Bit Perfection and Alchemy

Andrew_Stein · October 11, 2018, 2:27pm

I have integrated Roon with my BlueSound series-2 system, which connects to various BlueSound components by Ethernet. I have a couple of Pulse 2s, plus a Node 2 and a Power Node 2. The Node 2 connects to an external DAC, which feeds into an amp, which powers floor-standing speakers. The Power Node 2 powers in-wall speakers. Again, the whole system connects by Ethernet, so I am not using wireless technology.

Recently, BlueSound announced its 2i series. While it seems the 2i series might use improved components for speakers, I am concerned mostly with the improvements to the Node and to the Power Node. The Node 2i, which is their streamer without an amp, has new bells and whistles, but they appear to involve mostly wireless technologies, such as aptX HD, WiFi and Bluetooth improvements, and AirPlay 2. (They also mention MQA decoding, but I thought the series 2 already supported it.)

One review of the Node 2i gushes that “[t]he richness across the frequencies is retained, but the soundstage appears further opened and with even more granular detail fed in.” It continues to billow with similar purple prose common to stereo reviews, e.g., “It is in the subtleties of a composition that the Node 2i really thrives, showing its ability to pick out the varying intensities of a fingerpicked guitar, arpeggiated piano line or call-and-answer arrangement that may provide rhythm as much as hold a melody.”

I am far from an audiophile, so please allow me a simple question: if BlueSound series 2 already streams bit perfectly (if that’s a phrase) to one’s external DAC, how could anything in the series 2i improve the sound quality in that setup? (Now, maybe the reviewer was not using an external DAC, but that seems doubtful.)

Perhaps the Node 2i could sound better if one used its internal DAC, or the PowerNode 2i could sound better than the PowerNode 2 because each uses its own internal DAC and different components to feed out an analog signal, but how could the Node 2i sound better when using an external DAC?

For that matter, as long as one is using Roon to run a stereo system to stream digital data to a DAC, how could any bit-perfect streaming device sound better than another bit-perfect streaming device?

Frank_Daman · December 8, 2018, 10:37pm

Andrew_Stein:

I am far from an audiophile, so please allow me a simple question: if BlueSound series 2 already streams bit perfectly (if that’s a phrase) to one’s external DAC, how could anything in the series 2i improve the sound quality in that setup? (Now, maybe the reviewer was not using an external DAC, but that seems doubtful.)

Perhaps the Node 2i could sound better if one used its internal DAC, or the PowerNode 2i could sound better than the PowerNode 2 because each uses its own internal DAC and different components to feed out an analog signal, but how could the Node 2i sound better when using an external DAC?

For that matter, as long as one is using Roon to run a stereo system to stream digital data to a DAC, how could any bit-perfect streaming device sound better than another bit-perfect streaming device?

The reviewer probably wasn’t using an external DAC.

When you feed the digital output to an external DAC, you listen to the output from an external DAC. The intermediate device should just act as a passthrough.

That said, no one actually knows what happens to the stream inside any streaming device. ‘Bit perfect’ should be self evident but unless you could do a bit-by-bit comparison, you can never be sure. You can never be certain that the intermediate device or software ( like Roon) doesn’t change the bitstream.

Still, when using an external DAC basic logic dictates that as long as the external DAC receives an identical bitstream, it will output the same analog signal, no matter where the bitstream originates. As long as the sequence of zeroes and ones arrives with the same accuracy (no drop-outs, no clock speed deviations) the end result should be the same whether the bitstream is passed through a cheap streamer or a ridiculously overpriced 18.000 Euro streamer, since you’re not listening to the streamer anyway.