I have done a lot of testing and experimentation with digital COAX S/PDIF cables. I have owned the DH Labs D-750 cable. It is a very good cable for the money, excellent bass. However, you have two things going against you. The .5 meter cable is just TOO SHORT for a good S/PDIF cable. You really need 1.5 to 2 meters to avoid signal reflections back to the source transmitter (I always use 2 meter). A short cable will cause a loss of high frequency detail and the music just does not sound right (reflections causing distortions in the digital square wave pulses). The second reason is using RCA connectors on the cable. Granted, I understand the Chord Qutest has BNC input which is great, but the Bluesound will only have RCA. I have tested all sorts of RCA connectors for digital coax (the DH Labs D75, WBT Nexgen, Eichmann Bullet Plugs, Furutech Rhodium). The DH Labs makes an OK rca plug, but with all RCA plugs, you have a loss of high frequency detail as well.
The best results I have had is from cables that have BNC terminations and used BCN-to-RCA adapters for RCA sockets. The BNC combined with BNC-to-RCA adapter presents a closer impedance to 75ohm than just a raw RCA connector (which is closer to 25-30 ohms).
The Black Cat cables recommended may be a good choice. If you can find a Nordost Heimdall at 2 meter, that would be a good choice. The Heimdall has excellent bass and incredible depth of sound, but it is slight laid back in the upper mids/highs. Excellent sound. The Black Cat cables may have better resolution, but I have not listened to them.
Another cable that you could try (if you wanted) is the Oyaide DR-510 with the Oyaide BNC connectors. They make a 1.3 meter version. It is $315 retail, but you can find it on ebay from Japan sellers for under $200. It uses a 20awg solid-core silver conductor.