Frequently Asked Questions
Q: What makes SonoAlti different from other audible altimeters?
A: SonoAlti is different in several respects. Most audible altimeters are not very user-friendly when it comes to setting the unit. SonoAlti is the first audible that interfaces with an app via Bluetooth® wireless technology. This powerful interface provides the user with an unprecedented level of control over all aspects of the audible altimeter's functions.
Q: How long does the battery last?
A: This will depend on how often the audible is used as well as where it is stored. If the altimeter is often in a moving car in hilly territory, the battery will be drained more quickly. Generally speaking, the user should be able to get approximately 200 jumps on the unit before it needs to be recharged. When stored charged, the battery can last as long as three months. The units should be able to be able to get approximately 300-400 charge cycles.
Q: Can I set the altimeter on the way to altitude?
A: No you cannot. The altimeter must be in Bluetooth mode to be programmed and it does not register altitude in that mode. If you want, you could bring your mobile device with you and program it in the plane on the ground, just before take-off.
Q: What helmets does it fit?
A: SonoAlti fits most skydiving helmets that are intended to house an audible altimeter. It has been tested in the G3, Kiss, Bonehead helmets and many more. It is also approximately the size of the N3 by Alti-2, which many helmets fit. Feel free to contact us for more information if you have a question about a specific helmet.
Q: Does my mobile device need to be connected to the altimeter for it to work?
A: No, in fact, Bluetooth needs to be switched off for the altimeter to work.
Q: Do I need Wi-Fi (or an Internet connection) to connect to the altimeter?
A: No, but Bluetooth needs to be switched on, both on the altimeter as well as on your mobile device.
Q: Why do my freefall speed graphs look so spiky?
A: SonoAlti (and all barometric altimeters) read altitude based on air pressure. This means that if you change body positions, or are flying in someone's burble, there will be some inconsistencies in altitude readings. These inconsistencies cause the spikiness in the vertical speed graphs. Even the most advanced barometric altimeter in the world would be susceptible to this issue.
Q: Is SonoAlti water resistent?
A: No it is not. If the altimeter is submerged in water it will sustain damage.
Q: I can't hear my freefall alarms. Why is that?
A: There could be multiple reasons. First, make sure that you have the speaker (the hole in SonoAlti) pointed towards your ear.
Also make sure you have chosen an alarm that was intended for freefall (see this page for a list of all alarms). SonoAlti has been engineered to be very loud. If you cannot hear it and you have it
turned up all the way and facing the correct direction, you may consider wearing earplugs, as you are likely experiencing very high sound pressure levels.
Q: Is there a differentiation between canopy and freefall alarms?
A: Yes. Users can choose from 64 possible alarms for any of the four types of alarms. SonoAlti differentiates between the four types of alarms in the following order of precedence: freefall, canopy, speed tracker, ascent. The volume of each of these types of alarms can be set independently. Freefall alarms are continuous as long as the jumper exceeds freefall speeds. Canopy alarms last for a span of 50 feet (or 150 feet in Swoop Mode). Ascent alarms last approximately three seconds.
Q: Can SonoAlti play audio files or speak the altitude one is currently at?
A: No it cannot. SonoAlti does not contain an output for an earplug or headphones, which is generally required to understand speech in freefall.
Q: I am hearing an alarm I didn't set at 1000 feet on ascent. What is this?
A: SonoAlti has a low-battery warning when there are only a few jumps remaining on the unit. This consists of a five-second beep at 1000 feet.
Q: I notice some deviation between my wrist-mounted altimeter and my audible. Is this normal? Which is correct?
A: Yes. Because barometric altimeters are subject to wakes and burbles, their placement can affect their readings. Which is closer in accuracy will depend on the type of jump you are doing and how you have the altimeters mounted. In most cases, the deviation is not larger than a couple hundred feet at the very most. If the deviation is more, see whether the altimeters are at least synchronized during ascent in the plane and go from there. If they are synchronized in the plane or under canopy but not in freefall, then the placement of the altimeters is certainly affecting their synchronization in freefall. Altimeters placed in a wake will read higher than those in clean air. So if you are, for example, sit-flying or doing a tandem, it isn't an unlikely possibility that your altimeter is being subjected to a significant burble.
Q: I am a swooper concerned about synchronization of my altimeters. How can I be sure they are synchronized?
A: See the answer above. Our altimeters are very accurate but different manufacturers use different algorithms in their firmware. Test the synchronization and the consistency of your altimeters' synchronization out before attempting high performance landings. It is possible to adjust the landing zone elevation as well if you think this is affecting your altimeter.
Q: Does Freefall Data Systems LLC collect data from its customers?
A: Nothing other than the information required to ship and provide a warranty to our customers. We respect our customer's privacy: Freefall Data Systems LLC's philosophy is that if a customer bought our product, then the data gathered with it should belong to them.