It can play very loud and manage to sound full and retain good definition with minimal distortion even when you crank it to eleven. That's right, in a nod to "This is Spinal Tap," you can tap the "T" button on the unit or use Riva's free Ground Control app for iOS and Android to engage the turbo mode and take the volume to 11, giving you an additional 7db of sound (volume 10 is rated at 75db). Via the app you can also check the exact amount of battery life you have left.
While the speaker manages to hold together relatively well at 11 (there is a bit of distortion and harsher-sounding music does sound even harsher, sometimes unbearably so), I'm not sure how often you'll actually use the turbo mode (it does reduce battery life down to 6 hours if you leave it on continuously so it's best to use when you've got the speaker on AC power). But it's there for taking.
So is a "surround" mode, which is designed to create a wider soundstage (the company's ADX Trillium audio technology is the force behind the more open sound). The problem with all these compact Bluetooth speakers is that their drivers are so close together that you don't get any stereo separation. The Riva's surround mode does help create a wider soundstage but for real stereo separation you'll still do better with a pair of separate Bluetooth bookshelf speakers.
You'll also do better with a pair of wired speakers that cost less. Which is why I say that the Turbo X sounds really good "for what it is," a portable Bluetooth speaker. CNET contributor Steve Guttenberg and author of CNET's Audiophiliac column was a little less kind when he wrotecomparing an old JVC boom box to several Bluetooth speakers, including the Turbo X.
He said: "Armed with ADX Trillium audio technology and seven custom ADX transducers, the Turbo X wasn't bad, but the JVC PC-X100's size advantage was obvious. The little Turbo X's bass had nice impact, but the midrange and treble sounded like a small table radio. Dynamic range was compressed and limited, so the JVC PC-X100 stomped all over the Turbo X."
That sounds pretty harsh, but everything's relative. Steve doesn't like any Bluetooth speakers and for him to say the Turbo "wasn't bad" is something of compliment. Congrats Riva.
Riva's "it goes to 11" turbo mode is a gimmick, but hey, the Bluetooth speaker market is crowded and at least the Turbo X manages to stand out from the pack a bit with some interesting extras and strong performance, which includes battery life.
I only wish it cost less. While there's a lot to like about it, I wasn't quite sure I was ready to go out and drop $350 on it. But others looking for a beefier portable speaker that can be used at home or outdoors, may feel it's worth dropping a little extra dough on.