Frequently asked questions

With Immersive Audio, the listener is surrounded by sound coming from all directions: Front-Back, Left-Right and Up-Down. This is what we call 3-dimensional sound and this is exactly what we experience in our daily life and for example when we listen to a live concert. Sounds from the performing artists are reflected in different surfaces and objects and reaches our ears from all possible directions and defines the acoustic environment.

In the late 50s, the audio industry traversed from mono to stereo recordings in an attempt to create a richer listening experience. 5.1 surround was invented already in the 70s, but became available to a broader public in the 90s when movies were distributed on DVD. In a 5.1 system, five speakers are placed at ear level (three in front, two in the back), surrounding the listeners. Fairly soon, even music was produced for 5.1, but the response from the audience has so far been quite reserved. One reason for this might be that most music enthusiasts are listening to music in headphones.

Immersive Sound is the Next Generation Audio (NGA) where height information is added with speakers in the ceiling and sometimes also on the floor. However, Immersive Sound can also be listened to and experienced in headphones! On streaming sites such as Apple Music and Tidal, music produced in Dolby Atmos or Sony360 can be listened to in headphones, provided that the settings in your device are set properly. Look for the Dolby Atmos or Sony360 logo.

Since 2021, productions made by Per Sjösten for Footprint Records are produced in Dolby Atmos and you can find them in our shop by selecting “immersive” under Audio Format. The immersive versions available for these are binaural renderings from the Dolby Atmos mix, i.e. what you would hear if you stream from Apple Music or Tidal. If you, dear listener, are interested in a full Dolby Atmos version that can be listened to on a surround speaker system, please do not hesitate to contact us.

See also Binaural Sound

Regardless of the chosen audio format, a booklet in the form of a PDF file is included.

Low resolution

This is the audio format with the lowest resolution we have. As a consequence, this audio format renders the smallest files on your computer or smart phone. It is similar to mp3, but with a slightly improved audio quality. The file extension is usually m4a.

For more information see What is mp3 and aac?

Immersive

This is the Next Generation Audio (NGA). The step from Stereo to Immersive is comparable to the transition from Mono to Stereo and the purpose is to achieve a listening experience that is closer to a Live performance. The mix is made in three dimensions and the version available here is a binaural rendering intended for headphone listening, simulating sound sources in a half sphere around the listener.

The word Binaural simply means that we have two ears, resulting in certain directional properties for our hearing. In Audio, Binaural is the term used when we simulate that sound is reaching our ears from different directions. The Binaural version is available for some of our albums and this version is rendered from a surround mix in 3 dimensions, speakers at ear level and top level. The listening experience varies between listeners, but the usual perception is that the music is coming from outside your head, in contrast to the in-your-head perception of stereo sound over headphones.

We use the Low resolution format for these files. You can play these files in your favourite music player, but please note that they should preferably be listened to in headphones only. They don’t sound natural over loudspeakers.

Medium resolution

The medium resolution files are comparable to the audio resolution on CDs, but with a better dynamic resolution (24 bits instead of 16 bits). A full album in PCM format normally requires around 1 Gb of storing space. We deliver files converted to FLAC (Free Lossless Audio Codec), which is a non-destructive audio compression format and the storage requirement is reduced to somewhere between 600 and 800 Mb.

High resolution

The high resolution version, sometimes referred to as High Definition (HD) Audio, is for the Audiophiles. People with high demands on the audio quality. A common description is 24/96, meaning 24 bits of amplitude resolution and 96 kHz sampling frequency.

Extreme resolution

The extreme resolution files, DXD, are today as close as we can get to analog sound. The amplitude resolution is 24 bits, but the sampling frequency is the jaw-dropping 352,8 kHz. With a sampling rate 8 times higher than for the CD, the time resolution is unsurpassed. The file sizes are very big and there can be problems downloading them if you don’t have a stable and fast internet connection.

We use the DXD format when digitizing analog master tapes, such as for the Opus 3 albums you can find in our shop.

Surround formats

We’ve been doing surround versions for very many years and several of our productions are available in this format. However, with the advent of Dolby Atmos Music, we will no longer produce 5.1 versions of our albums. If the settings in your audio gear is correct, the Dolby Atmos version, mixed in 7.1.4 – 7 speakers at ear level, 4 top speakers and LFE – will adapt to the reproduction setup you are using, for example stereo or 5.1.

When listening in headphones, Dolby Atmos produces the binaural version which can actually have a higher spatial resolution than the channel based version. The binaural version found in our shop is rendered from the Dolby Atmos file, but for the present, we are not setting up the full Dolby Atmos files in the shop. If you’re interested, contact us using the form on this website.

The word Binaural simply means that we have two ears, resulting in certain directional properties for our hearing. In Audio, Binaural is the term used when we simulate that sound is reaching our ears from different directions. The Binaural version is available for some of our albums and this version is rendered from a surround mix in 3 dimensions. The listening experience is different for different listeners, but the usual perception is that the music is coming from outside your head, in contrast to the in-your-head perception of stereo sound.

We use the iTunes audio format (aac) for these files. Please note that these files should be listened to in headphones only.

Read more about Immersive Audio Why is Immersive Audio relevant to me?

Apple Digital Master (ADM, previously “Mastered for iTunes”) is a mastering procedure to ensure that there are no clipped samples in the encoded audio files. Clipping can occur for two different reasons:

1) Intersample overloads. A sharp peak in the audio signal can have its True Peak between two samples at maximum amplitude. As the signal is converted back to the analog domain, the analog signal would have a peak that is higher than 0 dBFS and is therefore clipped.
2) In an encoded signal using perceptive coding such as mp3, aac or ogg, signal components that we supposedly do not hear are removed – not encoded – in order to save bits. As a result, the time signature is altered and may result in overloads although the original audio in PCM format is not overloaded.

When mastering for iTunes, the audio files are encoded using the AAC codec in the OS X operating system and are then checked to make sure that no samples are clipped and that there are no intersample overloads.

MP3 and AAC are two encoding schemes for audio based on the properties of human perception. One such property is that high levels of low frequency sound makes higher frequency sounds with lower levels inaudible. This is one example of a masking effect and as a result of that, fewer bits can be used to represent the audio signal.

When a PCM signal is converted to MP3 or AAC, supposedly inaudible parts in the original signal are removed and sometimes we refer to this as destructive or lossy encoding. An audio signal encoded as MP3 or AAC reduces the amount of data with about 90% and cannot be restored to the original PCM signal.

When an analog audio signal is converted to a digital signal, a sample is taken from the analog signal 44100 times per second for CD resolution and 96000 times or more per second for High Definition (HD) recordings. For each sample taken, the signal voltage is measured and converted to an integer number. This number – the sample value – represents the voltage at one time instance with some precision, referred to as the resolution and depends on the number of bits in the integer word.

The CD resolution is 16 bits according to the Red Book standard and because of this, the allowable input voltage range for the AD-converter (typically ±12.3 V for a professional AD-converter) is divided into 65 536 (2^16) voltages that can be represented by the integer sample values. The discrepancy between the true analog voltage and the voltage represented by the sample is an error, which is sometimes referred to as noise. Under some assumptions, a maximum signal-to-noise ratio (SNR) can be calculated and is typically given roughly as 6 dB per bit, resulting in 96 dB for a Red Book CD.

Nowadays, most AD-conversions are made with 24-bit converters with 16 777 216 discrete voltages and a maximum signal-to-noise ratio of 144 dB. This is actually a much larger signal-to-noise ratio that what we can achieve with analog circuits, so in effect the (SNR) is determined by the analog circuits (typically microphones and microphone amplifiers) preceding the AD-converter.

A PCM-encoded signal is thus a stream of digital numbers represented as 16, 24 or 32 bit integers or 32-bit floating point numbers. The floating point numbers typically have a 24-bit mantissa (determining the SNR) and an 8-bit exponent (determining the dynamic range). This is the format used in e.g. WAV files. PCM stands for Pulse Code Modulation.

When you buy an album and the payment has been accepted, you will see buttons to download your goods. One of the buttons is for the PDF Booklet, containing all the information about the recording. The other button(s) let(s) you download the audio files.

The audio files are normally contained in a zipped folder, that you download to your computer, or other device. Very large files (DXD and DSD) may be stored in one file per track.

When the file is downloaded, you will need to unzip the folder. On a Windows device, this is done by right-clicking on the zipped folder and choose “Extract All” from the context menu. When the folder is unzipped, you can move the files to a suitable location, or you can select the album e.g. with iTunes or any other media software of your choice.

When you buy an album and the payment has been accepted, you will see buttons to download your goods. One of the buttons is for the PDF Booklet, containing all the information about the recording. The other button(s) let(s) you download the audio files.

The audio files are normally contained in a zipped folder, that you download to your computer, or other device. Very large files (DXD and DSD) may be stored in one file per track.

When the file is downloaded, you will need to unzip the folder. On an Apple device, this is done by double-clicking on the zipped folder. When the folder is unzipped, you can move the files to a suitable location, or you can select the album e.g. with iTunes or any other media software of your choice.

FLAC is a process to reduce the data size of an album, without compromizing the audio quality. This makes it easier to download the album. FLAC is an acronym for Free Lossless Audio Codec, which means that a decoded album is identical to the original.

Albums labeled as Extreme Resolution are recorded in DXD format. The sampling rate is eight times that of a standard CD, 352.8 kHz, and 24 bits. The resulting digital audio is as close to the analog original as we can get today.

You need to have a digital-to-analog converter that can handle DXD to be able to reproduce the audio, eg the Nadacfrom Merging Technologies.

Yes you can. Contact us at info(a)footprintrecords.com.

We have set a flat rate for postage and packing, no matter how many CDs you are ordering.

• Within Sweden: € 4.50
• Outside Sweden: € 7.90