surround question

My father is in the process of having a house built and is having his entertainment room wired for his surround speakers. His current receiver only has two channels of power for surround speakers, and is only stable into a 6-ohm nominal load ( w/ 80W per channel into 8-ohm loads). In order to be somewhat future-proof, he has installed 4 surround speakers (which will work with the new 7.1 surround-side/surround-back formats). To make use of the extra set of surrounds (until my father upgrades to an actual 7.1 system), the electrician/installer is suggesting that he can hook all 4 speakers up to the two surround channels through a switcher box and that there will be a) no damage to the receiver; and b) no sound degradation. Does this sound possible?

It seems to me that the switching box may degrade the signal coming from the two surround channels, and that driving 4 8-ohm speakers in the two channels will drop each channel’s load to 4-ohms, lower than the required 6-ohm minimum. In addition, the two pairs of surrounds will play at the same volume, but will be at different locations relative to the listener (so the resulting perceived volume will be different, and the delay times specified within the receiver based on distance to the listener will be mis-specified, leading to degraded coherency among the rear and side surrounds).

Does anyone have experience with these boxes and how well they perform? Would you suggest leaving one of the pairs idle instead (or manually switching between the two based on movie/music use)? I’m not entirely sure if this electrician/installer has a complete grasp of audio issues, so I wanted to double check!
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It sounds as if the rear speakers will be receiving the same signal as the side speakers so as far as the surround aspect is concerned there won't be any. Personally I would just connect the two rear speakers and enjoy the movie/music as intended. Good luck.
I agree with once bitten. The "switch box" would most certainly degrade the sound quality, although it sounds like the reciever will be doing most of the sound degredation already. You could connect the two pairs of speakers in parallel for a nominal 16 ohm load, but 40 watts per speaker generally wouldn't be enough for typical HT SPL's, although it really depends on the size of the room. But this new 7.1 technology is really quite pointless anyways, because the human ear can differentiate sound placement much behind the axis of the ears. Surround speakers are designed to be placed on the sides for this reason, not behind the listener. I'd hook up the sides and leave the rears to the fishes.
Go ahead and wire it for 7.1 but don't use it that way until you have different signals for the side and rear channels. Their delays should be different as is the material (to a small degree). The only way I would have both side and rears is for movies vs music. Movies are generally recorded to have a dipole at the null (same plane as the listener). Music generally sounds better with sound coming from behind. For me, I don't really care for any of the music I've heard in 5.1 format. Now, that still leaves the question of sides vs rears for the interium for movies. Movies should be a dipole firing foward and backward at the same plane of the listner (to the side). However, if the side speakers are not dipoles and aimed at the listener, as they generally are for 7.1 format, then I would recommend you use the rear speakers, until you (your father) gets the full 7.1 compliment.
The above statement by Hueske is incorrect; when two 8 ohm speakers are connected in parallel the impedence drops to 4 ohms and not 16 ohms as it would be if they were wired in series. And 4 ohms would be real tough for that low powered surround channel amp to handle, especially if they were inefficient speakers to boot! Like above I would stick with a single pair of efficient 8 ohm surround speakers.
Sorry...I mean series, not parallel. Oops! They need a Kirchoff's law checker on this forum!