diff --git a/CHANGELOG.md b/CHANGELOG.md
index 616deb65..5809d563 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - HashMap iterators now implement `size_hint` which should result in slightly better generation of code using those iterators.
 - Transparency of backgrounds is now set once in the toml file rather than once for every image.
 - Palette generation now takes into account every single background a toml definition rather than one at a time, you can now find it in the PALETTES constant rather than in every individual image.
+- Sound frequency is no longer a crate feature, instead set when initialising the sound mixer.
 
 ### Fixed
 - Fixed the fast magnitude function in agb_fixnum. This is also used in fast_normalise. Previously only worked for positive (x, y).
diff --git a/agb-sound-converter/Cargo.toml b/agb-sound-converter/Cargo.toml
index 5d6f316d..caea2f60 100644
--- a/agb-sound-converter/Cargo.toml
+++ b/agb-sound-converter/Cargo.toml
@@ -18,10 +18,6 @@ debug = true
 [lib]
 proc-macro = true
 
-[features]
-freq18157 = []
-freq32768 = []
-
 [dependencies]
 hound = "3.5"
 syn = "1"
diff --git a/agb-sound-converter/src/lib.rs b/agb-sound-converter/src/lib.rs
index b04f280b..5cbc2446 100644
--- a/agb-sound-converter/src/lib.rs
+++ b/agb-sound-converter/src/lib.rs
@@ -6,15 +6,6 @@ use quote::{quote, ToTokens};
 use std::path::Path;
 use syn::parse_macro_input;
 
-#[cfg(all(not(feature = "freq18157"), not(feature = "freq32768")))]
-const FREQUENCY: u32 = 10512;
-#[cfg(feature = "freq18157")]
-const FREQUENCY: u32 = 18157;
-#[cfg(feature = "freq32768")]
-const FREQUENCY: u32 = 32768;
-#[cfg(all(feature = "freq18157", feature = "freq32768"))]
-compile_error!("Must have at most one of freq18157 or freq32768 features enabled");
-
 use quote::TokenStreamExt;
 struct ByteString<'a>(&'a [u8]);
 impl ToTokens for ByteString<'_> {
@@ -37,13 +28,6 @@ pub fn include_wav(input: TokenStream) -> TokenStream {
     let wav_reader = hound::WavReader::open(&path)
         .unwrap_or_else(|_| panic!("Failed to load file {}", include_path));
 
-    assert_eq!(
-        wav_reader.spec().sample_rate,
-        FREQUENCY,
-        "agb currently only supports sample rate of {}Hz",
-        FREQUENCY
-    );
-
     let samples: Vec<u8> = samples_from_reader(wav_reader).collect();
     let samples = ByteString(&samples);
 
diff --git a/agb/Cargo.toml b/agb/Cargo.toml
index 83afc851..29070813 100644
--- a/agb/Cargo.toml
+++ b/agb/Cargo.toml
@@ -17,8 +17,6 @@ debug = true
 
 [features]
 default = ["testing"]
-freq18157 = ["agb_sound_converter/freq18157"]
-freq32768 = ["agb_sound_converter/freq32768"]
 testing = []
 
 [dependencies]
@@ -34,7 +32,3 @@ rustc-hash =  { version = "1", default-features = false }
 [package.metadata.docs.rs]
 default-target = "thumbv6m-none-eabi"
 targets = []
-
-[[example]]
-name = "mixer_32768"
-required-features = ["freq32768"]
\ No newline at end of file
diff --git a/agb/examples/mixer_32768.rs b/agb/examples/mixer_32768.rs
index b10bf8d3..8dd38120 100644
--- a/agb/examples/mixer_32768.rs
+++ b/agb/examples/mixer_32768.rs
@@ -7,7 +7,7 @@ use agb::{
         Font, Priority,
     },
     include_font, include_wav,
-    sound::mixer::SoundChannel,
+    sound::mixer::{Frequency, SoundChannel},
     Gba,
 };
 
@@ -40,7 +40,7 @@ fn main(mut gba: Gba) -> ! {
     let mut timer = timer_controller.timer2;
     timer.set_enabled(true);
 
-    let mut mixer = gba.mixer.mixer();
+    let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
     mixer.enable();
     let _interrupt = mixer.setup_interrupt_handler();
 
diff --git a/agb/examples/mixer_basic.rs b/agb/examples/mixer_basic.rs
index 1419562b..e3fc76f9 100644
--- a/agb/examples/mixer_basic.rs
+++ b/agb/examples/mixer_basic.rs
@@ -3,7 +3,7 @@
 
 use agb::fixnum::Num;
 use agb::input::{Button, ButtonController, Tri};
-use agb::sound::mixer::SoundChannel;
+use agb::sound::mixer::{Frequency, SoundChannel};
 use agb::{fixnum::num, include_wav, Gba};
 
 // Music - "Dead Code" by Josh Woodward, free download at http://joshwoodward.com
@@ -14,7 +14,7 @@ fn main(mut gba: Gba) -> ! {
     let mut input = ButtonController::new();
     let vblank_provider = agb::interrupt::VBlank::get();
 
-    let mut mixer = gba.mixer.mixer();
+    let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
     mixer.enable();
 
     let channel = SoundChannel::new(DEAD_CODE);
diff --git a/agb/examples/stereo_sound.rs b/agb/examples/stereo_sound.rs
index ca293cf5..66dbcdee 100644
--- a/agb/examples/stereo_sound.rs
+++ b/agb/examples/stereo_sound.rs
@@ -7,7 +7,7 @@ use agb::{
         Font, Priority,
     },
     include_font, include_wav,
-    sound::mixer::SoundChannel,
+    sound::mixer::{Frequency, SoundChannel},
     Gba,
 };
 
@@ -40,7 +40,7 @@ fn main(mut gba: Gba) -> ! {
     let mut timer = timer_controller.timer2;
     timer.set_enabled(true);
 
-    let mut mixer = gba.mixer.mixer();
+    let mut mixer = gba.mixer.mixer(Frequency::Hz10512);
     mixer.enable();
 
     let mut channel = SoundChannel::new(LET_IT_IN);
diff --git a/agb/src/display/tiled/infinite_scrolled_map.rs b/agb/src/display/tiled/infinite_scrolled_map.rs
index 773ff782..ed30997d 100644
--- a/agb/src/display/tiled/infinite_scrolled_map.rs
+++ b/agb/src/display/tiled/infinite_scrolled_map.rs
@@ -160,7 +160,7 @@ 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();
@@ -235,7 +235,7 @@ 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 ac01dba7..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;
 
@@ -138,8 +138,8 @@ impl MixerController {
     }
 
     /// Get a [`Mixer`] in order to start producing sounds.
-    pub fn mixer(&mut self) -> Mixer {
-        Mixer::new()
+    pub fn mixer(&mut self, frequency: Frequency) -> Mixer {
+        Mixer::new(frequency)
     }
 }
 
@@ -149,6 +149,43 @@ enum SoundPriority {
     Low,
 }
 
+/// The supported frequencies within AGB. These are chosen to work well with
+/// the hardware. Note that the higher the frequency, the better the quality of
+/// the sound but the more CPU time sound mixing will take.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum Frequency {
+    /// 10512Hz
+    Hz10512,
+    /// 18157Hz
+    Hz18157,
+    /// 32768Hz - note that this option requires interrupts for buffer swapping
+    Hz32768,
+}
+
+// list here: http://deku.gbadev.org/program/sound1.html
+impl Frequency {
+    pub(crate) fn frequency(self) -> i32 {
+        use Frequency::*;
+
+        match self {
+            Hz10512 => 10512,
+            Hz18157 => 18157,
+            Hz32768 => 32768,
+        }
+    }
+
+    pub(crate) fn buffer_size(self) -> usize {
+        use Frequency::*;
+
+        match self {
+            Hz10512 => 176,
+            Hz18157 => 304,
+            Hz32768 => 560,
+        }
+    }
+}
+
 /// Describes one sound which should be playing. This could be a sound effect or
 /// the background music. Use the factory methods on this to modify how it is played.
 ///
@@ -185,7 +222,7 @@ enum SoundPriority {
 ///
 /// // 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);
@@ -204,7 +241,7 @@ enum SoundPriority {
 ///
 /// // 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);
 /// # }
@@ -241,7 +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");
     ///
@@ -283,7 +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 80b5b139..44c17c4f 100644
--- a/agb/src/sound/mixer/sw_mixer.rs
+++ b/agb/src/sound/mixer/sw_mixer.rs
@@ -1,12 +1,14 @@
 use core::cell::RefCell;
-use core::intrinsics::transmute;
 
+use alloc::boxed::Box;
+use alloc::vec::Vec;
 use bare_metal::{CriticalSection, Mutex};
 
-use super::hw;
 use super::hw::LeftOrRight;
+use super::{hw, Frequency};
 use super::{SoundChannel, SoundPriority};
 
+use crate::InternalAllocator;
 use crate::{
     fixnum::Num,
     interrupt::free,
@@ -46,7 +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);
 /// # }
 /// ```
 ///
@@ -58,13 +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);
@@ -80,6 +82,7 @@ pub struct Mixer {
     buffer: MixerBuffer,
     channels: [Option<SoundChannel>; 8],
     indices: [i32; 8],
+    frequency: Frequency,
 
     timer: Timer,
 }
@@ -96,7 +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
@@ -108,9 +111,10 @@ pub struct Mixer {
 pub struct ChannelId(usize, i32);
 
 impl Mixer {
-    pub(super) fn new() -> Self {
+    pub(super) fn new(frequency: Frequency) -> Self {
         Self {
-            buffer: MixerBuffer::new(),
+            frequency,
+            buffer: MixerBuffer::new(frequency),
             channels: Default::default(),
             indices: Default::default(),
 
@@ -123,7 +127,7 @@ impl Mixer {
     /// You must call this method in order to start playing sound. You can do as much set up before
     /// this as you like, but you will not get any sound out of the console until this method is called.
     pub fn enable(&mut self) {
-        hw::set_timer_counter_for_frequency_and_enable(&mut self.timer, constants::SOUND_FREQUENCY);
+        hw::set_timer_counter_for_frequency_and_enable(&mut self.timer, self.frequency.frequency());
         hw::set_sound_control_register_for_mixer();
     }
 
@@ -138,7 +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();
@@ -167,7 +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();
@@ -184,7 +188,7 @@ impl Mixer {
             .set_cascade(true)
             .set_divider(Divider::Divider1)
             .set_interrupt(true)
-            .set_overflow_amount(constants::SOUND_BUFFER_SIZE as u16)
+            .set_overflow_amount(self.frequency.buffer_size() as u16)
             .set_enabled(true);
 
         add_interrupt_handler(timer1.interrupt(), move |cs| self.buffer.swap(cs))
@@ -205,7 +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();
@@ -244,7 +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
@@ -293,7 +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
@@ -313,47 +317,32 @@ impl Mixer {
     }
 }
 
-// These work perfectly with swapping the buffers every vblank
-// list here: http://deku.gbadev.org/program/sound1.html
-#[cfg(all(not(feature = "freq18157"), not(feature = "freq32768")))]
-mod constants {
-    pub const SOUND_FREQUENCY: i32 = 10512;
-    pub const SOUND_BUFFER_SIZE: usize = 176;
-}
-
-#[cfg(feature = "freq18157")]
-mod constants {
-    pub const SOUND_FREQUENCY: i32 = 18157;
-    pub const SOUND_BUFFER_SIZE: usize = 304;
-}
-
-#[cfg(feature = "freq32768")]
-mod constants {
-    pub const SOUND_FREQUENCY: i32 = 32768;
-    pub const SOUND_BUFFER_SIZE: usize = 560;
-}
-
-fn set_asm_buffer_size() {
+fn set_asm_buffer_size(frequency: Frequency) {
     extern "C" {
         static mut agb_rs__buffer_size: usize;
     }
 
     unsafe {
-        agb_rs__buffer_size = constants::SOUND_BUFFER_SIZE;
+        agb_rs__buffer_size = frequency.buffer_size();
     }
 }
 
-#[repr(C, align(4))]
-struct SoundBuffer([i8; constants::SOUND_BUFFER_SIZE * 2]);
+struct SoundBuffer(Box<[i8], InternalAllocator>);
 
-impl Default for SoundBuffer {
-    fn default() -> Self {
-        Self([0; constants::SOUND_BUFFER_SIZE * 2])
+impl SoundBuffer {
+    fn new(frequency: Frequency) -> Self {
+        let my_size = frequency.buffer_size() * 2;
+        let mut v = Vec::with_capacity_in(my_size, InternalAllocator);
+        v.resize(my_size, 0);
+
+        SoundBuffer(v.into_boxed_slice())
     }
 }
 
 struct MixerBuffer {
     buffers: [SoundBuffer; 3],
+    working_buffer: Box<[Num<i16, 4>], InternalAllocator>,
+    frequency: Frequency,
 
     state: Mutex<RefCell<MixerBufferState>>,
 }
@@ -391,16 +380,26 @@ impl MixerBufferState {
 }
 
 impl MixerBuffer {
-    fn new() -> Self {
-        set_asm_buffer_size();
+    fn new(frequency: Frequency) -> Self {
+        let mut working_buffer =
+            Vec::with_capacity_in(frequency.buffer_size() * 2, InternalAllocator);
+        working_buffer.resize(frequency.buffer_size() * 2, 0.into());
 
         MixerBuffer {
-            buffers: Default::default(),
+            buffers: [
+                SoundBuffer::new(frequency),
+                SoundBuffer::new(frequency),
+                SoundBuffer::new(frequency),
+            ],
+
+            working_buffer: working_buffer.into_boxed_slice(),
 
             state: Mutex::new(RefCell::new(MixerBufferState {
                 active_buffer: 0,
                 playing_buffer: 0,
             })),
+
+            frequency,
         }
     }
 
@@ -413,15 +412,16 @@ impl MixerBuffer {
 
         let (left_buffer, right_buffer) = self.buffers[buffer]
             .0
-            .split_at(constants::SOUND_BUFFER_SIZE);
+            .split_at(self.frequency.buffer_size());
 
         hw::enable_dma_for_sound(left_buffer, LeftOrRight::Left);
         hw::enable_dma_for_sound(right_buffer, LeftOrRight::Right);
     }
 
     fn write_channels<'a>(&mut self, channels: impl Iterator<Item = &'a mut SoundChannel>) {
-        let mut buffer: [Num<i16, 4>; constants::SOUND_BUFFER_SIZE * 2] =
-            unsafe { transmute([0i16; constants::SOUND_BUFFER_SIZE * 2]) };
+        set_asm_buffer_size(self.frequency);
+
+        self.working_buffer.fill(0.into());
 
         for channel in channels {
             if channel.is_done {
@@ -434,7 +434,7 @@ impl MixerBuffer {
                 channel.playback_speed
             };
 
-            if (channel.pos + playback_speed * constants::SOUND_BUFFER_SIZE).floor()
+            if (channel.pos + playback_speed * self.frequency.buffer_size()).floor()
                 >= channel.data.len()
             {
                 // TODO: This should probably play what's left rather than skip the last bit
@@ -450,7 +450,7 @@ impl MixerBuffer {
                 unsafe {
                     agb_rs__mixer_add_stereo(
                         channel.data.as_ptr().add(channel.pos.floor()),
-                        buffer.as_mut_ptr(),
+                        self.working_buffer.as_mut_ptr(),
                         channel.volume,
                     );
                 }
@@ -461,7 +461,7 @@ impl MixerBuffer {
                 unsafe {
                     agb_rs__mixer_add(
                         channel.data.as_ptr().add(channel.pos.floor()),
-                        buffer.as_mut_ptr(),
+                        self.working_buffer.as_mut_ptr(),
                         playback_speed,
                         left_amount,
                         right_amount,
@@ -469,7 +469,7 @@ impl MixerBuffer {
                 }
             }
 
-            channel.pos += playback_speed * constants::SOUND_BUFFER_SIZE;
+            channel.pos += playback_speed * self.frequency.buffer_size();
         }
 
         let write_buffer_index = free(|cs| self.state.borrow(cs).borrow_mut().active_advanced());
@@ -477,7 +477,7 @@ impl MixerBuffer {
         let write_buffer = &mut self.buffers[write_buffer_index].0;
 
         unsafe {
-            agb_rs__mixer_collapse(write_buffer.as_mut_ptr(), buffer.as_ptr());
+            agb_rs__mixer_collapse(write_buffer.as_mut_ptr(), self.working_buffer.as_ptr());
         }
     }
 }
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 9e1f4823..cd61df84 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::{TiledMap, 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 e5592fa3..b69c1a48 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::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 ce906f9a..922b4e3a 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);