How to connect multiple sets of speakers?


 am currently using a Denon AVR - 1905 for my receiver. I am using it like a 2.1 system. I have my mains on the speaker A channel and the other 3 pairs of speakers on the B channel.  The individual sets of speakers and controlled by a speaker selector.  At moderately high t high volumes I get a very loud bass rumble.  I was explained to me that each channel has it's own amplifier in my receiver.  Since I have 3 sets of speakers on 1 channel the Ohms have gone from 8 ohms all the way down to 2 ohms because of the 3 total sets on one channel.  Short of get a whole new amplifier setup(Yes, I eventually will do this, just not able to do it now), what is the best way to connect the sets(4 total)? 2 sets per channel with 2 speaker selectors?  I appreciate any help on this matter!!

Kevin McAlley
ksmcalley
Search series and parallel resistance. If you know the ohms of each speaker then you'll be able to use the formula to figure out what combination will get you the total impedance you want, up around 8 to 16 ohms. Or at least up to 4. You may have to go series on 2, parallel on one, something like that. You don't need a separate wire to each speaker. Its okay to run one wire speaker to speaker. My subs are like that. Its the way they're wired- in series or parallel- that determines the total impedance.
@ksmcalley - Do the speakers on the "A" channel sound OK? Do the speakers on the "B" channel sound OK if you are only playing one pair of those speakers at a time by un-selecting the other pairs of speakers using your speaker selector? What if you play 2 pair of speakers on the "B" channel? Is it only when you play all 3 pair of speakers on the "B" Channel that you have the issue?

Is this a "whole house" music setup where you have the 4 sets of speakers in 4 different areas of your home? Please explain where the speakers are located, and how you use them. It may help with recommendations. Also, your Denon AVR-1905 is a multi-channel home theater receiver. Are you using it for multi-channel HT in the main room? In other words, do you have a 5.1 channel HT setup (5 speakers plus a subwoofer - L&R front, L&R rear, center channel and a subwoofer) in the main room and use the speakers on "A" channel as the front L&R speakers? Or are you only using a single pair of speakers in the main room?