Summary: Good clean, tight bass. Very powerful without being overwhelming. But if you are looking for mind blowing loud that rattles the walls and makes everything sound boomy, it might not be the one for you. You might want to go with a ported sub.
Summary: This sub sounds great. I use it basically for music and it provides clear bass, that is not muddy or washed out. It is a perfect match to my JBL L890 speakers. The enclosure is compact, and the sub was easily concealed under an end table.
Summary: Very powerful for its compact size. I was quite surprised. I was worried about the chirping thing but mine doesn't do that. It definitely does power down too often when you are watching TV without much bass in it, though. Wish it didn't do that. That's my only (small) complaint. I've had it for 2 1/2 years and I still love it.
Summary: Kudos to Amazon for their customer service but at the same time it shouldn't have happened. The first sub I received was clearly a repackaged return (still had the old shipping label) and was blown with a rattle to it. A quick call to Amazon and they had a new one shipped overnight to me and dispatched UPS to pick up the bad one. Once that issue was resolved, this thing is rock solid and fills my room with beautiful deep sounds.
Summary: I bought one of these for a living room/home theater setup. I got it to replace a JBL PSWD112 Powered Subwoofer that I bought in 1999, replaced under warranty in 2000, and has been thumping along ever since. The old unit started to crackle so I thought I'd upgrade all of my speakers.
Excerpt: Bought this monster back in May of 2007, and ever since have been enjoying movies and music like they really should be heard - and felt :) I also have JBL's Studio L880 towers, which produce pretty strong bass, but the L8400P goes beyond them, with even deeper reproduction, and more "oomph". The only thing I would have preferred in this sub would be a different design for the feet. But that's very minor, and a personal preference.