Which Ohm setting do I use?

Question

I have a Pioneer 56TXi receiver with a 5.1 speaker setup. I was wondering which setting on the receiver I should use since the front 3 speakers are 4ohms and the 2 rear are 8ohms. My choices are 6-8ohms or 8-16ohms. It appears to work with both without problems, but I don’t want to overload or overheat my receivers’ amp.

Also would I have to calibrate them differently? The rears sound a little loud after I recently used the MCACC. I usually use the test tones in my receiver and my SPL meter and calibrate them to 75db.

Thanks

Answer 1

The 6-8 ohm setting should work fine.

Answer 2

6-8 ohms most closely matches your speaker array. You might want to start thinking about finding a pair of rears that match your fronts. You'll find that everything will calibrate better and sound better if you do.

Answer 3

You will not want to use that receiver with those speakers. The impedance missmatch can damage both components

Answer 4

If the pioneer settings work like the Yamaha, the switch does not affect the power/operation of the speakers at all.

Better receivers have protection circuits that shut down the receiver if the speaker wires become shorted, or the receiver gets too hot (by playing too loud).  The "6-8" setting makes the protection circuit respond quicker/sooner than the "8-16" setting.  

The MCACC calibration should take care of efficiency/impedence/distance/angle/etc differences of your speakers.  The point of calibration is to hide these differences.

Note: I would encourage you to get a set of 5 tone-matched speakers. Using a mix of different makes/models tends to disrupt the soundfield and ruin the surround illusion.

Answer 5

Use the 6-8 Ohms setting, but don't drive your speakers too hard or the 4 Ohms speakers will overload your receiver's amp section.  I would recommend that you trade out either your front three speakers for 6-8 Ohm nominal speakers, or get a receiver that is rated for 4 Ohms speakers.