Crossfeed and spatial processing

Features, settings and controls

Answers on this topic

• What does Rob think of room correction, HRTF processing and surround sound?
• What does crossfeed do, which setting should I use, and why didn't the original Mojo have it?

Everything he said on this topic (51)

One-line summaries in our words, oldest first. Each link opens the original.

• 2014-08-31Watts recommends max crossfeed for a hard-panned 1967 album and explains Hugo's crossfeed runs on its own 16FS 48-bit cores using first-order EQ like analog crossfeed. Head-Fi, Aug 2014
• 2014-11-18Watts says the two sockets exist simply to allow other listeners, and crossfeed is most noticeable on older recordings panned hard left and right. Head-Fi, Nov 2014
• 2015-12-04Watts gives the Malaysian distributor's details, clarifies that Dave's crossfeed control defaults to 0 (off), agrees crossfeed makes no sense for binaural recordings, and lists show dates. Head-Fi, Dec 2015
• 2016-02-18Watts says the crossfeed settings are 0 for none, 1 minimum and 3 maximum, the same as Hugo. Head-Fi, Feb 2016
• 2016-02-19Watts says production Dave has short-circuit protection resistors on the balanced XLR, so it will not drive headphones, and he prefers crossfeed setting 3 as closer to loudspeakers. Head-Fi, Feb 2016
• 2016-08-01Watts says DAVE's crossfeed is mathematically identical to 1980s analog crossfeed, DAVE adds no reverb, and he recommends hearing it at home since show listening is less sensitive. Head-Fi, Aug 2016
• 2016-09-06Watts says the crossfeed is the same as an analog crossfeed but done digitally. Head-Fi, Sep 2016
• 2016-11-14Watts says the Goldmund's Linkwitz-based crossfeed is very similar to his setting 3, and he would like a more advanced scheme bringing loudspeaker depth to headphones. Head-Fi, Nov 2016
• 2017-03-15Watts posts his CanJam Singapore Hugo 2 slides: WTA2 to 256FS, filter options and advice, DSD filtering, noise shapers and depth, crossfeed, and APx555 measurements showing no noise floor modulation. Head-Fi, Mar 2017
• 2017-04-04Watts says crossfeed EQ boosts LF by 1.5dB for head shadowing, explaining a warmer balance, and he finds crossfeed essential for depth when using Hugo 2 on flights. Head-Fi, Apr 2017
• 2017-04-05Watts says crossfeed settings boost DC to 1 kHz by about 1, 1.5 and 1.9 dB, and improved depth shows transparency is not lost, since DSP problems collapse depth. Head-Fi, Apr 2017
• 2017-04-06Watts reports no consistent grounded versus ungrounded difference with a battery laptop, but turning crossfeed on (max blue) more than doubled perceived depth. Head-Fi, Apr 2017
• 2017-04-07Watts gives crossfeed settings (blue 700 Hz 4.5 dB, green Chu Moy 700 Hz 6 dB, red Jan Meier 650 Hz 9.5 dB), run as IIR at 705/768 kHz. Head-Fi, Apr 2017
• 2017-04-12Watts says Hugo 2's crossfeed code is identical to DAVE's PCM+ crossfeed. Head-Fi, Apr 2017
• 2017-09-06Watts says crossfeed on Hugo 1 suited only older recordings, but on Hugo 2 it gives better soundstage depth on all recordings. Head-Fi, Sep 2017
• 2017-09-09Watts says Hugo 2's crossfeed code is unchanged from Hugo, but better depth makes crossfeed have a big impact on perceived depth, as also happens with Dave. Head-Fi, Sep 2017
• 2017-09-19Watts says crossfeed tames hard-panned early stereo; on Hugo 1 it gave normal recordings no depth benefit, but on Hugo 2 depth is deeper and sounds seem outside the head. Head-Fi, Sep 2017
• 2017-09-19Watts explains headphone depth perception, why Hugo 2 crossfeed gives out-of-head sound, and why small-signal accuracy to -301 dB lets the brain use depth cues. Head-Fi, Sep 2017
• 2017-10-05Watts says crossfeed adds a small bass boost, 1.8dB on full and 1dB for red, because simulating loudspeakers needs it to provide the inter-ear delay. Head-Fi, Oct 2017
• 2017-11-01Watts says he sets crossfeed to the maximum, blue, because it sounds closer to speakers, but there is no right or wrong setting. Head-Fi, Nov 2017
• 2018-01-04Watts says gate count is the reason: crossfeed runs serially at 16FS, but DSD512 would need costly parallel DSP, and the new filter removes the need for DSD plus mode. Head-Fi, Jan 2018
• 2018-02-17Watts says he meant DAVE's crossfeed to disable outside headphone mode but kept it available because people like it, so users must unset it for speakers. Head-Fi, Feb 2018
• 2018-05-22Watts explains TT2's digital DC servo with no coupling caps, confirms separate crossfeed for headphone and amp/DAC modes, and says -3dB volume equals 3V RMS as on Dave. Head-Fi, May 2018
• 2018-09-21Watts confirms TT2 remembers separate crossfeed settings for headphone mode and DAC/amp modes. Head-Fi, Sep 2018
• 2019-06-01Watts says crossfeed improves depth on Dave, Hugo 2 and TT2, not Hugo, due to 350dB noise shaping; Dave took 2 to 3 years and later DACs reuse its code. Head-Fi, Jun 2019
• 2019-08-05Watts says crossfeed is done at 16FS (705/768k), after WTA1, since all sources end up at that point. Head-Fi, Aug 2019
• 2020-12-04Watts used crossfeed on Hugo only for hard-panned 60s recordings but runs it at max on Hugo 2 for depth; shrinking dimensions by a third would more than double temperature. Head-Fi, Dec 2020
• 2020-12-30Watts says Mojo lacked crossfeed because of button count, power dissipation and his lesser enthusiasm then; Hugo 2's transparency and depth made crossfeed essential for him. Head-Fi, Dec 2020
• 2021-04-10Watts says Carver-style processing tries to make loudspeakers sound like headphones, preferring crossfeed on headphones, and dislikes out-of-phase signals as phasey and false. Head-Fi, Apr 2021
• 2021-04-16Watts sets crossfeed to maximum on headphones and to minimum on his office HMS and Dave speaker system, saying depth improves in both. Head-Fi, Apr 2021
• 2021-04-16Watts says his speakers are close to ideal spacing, so they need only a small amount of crossfeed for most recordings. Head-Fi, Apr 2021
• 2021-04-20Watts says TT2 easily drives two headphones at once, and that two units share the same algorithm and crossfeed code, so a sound difference has another cause. needs context Head-Fi, Apr 2021
• 2022-01-07Watts says HRTF works if your own HRTF is modeled with very accurate DSP, 64 bit floating point is inadequate, and HRTF fixes direction but degrades depth. Head-Fi, Jan 2022
• 2022-01-31Watts says with the DSP core in place crossfeed cost no gates, which matter for Mojo's power dissipation; he cannot use headphones without it, though some hear little difference. Darko.Audio 47:26
• 2022-01-31Watts says formula, coefficients and four settings match DAVE, Hugo 2 and Hugo one; only implementation differs, using biquads instead of Hugo 2's dedicated serial DSP core. Darko.Audio 48:10
• 2022-02-05Watts explains Mojo 2's USB-ground ferrites, when external filters might help (optical is best), how crossfeed mimics loudspeaker listening, and reduced 2G buzz. Head-Fi, Feb 2022
• 2022-03-19Watts says the broad tone controls can fix headphone bass but not a 6 kHz resonance, and that crossfeed was added; with Hugo 2 he cannot listen without crossfeed. MFG Audio Reviews 40:53
• 2022-03-19Watts says crossfeed on Hugo 1 gave no out-of-head sense, but on Hugo 2 it improved depth, and Mojo 2 is similar thanks to better small signal accuracy. MFG Audio Reviews 41:42
• 2022-03-19Watts says crossfeed improves depth, a permanently on DSP HF filter flat to 20 kHz helps all sources, especially 96 and 192 kHz, and UHD DSP loses no depth. MFG Audio Reviews 42:27
• 2022-04-26Watts says he and John Franks wanted to add crossfeed, which he always uses with headphones, and remove the single coupling capacitor after the pulse array, which adds warmth. Audio Force 5:22
• 2022-06-12Watts recounts crossfeed giving an out-of-head experience with a Hugo 2 prototype on a flight, never with the original Hugo, linking better small-signal accuracy to more effective crossfeed. Head-Fi, Jun 2022
• 2022-06-27Watts says TT2's crossfeed code is identical to DAVE's, but its benefits may be more apparent on DAVE because of DAVE's better depth and detail resolution. Head-Fi, Jun 2022
• 2023-01-16Watts turns DAVE's HF filter off with the M scaler, doubts a Hugo 2-priced portable scaler-DAC by 2032, sets crossfeed to max, and says more taps add depth. Head-Fi, Jan 2023
• 2023-01-21Watts says his Blumlein recordings show lateral imaging is already perfect with crossfeed on Mojo 2 and Stealth; depth, attack and timbre need improving, digital sounding too soft. Head-Fi, Jan 2023
• 2023-01-26Watts says matching the microphone's image width needs maximum crossfeed (blue on Hugo 2/Mojo 2), which he generally uses because older recordings were hard-panned. Head-Fi, Jan 2023
• 2023-04-03Watts says improving Mojo meant adding crossfeed, essential for headphones, and moving toward Hugo 2's sound by going DC coupled, dropping the coupling capacitor that gave Mojo its warmth. Amplify Audio 10:23
• 2023-05-04Watts says his crossfeed is mathematically identical to 1980s analog crossfeed, but transparent digital implementation needs very high sample rates and noise shaping on internal nodes. Head-Fi, May 2023
• 2023-10-01Watts says crossfeed is so important that for him it is absolutely essential. The Source AV 13:13
• 2023-10-01Watts says crossfeed makes listening more speaker-like, makes hard left-right-center mixes on 1960s Beatles recordings less annoying, and opens up the soundstage so depth is better. The Source AV 13:19
• 2024-06-01Watts explains transients and localization, how crossfeed narrows headphone width, and ranks rectangular, triangular and pseudo-Gaussian dither below noise shaping, best for depth. Head-Fi, Jun 2024
• 2025-01-28Watts reports final PCB revisions for a product in development, a filter-accuracy improvement, and crossfeed at 768kHz whose benefits will show less on other DACs. needs context Head-Fi, Jan 2025