The Sound Oasis S-650-01 uses interchangeable sound cards to store and play sounds. You can have a large collection of sounds if you choose to expand. Each sound profile is preloaded onto an interchangeable sound card that you plug into the bottom of the sound machine. When you get tired of one set of sounds, you can purchase another sound card and get more. The preloaded sound card we used has 12 different sounds, many of which are unique among sound machines.
The rain sound profile doesn’t sound as good as other sound machines that we've reviewed, including the HoMedics Deep Sleep. In the thunderstorm sound option, the rain has more bass and isn’t very loud. The rain option sounds less realistic and has a higher pitch than the thunderstorm's rain.
There are six sound options unique to this sound machine: energy chimes, tranquility, alpha clouds, delta voyage, sleep surf and dream echoes. Some of these sounds are relaxing and are reminiscent of spending the day at the spa, but some aren't calming at all. The tranquility and delta voyage sound options use tones that seem to build tension as opposed to relaxation.
The speaker is located on the back of the machine. If you have the display facing you, the sounds project away from you. A speaker that faces forward or upward is more desirable and disperses sound better throughout the room. This speaker design does not help the white noise generator to mask unwanted sound. During our testing, the sound machine did not effectively block out environmental sounds. The noise produced by the vacuum cut right through the white noise profile and was still abrasive and loud. White noise did not do much to mask music either. It did almost completely mask the traffic outside of our testing facility, which most sound machines were able to achieve. Overall, this Sound Oasis sound machine didn't do well in the sound masking tests.
The Sound Oasis S-650-01 stands 5.7 inches tall and has rubber feet at its base. Since the unit is so tall, you can’t push the Sleep Enhancement button at the top of the unit without holding the device in place or it will tip over. The rubber feet struggle to keep the machine in place.
You select different sounds by pressing the button on the bottom on the sleep machine. This is the only way to select sounds, and you can't move back to a previous sound once you've passed it. You have to cycle through the entire library, which is a bit inconvenient.
The sleep machine has a convenient display and a built-in alarm clock. The LCD backlight is a little bright in the middle of the night and isn't adjustable. Setting the time is a major inconvenience. To set the time, you have to hold the clock button down and wait for it to count up to the correct time. You can't set the hours and minutes separately. The same goes for the alarm clock.
You can set a timer to turn the sleep sound off after 30, 60 or 90 minutes of play. This noise machine also has a sleep enhancement feature that gradually slows down the sleep sound as you sleep. This feature is supposed to keep you asleep longer throughout the night.
The alarm gradually wakes you up regardless of whether you choose to wake up to a beep or sound profile. The alarm tone starts off quiet and gradually gets louder to ease you awake. It's nice that the alarm doesn't startle you with a loud noise like standard alarm clocks.
The Sound Oasis S-650-01 has its share of pros and cons. The alarm clock and display are nice to have but difficult to set. Some of the sounds are great, while others are strange choices. This is one of the few sound machines we reviewed that is also an alarm clock, which adds extra value to this machine and makes it worth consideration.