What does Rob think of room correction, HRTF processing and surround sound?
Short answer
Watts does not endorse DSP room correction: in 2017, 2021 and at a Munich show (most likely May 2024; published February 2025) he said to treat the room acoustically instead Head-Fi, Nov 2017Head-Fi, Jan 2021audio-2G 13:59. He describes Mojo 2's EQ as a broad tone control, not a resonance fixer Head-Fi, Feb 2022MFG Audio Reviews 40:53, and says Quartet's ten-band EQ costs no transparency article, Oct 2026. With headphones he calls crossfeed essential Head-Fi, Jun 2024. He has said he does not like surround sound The Source AV 4:38 and that HRTF needs really good DSP Head-Fi, Jan 2022.
Practical answer. Do not expect him to recommend electronic room correction: in 2017, 2021 and in a Munich-show interview (most likely May 2024, published February 2025) he said to fix a room acoustically Head-Fi, Nov 2017Head-Fi, Jan 2021audio-2G 13:59. Mojo 2's EQ is, in his words, "a broad tone control" MFG Audio Reviews 40:53. With headphones he calls crossfeed essential Head-Fi, Jun 2024. For video, Chord DACs and scalers take stereo PCM, so set the source to decode surround to stereo Head-Fi, Sep 2017Head-Fi, Jul 2022.
Room correction
In November 2017 he described a friend who scrapped a loudspeaker DSP EQ after a Hugo demo, because "the losses in the DSP vastly outweighed the benefits"; he added "fix room problems with room treatment" Head-Fi, Nov 2017. In January 2021 he wrote that he had never been attracted to DSP for room problems, because the brain compensates for room acoustics while DSP degrades image, depth, separation and timbre: "I would sooner tune my room using good old fashioned acoustic set-up" Head-Fi, Jan 2021.
In an interview recorded at a Munich show, most likely May 2024 (date unconfirmed; published February 2025), an interviewer asked about digital room correction. Watts answered "I don't like room EQ", and that if a room sounds bad "you treat the room, you don't use artificial means because you can never cancel resonances out" (check the recording) audio-2G 13:59.
In March 2022, writing about a recording he made and why he made Mojo 2's EQ lossless, he said "Gentle EQ is appropriate (so long as it's completely transparent) for transducer and acoustic problems" Head-Fi, Mar 2022.
The EQ in Mojo 2 and Quartet
In January 2022 he listed Mojo 2's EQ as a 20 Hz peak, a 20 kHz peak, a bass shelf and a treble shelf, with plus or minus 9 dB stated for the first three (check the recording) Darko.Audio 39:52. In February 2022 he said it is for headphone and IEM bass problems and overall balance, and "not intended to solve headphone HF problems" Head-Fi, Feb 2022. At CanJam NYC in late February 2022 (video published March 2022) he said that if you have a 6 kHz headphone resonance to null out, "forget it" MFG Audio Reviews 40:53. Asked about loudspeakers with lively treble, he said "Absolutely, yes", adding that in his own room "I don't need EQ for that" Darko.Audio 46:24.
In July 2023 he said a full parametric EQ "wouldn't be a good idea" because "using resonators to cancel other resonances is impossible to do properly" Head-Fi, Jul 2023. A day later he wrote "If you need EQ - and I use it with my Stealths - then the issue is to do it transparently" Head-Fi, Jul 2023. In the Munich-show interview he called Mojo 2's EQ transparent and said Quartet has a similar DSP core audio-2G 14:59audio-2G 18:39. In a Soundnews interview recorded in fall 2026 (published October 2026) he said of Quartet's EQ "I use it a lot", and that alternating half-dB settings on its ten bands lost no transparency, detail or depth article, Oct 2026.
Crossfeed on headphones
Dave, Hugo 2 and Mojo 2 share the same crossfeed coefficients and four settings, 0 being off Head-Fi, Feb 2016Head-Fi, Apr 2017Darko.Audio 48:10. In 2017 he said Hugo 2 crossfeed improves soundstage depth on all recordings, whereas on Hugo 1 it suited only older ones Head-Fi, Sep 2017. He said "I couldn't exist with headphones without CrossFeed" in January 2022 Darko.Audio 47:26; "For me, cross-feed is absolutely essential" in 2023 The Source AV 13:13; and "I find cross-feed essential with headphones" in June 2024 Head-Fi, Jun 2024. In 2015 he agreed that "cross-feed does not make sense for binaural recordings" Head-Fi, Dec 2015.
For loudspeakers, he wrote of his March 2022 recording that "Loudspeakers will be fine with no cross-feed" Head-Fi, Mar 2022. In 2018 he said Dave's crossfeed stays selectable outside headphone mode, as he had "once or twice found it useful myself with some speaker set-ups", and "you need to remember to unset it though when going back to speakers" Head-Fi, Feb 2018.
HRTF
In January 2022 he wrote "HRTF does work quite well - but - it needs accurate modelling of your own HRTF, and it needs really good DSP". He said 64 bit floating point is not up to the task and that HRTF sorts out direction, not depth Head-Fi, Jan 2022.
Surround sound and video
In September 2017 he said Dolby and DTS data "does sound bad" through his DACs, so set the source to decode surround to stereo PCM Head-Fi, Sep 2017. He wrote "I have not been a fan of surround" in 2018 Head-Fi, Sep 2018 and "I have never liked surround sound" in 2021, hedging "It's not something I have investigated, so take my comments with a pinch of salt, but my inclination would be to agree with Bob Lefsetz" Head-Fi, Jun 2021. In July 2022 he wrote "All Chord DACs and scalers work with stereo PCM" Head-Fi, Jul 2022; in September 2022 he said "And I don't like surround sounds" The Source AV 4:38.
What the archive does not show. None of his room statements names Dirac Live, Audyssey or another measurement-based room correction product. The HRTF follow-up he promised Head-Fi, Jan 2022 did not turn up in searches.
Quotes
“you treat the room, you don't use artificial means because you can never cancel resonances out.”2024-05 (likely; published 2025-02) audio-2G 13:59
“I would sooner tune my room using good old fashioned acoustic set-up - as this won't damage musicality.”2021-01-02 Head-Fi, Jan 2021
“Gentle EQ is appropriate (so long as it's completely transparent) for transducer and acoustic problems.”2022-03-16 Head-Fi, Mar 2022
“It's not intended to solve headphone HF problems, as these tend to be sharper resonances.”2022-02-03 Head-Fi, Feb 2022
“I find cross-feed essential with headphones, as it makes it sound like loudspeaker positioning, or more like a real concert in terms of width”2024-06-01 Head-Fi, Jun 2024
Dated positions
| When | Products | Position |
|---|---|---|
| 2017-11 | Hugo | Watts relayed that a friend's loudspeaker DSP EQ was scrapped after a Hugo demo showed DSP losses outweighed the benefits, and agreed room problems should be fixed with room treatment. Head-Fi, Nov 2017 |
| 2021-01 | General | Watts said he has never been attracted to DSP to compensate for room problems, since the brain compensates for room acoustics, and would sooner tune the room acoustically. Head-Fi, Jan 2021 |
| 2022-03 | Mojo 2 | Discussing a recording and Mojo 2's lossless EQ, Watts wrote that gentle, completely transparent EQ is appropriate for transducer and acoustic problems. Head-Fi, Mar 2022 |
| 2022-01 to 2023-07 | Mojo 2 | Watts described Mojo 2's EQ as a broad tone control for headphone low-frequency problems and taste, not for nulling resonances; said people would use it for lively loudspeakers; and said full parametric EQ would not be a good idea. He uses EQ with his Stealth headphones. Head-Fi, Feb 2022MFG Audio Reviews 40:53Darko.Audio 46:24Head-Fi, Jul 2023Head-Fi, Jul 2023 |
| 2024-05 (likely; published 2025-02) to fall 2026 | Mojo 2, Quartet | Asked about digital room correction, Watts said he does not like room EQ and would treat the room; he said Mojo 2 has transparent EQ, Quartet a similar DSP core, and that Quartet's ten-band EQ shows no loss of transparency. audio-2G 13:59audio-2G 14:59audio-2G 18:39article, Oct 2026 |
| 2015-12 to 2024-06 | Dave, Hugo 2, Mojo 2 | Watts calls crossfeed essential for headphones (2022, 2023, 2024), not sensible for binaural recordings, and generally unneeded on loudspeakers, though he has once or twice found it useful with some speaker set-ups. Head-Fi, Dec 2015Head-Fi, Sep 2017Darko.Audio 47:26The Source AV 13:13Head-Fi, Jun 2024Head-Fi, Mar 2022Head-Fi, Feb 2018 |
| 2022-01 | General | Watts said HRTF works if your own HRTF is accurately modeled and the DSP is very good, that 64 bit floating point is not enough, and that it fixes direction but not depth. Head-Fi, Jan 2022 |
| 2017-09 to 2022-09 | Hugo 2, Hugo M Scaler | Watts said Dolby and DTS data sound bad and should be decoded to stereo PCM at the source, that Chord DACs and scalers take stereo PCM, and that he does not like surround sound (with a 2021 hedge that he had not investigated it). Head-Fi, Sep 2017Head-Fi, Sep 2018Head-Fi, Jun 2021Head-Fi, Jul 2022The Source AV 4:38 |
Caveats and open points
- His March 2022 remark that gentle transparent EQ suits acoustic problems was made about a recording chain, not about room correction in playback.
- The archive has no Watts statement on measurement-based room correction products by name.
- The HRTF follow-up he promised in January 2022 was not found in the archive.
- Crossfeed statements are included because it is the spatial processing in his headphone-capable products; he does not call it HRTF.
Topics: EQ, tone controls and room correction, Crossfeed and spatial processing, Latency, video and surround