Can I rig a home theater amp to run in wall speakers?

" His new house has 8 in wall speakers distributed throughout the house."

8 mono speakers, 4 pair stereo. or 8 pair stereo? 

"using the pre-outs from the Marantz"

Stereo or A/V, and if A/V, main preout or zone 2 preout?

Any way to control volume of individual rooms?

"Do the RCA splitters have any major negative effect?"

I would be more concerned about the speaker distribution box. Some have as much as a 50% power loss. Do you know the model number of this box?

Hi Mark,

Happy to try and help. Retired now but worked in the A/V industry many years with experience in HT and distributed audio. I have some ideas but need more info to see if there is a way to use what he has and make it function correctly, safely, and be user friendly.

Do you know if the single speakers are what is called a summing speaker, plays both channels with L&R connection on the single speaker? One way to find out is look at the selector box to see if that position has both channels connected, assuming a 6-way selector box. If it's a 4-way box then he may have L speaker in one location and the R speaker in the other. Model number of the selector box would be great or does it have knobs and switches or just switches and how many, 4 or 6?

Can you get me the model number of the Marantz? Should be close to the name on front, in small print.

I know I'm asking for detailed info, but without it is like shooting at a target blindfolded. Get what you can and we will kept working toward a solution.

Outdoor speakers would be my guess as well. On the SS6, 3 positions are connected normal, L&R. Then 2 positions, hallway and kitchen, have only one channel connected. Correct?

I do have a couple of ideas, but really need to know the model number of the Marantz to know it's capabilities.

OK, with the SS6, I'll assume the single speakers are summing speakers as I described above, and he is using 5 of the push button switches, one for each location, 3 rooms, hallway, and outdoors. When playing multiple locations, which one could use a little more volume?

Thanks Mark, and I have taken a look at the manual. Hopefully I can clarify some of the info provided by "dtc".

Zone 2 - When using Zone 2 speaker output, 7.1 is not an option for HT, however when only using Zone 2 pre-outs, you can do 7.1 HT. These Zone 2 pre-outs can drive 2 channels of the Rotel amp, but not directly. A passive VC will need to be inserted between the Zone 2 pre-outs and the Rotel amp. The manual implies that the Zone 2 pre-out is a fixed output, so depending on its level, it could overdrive the amp. It is true that Zone 2 will only play sources from analog inputs or the tuner. Any sources from HDMI or digital inputs are not available for Zone 2.

Using the stereo (L&R) preout - I believe this is the current setup. It will be necessary to select stereo only on the SR5006, no surround. Then the main VC will affect the volume of all speakers. "Is there a way to disable the speakers on the Marantz HT Receiver while the pre-outs send signal to the other speakers?" Yes, assuming there are no speakers connected to the speaker B outputs. The "Speaker A/B" switch on the remote will toggle, (A) - (B) - (A+B), then back to A. Set this to "B", then the HT main speakers will not play. Since stereo only was selected on the receiver, center and surrounds will not be playing as well. Also, if stereo only is not selected, these preouts will only output the L&R of a 5.1 signal, and likely sound poor on the in-wall speakers .

Trying to use more than 2 channels of the Rotel amp - possible, but a few ways to do this. Rather than list all the scenarios, is it possible to get a little info on what sources are used for the distributed audio, analog, digital, or both? For example, 2 channels in addition to how things are currently setup could be driven from Zone 2 pre-outs as described above, but those speakers would only play an analog source. RCA splitters could also be used, but depending on the arrangement, additional devices may be necessary. 

dtc, I agree with the idea of a mono due to no "sweet spot", however, IMHO, I would not just use a simple "Y" cable on the L&R pre-outs of the SR5006, main or Zone 2. This just shorts the 2 channels together, and may cause adverse effects. It would be best to use some type of a stereo to mono converter, even something as simple as a "Y" with resistors inline on the signal connections.

Here is an option that is very simple to use 4 channels of the Rotel.

(Example only, quality should be same as interconnects used.) Use this type of Y adapter on each (L&R) of the SR5006’s main pre-outs.

https://www.amazon.com/Hosa-YRA-104-Dual-RCAF-Y-Cable/dp/B000068O4Y/ref=sr_1_2?s=electronics&ie=UTF8&qid=1465579594&sr=1-2&keywords=rca+y+adapter

This gives you 2 pair of stereo RCA outputs with a female connection. That way, you can use normal interconnects for everything. (The splitter box from the link in your post would work also, just using 2 of its 4 outputs.) Use one of the pairs for 2 channels on the Rotel to the SS6 like the current setup. Then connect the other pair to the input of a passive volume control,

cheap passive VC -
https://www.amazon.com/Axxess-AALC-Controller-Discontinued-Manufacturer/dp/B003FPD3IS/ref=pd_sim_107...

better passive VC - only one input would be used
http://schiit.com/products/sys

with the passive VC output driving 2 more channels of the Rotel to the outdoor speakers. Indoor speakers will play as they do now, but outdoor speakers will be able to play louder due to the increase in available power not being connected to the SS6. The main volume on the SR5006 will still affect all speakers, but the passive VC on the outdoor speakers can be turned down or completely off allowing a desired volume inside. Keep in mind that the passive VC only attenuates, so maximum volume of outdoors will still be determined by the SR5006 volume control. No doubt the outdoor speakers will be able to play as loud or louder than they do now with a given indoor volume, but more important, this solves the problem to turn outdoor down or off.

Now to try and use that 5th channel on the Rotel gets a little more complex. You would need the splitter box from your link, 2 passive VC’s, and a stereo to mono converter like this,

http://www.mcmelectronics.com/product/MONACOR-SMC-1-/50-9042

I do not advise using a simple Y adapter to convert stereo to mono. See previous post.

I would definitely use 4 channels of the Rotel as this creates more flexibility between indoor and outdoor speakers, but not sure about trying to use that 5th channel. Is there a major problem with volumes between the indoor speakers? Something too loud, not loud enough? And if so, what?