[Editorial] On quality of High Resolution Digital Downloads

March 2014 eidtorial

High Resolution Digital DownLoads: value for money?

Author: Mike Cox - TNT UK
Published: March, 2014

Over the last couple of years I have used music download sites such as Linn Records and HDTracks to purchase some "High Resolution" albums, usually albums that had passed me by originally. The service they offer is excellent , I have never had a problem downloading and playing the music. With all the downloads I have always been disappointed, I was expecting more from the 24bit 96Khz recordings. Over the last month or so this has got me wondering what is going on, are my ears at fault or my system sub standard?

Reading the payed for HiFi press it is obvious that some material available as HiRes downloads is nothing more than up-sampled CD quality. I am not saying that is the case from either HDTracks or Linn Records. Some music dates back to times when recording beyond 20Khz was difficult so will benefit little from the additional bandwidth. So is the source file the only problem, probably not, the replay chain is also a significant factor I believe. The wider bandwidth recording will only show through if the entire replay chain is equally wide bandwidth. The system is only as good as the weakest link! If we start at the front end, the computer and connection to the DAC need to be able to handle the higher data rate without introducing significant jitter. I have found that some computers are better than others, on my Apple MAC the USB interface seems marginal, particularly with the ability to supply the 5v that most DACs require to power up the USB input. USB cables are variable in their ability to deliver the data, price is not necessarily a measure of good cable. I am rapidly coming to the conclusion that USB is not a reliable mechanism for delivering the data form a computer to a DAC. Shortly I will be reviewing an I2S interface card for a PC that claims to be better. Next up is the DAC, there are many available these days, all offering excellent specifications including support for 24bit 192Khz data and more. They don't all sound the same, even those using the same chip sets.

These days amplifiers are usually wide bandwidth but distortion and noise will impact the ability to deliver the best from a high resolution recording. If you believe all the hype on cables they will also have some influence. Finally the speakers, possibly the most significant factor in any replay chain. The speakers can appear wide bandwidth but still sound lacking in detail and slow paced, this will affect the ability to deliver the extra resolution and detail from a HiRes source. Room position for the speakers and the room also affects the quality. The source material is only a small factor in determining the quality of what you hear. If the original recording was done at high resolution but the recording engineer was not experienced enough any of the benefits could be lost. I have some CDs where the recording quality is outstanding, artists such as Diana Krall and Mary Black. I do have one Diana Krall album at 24bit 96Khz, it does sound very nice but is is worth the significant extra cost (~40%)?

Please share your experiences with us either via the yahoo group forum or email me directly and we will add this to our letters page.