My Nakamichi RE-10 stereo receiver just quit working. And I also just got a new plasma TV. So it's time for an AV receiver. But I don't know how to connect up a new AV receiver to my existing multi-room speaker system, nor what receiver(s) might be compatible with my system. My whole-house audio system was installed professionally about 8 years ago, with the Nakamichi receiver, 3 pairs of B&W speakers, a Niles SPS-4 speaker selector & separate Niles volume controls on the two remote speaker sets. All four speaker terminals on the SPS-4 connected, I think the two main speakers in the living room must get double power (they are larger than the other two pairs).
On the back of the Nakamichi, which is rated at 100W into 8 ohms, four wires run to the speaker selector from the Left A&B speaker terminals only. NOTHING is connected to the Right A&B speaker terminals. I think this must be "bi-amping"? I assume the Nakamichi must have been programmed to send Right to the left A speaker, and Left to the left B speaker output (or vice versa), thereby doubling power to each channel. Does this sound right? If not why is nothing plugged into the right channel terminals?
Anyway, my question is what do I need in an AV receiver to continue to drive the remote stereo speakers at the right power level, and possibly upgrade the living room speakers to surround in the future? I can't afford high-end components this time around, nor professional installation, so am looking for a mid-priced receiver or components that can do the job.
Thanks for any advice in figuring out my current system and how to upgrade it. I think the problem of replacing a stereo receiver with an AV receiver must be a pretty common one, so hopefully the advice generated here will be useful to others as well.
"All four speaker terminals on the SPS-4 connected, I think the two main speakers in the living room must get double power (they are larger than the other two pairs)."
Not exactly, the speaker selector itself cannot raise the wattage of the amplifier. However, the amplifier will produce slightly more wattage into a lower impedance load - which is what it will see when more than one pair of speakers are connected in parallel (as they would be with the Nakamichi's speaker switching). Caution though, that lower impedance also makes the amplifier less stable which causes the amplifier to run closer to its limits. Unless you run the volume at fairly high levels the extra wattage probably is not of any consequence yet the instability of the amplifier is.
"four wires run to the speaker selector from the Left A&B speaker terminals only. NOTHING is connected to the Right A&B speaker terminals. I think this must be "bi-amping"?"
Nope, not bi-amping. You cannot be referring to the left and right channels of the amplifier. You're more likely looking at the left side speaker connectors which include left and right channels and the other set of speaker connectors which would be either the "A" or "B" speaker output (probably "B").
"I assume the Nakamichi must have been programmed to send Right to the left A speaker, and Left to the left B speaker output (or vice versa), thereby doubling power to each channel. Does this sound right? If not why is nothing plugged into the right channel terminals?"
No programming. The "A" and "B" speaker outputs/connectors are fed from the same amplifier outputs. (Left and right channels, however, are discrete - separate from one another.) They are the same with only a switch between them to select a pair of speakers. If you are connected to "A", connecting the same speakers or more speakers to "B" will make an internal connection to the same amplifier channels. This is how impedance is lowered as more speakers are added to the ampifier's load.
Again you're not looking at the "right" channel, is my guess. You're probably simply confusing "A" and "B" speaker output banks with the left and right channel connections.
"Anyway, my question is what do I need in an AV receiver to continue to drive the remote stereo speakers at the right power level, and possibly upgrade the living room speakers to surround in the future?"
You need a new AV receiver that will drive low impedance loads without problems. I would look for a receiver which can actually drive low impedance loads and not a receiver which has a "low impedance" switch to protect the amplifier. You already have the speaker selector so you need to find an AV receiver with "A" and "B" speaker selection. Now, "A" will be the main surrround system and "B" will feed the additional house speakers. You should swap out the Niles to provide better protection to the amplifier but the proper way to accomplish this is with an autoformer based switching system - which isn't that cheap. The Niles' "protection" switch is very crude and does no more than throw a large value load resistor against the amplifier's outputs. This is not the right way to perform "protection" when adding speakers to the amplifier load as the additional resistor will eat up considerable amounts of power which will in turn make the amplifier work harder - which is what you should be trying to avoid.
If you want to simultaneously run all speakers with the same source material (TV,CD, Tuner, etc.), I would strongly suggest you spend the money for the autoformer switch. If you prefer to have two zone operation which allows TV in the main room and another source elsewhere, then you'll need a two zone AV receiver. They'll be more expensive so, unless you have the cash to spend, the difference between the simpler receiver with the better switch and the more flexible receiver with the existing switch is mostly a wash.