Uh, buddy:

A cool thing about 4 ohm speakers is that they will draw more current from your amp meaning that they will be producing more watts.

For example, an Outlaw 770 is rated at 200w x 7 into 8 ohms and 300w x7 into 4 ohms. Because I have all 4 ohm speakers, i'm running at 300 watts per channel instead of the wimpier 200wpc.

-sbc

There are a few real disadvantages about running 4 ohm speakers that offset the power gain. Firstly, the effective damping factor will be halved, since the ratio of cable/amplifier output impedance to speaker impedance is 1/2 what it would be with an 8 ohm speaker. Secondly, cable gauge and length will be more of an issue since twice as much potential current flows into half the load impedance - the cable's resistance effects the circuit by a factor of two. Lastly, most current power amplifiers, even if "rated" into 4 ohms, do not perform as well into this load as into an 8 ohm load. The distortion is usually higher among other things.

A power rating of twice, i.e. 400 watts verses 200 watts will yield a 3db increase in potential dynamic range, assuming the speaker can actually handle it! Almost no current speakers can handle 100 watts of continuous power, let alone 300 watts - they will simply fail outright or warp their voice coil formers.

Another consideration is the fact that by far the highest power demands are in the bass region and if a subwoofer is used in conjunction with bass management, the mains do not need all that much power at all - even 100 watts in a typical home theater is more than enough in most cases.

This used to not be the case in the days of "stereo" - speakers then were much less efficient and were expected to reproduce the entire frequency range. Power amplifiers were only two channels and this allowed a higher current capacity per channel verses a 5 or 7 channel amplifier. You simply have only around 1800 watts available from your AC wall outlet too, and this used to be available for only two channels, not 5 or 7. Stereo power amplifiers used to be built with more output devices per channel, and this translated to more current delivery capability. As a gauge, a "perfect" amplifier should be able to double it's power output for each halving of load impedance. Thus, a 200 watt into 8 ohm amplifier would deliver 400 watts into 4 ohms, and some amplifiers of that era would even deliver 800 watts into 2 ohms.

Yeah, all that other stuff he said. So you're looking at something like 2 db more output. Not all that huge. But you could look at it this way, yours can go to 11!

[This message has been edited by JT Clark (edited May 18, 2004).]

gasp, i think sh said it best about 4vs8 ohm speakers.

You can also increase the volume by doubling your speaker number per channel. For example, you can connect two speakers per channel. ( usually 1 per channel ) If you have a 7 channel amp, you just add 1 more speaker per channel and you can have 14 channels total by using this method to increase overall volume. But, this method put heavy stress on your amp. Make sure your amp can be abused this way. I also abuse my amp this way. and it smells hot from the heat sink!! But it sounds awesome

Do you understand wiring at all? You do not have 14 channels. You still have 7 at most. You can hook up 100 speakers to output of the amp and it will still be 1 channel. Also, you do understand that speakers have and impedance don't you? Amps can only play down so low before they overheat. Also, you understand that the additional speakers will take up additional volume in the room? Most every member here is also concerned with looks to some extent. Also the price of the extra sets. Don't forget setting up a sound stage so that it sounds good.

Ya, sorry about that man. I should say 14 speakers. I know it is the identical signal; you just duplicate the channels, but this method is to increase the overall volume without adding additional amplifiers. Also, additional speakers placed close to the original ones will acoustically couple so they act like a much larger speaker receiving twice the power. I found that using 2 pair of speakers for stereo sounds fuller, louder than using 1 pair. You can put that additional pair on the side wall near your ear height. It sounds better than using 1 pair. For ohm, if you connect two 8 ohm speakers per channel, the amp will see it as 4 ohm load. If you connect two 4 ohm speakers per channel, the amp will see it as 2 ohm load. That's why I said the amp will run hot by using this method. Sorry about confusing, bro.

I wouldn't plan on your amplifier's manufacturer honoring any warranty that might be left - electronics do not like abuse and will just fail, leaving you with no volume at all.

You have to check what your amp can do before you go wiring things up like that. I don't think all speakers can be coupled so easily either. Mine are omnipolar. I doubt the reflections will work exactly the same as before. If you have decent speakers they should be able to get loud enough.