How good is Bluetooth on Hugo and Hugo 2, and are aptX HD or LDAC lossless?
Short answer
Watts says he does not use Bluetooth (2014) and that his experience of it is very limited (2018). On record: the original Hugo's Bluetooth input tops out at 16 bits and 48 kHz Head-Fi, Apr 2015; aptX HD and Sony's LDAC are lossy, not lossless Head-Fi, Sep 2017; and Chord's view, which he relayed in 2014, was that aptX beats standard Bluetooth, which "will sound noisy" Head-Fi, Apr 2014. This archive has no Hugo 2 Bluetooth sound-quality verdict from him.
Practical answer. Watts does not present himself as a Bluetooth authority. In April 2014, in the Hugo thread, he wrote "I don't use BT at all" Head-Fi, Apr 2014, and in March 2018, in the Hugo 2 thread, he wrote "my experience of Bluetooth is very limited" Head-Fi, Mar 2018. What he did say is narrow: the original Hugo's Bluetooth input has fixed data limits Head-Fi, Apr 2015, aptX HD and LDAC are lossy Head-Fi, Sep 2017, and a noise problem some owners reported was something he and Chord investigated Head-Fi, Apr 2014.
Are aptX HD and LDAC lossless?
No, according to Watts. On 2017-09-27, in the Hugo 2 thread, he wrote that "aptX HD is still a lossy format even at 48 kHz," giving a data rate of 576 kbps and a lossy compression ratio of 4:1, and he added that "The Sony LDAC is also lossy" Head-Fi, Sep 2017. The post does not say which codecs Hugo 2 supports. The links he gave for details did not survive in the archive, so the post gives his figures but not his sources.
What the original Hugo's Bluetooth can do (2014 to 2015)
- Limits. On 2015-04-20 he listed the maximum data widths for the original Hugo: "SD USB and BT is 16 bits," with a maximum sample rate of 48 kHz for both SD USB and BT Head-Fi, Apr 2015. He noted these are the maximums it will work at, and added that if possible the source should be set to bit perfect unless you really need some EQ Head-Fi, Apr 2015.
- aptX versus standard Bluetooth. On 2014-04-17 he relayed an answer from Matt at Chord: aptX is "a much better solution for BT than standard BT, which will sound noisy," because "you can't get away from the low data rates of BT" Head-Fi, Apr 2014. He introduced this as Matt's answer, since he does not use Bluetooth himself Head-Fi, Apr 2014.
- Intended use. On 2015-01-23 he said "BT was intended for mobile in one pocket, Hugo in another one" Head-Fi, Jan 2015.
If you hear noise over Bluetooth (original Hugo, April 2014)
On 2014-04-26 he said he had re-checked his own Hugo with a Sennheiser BTD 300 connected to a Windows 8 machine, in DAC mode and in fully portable mode, and heard "absolutely no noise" Head-Fi, Apr 2014. He reported that Matt at Chord re-ran tests with current production units: "Absolutely no problems with iPhone, IPad and Samsung phone BT sources" Head-Fi, Apr 2014. He said he was not trying to play down the reports, but that to fix an issue Chord must see it demonstrated in his or Chord's labs Head-Fi, Apr 2014.
He presented the explanation as "the thinking" after talking to Matt: the 2.4 GHz signal is amplitude modulated by noise on the source transmitter's local power supply, picked up by the headphone cable, and demodulated either inside Hugo or in the headphone. He said the effect varies with the quality of the Bluetooth transmitter and the RF characteristics of the headphone and cable, and that keeping Hugo close to the source helps because the transmitter then uses lower power Head-Fi, Apr 2014. His suggestion was "to try cylindrical ferrite cores" on the headphone cable; he said he suspected this might solve the problem and asked for feedback Head-Fi, Apr 2014.
Hugo 2 and other products
- Hugo 2. The only Bluetooth statements in the Hugo 2 thread are the 2017 aptX HD and LDAC post and a March 2018 reply to a report he had "never heard" of, in which he said "We use a high quality module that handles everything," so the issue was most likely the source Head-Fi, Sep 2017Head-Fi, Mar 2018. That reply does not name the module, its codecs or its limits.
- Dave. On 2022-07-25 he said he could not remember whether a Bluetooth function was ever envisioned for Dave, "as it's a feature I would have strongly reacted against" Head-Fi, Jul 2022.
- Poly and 2Go. In an April 2018 interview, asked why Chord made Poly for Mojo instead of adding aptX HD or LDAC, he said he was not involved in the Poly project and that the rationale was clear: "we wanted 768 kHz operation, and you can only do that via Wi-Fi" article, Apr 2018article, Apr 2018. In February 2020 he said he had "No involvement with 2Go" and that it has the same developer as Poly Head-Fi, Feb 2020.
What he has not said
This archive has no statement from him on how Hugo 2's Bluetooth sounds or whether a wired input is better than Bluetooth for a given model. His 16-bit and 48 kHz figures were given for the original Hugo in 2015 Head-Fi, Apr 2015, and he does not say they apply to later products. The aptX comparison and the noise explanation came from conversations with Matt at Chord, not from measurements Watts reported himself Head-Fi, Apr 2014Head-Fi, Apr 2014.
Quotes
“aptX HD is still a lossy format even at 48 kHz.”2017-09-27 Head-Fi, Sep 2017
“SD USB and BT is 16 bits, HD USB set to 32 bits.”2015-04-20 Head-Fi, Apr 2015
“my experience of Bluetooth is very limited.”2018-03-27 Head-Fi, Mar 2018
“I was not involved in the Poly project”2018-04-04 article, Apr 2018
Dated positions
| When | Products | Position |
|---|---|---|
| 2014-04 | Hugo (original) | He does not use Bluetooth himself and relayed Matt at Chord's answer that aptX is a much better solution than standard Bluetooth, which will sound noisy because of its low data rates. Head-Fi, Apr 2014 |
| 2014-04 | Hugo (original) | He and Chord found no Bluetooth noise with current production units on the sources they tested, theorized that source-transmitter noise is picked up by the headphone cable, and suggested ferrite cores. Head-Fi, Apr 2014 |
| 2015-01 to 2015-04 | Hugo (original) | Bluetooth on the original Hugo has maximums of 16 bits and 48 kHz, was intended for a phone in one pocket and Hugo in another, and the source should if possible be set to bit perfect. Head-Fi, Jan 2015Head-Fi, Apr 2015 |
| 2017-09 | Hugo 2 | He wrote that aptX HD (576 kbps, 4:1) and LDAC are lossy formats. Head-Fi, Sep 2017 |
| 2018-03 | Hugo 2 | His Bluetooth experience is very limited; Chord uses a high quality module and a reported issue was most likely the source. Head-Fi, Mar 2018 |
| 2018-04 | Mojo (original) | He was not involved in Poly, whose rationale was 768 kHz operation, possible only over Wi-Fi. article, Apr 2018article, Apr 2018 |
| 2020-02 | Hugo 2 | He had no involvement with 2Go, which has the same developer as Poly. Head-Fi, Feb 2020 |
| 2022-07 | DAVE | He could not remember a Bluetooth function being envisioned for Dave and said he would have strongly reacted against it. Head-Fi, Jul 2022 |
Caveats and open points
- Most Bluetooth statements concern the original Hugo (2014 to 2015); none gives a Hugo 2 Bluetooth sound-quality verdict.
- The aptX HD and LDAC figures are his, posted with links that did not survive in the archive.
- The 2014 aptX comparison and the RF explanation were relayed from Matt at Chord, not his own measurements.
- Poly and 2Go were not his projects.
Topics: Choosing and comparing inputs, MQA, lossy codecs and streaming services