hey guys. i am considering to put my home focal speakers to my car.(since my family upgraded the home audio, i got a set of extra sitting in my store room). i only have car audio amp to run them . my focal speaker is using 8ohm but my car audio amp just mention they can run 4ohm. so, it make me confess.
can i run them with this match up? car audio amps 4ohm to run 8ohm home speaker in car?

PHD

yeah they will run fine but at 8 ohm they wil only recive half the power compared to 4 ohm.

eg. 200wrms at 2ohm
100wrms at 4ohm
50wrms at 8ohm
25wrms 16ohm

only a rough guide because not all amps halve or double the power. my q4000 puts out 60rms at 4ohm and 100ms at 2ohm.

hi,
it'll definately work without problems...just that u get a little less power to play with. But wat a waste, why rip up a perfectly decent speaker/case/crossover/finish. Your focal speaker must have cost quite a bit/ dun think ive seen anything cheap come out of jmlab. if u only need the drivers why not just pick from their car audio range instead. Sell away your speaker n have enough money n plenty of leftover cash.

i did the same thing with some canadian speakers 'Mirage' and left them in there boxes and put them under my rear shelf which was just cloth anyway, and they sounded fantastic so there is no reason why it cant be done...

how many power does your speaker need and how many power does your amps provide? are they as same as my case? 8ohm for home speaker and 4ohm for car audio amp? is it all installtion same as other car udio speaker?

PHD

the speakers were rated at 100rms each 8ohm and i literally just hooked them up to my head unit and they sounded good so i left them there for a few months....but maybe your missing the basics, for example all car audio speakers run at 4 ohm, sub woofers are a different story, most home speakers are designated to run at 8 ohm...so if you hook up your home speakers to your car then your just not going to be supplying them with as much power, as the lower the ohmage the higher the power generally.

If you have another set of 8ohm speakers you can set them up parrallel and that will bring it down to 4ohms. But then you're driving two speakers for each channel and it might end up the same.

Ohms is basically a measure of resistance.

More ohms, more resistance. An amplifier will happily power a speaker with a very high resistance (eg 8 or 16 ohms) but it produces less power.

The average amplifier is much less comfortable powering speakers with very little resistance (eg 1 or 2 ohms).

An amplifier produces power into all different sorts of speaker resistances, the rated "XX watts at 4ohms" is simply to give you a reference to compare amplifiers.

For example, a car might be rated at 200kw @ 5200rpm.
This is not to say that the engine ONLY runs at 5200rpm. It will also work at 2000 or 6000rpm.

Make sense?

You can do it, yes.

Few things to consider

A) In home speakers are designed for in-home environments. Which isnt as harsh. A car has to contend with moisture (condensation) heat, humidity, direct sunlight, etc etc. Most "home" speakers wont like this AT ALL For too long

b) Cabinets. You'll find most home speakers come in some form of enclosure. MAKE SURE that if you put these in your car (such as on the rear parcel shelf) that you secure these. Extremely well.

At 100kph an hour, a loaf of bread on your parcel shelf is as solid as a brick, and can easily fly out your windshield and down the road in a crash. . Imagine a speaker box.



Most. But certainely *NOT* all. Lots of tweeters, and lots of components in 3-way sets, are not 4ohm.

edit : Oh, and i'm catching you stazed. 200 posts up, but 5 months earlier..hmm.

I don't post as much anymore, I think I'll limit myself to one post a day, this is today's one

wow i was unaware that 3 way set ups came in different ohmage...interesting