ask-avk

That is the rainbow effect, a known characteristic of single-chip DLP projectors, and it is not a fault with your unit. It is how the technology draws colour.

Both things are true at once, which is why the argument never ends: the speaker changes a little, and you change more.

Two different situations, and only one of them is worth worrying about.

You can stress an amplifier with a harder load than it is designed for. Speakers, on the other hand, are almost never damaged by impedance itself; they are damaged by clipping from a small amp driven too hard. Keep those two facts separate and the whole topic gets calmer.

Almost always a signal-type limitation, not a fault. Zone 2 on most AVRs will only pass certain kinds of audio, and HDMI audio is the one it most often refuses.

The soft click inside the receiver is a relay doing its job and you can ignore it. Small pops through the speakers at normal volume are common and harmless. Loud cracks on every switch are the one version worth acting on.

First localise it: pause on a plain white image, then look at what the artefact does. That one test tells you which of three things you have.

A projector that has grown louder is telling you about heat, and the message is usually about the filter rather than the fan.

Bi-wiring: skip it. Passive bi-amping from spare AVR channels: try it, it is free. Full active bi-amping: another world, not a weekend job.

A DAC converts digital audio to the analogue signal your amplifier and speakers use, and every digital device you own already has one. So the real question is not whether you need a DAC (you have several) but whether a better one would be audible in your particular chain. Usually the answer is not yet.

Multi-room audio is the same or different music in several rooms, controlled from your phone. What you need depends almost entirely on what stage your house is at, so that is the first question, before any brand.

Update, on your terms. Not mid-movie-night, not on unstable power, and not because a notification nagged you.

Yes to the first, and mostly no to the second, which is why prevention is the whole conversation.

The dB scale on your AVR is not "how loud". It is "how far below reference", so needing minus 20 for a satisfying volume is completely normal and says nothing about a weak amplifier.

HD works and 4K HDR does not: that is a bandwidth problem, and the usual suspect is the cable or a port. One of the few AV problems where the cheap fix is also the correct one.

That is HDMI-CEC doing its job, just not the job you wanted. CEC is the control channel that lets devices switch each other on, change inputs and share a remote. Useful when it behaves, maddening when devices from different brands interpret it differently.

Accept the split first: speakers are long-term assets, electronics are period pieces. Everything sensible about future-proofing follows from that one sentence.

Wireless surrounds and subs are good where wiring is truly impossible, and wired remains the reliable choice where wiring is merely inconvenient. That is our rule, and it has not needed revising.

Check the AVR's spec page for the HDMI generation and features on its inputs, and check how many of the ports actually carry them. That second half is where most gaming disappointments start.

Speakers age gracefully. Electronics age in formats. Usually that means keep half and replace half, and the maths favours the upgrade over a full replacement.