Taken from : http://www.macnn.com/reviews/aircurve-play-for-iphone-4.html
AirCurve Play for iPhone 4
April 29th, 2011AirCurve Play amplifies the sound of your iPhone.
The Griffin AirCurve Play simply amplifies the sound of your iPhone. This simple clear polycarbonate case fits your iPhone perfectly and does one job well at a reasonable price.
Sometimes you see a product that looks useless, but once you use it, you discover perfect simplicity. Thatís my first and last impression of the Griffin AirCurve Play. When I first received it, I couldnít imagine why I might want to use it, but after a few minutes, I realized it served my undiscovered needs perfectly. This cradle, for lack of a better term, simply amplifies the sound of your iPhone.
I really like the form factor of the Amplify. Itís a weighty clear polycarbonate case with silver metal hex-screws in the corners, in which your iPhone seats into a rubber gasket. No wires or paraphernalia to disturb your desk or table space. It produces sound that is 10 decibels louder than your iPhone can produce on its own. According to Griffin Tech, it ďcollects the sound from the built-in speaker of your iPhone, amplifies it in a built-in coiled waveguide, and projects it.Ē This works like the horns on the antique phonographs, but the ďhornĒ is coiled inside the cradle.
Empty AirCurve Play
Your iPhone fits securely into a removable rubber housing, so that you can carry the AirCurve Play around without worrying that the device may fall out. All of your ports remain accessible. Although itís not easy to put in your iPhone incorrectly, it can be done, and that renders the volume buttons useless. An etched outline of your iPhone in the rubber reminds you of the correct placement.
Itís heavy (11.36 oz.), so you would be hard pressed to knock it over. The sturdy metal stand clicks into place in many positions, and it does not collapse. You can orient the display horizontally (landscape) or vertically (portrait). It displays your iPhone perfectly for FaceTime or viewing movies and other video.
Itís not meant to fill a room with sound, but allows you to use your iPhone as a personal listening device. You may need to crank up the volume and turn on the speaker, but once you insert the iPhone, no cables are required.
Deep bass does not reproduce well, it is a bit noisy and that masks the tones. Highs are surprisingly clear and do not suffer from amplification. In some music, it introduces almost a white noise sound, but lowering the volume solves that problem. It works great for phone conversations without distorting the sound. High voice tones reproduce better without the AirCurve Play, but not significantly. I tested it outside and live less than a mile from a noisy major highway and could hear and be heard fine. It is a convenient way to listen to music or watch podcasts.
Horizontal Orientation with Charging Cable
If you donít want to run your phone battery down while in use, you can tether it to your computer with your charging cord. The case is just high enough to provide room for the end of the cord to sit in the phone without crunching it against your table or desk, but I recommend you place it horizontally, so that no pressure rests on the cord. While using it in a car may be a bit unwieldy, it certainly beats an annoying device hanging out of your ear; just set it on the dashboard, passenger seat, or console, and you can talk without holding the phone. (Just don't take any fast corners.)
If you need a reasonably priced gift for the iPhone 4 owner in your life, I highly recommend the AirCurve Play. It is a perfect Motherís Day gift. I can imagine any cook will find it easy to listen to directions while bustling around the kitchen. Buyer beware, the product listed on Amazon is the old model, not this newer iPhone 4 AirCurve Play.
-Amplifies iPhone 4 sound well.
-Securely holds iPhone 4.
-Aesthetically pleasing design.
-Stand clicks into multiple positions.
-Must remove any iPhone4 case to use.
-Ringer switch inaccessible.