Man, it really hurts when you see naked evidence that the brain is going soft on you.
Yesterday I was devising an array of four speakers to use as my center front speaker in my home theater system, and trying to keep the impedance from being too far out of whack from what the amplifier needs to see. I used to be able to do this stuff at the drop of a hat, but I was REALLY struggling to figure out the wiring. In a nut shell, I had to have 4 total speakers (each 8 ohms) connected in such a way that the array would retain the original impedance of a single 8 ohm speaker. When you put two speakers in parallel, the impedance is halved. When you put them in series, the impedance is doubled. So with 8 ohm speakers, each of the pairs of two being in parallel made them 4 ohms each for each pair. Putting the two pairs in series, made the whole array then back to 8 ohms.
What was throwing me was that I had one speaker right below the TV, and the other three were on a lower shelf below the TV. I had to make up 4 drawings to figure the wiring out, and even then, I was holding my breath when I turned on the amp, hoping I wasn't going to dead short the center channel if I screwed up. Seemed a whole lot easier on paper than when I had the speakers laying in my lap with wires running everywhere. :crazy02:
Yesterday I was devising an array of four speakers to use as my center front speaker in my home theater system, and trying to keep the impedance from being too far out of whack from what the amplifier needs to see. I used to be able to do this stuff at the drop of a hat, but I was REALLY struggling to figure out the wiring. In a nut shell, I had to have 4 total speakers (each 8 ohms) connected in such a way that the array would retain the original impedance of a single 8 ohm speaker. When you put two speakers in parallel, the impedance is halved. When you put them in series, the impedance is doubled. So with 8 ohm speakers, each of the pairs of two being in parallel made them 4 ohms each for each pair. Putting the two pairs in series, made the whole array then back to 8 ohms.
What was throwing me was that I had one speaker right below the TV, and the other three were on a lower shelf below the TV. I had to make up 4 drawings to figure the wiring out, and even then, I was holding my breath when I turned on the amp, hoping I wasn't going to dead short the center channel if I screwed up. Seemed a whole lot easier on paper than when I had the speakers laying in my lap with wires running everywhere. :crazy02:
