The JBL Cinema SB400 is a couple of steps up from the SB100 in the company's model hierarchy, and a bit more than twice as expensive. But for that you get better and more drivers in the soundbar — two proper 25mm tweeters and four bass/midrange ones. Also, double the power (60 watts peak per channel). Plus a subwoofer with a 203mm driver and a 100 watts of its own power. And a wireless connection.
You also get more inputs: including three HDMI ones and a HDMI output to match. This last is Audio Return Channel enabled so that your TV can control the soundbar automatically, and feed sound back down this HDMI cable to the soundbar. Because of the three inputs you can use it pretty much like a compact home theatre receiver. If your TV doesn't support ARC then you can just plug the TV's optical output into the soundbar.
It's 1100mm wide but quite compact otherwise, only 95mm tall and 64mm deep. It comes with a metal bracket for wall mounting, but can also sit on your TV's bench (if it's wide enough — the bar's legs are a good metre apart).
In addition to the physical connections the unit supports streaming audio via Bluetooth. There's an iOS app called JBL Music that's supposed to be an optimised music player for this unit. Perhaps, but it would not run on my iPad Mini, crashing out within a second of starting. I just used the regular music apps on both iOS and Android to stream Bluetooth and these worked fine.
Unusually the subwoofer and soundbar are not pre-paired (perhaps because they come in separate cartons, so inventory management could be tricky). Doing the pairing is easy though. Just press the appropriate buttons on both units within thirty seconds of each other. That worked perfectly first go.
Another thing you should do is set the level of the subwoofer so that it is appropriate for the soundbar. That presented a problem, thanks to a miscalibration that you can't adjust.
When you have small speakers — including a soundbar — the subwoofer has two jobs to do. One is to reproduce the bass that is in the main five channels, but is too deep for them to handle. The other is to reproduce the standalone Low Frequency Effects (LFE) channel provided in such audio formats as Dolby Digital 5.1 and DTS 5.1. The ".1" is the LFE channel.
So the first thing I did was balance the subwoofer (you have to dart over and adjust its level knob) using the LFE channel in a 5.1 channel Dolby Digital test disc. But once I had that right the voice of the narrator on the test disc sounded terrible. It was horribly boomy, to the point where the bass components of the voice sounded quite disconnected from the rest of the voice. The LFE was the right level, but the bass redirected from the other channels was way too high. I used another test disc — stereo only this time — to adjust that to the correct level, and the LFE channel from Dolby Digital content was too low. Ten decibels too low in fact.
I left it like that anyway. The sound was intolerable otherwise, and with many movies the LFE channel is rather less employed than you might expect.