SyncHz 2.4.0 — Choritsu is now SyncHz

SyncHz 2.4.0 is the first release under the new name. Choritsu is now SyncHz (同频 in Chinese), and this release fixes the silent EQ in 2.3.0.

Choritsu is now SyncHz (同频)

• Same app, new name. The job comes first and the unit last: it syncs your output's hertz to the track.
• The bundle id and the EQ profile folder (~/Library/Application Support/Choritsu) are unchanged, so your settings and EQ profiles carry over.
• macOS may ask once more for Apple Music and audio access, because this build has a new signature.

The EQ no longer goes silent

In 2.3.0, turning on the EQ muted Apple Music and nothing came through. There were three causes, and all are fixed:

• SyncHz now declares audio input, which the hardened runtime requires before an app can read a process tap. Nothing is recorded.
• On DACs that also have a mic or line input, the tap is now read from the correct input stream.
• The tap follows the output device's own stream instead of a fixed 48 kHz stereo mixdown, so it works at every rate from 44.1 to 192 kHz.

If audio access is denied, SyncHz now refuses to start the EQ instead of muting Music.

An EQ that matches AutoEq and PEQdB

• Same filters. RBJ cookbook peaks and shelves, Equalizer APO BW Oct bandwidths, glued units (105Hz), comma decimals and multiple Preamp: lines.
• Re-fitted at every playback rate. AutoEq fits its published presets at 44.1 kHz and PEQdB fits at 48 kHz. Played as-is at 96 or 192 kHz, the top octave drifts by up to 4.3 dB. SyncHz re-fits each band at the playback rate, which brings real presets to within about 0.04 dB. The EQ panel shows the design rate (Fitted at 44.1 kHz), and you can change it.

Runs on Accelerate

• The filter cascade runs on Accelerate's vDSP_biquadD in double precision. 16 stereo bands at 192 kHz use about 0.55% of one core, down from about 10%.
• Parameter changes are handed to the audio thread without locks and crossfaded over 20 ms, so edits don't click. The output is protected against NaN and clipping.

Follow the track, or hold 48 kHz

By default the EQ runs at the track's own rate. If your DAC prefers a single rate, hold the EQ at 48 kHz from the EQ panel's processing-rate menu, and Core Audio does the conversion.

Also new

• 12 languages: English, 简体中文, 繁體中文, 日本語, 한국어, Deutsch, Español, Français, Italiano, Nederlands, Português (Brasil) and Русский. You can switch between them live from the ⋯ menu.
• New icon: a 96 kHz readout over two faded sine waves.
• Flat redesign: it looks the same on macOS 15 and 26, and a piano-key spectrum sits behind the EQ curve.
• macOS 15 Sequoia is now supported (2.3.0 required macOS 26).

Install

1. If Choritsu is running, quit it.

2. Open SyncHz-2.4.0.dmg and drag SyncHz to Applications.

3. This build is ad-hoc signed and is not notarized, because there is no Developer ID certificate yet. Check the SHA-256 below, then clear the quarantine flag before the first launch:

   xattr -dr com.apple.quarantine /Applications/SyncHz.app

4. Move the old Choritsu.app to the Trash.

Package

• macOS 15 or later
• Universal binary: Apple silicon and Intel
• SHA-256 SyncHz-2.4.0.dmg: 75938bcb1ceac222ef8d837d1acf0cb2c649a4f2a3b9401d296169c8660ecc97

Choritsu 2.3.0 — Update checking

Choritsu 2.3.0 adds an in-app update check.

What's new

• Choritsu now checks GitHub Releases once per launch, and on demand from Check for Updates… in the ⋯ menu. When a newer release exists, the menu offers to open its page.
• The check is an unauthenticated GET to a public endpoint. No account, no identifier, and no data about you or your library is sent, and nothing is cached to disk.
• Choritsu never downloads or installs an update by itself. These builds are ad-hoc signed, and an app in that state cannot replace itself without leaving a quarantined bundle that macOS refuses to launch — so the install stays a deliberate drag into Applications.
• Failures during the launch check stay silent; only a check you start yourself reports an error.
• Eleven new tests cover version ordering (2.2.10 above 2.2.9), v-prefixed tags, prerelease suffixes, a development build ahead of the latest release, and HTTP and transport failures. 24 tests pass in total.

Install

Two formats, same app — pick either.

• Choritsu-2.3.0.dmg — open it and drag Choritsu.app to Applications.
• Choritsu-2.3.0.zip — unzip and move Choritsu.app to Applications.

This build is ad-hoc signed and is not notarized, because a Developer ID certificate was not available for this release. If macOS quarantines the app, after verifying the checksum you can run:

xattr -dr com.apple.quarantine /Applications/Choritsu.app

Package

• macOS 26 or later
• Universal binary: Apple silicon and Intel
• SHA-256 Choritsu-2.3.0.dmg: add00e8a7b742c95f5b3d4686e87b28915eeb43d05bd0e2b2a24cc7452d0d33f
• SHA-256 Choritsu-2.3.0.zip: 4c209b4471db0c255125f7390a60c2d6e1e9e47c955958fc3d3d57f401553f23

Choritsu 2.2.1 — Safer sample-rate detection

Choritsu 2.2.1 is a maintenance release that hardens sample-rate detection against unrelated log metadata.

What's fixed

• Numeric fields in a JSON log record such as threadID or processID are no longer treated as sample-rate evidence. Six such records could previously satisfy the initial lock threshold and reach the automatic output-rate switch.
• Counter fields like sampleRateChangeCount no longer match as sample-rate keys.
• A JSON record's serialized text is no longer rescanned as an audio message, so metadata such as "metadata": "48 kHz" no longer produces a rate.
• Explicit sampleRate / mSampleRate fields, nested objects and arrays, and plain-text log messages all continue to work as before.
• Seven new parser regression tests join the existing six DSP tests (13 passing).

Reported and fixed by @chitacdcolorrrr in #5 / #6.

Install

This release ships in two formats — they contain the same app, pick either.

• Choritsu-2.2.1.dmg — open it and drag Choritsu.app to Applications.
• Choritsu-2.2.1.zip — unzip and move Choritsu.app to Applications (same format as earlier releases).

This build is ad-hoc signed and is not notarized, because a Developer ID certificate was not available for this release. If macOS quarantines the app, after verifying the checksum you can run:

xattr -dr com.apple.quarantine /Applications/Choritsu.app

Package

• macOS 26 or later
• Universal binary: Apple silicon and Intel
• SHA-256 Choritsu-2.2.1.dmg: afff172feddfd954fb3f92fc638403dcef693b1aeb6dddbe619a3fa6d38a0c33
• SHA-256 Choritsu-2.2.1.zip: 6a1a872b56941559efbd3160bffff6bd1da1afc77c7162a4103eff7f2f0cbb7c

Choritsu 2.2.0 — Safer realtime PEQ

Choritsu 2.2.0 rebuilds the PEQ interaction model and hardens its realtime audio path.

What's new

• Peak and Shelf handles now sit on their response-curve vertices.
• Use the mouse wheel over a band to adjust Q and see the curve update immediately.
• PEQ display and DSP use the active audio sample rate.
• Filter updates crossfade smoothly; bypass changes use a short ramp to avoid clicks.
• Safer handling of format/device changes and interleaved audio buffers.
• Automatic headroom, output limiting, stricter profile validation, and six DSP regression tests.

Install

Download Choritsu-2.2.0.zip, unzip it, and move Choritsu.app to Applications.

This build is ad-hoc signed and is not notarized, because a Developer ID certificate was not available for this release. If macOS quarantines the app, after verifying the checksum you can run:

xattr -dr com.apple.quarantine /Applications/Choritsu.app

Package

• macOS 26 or later
• Universal binary: Apple silicon and Intel
• SHA-256: 09ccbb02da20e5dca594c52d45c3339afc7203b4b0fe1d5c2a9e2fa0dc400a03

Choritsu 2.1.0 — Sharper EQ, new wave mark

Choritsu 2.1.0 sharpens the parametric EQ and refreshes the brand mark. The lossless sample-rate switching and the EQ engine itself are unchanged.

What's new

• New app icon & brand mark — two offset sine waves on sumi ink: a cream signal wave carrying two EQ band nodes, shadowed by a 利休-green afterimage (the output trailing the source as the sample rate shifts). Replaces the old boost-bell curve. The menu-bar icon and the panel's top-left logo use the same mark.
• EQ curve renders high-Q bands correctly — the response graph now samples each band's centre frequency, so narrow (high-Q) peaks show their true height and width instead of flattening out above Q≈1. Imported AutoEQ presets keep their full Q range.
• Glass UI polish — the EQ toolbar's Import / add / reset buttons are now uniform capsule glass; per-band enable checkboxes are tinted 利休 green; the EQ panel is a fixed size, so adding bands no longer makes the window jump.
• Smoother, lighter spectrum — neighbour-blended with a gentle attack so it reads as a soft envelope, and drawn on its own layer (64 bins @ 24 fps) so it no longer forces the static response curve to repaint.
• Instant EQ panel — opening the EQ no longer plays a transition that could stutter.
• Import dialog comes to the front — the AutoEQ file picker now activates the app instead of opening behind whatever's frontmost.

Install

1. Download Choritsu-2.1.0.zip, unzip, and move Choritsu.app to /Applications.
2. This build is ad-hoc signed (not notarized), so Gatekeeper blocks it on first launch. Clear the quarantine flag, then open:

   xattr -dr com.apple.quarantine /Applications/Choritsu.app
   

Requirements

• macOS 26 Tahoe or later
• Apple Music (subscription or local library)

On first run, macOS asks to control Music (Automation) and access Media & Apple Music. Turning on the EQ adds a one-time audio-recording prompt (the muted process tap).

Choritsu 2.0.1 — New wave mark

Choritsu 2.0.1 is a visual-identity update. The app behaves identically to 2.0 — this release exists to ship the new brand mark.

What's new

• New app icon — two offset sine waves on sumi ink forming a parametric-EQ response curve (a boost bell + a soft cut) with draggable band-handle nodes, shadowed by a 利休-green afterimage: the output following the source as the sample rate shifts. Built as two Icon Composer layers, so the system parallaxes them into real Liquid Glass depth.
• Matching marks everywhere — the menu-bar icon and the in-panel top-left logo now use the same wave mark (no more kanji).
• Repository renamed to apple-music-lossless-eq, with a refreshed README.

No changes to the lossless sample-rate switching or the parametric EQ since 2.0.

Install

1. Download Choritsu-2.0.1.zip, unzip, and move Choritsu.app to /Applications.
2. This build is ad-hoc signed (not notarized), so Gatekeeper blocks it on first launch. Clear the quarantine flag, then open:

   xattr -dr com.apple.quarantine /Applications/Choritsu.app
   

Requirements

• macOS 26 Tahoe or later
• Apple Music (subscription or local library)

On first run, macOS asks to control Music (Automation) and access Media & Apple Music. Turning on the EQ adds a one-time audio-recording prompt (the muted process tap).

Choritsu 2.0 — Headphone Parametric EQ

Choritsu 2.0 adds the feature I built the app for: a HiFi headphone parametric EQ that follows Apple Music — on top of the automatic, bit-perfect sample-rate switching from 1.0.

New

• Headphone & speaker parametric EQ — multi-band PEQ applied to Apple Music through a muted Core Audio process tap. No driver, no admin rights.
  • Import AutoEQ ParametricEQ.txt presets (one profile per pair of headphones)
  • Interactive response graph — drag a point for frequency × gain, scroll for Q
  • Live spectrum of the processed output, behind the curve
  • Coefficients recompute on every rate change, so a correction stays correct from 44.1 to 192 kHz
  • Opt-in, and clearly marked non-bit-perfect while active
• Wabi-sabi redesign — the accent moves from vermilion to a muted 利休 (Rikyū) green-gold; smoky 藍鼠 indigo spectrum, quiet 苔 moss "in sync".
• EQ panel docks to the right of the main panel as one continuous popover, localized for ja / zh-Hans / zh-Hant.

Still there

Automatic source-matched sample-rate switching (44.1 → 192 kHz), now-playing panel, transport, manual rate override, device picker, and hardware volume.

Install

Requires macOS 26 Tahoe or later. The build is ad-hoc signed and not notarized, so Gatekeeper will block it on first launch. After unzipping:

mv Choritsu.app /Applications/
xattr -dr com.apple.quarantine /Applications/Choritsu.app
open /Applications/Choritsu.app

On first run, allow control of Music (and audio recording when you turn the EQ on). Or build from source — see the README.

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调律 2.0：在 1.0 的自动采样率切换之上，加入了面向 HiFi 耳机/音箱的参数均衡器（PEQ）——跟随 Apple Music 音源，支持导入 AutoEQ 预设、拖动响应曲线、实时频谱、按耳机存档，无需驱动或管理员权限。界面改为侘寂风格（利休暗绿金）。需 macOS 26+；安装见上方命令。

Choritsu 1.0.0 · 調律

First public release of Choritsu（調律 / 调律） — automatic sample rate switching for Apple Music on macOS.

Highlights

• Auto-switches the default output device sample rate to match the current Apple Music track (bit-perfect, no Core Audio resampling)
• Liquid Glass panel: now playing with artwork, play/pause & skip, source → output rate view with manual override, output device picker, hardware volume slider
• Localized: English / 简体中文 / 繁體中文 / 日本語

Install

1. Download Choritsu-1.0.0-macOS.zip below and unzip
2. Move Choritsu.app to /Applications
3. First launch: right-click the app → Open → Open (this build is not notarized yet; alternatively run xattr -d com.apple.quarantine /Applications/Choritsu.app)
4. Allow the Automation → Music permission when prompted

Requires macOS 26 Tahoe or later.

安装说明

下载并解压 zip，把 Choritsu.app 拖入「应用程序」。本版本尚未公证，首次打开请右键 → 打开 → 打开（或执行上面的 xattr 命令移除隔离属性），并在弹窗中允许对 Music 的自动化控制权限。需要 macOS 26+。

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Inspired by LosslessSwitcher by Vincent Neo.