How to prepare Audio Files for different Physical Media Formats: CD, Vinyl and Cassette

monotypepressing blog post how to audio file submission all formats

Technical Requirements for Audio Files for VINYL

  1. Maximum Length
  2. Maximum Level of Digital Source Signal
  3. Frequency Bandwidth
  4. Sibilants
  5. Phase and Correlation
  6. Dynamics and non-linear Distortion
  7. Playback Quality
  8. File Formats and Naming Conventions
  9. Other Vinyl Specifications

MAXIMUM LENGTH

The maximum length for vinyl depends on the vinyl format (7”, 10”, 12”) as well as the RPM/SPEED.

monotype monotypepressing vinyl producticon single 12"

For 12” vinyl pressings:

  • with 33⅓ RPM, the recommended/optimal is 19:30 min per side (maximum length: 23:00 min per side)
  • with 45 RPM, the recommended/optimal is 12:00 min per side (maximum length: 14:30 min per side)
monotype monotypepressing vinyl producticon single 10"

For 10” vinyl pressings:

  • with 33⅓ RPM, the recommended/optimal is 13:30 min per side
  • with 45 RPM, the recommended/optimal is 10:00 min per side
monotype monotypepressing vinyl producticon single 7"

For 7” vinyl pressings:

  • with 33⅓ RPM, the recommended/optimal is 6:40 min per side
  • with 45 RPM, the recommended/optimal is 10:00 min per side

→ NOTE: If the optimal time is exceeded, we reserve the right to deny complaints regarding sound quality.

MAXIMUM LEVEL OF DIGITAL SOURCE SIGNAL

The digital source signal’s maximum level should not exceed 0.0 dB True Peak. Please note that the True Peak Level differs from Peak Level.

FREQUENCY BANDWIDTH

Both ends of the audible bandwidth (below 30 Hz and above 18 kHz) should be maintained at a balanced level, not exceeding the rest of the audible spectrum. High-frequency bandwidth is especially limited towards the end of a disc side, particularly on 7” discs played at 33 1/3 RPM. This phenomenon is unavoidable and cannot be corrected through pre-emphasis/de-emphasis.

SIBILANTS

A high level of sibilants (e.g., sss, shhh, zzzz) and upper-band content (e.g., hi-hats) are unsuitable for vinyl, as they can cause cross-modulation effects, leading to distortion and an unstable stereo image. It is strongly recommended to control these sounds at a moderate level using de-essers and other techniques during the pre-mastering process.

PHASE AND CORRELATION

The overall stereo correlation should not exceed 90%. A 0% correlation represents mono, while 180% represents anti-phase. For frequencies below 200 Hz, the correlation should be even narrower, and for those below 100 Hz, it should be 0% (mono). Exceeding these specifications may result in additional clicks, crackles, and distortions.

DYNAMICS AND NON-LINEAR DISTORTION

It is strongly recommended to avoid excessive use of maximizers during the pre-mastering process. A loudness level of -10 dB LUFS is sufficient for a loud and undistorted vinyl. The cutting and vinyl reproduction process is inherently analogue, introducing its own non-linear distortion to the sound. Consequently, all non-linear effects can lead to unpredictable variations on vinyl and should be considered.

PLAYBACK QUALITY

Demanding or pivotal tracks should be positioned towards the beginning of the side (closer to the outer edge of the disc), rather than towards the end. This is because playback conditions deteriorate as the needle approaches the center of the record. For 7” discs played at 33 RPM, this effect is most pronounced, as the linear speed of the record decreases towards the center. This reduction in speed notably affects the sound quality, particularly for high frequencies, which may experience alteration and degradation. Overall playback quality is influenced by the technical specifications of the playback equipment.

FILE FORMATS AND NAMING CONVENTIONS

We accept two file formats: .wav and .aiff. The sampling frequencies and bit depths should be: 44.1 kHz (16, 24 bits); 48 kHz (16, 24 bits); 88 kHz (24 bits); 96 kHz (24 bits). Files of 192 kHz (24 bits) are accepted on special request.

For vinyl, we prefer 24-bit single .wav files for each side (2 files per single double-sided vinyl disc). If submitting separate files, please name them in a way that allows alphabetical sorting in the correct sequence by the computer browser. For instance: A_01, A_02, B_01, B_02, C_01, C_02, D_01, D_02. This ensures clarity in assigning sides A, B, C, or D of your album when placed in a single folder. File names should avoid diacritic characters.

The files must be accompanied by a completed Vinyl Master Specifications for Lacquer Cutting tracklist document. This tracklist specifies the placement of VTMs (Visual Track/Time Markers) – visual breaks between tracks on the record indicated by widened grooves. VTMs are included by default in all vinyl productions. If you prefer not to include VTMs, please specify this in the order form.

→ NOTE: Pauses between tracks should be embedded in the submitted files as part of the audio material. VTMs do not interrupt the audio signal; uninterrupted music plays across them.

OTHER VINYL SPECIFICATIONS

If you want to add pauses or interferences into the material (including adding pauses or equalizing pauses) into the material please arrange that with our MonotypePressing team. If the order form does not include any information about these modifications, the ordered material will be pressed according to the original files submitted by you.

Technical Requirements for Audio Files for CD/DVD

  1. Maximum Length for CDs and Maximum Capacity for DVDs
  2. CD/DVD Content
  3. File Formats and Naming Conventions
  4. Other CD/DVD specifications

MAXIMUM LENGTH FOR CDS AND MAXIMUM CAPACITY FOR DVDS

Regarding the Philips Red Book, the CD maximum length should not exceed 74 minutes and 44 seconds. Even though most CD audio players support long-play discs with up to 80 minutes, not all players will work properly with discs longer than 78 minutes.

→ NOTE: If the duration exceeds the optimal 78 minutes, we reserve the right to reject any complaints regarding the sound quality or proper functioning of the discs

The DVD maximum capacity depends on the specific DVD format. The maximum disc capacity for DVD-5 is 4.7 GB, for DVD-9, 8.54 GB and for DVD-10, 2 x 4.7 GB max.

CD/DVD CONTENT

There are two options on how you can provide your audio files; you can provide digitally in DDP 2.0 format with MD5 checksum or traditionally, on a CD-R/DVD-R disc (2 copies).

Disc Description Protocol (DDP)

Disc Description Protocol (DDP) is a format used to define the content of optical discs such as CDs and DVDs. It is commonly employed for delivering disc premasters for replication and must include four components:

  1. Audio image(s) (.DAT file(s))
  2. DDP Identifier (DDPID)
  3. DDP Stream descriptor (DDPMS)
  4. Subcode descriptor (PQDESCR)
  5. An optional text file can also be included, which will contain the track titles and timings

If you are unable to provide a DDP, we can create a DDP 2.0 (+MD5) image from .wav, .aiff files upon your special request and for an additional fee. On request, we can add a CD-TEXT to a DDP file. In that case, you have to provide a text document that may include these elements: the author, the album title, the track title, ISRC code, UPC/EAN code.

MD5 checksum

MD5 checksum is one of the most effective ways to verify the integrity of digital data. It allows you to ensure that the file has been correctly transferred from one computer to another. There are many programs available for both Mac and PC that can generate an MD5 checksum file, some of which are free, while others require a license, such as MD5summer, Sophos, PowerShell, Hash Generator, MD5 & SHA Checksum Utility, and others.
If the customer notices errors that may have been introduced during the transfer of digital files but did not attach an MD5 checksum to them, any claims in this regard will not be considered.

CD-R/DVD-R

All masters sent on CD-R/DVD-R should be production-ready, of high quality, and free from physical damage or errors. They must be edited to match the final product requirements and be well-protected against damage, dirt, and other issues during transportation. Defective masters or those not meeting the specifications may cause delays and affect the complaint process. Non-copy-protected replicas can also be used as masters. The image on DVD-Rs should be burned to the disc’s main sector. DVD-R DL is acceptable for DVD 9 production.

FILE FORMATS AND NAMING CONVENTIONS

We accept files in .wav and .aiff format, as well as ISO and NRG formats (excluding DVD formats). The files should be named in such a way that the computer browser can line them up alphabetically in the correct sequence. For instance: 01 02 03 04 05, etc. The names of all the files, including the main folder, should not contain diacritic characters.

OTHER CD/DVD SPECIFICATIONS

Breaks and Interferences

If you want to add breaks or any other interference into the material please arrange that with our MonotypePressing team.

Personalised Matrix Name

If you want to add a personalized matrix name on the disc, you can do so navigating to the bottom part of the CD/DVD configurator in the ‘CHOOSE ADDITIONAL OPTIONS’. You can specify the desired matrix name in the ‘ADDITIONAL COMMENTS’ text field; the number of marks on a matrix cannot exceed 110 characters.

→ NOTE: Please be aware that we utilize a glass master for CD/DVD replication, and once the process has begun, the matrix name cannot be altered.

Technical Requirements for Audio Files for CASSETTE

  1. Maximum Length
  2. Sound Quality
  3. File Formats and Naming Conventions

MAXIMUM LENGTH

The maximum length of one side is 45 minutes and must not be exceeded. The duration of side A should be slightly longer than the duration of side B; otherwise, we won’t be able to duplicate the material. If side A is shorter, you will need to add the necessary amount of silence to match side B. If you are unable to add the silence yourself, we can do it for you upon your special request and for an additional fee.

SOUND QUALITY

Before supplying the master for cassette tape duplication, you are obliged to check its sound quality, potential errors, track sequence, and integrity of the audio material.

FILE FORMATS AND NAMING CONVENTIONS

We accept .wav files with a sampling frequency of 44.1 KHz and a depth of 16 bits.

All masters should be provided as single files for each side (two files per single double-sided cassette) along with an MD5 checksum file. If your submitted master is divided into individual tracks, our engineering studio can create new single-side files by merging the individual tracks for an additional fee. Please provide a tracklist document indicating the correct naming and sequencing of all tracks (alphabetically per side, e.g., A_01, A_02, B_01, B_02) and ensure suitable pauses are included between tracks for seamless assembly.