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## Re: 10-inch-diameter speakers

 Subject: Re: 10-inch-diameter speakers "Tam/WB2TT" Wed, 31 May 2006 09:46:32 -0400 sci.electronics.basics, sci.electronics.design
 ```"John Fields" wrote in message news:vr4r72h9dp1hnvsaiihkcfilb9d962lo9f@xxxxxxxxxx > On 31 May 2006 01:20:04 -0700, epiang@xxxxxxxxx wrote: > >> >>Pooh Bear wrote: >> >>> What youd need to watch is the impedance. Car speaker are normally 4 >>> ohms to get >>> more watts from a limited voltage source. Hi-fi loudspeakers are >>> typically 8 >>> ohms. Just be sure your receiver's happy with driving 4 ohms. >> >>Oh yeah... limited voltage source. So, from V=IR, is it typically >>about 24V or so driving hi-fi loudspeakers? > > --- > Depends on how much power your receiver can pump out. > > Assuming it's a voltage source and is rated to put 100 watts into 8 > ohms means that the voltage it needs to supply into across that > impedance will be: > > > E = sqrt(PR) = sqrt (100W * 8R) ~ 28VRMS > > And the current: > > E 28V > I = --- = ----- ~ 3.5ARMS > R 8R > > Since the current the amp can supply is what will limit how hard the > 4 ohm load can be driven, we can say: > > > P = I²R = 3.5A² * 4R = 50W > > > It's 50 watts instead of 49 because of the rounding we did earlier, > but the point is that with a load of 4 ohms instead of 8 ohms you > can only get half the rated power from the amp. There are a few > more things to consider, like how much voltage headroom the amp has > and how hard you can overdrive it before you hurt it, but with a 4 > ohm load you should start hearing distortion with the volume control > cranked to a little over "5". > > > -- > John Fields > Professional Circuit Designer That is not true if the amp is capable of driving a 4 ohm load. The specs on my Onkio are: 70 W/Ch into 8 ohms 90 W/Ch into 4 Ohms He could get around the whole problem by buying 2 pairs of speakers, and having 2 in series for each channel. Still, there is the question of what's the point? To get hi-fi sound, he would have to add a crossover network and high frequency speakers. Everything would depend on the desighn of the cabinet. Probably better off buying packaged speakers. Tam ```
 Current Thread Re: 10-inch-diameter speakers, (continued) Re: 10-inch-diameter speakers, GregS Re: 10-inch-diameter speakers, mrdarrett Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, Ben Bradley Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, epiang Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, John Fields Re: 10-inch-diameter speakers, Tam/WB2TT <= Re: 10-inch-diameter speakers, Chris Re: 10-inch-diameter speakers, Richard Henry Re: 10-inch-diameter speakers, epiang Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, epiang Re: 10-inch-diameter speakers, Pooh Bear Re: 10-inch-diameter speakers, Spehro Pefhany Re: 10-inch-diameter speakers, Michael A. Terrell Re: 10-inch-diameter speakers, Boris Mohar Re: 10-inch-diameter speakers, John Fields