Screen
The TVs with the best image quality are QLED and OLED. Two different technologies.
QLED, (quantum dot LED) like an LCD screen, LED backlighting, vibrant colors close to reality. Colors and brightness remain almost unchanged after several years, using inorganic particle technology. Screen from 32 inches and more affordable price. Beautiful brightness in a well-lit room.
OLED (organic light-emitting diode) all pixels emit their own light unlike an LCD screen. No matter how bright the room is, a much more contrasted, detailed image and absolute black. No matter the location, even beyond 45 degrees, you do not lose contrast and color, because the screens also offer better uniformity of viewing angles. Advantage if several people in the room watch the screen. Sensitive image quality for poor quality streaming. Low power consumption and screen size from 42 inches. Low delay for video games and better brightness, but the price will be higher.
Sound amplifier
Opt for a new generation receiver, because the different surround modes and HDMI sockets are evolving. Preferable speakers of the same brand.
Not this based on price and power, because the correct measurement taken between two channels should have a frequency of 20 to 20,000 Hz on an impedance of 8 ohms. So if we have 100 watts on two channels, the power will be around 40 watts for each of the 5 speakers connected.
Place the speakers at ear height.
Basic subwoofers are essential to fully experience the emotion of a soundtrack.
A 5.1 set (two speakers and a central one at the front, then two at the rear) will benefit from surround sound.
7.1 set for better sound immersion. However, it will have different, 4 speakers around the couch for greatly improved effects.
5.1.2 will have vertical effect loudspeakers, placed on the front loudspeaker or rear wall, cut at 45 degrees, diffusing the sound towards the ceiling or downwards.
You can contact an expert for a better atmosphere depending on each space. 11.1.8, possibility of up to 20 speakers for better sound quality.
Soundbar
A sound bar, saves speaker space and is less expensive, improves the sound of the screen, also on the 65 inch 4k. However, the bar must not exceed the screen.
An extra touch really added to the sound if you added a subwoofer as well as a rear speaker. For rich songs and action films, this will be ideal!