said, indeed they would be 8 ohm speakers. You wouldn't be feeding them with any ohms at all compared to what he said. An amp does not "put out" anything. The drivers (speakers) pull from the amp. Wattage is pulled from the amp in terms of current and voltage dependent of resistance. Car audio equipment is designed to be most efficient with a 4 ohm load, or resistance. That's not to say you can't connect an 8 ohm load or down to a 2 ohm load or lower. It will still work. With 8 ohm drivers, the wattage would be cut approximately in half, 2 ohm it would be approximately doubled.
Note, it takes 10 times the power being pulled from an amp to double the sound volume. Thus, your sound volume would not be cut in half, only your wattage being pulled from the amp.
I know nothing about the design of PA speakers, but I very much doubt they would sound good at all. Whether or not they are similar to a subwoofer I do not know. If similar enough to a subwoofer, you could drive it with a dedicated amp with sufficient wattage with a filtered signal.
But from previous threads of yours, I think all you have is a head unit and not an entire system. The internal amplifier of a head unit is not powerful enough to drive any sort of speaker decently, let alone a speaker of 8 ohms.
With a dedicated amp, it would be possible to bridge the amp to a mono signal and wire the drivers up in parallel and it would then be a 4 ohm load, pulling the correct wattage from the amplifier. I doubt you can bridge the internal amplifier of a head unit (you couldn't when I was into car audio).
Simply put, they are going to sound like garbage. But then again, anything being driven from a head unit's internal amp is going to sound like garbage if you are use to something even half decent.
My credibility.... FWIW, I had a very small extremely clean 4 channel 16W RMS amp bridged to 2 channels running 6 speakers at a 1.333 ohm load with a 50W RMS 2 channel bridged to one channel driving 2 subs wired parallel for a 2 ohm load. It was not a system built for pounding out cRAP, but built for accurate reproduction of Pink Floyd (was a stoner back then and good Pink Floyd music was extremely important back then.)
So, what i said then mrodgers. It will work with these speakers, bu tit may not sound that good. So many things to remember, volts, watts, ohms, i get muddled up.
You can use every speaker in car. Depends, if youre using subwoofer - then it needs a right sized box. If something smaller, maybe u can mount this on the backplate of the rear window on in doors. In doors, u should make a little box in there too for better quality.
Awwww it's ok Jamie, just make your own like i used to, no-one can hear you in your helmet, atleast thats what i thought :P