Do I need a separate Atmos speaker with these towers?

No. Each tower has a built-in upfiring driver that reflects sound off the ceiling, so a compatible Atmos receiver can use them as front height channels without extra speakers.

What amplifier power do they need?

Monoprice recommends roughly 100 to 250 watts per channel, and the 4-ohm nominal impedance means a high-current amp or a receiver rated for 4-ohm loads is the safe choice.

Are they good for music as well as movies?

Yes. The 3-way design with a silk dome midrange and tweeter is smooth enough for music, though the bass-heavy tuning and size favor home theater.

How do they compare with the THX-365T?

The 465T is the larger tower with four 6.5-inch woofers instead of the 365T's smaller drivers, so it plays louder and deeper. It also takes up more floor space and needs more amplifier power.

What comes in the box?

You get the tower, a detachable grille, and an extra set of speaker wires. Speaker cable for the run to your amplifier is not included.

Can I use them without a subwoofer?

For many rooms yes, since the four woofers deliver solid bass. A subwoofer still helps for the deepest movie effects and for rooms where the towers cannot be placed near a wall.