OpenAL - sources don't mute completely beyond maximum distance

my sources change in volume nicely between the reference distance and the maximum distance. however - all sources beyond the maximum distance i can hear too - theyr volume is low but they're not completely muted.

how to make sure that they get completely muted if they'开发者_StackOverflow社区re farther away than the maximum distance?

Platform is iOS.

Did you check the specification? Try configuring attenuation models to your needs. Make sure AL_MIN_GAIN is zero.