WiMP HiFi – Lossless Music Streaming

WiMP HiFi – Lossless Music Streaming

Like you, we at WiMP love music. Everything about it. And we want your listening experience to be as good quality as possible whatever the situation.

Sound quality is defined by physics, but add your favorite artists and their songs to the mix and it is also defined by feelings.

August 2012, we had a feeling that we wanted to redecorate. From early on, the music arrived at our door in lossy formats. That was just how it was done in the 00s. So our servers were full of a variety of sourcing material and it just didn’t feel right.

So we set out with a commitment of

Sourcing everything over again in lossless quality
Encoding everything over again with the best possible formats for all clients
Offering a lossless streaming option, and
Putting active listening and great sound experience back on the map

Almost to the day a year later we have sourced and encoded everything again and also launched WiMP HiFi. And we are happy and proud.

Why did we put all this effort into the standard and high qualities as well as offering a lossless option? Well, it’s ok to be pragmatic. We believe that you need lossless when you want a good listening experience with good headphones or a home stereo. However, sometimes you are in places with poor internet connection, or you want to binge in your favorite albums by getting as much as you can into your offline mode. Our AAC+ 96 and AAC 320 are more valid alternatives than ever.

But if you really want to get back to the full listening experience, there is nothing that beats going back to the source and listen without compromising.

We have not done this entirely alone. Early in the process, I involved Chis Sansom at Propeller Mastering in Oslo. He happens to be an old friend and we threw a lot of test music at him to find the optimal settings from our Dolby Media Generator encoder. A lot of tedious work later he gave his thumbs up.

We have also had a lot of extremely helpful beta testers in all countries and the feedback we have received is invaluable for the now public product. You have been both patient and fun. And among all the beta testers, the most enthusiastic has been the crowd at Hi-Fi Klubben and Neby HiFi. We thank and salute you for trying every day to bring good listening experiences to everyone.


For full lossless experience we use FLAC on everything apart from on iOS, where we use ALAC (Apple Lossless). It is all in 44.1 kHz / 16 bit, which is exactly same files as on CDs.

To get as close as possible to CD quality but with smaller files, we use AAC 320 kbps.

To achieve best possible sound but a very efficient file size we use AAC+ 96. AAC+ is the same as HE AAC and we use version 1 with spectral band replication.

Android, AAC+ 96, AAC 320, FLAC *
iOS, AAC+ 96, AAC 320, ALAC
Desktop, AAC+ 96, AAC 320, FLAC
Sonos, AAC 320, FLAC
Bluesound, AAC 320, FLAC
Squeezebox, MP3 256, FLAC
Download, MP3 256
Canal Digital, AAC 320
N, AAC 320

* FLAC requires Android 3.1 or higher

A lossless file in 44.1 kHz/16-bit is theoretically 1411 kbps (the formula is (sample rate) x (bit rate) x (number of channels) = kbps, so CD-quality is 44 100 x 16 x 2 = 1411kbps). But since PCM has a variable bit rate by nature, our experience from our testing is that a lot of repertoire is in the region of 700-900 kbps. So if you are using the AAC 320 option today, you are looking at doubling plus some. But remember that if bandwidth is not an issue, decoding a lossless file is much easier – so the general experience is actually quicker than with AAC.

It is of course possible to offline FLAC and ALAC files. It will save you a lot of data traffic to offline music you listen to often. On Android it is also possible to use an SD card to store things offline.

Just look in Settings. There are separate settings for streaming and offline mode to give you full flexibility. On Bluesound and Sonos, there are no controls – it just follows what is set in the subscription. On Squeezebox, there is a Streaming quality setting at the bottom of the front menu.

Needless to say, WiMP HiFi works really well on 4G/LTE network. We have also had great results streaming over 3G. But remember that when you move quickly like on a car or train, offline mode is always recommended.

On iOS and Android, there are visual indicators to tell you whether the source is lossless or not.

We chose to go with Apple Lossless (ALAC) on iOS devices. Simply because it is native support and this saves us a lot of potential heartache in the future. Disk space is always cheaper than a lot of issues. With ALAC onboard, AirPlay also works like a dream. A very good way of getting lossless from your iPhone or iPad to the stereo.

Up until now, Bluetooth has not been a viable solution for lossless audio formats. It has actually been better to use AAC as there has been support for both transmitting and receiving this codec. Now, with Apt-X as an extension to A2DP (Advanced Audio Distribution Protocol), we are a step closer towards good sound over Bluetooth. However, it is not a lossless solution yet.

We get asked this a lot, for natural reasons. Well, now we have WiMP HiFi and lossless audio. For the other formats, a lot of people are really hung up about just the bit rate. Yes, bit rate describes a little when it comes to compressed music, but there are also a lot of other factors. Spotify is running Ogg Vorbis, where Ogg is the container and Vorbis is the codec. WiMP is running MPEG-4 as the container and the codec is AAC. When you encode to higher bit rates such as 320 kbps, the difference between the codecs become smaller and smaller. On the standard format however, we really think AAC+ 96 kbps encoded from a lossless source really makes a difference. Most of our users still stream and offline in standard quality so this improves the experience for most people. Many credible sources rank Vorbis to be in-between AAC+ and AAC in quality, but we’ll be generous enough to say that at 320 kbps the difference is more dependent on the encoder in use and the quality of the source.

The most common question I get is “but, can I hear the difference?”. To me, it is simple to answer yes. Like you can taste a good wine, but perhaps not tell one great from another. I like to turn it around: Given that you are usually listening to music in the quality it was created, can you hear the loss when it is poor audio quality? Most people instinctually know when something ain’t quite right.