Mastering Dungeon Synth, Ambient, and Underground Metal for Cassette and Bandcamp

If you record dungeon synth in a cold room at 2 a.m., or you mix ambient drones meant to be played end to end on a Type II cassette, most of the loudness advice online was not written with you in mind. A lot of it targets rap, pop, and radio ready country. The numbers that come with that world (hot streaming masters, aggressive limiting, chart competitive levels) don't really translate to the music we care about at Vandal Mastering.

This is the guide I wish existed when I started mastering for small labels. It covers what actually matters when your release is going to a small run cassette label, a Bandcamp lossless download, and maybe a Spotify upload as an afterthought.

Why underground genres need a different approach....

Dungeon synth, black ambient, drone, and raw black metal all share a few traits that tend to break generic mastering assumptions:

Dynamic range is part of the aesthetic. A quiet passage before a wall of sound is not a mixing error. It's the point. Most mastering AI flattens it because it was trained on Top 40 songs.

Cassette is a real format, not a novelty. Small tape labels treat the cassette as the canonical release, and that changes every decision in the mastering chain.

Bandcamp is where the audience actually listens. Bandcamp doesn't normalize loudness, so the file you upload is the file people download and play (Bandcamp Help Center; Mat Leffler Schulman). Chasing Spotify's normalization reference for a Bandcamp first release is usually the wrong move.

If your master sounds squashed and lifeless on a good pair of headphones, no amount of SEO is going to help you move tapes.

The 2026 loudness reality check

Streaming platforms normalize loudness now. Master too loud and the platform quietly turns your track down. Master with dynamics intact and it plays back at the same level as anything else.

Here's roughly where each platform sits in 2026:

For most of the work I take on, I'm mastering somewhere between 11 and 8 LUFS below full scale integrated, depending on the mix and what the artist wants. That's louder than the "streaming safe" reference numbers you see repeated online, but it's how I get a record to feel finished and confident without crushing what makes the music interesting. If a track sounds right at that level with the dynamics intact, streaming platforms just turn it down a touch on playback and no one notices.

Cassette mastering, and what actually changes

Cassette duplication is unforgiving of two things: uncontrolled low end and hyped top end. Both create noise, distortion, and imaging problems that magnify across a duplication run.

Working numbers I use for cassette:

Integrated loudness anywhere from about 16 to 10 LUFS below full scale depending on the record (Tape Lab; Tape Lab 2026 guide)

True peak at 1.0 dBFS or lower

Peak level per plant: many duplication houses ask for 3 dBFS peaks or lower, some specify 6 dBFS.

Low end: high pass below 30 Hz, gentle shaping up to 50 Hz, sometimes a small bump around 80 Hz so the bass still feels present without muddying the tape.

Top end: no need to hype above 10 kHz. Cassette bias adds its own high frequency character, and pre hyping just stacks with duplication distortion.

File format for the plant: 24 bit WAV at the session sample rate, Side A and Side B clearly labeled, intentional track spacing baked in.

The most common thing I see from labels sending premasters is that the mix was already limited hard for streaming. There's nothing left for the tape to work with, and the duplication run turns those crushed transients into audible distortion.

If you can, send at least 3 dB of headroom on the mix bus and skip the master bus limiter. Let the mastering pass make the cassette specific calls.

Bandcamp: master for the download, not the stream

Bandcamp streams a lower bitrate MP3 preview in the browser (around 128 kbps) but delivers the actual lossless file on purchase or free download (mp3.now). Two things follow:

Upload your real lossless master. WAV at 24 bit / 44.1 kHz minimum. Uploading MP3s is discouraged by Bandcamp itself.

Leave a little headroom for transcoding. For 24 bit uploads Bandcamp asks for at least 0.5 dB of headroom to avoid clipping in the transcoded playback formats (Bandcamp Help Center on 24 bit uploads).

Because Bandcamp doesn't normalize, the master you upload is the master people hear. If a listener is playing a 40 minute dungeon synth album end to end on decent headphones, the dynamics you left in are doing real work.

If your release is streaming only, one master around 11 to 9 LUFS below full scale integrated at 1 dBTP, 24 bit WAV, will cover every platform without separate uploads. For the labels I usually work with, though, cassette and Bandcamp are the primary formats, and streaming is a byproduct.

What I ask for when you send a project

A lot of artists in these genres self record, which is a strength rather than a problem. It just changes what I need from you to do good work:

High resolution, uncompressed mix files. WAV, 24 bit if possible. No MP3 sources.

At least 3 dB of headroom on the mix bus, and no limiter on the master bus.

Metadata: artist name, track titles in play order, desired spacing and fades, sample rate and bit depth, any reference tracks that capture the sound you're going for.

Special instructions: cassette side breaks, dynamic passages you want preserved, spots where noise or hiss is intentional and should survive noise reduction.

Format goals: tell me whether this release is cassette first, Bandcamp first, streaming first, or all three. That decision shapes the whole chain.

I work on a pay what you can model because the music I love doesn't come out of a system with big advances. Most of my work is full albums rather than singles, mastered as one continuous listen from start to finish.

Vandal Mastering is a small mastering service built around independent music: dungeon synth, ambient, drone, black metal, and everything adjacent. I take cassette seriously as a format, I upload lossless files the way Bandcamp asks me to, and I'm not trying to squeeze every last dB out of a record to chase a normalization curve. If you're finishing an album for a small tape label or your own Bandcamp page and you want a mastering engineer who understands why your release doesn't need to sound like a Top 40 pop song, reach out through email: vandalorum.music@gmail.com

Frequently asked questions:

What LUFS should I master dungeon synth to?

There's no single right answer, but for the records I work on I usually land somewhere between 11 and 8 LUFS below full scale integrated with a 1 dBTP ceiling. That's louder than the "streaming safe" numbers you'll see quoted online, and it still leaves enough breathing room for the quiet passages the genre depends on. Streaming platforms will just turn a hot master down on playback.

Do I need a separate master for cassette?

If the cassette is a real release rather than a promo bonus, yes. Cassette specific masters handle the peak levels the duplication plant asks for (often 3 dBFS or lower), tape appropriate low end control, and Side A / Side B assembly with intentional spacing. A hot streaming master will noticeably distort on tape.

Should I upload the same master to Bandcamp and Spotify?

You can, and plenty of artists do. But Bandcamp doesn't normalize playback and Spotify does (Not Noise). For records with a lot of dynamic range, a slightly quieter, more open Bandcamp master rewards listeners who buy the download, while the streaming master hits the platform reference cleanly.

What files should I send for mastering?

Send a single stereo mix bounce per track as 24 bit WAV, with at least 3 dB of headroom and no master bus limiter. Include artist and track names, track order, spacing preferences, and any reference tracks that capture what you're going for.

Do you master genres outside dungeon synth and ambient?

Yes. Most of my regular work is dungeon synth, ambient, drone, and black metal, but I'm open to related underground genres too.