Notes on audio, from people who live in it
Formats and bitrates, keys and tempo, edits and recordings. Plain answers to the questions our free tools get asked, no fluff, no farmed content.
How to Train an RVC Voice Model: Data, Epochs, Settings
Training an RVC model comes down to three things: clean vocals, the right number of epochs, and testing before you trust it. Here is what each one means, with numbers from the RVC project itself.
Best RVC Settings: Pitch, Index Rate, Protect Explained
Most bad RVC conversions are a settings problem or an input problem, not a model problem. Here is what each setting does, a safe place to start, and what to change when it sounds wrong.
How to Use RVC on a Mac (Apple Silicon Guide)
Most RVC guides assume Windows and an NVIDIA graphics card. RVC does run on Apple Silicon Macs, though. Here are the three realistic ways to set it up and what each one costs you in time.
Applio vs RVC WebUI: What's the Difference?
Short answer: RVC is the voice conversion technology and the original WebUI is the project's own interface. Applio is a separate, open-source app built on top of RVC. Here is how they compare.
Where to Find RVC Voice Models (After Weights.gg)
Weights.gg was where a lot of people found and used RVC voice models. With it gone, here is where models are shared now, what to check before downloading, and why making your own is often better.
How to Merge Two RVC Models Into a New Voice
Blend two RVC voice models and you get a new original voice that sounds like neither of them. Here is how merging works, which models can mix, and how to do it without Python.
How to Use an RVC Model for Text to Speech (No Python)
RVC changes one voice into another, so it needs audio to start from. Here is how to make any RVC model read typed text: what the chain looks like, how to build it yourself, and how to do it in one click.
RVC vs TTS: What Each Does and How to Use Both
RVC and text to speech get mixed up because both make a voice say things. One starts from audio and one starts from text. Here is the difference, when to use each, and why chaining them is so useful.
How to Convert a Song to MIDI (Free, No Upload)
A song file holds sound, not notes. Here is how to get the notes out anyway: pull out the part you want, run a free AI note detector on it, and tidy the MIDI before it goes into your DAW.
432 Hz vs 440 Hz: Is 432 Better? Not Really
432 Hz tuning lowers a song by about a third of a semitone. Here is what that does to the sound, why 440 became the standard, where the bigger claims about 432 Hz and 528 Hz came from, and how to test the difference on your own music.
How to Make 8D Audio (Free, in Your Browser)
8D audio makes a song sound like it is circling your head. It is not eight dimensions of anything, just panning and a little room sound applied to a whole song. Here is how it works, how to make it free, and the settings that sound best.
How to Remove Background Noise From Audio
Hiss, hum, fans, and room noise can spoil a good recording. Here is how noise reduction works, how to clean a file for free without the underwater sound, what it cannot fix, and how to record cleaner in the first place.
Make Audio Louder Without Distortion (Free)
A recording that is too quiet is easy to fix and just as easy to ruin. Here is how to make audio louder without distortion, when to boost and when to normalize, what LUFS means, and the loudness streaming services actually play at.
WhatsApp Voice Note to MP3: Free, No Upload
WhatsApp voice notes are .opus files, and a surprising amount of software refuses to open them. Here is how to get the file off your phone and convert it to MP3 privately, right in your browser.
How to Make a Ringtone From a Song (Free, in Browser)
The best ringtone is the 20 to 30 seconds where the song becomes itself, not the intro. Here is how to cut it free in your browser and get it onto Android or iPhone, including the honest iPhone part.
How to Merge Audio Files Into One, Free and Private
Phone split your lecture in half, or your interview into three parts? Here is how to merge audio files into one clean file, and why naive concatenation gives you chipmunk audio when sample rates don't match.
Opus vs MP3: Opus Wins on Quality per Bit
Opus beats MP3 on quality per bit, dramatically at low bitrates. MP3 plays on everything. The right call is a compatibility decision, not a loyalty test.
How to Find the BPM of a Song: 3 Easy Ways
Three real ways to get a song's tempo: tap quarter notes by ear, read it in your DAW, or drop the file on a free in-browser analyzer. Plus how to dodge the half-time trap and handle tempo drift.
How to Find the Key of a Song: By Ear, Chords, or Analyzer
Three dependable ways to find a song's key: by ear, from the chords, or with a free in-browser analyzer. Plus what the Camelot wheel does and what to do with the key once you have it.
Best MP3 Bitrate for Music: 128 vs 192 vs 256 vs 320
An honest comparison of 128, 192, 256, and 320 kbps MP3: what the encoder actually discards, why converting a low bitrate up never helps, and which number fits archiving, demos, and car USB sticks.
FLAC vs MP3: What Lossless Really Means
Most people cannot reliably tell a 320 kbps MP3 from FLAC on normal gear, and that is fine. Here is what lossless actually buys you, when to convert each way, and what happens when you do.
WAV vs MP3: What Producers Should Use and When
WAV belongs inside the studio and MP3 belongs everywhere else. Here is where each format earns its place, and why bouncing to MP3 early is the mistake that surfaces a year later.
How to Make a Slowed and Reverb Edit (Free)
The slowed and reverb aesthetic is three moves: slower tempo, lower pitch, and a wash of space. Here is how to make one with a free browser tool and any audio editor, and how to pick the right amount of slowdown.
How to Make Nightcore (Free, in Your Browser)
Nightcore is the slowed and reverb edit run in reverse: sped up, pitched up, bright, and fast. Here is how to make one free in your browser, how much speed to add, and why the vocals come out sounding the way they do.
How to Record System Audio on Mac (Free, No Install)
Your Mac gives you no simple built-in way to record the sound it plays. Here is the free browser trick that captures system audio straight to WAV, plus the driver route for when you need more.
How to Change the Pitch of a Song, 3 Ways
Changing the pitch of a song means three different things: transposing into your vocal range, varispeed like tape, or slowing down for practice. Here is how each works and what it costs in sound quality.
Convert Voice Memos to MP3 (Free, Private, In-Browser)
iPhone voice memos are M4A files, and not everything plays them. Here is how to get a recording off your phone and convert it to MP3 in your browser, with nothing uploaded.
M4A vs MP3: M4A Sounds Better at Low Bitrates
AAC is the better codec on paper, but MP3 plays on everything. An honest look at when the difference matters and when converting costs more than it gains.
Is AIFF Better Than WAV? No, Same Audio
AIFF and WAV hold exactly the same uncompressed PCM audio. The real differences are metadata, platform history, and which software expects which wrapper.