diff --git a/agb/src/display/tiled/infinite_scrolled_map.rs b/agb/src/display/tiled/infinite_scrolled_map.rs
index 4021494b..391395ab 100644
--- a/agb/src/display/tiled/infinite_scrolled_map.rs
+++ b/agb/src/display/tiled/infinite_scrolled_map.rs
@@ -157,7 +157,7 @@ impl<'a> InfiniteScrolledMap<'a> {
     /// # );
     /// #
     /// # let vblank = agb::interrupt::VBlank::get();
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// let start_position = agb::fixnum::Vector2D::new(10, 10);
     /// backdrop.init(&mut vram, start_position, &mut || {
     ///     vblank.wait_for_vblank();
@@ -232,7 +232,7 @@ impl<'a> InfiniteScrolledMap<'a> {
     /// # );
     /// #
     /// # let vblank = agb::interrupt::VBlank::get();
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// let start_position = agb::fixnum::Vector2D::new(10, 10);
     /// while backdrop.init_partial(&mut vram, start_position) == PartialUpdateStatus::Continue {
     ///     vblank.wait_for_vblank();
diff --git a/agb/src/sound/mixer/mod.rs b/agb/src/sound/mixer/mod.rs
index c7fef302..64b82c46 100644
--- a/agb/src/sound/mixer/mod.rs
+++ b/agb/src/sound/mixer/mod.rs
@@ -14,17 +14,11 @@
 //!
 //! # Concepts
 //!
-//! The mixer runs at a fixed frequency which is determined at compile time by enabling
-//! certain features within the crate. The following features are currently available:
-//!
-//! | Feature | Frequency |
-//! |---------|-----------|
-//! | none    | 10512Hz   |
-//! | freq18157 | 18157Hz |
-//! | freq32768[^32768Hz] | 32768Hz |
+//! The mixer runs at a fixed frequency which is determined at initialisation time by
+//! passing certain [`Frequency`] options.
 //!
 //! All wav files you use within your application / game must use this _exact_ frequency.
-//! You will get a compile error if you use the incorrect frequency for your file.
+//! If you don't use this frequency, the sound will play either too slowly or too quickly.
 //!
 //! The mixer can play both mono and stereo sounds, but only mono sound effects can have
 //! effects applied to them (such as changing the speed at which they play or the panning).
@@ -38,12 +32,17 @@
 //! ```rust,no_run
 //! # #![no_std]
 //! # #![no_main]
+//! use agb::sound::mixer::Frequency;
 //! # fn foo(gba: &mut agb::Gba) {
-//! let mut mixer = gba.mixer.mixer();
+//! let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
 //! mixer.enable();
 //! # }
 //! ```
 //!
+//! Pass a frequency option. This option must be used for the entire lifetime of the `mixer`
+//! variable. If you want to change frequency, you will need to drop this one and create a new
+//! one.
+//!
 //! ## Doing the per-frame work
 //!
 //! Then, you have a choice of whether you want to use interrupts or do the buffer swapping
@@ -55,9 +54,10 @@
 //! ```rust,no_run
 //! # #![no_std]
 //! # #![no_main]
+//! use agb::sound::mixer::Frequency;
 //! # fn foo(gba: &mut agb::Gba) {
-//! # let mut mixer = gba.mixer.mixer();
-//! # let vblank = agb::interrupt::VBlank::get();
+//! let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
+//! let vblank = agb::interrupt::VBlank::get();
 //! // Somewhere in your main loop:
 //! mixer.frame();
 //! vblank.wait_for_vblank();
@@ -70,10 +70,13 @@
 //! ```rust,no_run
 //! # #![no_std]
 //! # #![no_main]
+//! use agb::sound::mixer::Frequency;
 //! # fn foo(gba: &mut agb::Gba) {
-//! # let mut mixer = gba.mixer.mixer();
-//! # let vblank = agb::interrupt::VBlank::get();
+//! let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz32768);
+//! let vblank = agb::interrupt::VBlank::get();
 //! // outside your main loop, close to initialisation
+//! // you must assign this to a variable (not to _ or ignored) or rust will immediately drop it
+//! // and prevent the interrupt handler from firing.
 //! let _mixer_interrupt = mixer.setup_interrupt_handler();
 //!
 //! // inside your main loop
@@ -99,7 +102,7 @@
 //! # #![no_std]
 //! # #![no_main]
 //! # fn foo(gba: &mut agb::Gba) {
-//! # let mut mixer = gba.mixer.mixer();
+//! # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
 //! # let vblank = agb::interrupt::VBlank::get();
 //! # use agb::{*, sound::mixer::*};
 //! // Outside your main function in global scope:
@@ -116,9 +119,6 @@
 //!
 //! Once you have run [`play_sound`](Mixer::play_sound), the mixer will play that sound until
 //! it has finished.
-//!
-//! [^32768Hz]: You must use interrupts when using 32768Hz
-
 mod hw;
 mod sw_mixer;
 
@@ -159,11 +159,10 @@ pub enum Frequency {
     Hz10512,
     /// 18157Hz
     Hz18157,
-    /// 32768Hz - note that this option requires the timer to do the buffer swapping
+    /// 32768Hz - note that this option requires interrupts for buffer swapping
     Hz32768,
 }
 
-// These work perfectly with swapping the buffers every vblank
 // list here: http://deku.gbadev.org/program/sound1.html
 impl Frequency {
     pub(crate) fn frequency(self) -> i32 {
@@ -223,7 +222,7 @@ impl Frequency {
 ///
 /// // somewhere in code
 /// # fn foo(gba: &mut Gba) {
-/// # let mut mixer = gba.mixer.mixer();
+/// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
 /// let mut bgm = SoundChannel::new_high_priority(MY_BGM);
 /// bgm.stereo().should_loop();
 /// let _ = mixer.play_sound(bgm);
@@ -242,7 +241,7 @@ impl Frequency {
 ///
 /// // somewhere in code
 /// # fn foo(gba: &mut Gba) {
-/// # let mut mixer = gba.mixer.mixer();
+/// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
 /// let jump_sound = SoundChannel::new(JUMP_SOUND);
 /// let _ = mixer.play_sound(jump_sound);
 /// # }
@@ -279,7 +278,7 @@ impl SoundChannel {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// // in global scope:
     /// const JUMP_SOUND: &[u8] = include_wav!("examples/sfx/jump.wav");
     ///
@@ -321,7 +320,7 @@ impl SoundChannel {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// // in global scope:
     /// const MY_BGM: &[u8] = include_wav!("examples/sfx/my_bgm.wav");
     ///
diff --git a/agb/src/sound/mixer/sw_mixer.rs b/agb/src/sound/mixer/sw_mixer.rs
index 4edc6107..44c17c4f 100644
--- a/agb/src/sound/mixer/sw_mixer.rs
+++ b/agb/src/sound/mixer/sw_mixer.rs
@@ -48,7 +48,7 @@ extern "C" {
 /// # use agb::sound::mixer::*;
 /// # use agb::*;
 /// # fn foo(gba: &mut Gba) {
-/// let mut mixer = gba.mixer.mixer();
+/// let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
 /// # }
 /// ```
 ///
@@ -60,13 +60,13 @@ extern "C" {
 /// # use agb::sound::mixer::*;
 /// # use agb::*;
 /// # fn foo(gba: &mut Gba) {
-/// # let mut mixer = gba.mixer.mixer();
+/// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
 /// # let vblank = agb::interrupt::VBlank::get();
 /// // Outside your main function in global scope:
 /// const MY_CRAZY_SOUND: &[u8] = include_wav!("examples/sfx/jump.wav");
 ///
 /// // in your main function:
-/// let mut mixer = gba.mixer.mixer();
+/// let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
 /// let mut channel = SoundChannel::new(MY_CRAZY_SOUND);
 /// channel.stereo();
 /// let _ = mixer.play_sound(channel);
@@ -99,7 +99,7 @@ pub struct Mixer {
 /// # use agb::sound::mixer::*;
 /// # use agb::*;
 /// # fn foo(gba: &mut Gba) {
-/// # let mut mixer = gba.mixer.mixer();
+/// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
 /// # const MY_BGM: &[u8] = include_wav!("examples/sfx/my_bgm.wav");
 /// let mut channel = SoundChannel::new_high_priority(MY_BGM);
 /// let bgm_channel_id = mixer.play_sound(channel).unwrap(); // will always be Some if high priority
@@ -142,7 +142,7 @@ impl Mixer {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// # let vblank = agb::interrupt::VBlank::get();
     /// loop {
     ///     mixer.frame();
@@ -171,7 +171,7 @@ impl Mixer {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// # let vblank = agb::interrupt::VBlank::get();
     /// // you must set this to a named variable to ensure that the scope is long enough
     /// let _mixer_interrupt = mixer.setup_interrupt_handler();
@@ -209,7 +209,7 @@ impl Mixer {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// # let vblank = agb::interrupt::VBlank::get();
     /// loop {
     ///     mixer.frame();
@@ -248,7 +248,7 @@ impl Mixer {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// # const MY_BGM: &[u8] = include_wav!("examples/sfx/my_bgm.wav");
     /// let mut channel = SoundChannel::new_high_priority(MY_BGM);
     /// let bgm_channel_id = mixer.play_sound(channel).unwrap(); // will always be Some if high priority
@@ -297,7 +297,7 @@ impl Mixer {
     /// # use agb::sound::mixer::*;
     /// # use agb::*;
     /// # fn foo(gba: &mut Gba) {
-    /// # let mut mixer = gba.mixer.mixer();
+    /// # let mut mixer = gba.mixer.mixer(agb::sound::mixer::Frequency::Hz10512);
     /// # const MY_BGM: &[u8] = include_wav!("examples/sfx/my_bgm.wav");
     /// let mut channel = SoundChannel::new_high_priority(MY_BGM);
     /// let bgm_channel_id = mixer.play_sound(channel).unwrap(); // will always be Some if high priority
diff --git a/examples/hyperspace-roll/Cargo.toml b/examples/hyperspace-roll/Cargo.toml
index 76c3f4bc..317e2525 100644
--- a/examples/hyperspace-roll/Cargo.toml
+++ b/examples/hyperspace-roll/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-agb = { version = "0.11.1", path = "../../agb", features = ["freq32768"] }
+agb = { version = "0.11.1", path = "../../agb" }
 bare-metal = "1"
 
 [profile.dev]
diff --git a/examples/hyperspace-roll/src/main.rs b/examples/hyperspace-roll/src/main.rs
index 9ec4cc1a..3df47f7d 100644
--- a/examples/hyperspace-roll/src/main.rs
+++ b/examples/hyperspace-roll/src/main.rs
@@ -10,11 +10,11 @@
 // which won't be a particularly clear error message.
 #![no_main]
 
-use agb::display;
 use agb::display::object::ObjectController;
 use agb::display::tiled::VRamManager;
 use agb::display::Priority;
 use agb::interrupt::VBlank;
+use agb::{display, sound::mixer::Frequency};
 
 extern crate alloc;
 use alloc::vec;
@@ -138,7 +138,7 @@ fn main(mut gba: agb::Gba) -> ! {
     let mut star_background = StarBackground::new(&mut background0, &mut background1, &mut vram);
     star_background.commit(&mut vram);
 
-    let mut mixer = gba.mixer.mixer();
+    let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
     mixer.enable();
     let _interrupt_handler = mixer.setup_interrupt_handler();
 
diff --git a/examples/the-hat-chooses-the-wizard/src/main.rs b/examples/the-hat-chooses-the-wizard/src/main.rs
index 133afb4e..eeffbe1d 100644
--- a/examples/the-hat-chooses-the-wizard/src/main.rs
+++ b/examples/the-hat-chooses-the-wizard/src/main.rs
@@ -17,6 +17,7 @@ use agb::{
     },
     fixnum::{FixedNum, Vector2D},
     input::{self, Button, ButtonController},
+    sound::mixer::Frequency,
 };
 use alloc::boxed::Box;
 
@@ -820,7 +821,7 @@ pub fn main(mut agb: agb::Gba) -> ! {
         vram.set_background_palettes(tile_sheet::background.palettes);
 
         let object = agb.display.object.get();
-        let mut mixer = agb.mixer.mixer();
+        let mut mixer = agb.mixer.mixer(Frequency::Hz10512);
 
         mixer.enable();
         let mut music_box = sfx::MusicBox::new();
diff --git a/examples/the-purple-night/Cargo.toml b/examples/the-purple-night/Cargo.toml
index 33f2e83d..eeac7e0f 100644
--- a/examples/the-purple-night/Cargo.toml
+++ b/examples/the-purple-night/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-agb = { path = "../../agb", version = "0.11.1", features = ["freq18157"]}
+agb = { path = "../../agb", version = "0.11.1" }
 generational-arena = { version = "0.2", default-features = false }
 
 [build-dependencies]
diff --git a/examples/the-purple-night/src/main.rs b/examples/the-purple-night/src/main.rs
index 07fc59cc..8ca239ef 100644
--- a/examples/the-purple-night/src/main.rs
+++ b/examples/the-purple-night/src/main.rs
@@ -22,6 +22,7 @@ use agb::{
     input::{Button, ButtonController, Tri},
     interrupt::VBlank,
     rng,
+    sound::mixer::Frequency,
 };
 use generational_arena::Arena;
 use sfx::Sfx;
@@ -2205,7 +2206,7 @@ fn game_with_level(gba: &mut agb::Gba) {
     let vblank = agb::interrupt::VBlank::get();
     vblank.wait_for_vblank();
 
-    let mut mixer = gba.mixer.mixer();
+    let mut mixer = gba.mixer.mixer(Frequency::Hz18157);
     mixer.enable();
 
     let mut sfx = sfx::Sfx::new(&mut mixer);