I'm still new to home theater so I apologize for my long-winded questions.
About a month ago, I got a 3.1 system with an Onkyo TX-RZ30, KEF R2 Meta center channel, R3 Meta front speakers, and SVS SB-3000 Revolution sub. I'd like to expand to 5.1 by adding Q4 Meta surrounds but, so far, I haven't found anyone who can install them at a reasonable cost.
Our TV room is kind of a hybrid. It's not a real home theater, but it's a closed living room of about 3200 cubic feet (16.7' x 17.5' x 10.8') that's used exclusively for watching movies (including 4Ks) and streaming shows. Our listening distance is about 9'.
We've been setting the volume between -20 and -10, depending on the source. We never watch/listen for more than 4 hours at a time, usually less. The Onkyo sits on top of the media console and gets plenty of ventilation.
TL;DR: (1) What impedance setting should I use in the Onkyo; and (2) Should I consider an external amp?
I'm still learning about this equipment and trying to learn about home audio in general. I've read a lot about how "power hungry" the KEFs are. This comes up in two general ways:
What impedance setting to use on the Onkyo.
I set it up at 4 ohms initially, following the product manual. Then I read a lot online about how it's better to use "6 ohms or above" because the 4 ohm setting is really there to meet regulatory requirements not audio performance and, in fact, using it compresses the audio, etc.
When I ask AI about this, I get two opposite answers. (Please don't down vote me for mentioning the dreaded AI - I'm just trying to learn.) I think Chat GPT is reading product manuals and Gemini is reading forums like this one.
In general, it seems that 4 ohms is better for protecting the AVR but might result in worse sound quality and (in extreme cases?) might actually harm the speakers, while 6+ ohms is better for the speakers but could be worse for the AVR. (Given the relative cost, I'm more worried about the speakers.)
I just tried switching to 6+ ohms at -15 as an experiment and didn't notice much difference. 6+ might have been slightly less compressed, but that could also have been my imagination.
Given that we don't listen from extremely far away or at extremely high volume levels, should I just leave it at 4 ohms? Or set it to 6+ and just check the AVR from time to time to make sure it's not getting too hot?
Adding an external amp
I've read a lot about the KEFs benefiting from an external amp. I've done some research and would lean toward the Buckeye NCx252MP 4-channel amp, but I'm not sure if I really need an amp at all.
Assuming I expand to 5.1, would you all recommend adding an amp to power the L/C/R speakers and letting the Onkyo just power the surrounds? If so, at 6+ ohms, I presume? Even if I don't need the power right now, is it still benefical, e.g., by extending the AVR's useful life?
Or, is that $1,000 I don't need to spend?
I know these questions have been discussed a lot, but everyone's situation is a little different. I'd appreciate any thoughts about my specific situation. My goal, really, is just to make our system sound as good as possible given the limitations of the room, while trying not to go too crazy on spending. (My wife thinks that ship has sailed.)
If I left out any relevant info, please let me know. Thanks!
P.S. I know additional room treatment - beyond our rug and soft furniture - is important. That's next on my list but i want to get the equipment kind of nailed down first.