After writing last week about how some listeners were upset about changes to the BBC 3 high quality/bitrate stream my curiosity was piqued about higher fidelity internet radio stations. So I set about finding stations that highlight sound quality by offering higher bitrate streams.
First, it’s important to define terms. For the purpose of this post I’ll be using the terms “high fidelity” and “high bitrate” which correlate, but not perfectly. Fidelity, of course, refers to how good the stream sounds, while bitrate refers to how much bandwidth the stream uses. All things being equal, higher bitrate streams deliver better sound quality. That said, if the source material isn’t well recorded or the signal path is not well designed, it’s also quite possible to deliver sub-par sound quality over a high bitrate stream. I listened to a few too many stations like that.
These days most internet radio streams use either MP3 or AAC compression. MP3 should be to familiar to just about anyone who listens to digital audio. AAC is a newer standard that is used by Apple for iTunes music downloads, and is a little more efficient than MP3. That means it delivers better sound quality at the same bitrate.
So, for “high bitrate” MP3 streams I’m using the same standard as BBC 3, 320 Kbps. Because AAC is a little more efficient, I’m using 256 Kbps as the minimum. Now, certainly one can argue that these standards seem arbitrary, and that very good sound can be had at levels below these. However, my experience is that these are the bitrates where the compression is least likely to impact the sound–if the quality is less than optimal it’s probably due to some other link in the chain. With AAC, in particular, I’ve heard some very nice sounding stations using the more advanced AAC+ codec streaming at bitrates as low as 96 Kbps. Nonetheless, the point of this examination is to find stations that push high fidelity, not just good fidelity.
“High fidelity” is a more subjective standard. For me, I consider a station “high fidelity” if it sounds as if I’m listening to purchased digital file from a music store like Amazon or iTunes, or even as good as a CD. For all intents and purposes nothing negative about the sound should call attention to itself. Examples of things I shouldn’t hear include the “underwater” quality associated with poorly encoded and low bitrate MP3s or a shimmery high-end heard on instruments like cymbals. I also shouldn’t get the sense that I’m missing some aspect of the sound, whether it’s high end or very low end content. In practical terms, at the very least I should very easily think I’m listening to a good analog FM broadcast.
As it turns out, there are plenty of stations that stream at 320 Kbps MP3, but not all of them qualify as high fidelity to my ears. In fact, many sounded poorer than stations streaming at 256 or 192 Kbps. My guess is that’s because they were often playing back MP3 files that don’t meet that standard as the source, which were simply being recompressed to 320 at playback. Such recompression–called “stacking codecs”–only further degrades sound quality, and never improves it. I also heard some college and community stations streaming at 320, but where it definitely sounded like there were wiring problems in the connection to the streaming computer, resulting in buzzes, hum or distorted audio.
There are fewer stations streaming in the AAC format to begin with, and even fewer meeting the high bitrate standard. In general these stations were more likely to sound good than the MP3 stations. I figure that’s because choosing AAC likely means that sound quality is more of a specific emphasis.
Finally there are a handful of stations that stream in full CD-quality, without any MP3 or AAC compression. Most use a standard called FLAC which reduces the amount of data needed by half, but without throwing away any data like both MP3 and AAC do. These stations stream at bitrates from about 768 Kbps to 1.44 Mbps (megabits). A decade ago those would have been considered outrageous bandwidth hogs. But given that HD streaming video requires 3+ Mbps, today that doesn’t seem so bad.
Now I will share some of my finds. These stations were selected because they both stream at a high bitrate and sound very good. For each station I’ve given direct links to the stream that will play in most audio apps like iTunes, Quicktime, WinAmp, Windows Media Player or VLC. I provide these links because often these stations’ web players only provide lower bitrate streams.
By no means is this a comprehensive list of high bitrate streaming audio sources. I welcome suggestions of other good stations in the comments.
High Fidelity Internet Radio Streaming in AAC (256+ Kbps)
Audiophile Stream Network – Greece
Multiple genres, all in 320 Kbps AAC
Baroque classical: http://188.8.131.52:2199/tunein/baroque.pls
Rock and blues: http://184.108.40.206:2199/tunein/enieopyy.pls
High Fidelity Internet Radio Streaming in MP3 (320Kbps)
Amys FM – Belgium
Soul, R&B: http://ns336770.ip–5–39–71.eu:2199/tunein/amysfm.pls
Hi OnLine Radio – Netherlands
Multiple genres, only some at 320kbps.
KRUI – University of Iowa
College radio: http://krui.student-services.uiowa.edu:8000/listen.m3u
Linn Radio – UK
Plays music from the record label of this high-end audio manufacturer.
Monster FM – Germany
Five different genre streams.
Top hits: http://stream.radiomonster.fm/tophits/listen.pls
German hits: http://stream.radiomonster.fm/schlager/listen.pls
WIUX – Indiana University
College radio: http://hannibal.ucs.indiana.edu:8080/wiuxultra.m3u
Uncompressed Internet Radio
All of these stations require the VLC player or another app that can play back FLAC streams. iTunes will not work.
Absolute Radio streams five different rock and pop stations in uncompressed FLAC, but is only available in the UK.