Box sets: how to check your files

Roon reads disc-level information from three places: its own catalog, your file tags, and your folders.

Where the catalog has data, you get it without doing anything. Where it doesn’t, your files can supply it, and where neither does, the disc editor lets you fix it by hand.

This post is what Roon looks for in your files, so you can tell whether a missing title or cover is your files, our data, or a bug.

Organizing your files

Keep each box in one folder, with one subfolder per disc, named CD1, CD2 (or Disc 1, Disc 2 — Roman numerals work too). A disc folder can also carry a name after the number, such as “CD1 - Pearl”. See “Disc folders with names” below.

Tag every track with its disc number, and start each disc again at track 1 with no gaps.

Disc and track numbers can also come from filenames (2-01 Song.flac) or the folder names, so files that already carry them don’t need retagging. That part is unchanged from the existing guidance; see our existing multi-disc sets KB article.

Note: our existing article above has not yet been updated to incorporate the information in this post

Roon also reads:

A disc-title tag on each disc’s tracks, the disc’s own title. Roon looks for it in this order: DISCSUBTITLE, SETSUBTITLE, SET SUBTITLE, TSST, DISCNAME. DISCSUBTITLE is the standard tag that Picard, mp3tag, foobar2000 and MusicBee write. “SET SUBTITLE”, with a space, is what some other tag editors write.
A folder.jpg, cover.jpg, front.jpg or albumart image inside each disc’s subfolder, that image becomes the disc’s cover. The image in the box’s top folder stays the box’s cover.

Where there’s no disc-title tag, Roon will also try the disc’s own ALBUM tag and the disc folder’s name, but DISCSUBTITLE is the reliable route, and it’s the one to use when reporting.

A tidy box:


The Complete Studio Albums/
    folder.jpg                 ← box cover
    CD1/
        folder.jpg             ← disc 1 cover
        01 Track.flac          ← DISCNUMBER=1, DISCSUBTITLE=Pearl
    CD2/
        folder.jpg
        01 Track.flac          ← DISCNUMBER=2, DISCSUBTITLE=…

Disc folders with names

Folders such as “CD1 - Pearl”, “Disc 1 - Live at the Fillmore” or “CD1-Pearl” group as one box, as bare “CD1” folders do. Roon takes the disc number from the start of the folder name, and uses the rest of the name as a disc title.

Roon reads these separators after the disc marker: " - ", “-”, “:”, “_”, a space, or “.” without a digit after it. A folder that starts with only a number, such as “01 - Pablo Honey”, is a separate album.

Roon reads every folder that starts with a disc marker as a disc of its parent folder. For example, separate albums in “CD1 - Ten” and “CD2 - Vs.” in one artist folder can show as one album with two discs. Names such as “CD 2 Pac” can do the same. If albums merge that should not, please tell us.

What you’ll see, and the rules that keep things hidden

Each disc can show a title, a year, a cover, and a link to the original album it reproduces. Three rules decide whether those appear, and all three are deliberate:

Disc titles show only when at least two discs have different titles. If every disc carries the same title, you see “Disc 1”, “Disc 2”.
Disc covers show only where discs differ. If every disc folder holds a copy of the same image, Roon uses the art embedded in each disc’s files instead.
Album links show only when at least two discs link to different albums. A linked disc shows that album’s original release year and cover. It also shows an Other versions button when the linked album is in your library or on one of your streaming services.

Links come from Roon’s catalog, from albums you merged into the box, or from identifying a disc yourself in the disc editor.

A box of four or more discs gets a scroll ruler beside the track list. It shows years when every disc has one and they run in chronological order with at least two different years; otherwise it shows disc numbers. On phones and tablets it’s a drag flag only.

Disc preferences in Import settings

Settings > Library > Import settings has a section named Metadata preferences for discs. It sits between the album and track sections, and decides whether Roon’s data or your file tags win for disc titles, years and artwork.

Setting	Choices	Default
Disc title	Prefer Roon, Prefer file	Prefer Roon
Disc year	Prefer Roon, Prefer file	Prefer Roon
Disc artwork	Prefer Roon, Prefer file, Prefer best	Prefer best

Every library starts at these defaults. If your files carry the disc titles and years you want, set those settings to Prefer file.

These settings apply to every disc that has no preference of its own. Roon decides each disc’s title, year and artwork in this order:

A value you type in the disc editor.
For title and year: the album you identified the disc as.
The preference you set for that disc in the disc editor.
The library setting above.

For artwork, the cover of the album you identified the disc as is used with Prefer Roon and Prefer best. With Prefer file, Roon uses the disc’s own image, and uses that cover only when the disc has no image.

With Disc year set to Prefer file, Roon reads ORIGINALDATE, then DATE. When neither tag is there, it uses a year in the folder name, or a year in brackets in the ALBUM tag. When every disc has the same file year, Roon reads it as the year of the box, and does not show it on each disc.

Rescanning

After changing tags or adding images to files Roon already has, rescan them. New folder covers can take a few minutes to appear on a large box.

To regroup a box that was split into one album per disc because of its folder names:

Select all of the box’s albums together.
Choose Rescan from the context menu.

Settings > Storage > Force Scan does not regroup them, because it scans only files that changed.

New functionality should work even if you upgraded with box sets already in your library, but in rare cases you may need to rescan the album or wait for the album to retrieve new metadata.

Fixing things inside Roon

To fix a box without touching files, use Roon’s editing features. If a box is still split into individual discs after a rescan, or you split it yourself earlier, select those albums in Roon, choose Edit, and then Merge.

Once the box set is properly grouped, you can edit further if you’re not getting the disc-level information you want. In Roon’s Album editor, the disc editor is the “Disc Metadata” section on the Edit Album tab. It lets you identify a disc against an album in Roon’s catalog, this retrieves title, cover and year for your library in one step, and can help improve Roon metadata for everyone in the future.

You can also type a title and year yourself. None of these edits change the favorites, ratings, tags or playlists associated with the tracks in your library.

Reporting

When you post about a set, include four things: the box’s name; how your folders are laid out, in one line (“box folder with CD1/CD2 subfolders”, or “flat folder, files named 1-01, 2-01”); which tags carry disc information (DISCNUMBER only, DISCSUBTITLE, titles in the ALBUM tag, something else); and where your disc images are, if any. With those we can tell a bug from a data gap from a layout we don’t read yet, and if enough people use the same layout we don’t read, that’s how it gets added.

Disc Titles, Covers, and Years in Multi-Disc Box Sets