SirenAlti is FDS’s upcoming audible altimeter built around synthesized siren and tone alarms driven by dual speakers. It is currently in development—coming soon.

No. Unlike VoxAlti and MetaAlti, SirenAlti communicates entirely through synthesized tones—beeps and sirens—rather than speech.

Yes! It works with our online logging system FDS Logbook.

Yes, SirenAlti is waterproof to IP67.

Yes—SirenAlti will ship with an optional, per-preset Tactical Mode intended for specialized low-altitude operations such as smokejumping and military static-line jumping. Tactical Mode should in no case be used for normal skydiving operations, as the altimeter functions entirely differently.

SirenAlti does not have GPS as that would reduce the battery life greatly and compromise dependability. Altitude measurements are based on barometric pressure changes.

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. Chest mounts deserve special mention: in freefall—and especially in a wingsuit—the largest burble forms around your center of mass, exactly where a chest mount sits. This makes chest-mounted altimeters the least accurate of all mounting locations in freefall—often off by many hundreds of feet. The deviation can even change direction as your body position changes (a wingsuit flare, for example), and every altimeter converges again under canopy once the air around you calms—which can make the audible seem to have “corrected itself” at pull time. It did not; the burble simply disappeared. See page 4 of the BPA Wingsuit Training Manual for more on altimeter placement in wingsuit flight.

SirenAlti is expected in September 2026. Follow FDS on social media or contact us for the latest on the release.