Stereo Power Problem

[GuyT]

Agree with Clark.

Ground return was the chassis of the car. Speaker still had - silence now - shhhhhh... AC. Man I hope LandsEnd didnt hear that!You ever notice that speaker impedance has dropped significantly over the years?Use to be 16 and 8 Ohms were norm.Now 8 and 4 and even 2 ohms are norm - what ever happened to 16 Ohms??Heres a clue - cost!Peopled realized that car amps can be made to handle more power cheaper if they dropped the speaker resistance/impedance.Biggest factor in mass production is cost reduction - Are ya listening ROCNA??Maybe Craig didn't hear that - I didnt use the word anch*r. Now his search engine wont even find it.

 

[Bob Poff]

I know I'm gonna regret this, but.....

Yes by all means audio is AC. So is "house current", 100 Kc Loran, AM Radio, Microwave, etc ad nauseum.What does A.C. mean? Alternating Current. Let's say you're listening to a 1000 cycle tone. Audio... yes? If you look at it on a scope, guess what you see. A sine wave. Now look at the "house current" with that scope. What do you see? A sine wave. But the distance between peaks is longer. A lower frequency (60 cycles to be exact). In theory the signal on that wire swings between some positive voltage through zero to an equivalent (hopefully) negative voltage.Simplistically stated, music or voice in a speaker is just a combination of multiples of those sine waves (maybe) in a multitude. And their harmonics (overtones), hetrodyne products, and so on.Where the confusion in this thread enters is that you have to power the amplifiers. Which is almost (I've seen a very few audio amps that use AC) always DC. But, since Volts*Amps = Watts, the lower the voltage on the device, the higher the current it has to pass for a given power. So in some cases you may chop up the DC, run it through a (square wave) transformer to a higher voltage, rectify it. Now you have a higher voltage DC. The amplifier still consumes the same power, but needs to pass lower current. So it stays cooler.It don't matter if your talking about audio or RF. Ya have to power the amp.So yes the SIGNAL is AC. But the device is POWERED with DC.But what do I know... I'm just a poor old Broadcast Engineer sittin' in the backyard with my laptop. Sailing's a lot more fun than electronics anyhow.

 

[Clark]

32?! That means they could use less current for the given power.

Ya think thay are *that* aggressive re: the use of copper?

 

[Fred Ficarra7897]

You guys are great!

Thanks for that Clark, Guy, Bob, etal. (did I spell that right? Haven't been sued in a while)

 

[Dan Johnson]

Fred...

Call the cops! Somebody stole the third pedal and the stick and ball that should be comin' out of your console!!! ;-)