program specification template for digital music download systems

MP3 (not hi-res): Popular, lossy compressed format ensures small file size, but far from the best sound quality. Here's a breakdown of all the main file formats: The relative merits of each of the formats can be argued, but the most crucial issue will be the file's compatibility with your chosen products and software. Other formats include the uncompressed WAV and AIFF formats, DSD (the format used for Super Audio CDs), and the more recent MQA (Master Quality Authenticated). They are 'lossless' as opposed to 'lossy'. They include the popular FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec) formats, both of which are compressed but in a way that means that, in theory, no information is lost. That's not all: there are also several different hi-res audio file formats to choose from, all of which have their own compatibility requirements.

The problem with hi-res audio is how you might be listening to it.

50 of the best hi-fi albums for audiophiles.

And streaming technologies like MQA (see below) have found a way to make packaging and streaming hi-res audio more efficient. Thankfully, storage is much cheaper than it used to be, so it's easier to get higher-capacity devices.

These large file sizes have been why Bluetooth hasn't yet been able to pass through hi-res audio without lossy compression yet.

A hi-res file can typically be tens of megabytes in size, and a few tracks can quickly eat up the storage on your device or be cumbersome to stream over your wi-fi or mobile network. Hi-res audio does come with a downside, though: file size. Hi-res audio files usually use a sampling frequency of 96kHz or 192kHz at 24-bit, but you can also have 88.2kHz and 176.4kHz files too. The more bits there are, the more accurately the signal can be measured in the first instance, so going from 16-bit to 24-bit can deliver a noticeable leap in quality. Sampling frequency (or sample rate) refers to the number of times samples of the signal are taken per second during the analogue-to-digital conversion process. In its simplest terms, hi-res audio tends to refer to music files that have a higher sampling frequency and/or bit depth than CD, which is specified at 16-bit/44.1kHz. In 2014, the Digital Entertainment Group, Consumer Electronics Association and The Recording Academy, together with record labels, formally defined high-resolution audio as “lossless audio that is capable of reproducing the full range of sound from recordings that have been mastered from better than CD quality music sources'. Unlike high-definition video, there’s no single universal standard for hi-res audio. Our current favourite portable music player, the Astell & Kern A&norma SR25 MKII (Image credit: Future) What is high-resolution audio?

Program specification template for digital music download systems