If you’ve recently tried setting up a media room, as we have, then you know the agony that prevails way before any ecstasy of audio-video nirvana is realized. So before attempting this home project — or completing it (and let’s be honest, media rooms are best done in stages so that your blood pressure can periodically reset to norm) — we recommend this primer from Smarthome. It may not prevent all the screaming and crying that comes with installing a home theater, but it will help you avoid some common mistakes and provide bits of hope amid the tangled nest of wires and impenetrable instruction manuals.