Do I need a subwoofer for music, or only movies?+
Music benefits too — most bookshelf speakers roll off between 45 and 60Hz, and kick drums, bass guitar, and synths live below that. The difference: movies demand output (effects at high SPL), music demands integration (a sub you cannot locate by ear). A properly crossed sealed sub at 80Hz improves a music system more than most speaker upgrades at the same price. If your speakers are towers with real sub-40Hz extension in a small room, you can defer it.
What size subwoofer do I need for my room?+
Size to cubic feet, not to enthusiasm. Under ~1,500 ft³ (a 12×14 bedroom): a sealed 10–12" is plenty, and room gain does the deep-extension work free. 1,500–3,000 ft³: a 12" sealed or ported. 3,000–5,000 ft³: a ported 12–15" starts earning its box. Over 5,000 ft³ or open-plan: consider dual subs — two moderate subs smooth room modes better than one monster.
Is 80Hz always the right crossover setting?+
It is the right starting point, not the right answer. 80Hz keeps the sub unlocatable and unloads small woofers — the convention THX popularized. Move it up (100–120Hz) for small satellites that strain below 100Hz; move it down (60Hz) only for towers with genuine low-frequency capability. Then verify by ear with a bass sweep: you should not be able to point at the sub with your eyes closed.
Sealed or ported sub for an apartment?+
Sealed. Apartment rooms are small, and small rooms add room gain below ~40Hz that compensates for a sealed sub’s gentle roll-off — you get the extension without the ported box’s output peak, which is exactly the energy that travels through shared walls. Add the practical wins (smaller box, easier level control) and sealed is our default apartment call. Then set the level a few dB lower than you want, and your neighbors will decide how long you keep the hobby.
Can neighbors hear my subwoofer — and what helps?+
Bass couples into the building structure, so yes — floors and shared walls carry it further than you think. What helps, in order of effect: lower the sub’s level (the honest fix), high-pass nothing below what you need, decouple the sub from the floor with an isolation platform, keep it away from shared walls, and prefer sealed alignments in small rooms. What does not help: pointing it a different direction — sub frequencies are omnidirectional.
How many watts do I actually need?+
Less than the marketing suggests, more than the minimum. The math: an 88dB-sensitive pair at ~2.5m plays ~78dB from 1 watt in-room, ~88dB from 10W, ~98dB from 100W — every +3dB doubles power. Target an 85dB average with 15dB of peak headroom and a typical room needs the ability to swing ~40–100W into 8Ω; the average draw at your seat is closer to 10W. Watch the 2.83V catch on 4Ω speakers: subtract 3dB to compare against true 1W ratings.