Whole House Audio trips the receiver

The receiver does not like the load. Depending on the VCs and how they are wired you may be able to make it work or not, but more info is needed. Some VCs are designed to directly match impedance in a system like this, some not. They may be wired incorrectly or simply not designed for this kind of application without some impedance matching or current limiting device inserted.

google the #'s on the VC's

it looks like recent construction (within the last 6 years), they look fairly new, and they're made in China

Probably impedance-matching

On most IMVC's you set some tiny switches to tell the VC how many speakers are being driven by that amp.

Find the instruction manual for those VC's, or email/call Russound.

Also, make sure the Denon is well-ventilated (amp may be overheating, and may not be the VC's).

What do you mean by 'a set of speaker wires'? A single pair? Each pair of speakers should have 4 wires, and all 4 connect to the amp. That's a total of 16 speaker wires connected to your amp. How did you connect them to the 'fronts' outputs of the AVR?

They are likely wired in parallel, though some of the wiring might be botched or reversed in polarity. Staples through wires or polarity problems can cause issues like this. More likely that the impedance matching was not set properly or you are driving the amp too hard. Where do you have the volume on the amp?

The instruction manual is here:
http://www.russound.com/altx2.htm

According to the manual and your picture, the VCs are set properly at 4X (for four sets of speakers in parallel). I would look at adequate ventillation as your possible problem.

Here are some standard issues with single source systems:

1. Check tht you are tapped at 4X on all volumes (provided you are connecting all 4 sets to the amp)

2. Check that your input/output wiring on the volume is correct and not reversed

3. Check that you aren't phasing speakers with reverse polarity

4. Ensure that you aren't ramping your master volume on the amp too high
( this will send amp into protect)

Good Luck

P.S.

Most amps needs to see an 8 ohm load ( higher end amps are also 4 ohm stable) so if you have only one set of speakers attached you need to tap it's volume at 1X . Ohm's law states that for every set of speakers you add to the system, the impedance is reduced by 1/2.

Where do you have the volume set on the receiver?

Speaker wires may connect to a 'connecting block'. How far can you track the 2 pairs of speaker wire, attached to the AVR? There is a chance it's an IM connecting block, if there is one.

Robertmee said that IMVC in the pic was set correctly, at 4x. What about the other 3?

Any labels on the 4 speaker wires visible?

Any chance the AVR was previously set to 'bi-amp', before it was re-purposed? Anyone know what problem this would cause? I'm guessing the isolated fronts may be at 4 ohms, if this was the case, thus the AVR settings should be changed. Denons can be somewhat tricky to figure out (3808 owner here, and still learning after a year).

Some receivers do not like the load presented by multiple controls like this. Have you verified that the wiring is correct at all junctions and that there are no shorts?