The general consensus is the "low impedance switch" isn't a "optimization circuit" as they'd have us think but rather a "limiter" which locks you out of playing as loudly. This is done to prevent heat buildup which makes it difficult for them to pass fire safety UL and CSA certification without investing an an expensive extra part: a cooling fan.
Throwing in the limitation circuit costs them 3 cents whereas the cooling fan would cost 87 cents each. Both lets them pass the tests but one saves them a ton of money.
I don't think 4 ohm will be a problem but be sure to provide good air circulation or invest in a cooling fan yourself. Sorry, it will cost you a lot more than 87 cents though.
Sooo... Bad news. the Emotiva C1 did sound good, but when I started pushing it my Amp kept shutting down. Towards the end of Rambo 2008 UHD during the climax with the receiver set down to - 3.0 db. It's mastered pretty loud anyways, but that was pretty loud for that movie. It had a fan on it and didn't really seem to even be getting warm. Must have a pretty conservative protection circuit. I don't watch at that level real often, usually around - 10 to - 8 db when I'm watching a movie, but I like having the option to. Typically -18 to -16 for my streaming or causal movie watching. Too bad. HTD Level 3 it will be. Receiver should have no problem pushing it since it's really meant and it's ratings on the spec sheet are all for a 8 ohm load.Thanks I'll probably invest in one of those cooling fans I'm seeing after searching that sit on top and pull the hot air out.
I do have a question reguarding the amps crossover settings. It almost always detects my speakers as "Large" and presets to that and a crossover of 40 hz which is below what any of them are rated for, so I change the setting to small and set crossover to 60hz. I have noticed if you flip it back to "Large" the freq gets grayed out, but remains what you just set it to as "Small". Is it using that freq, or just displaying what it was last set to but still defaulting to 40hz internally after that?