Transients, rhythm and flow

Perception and sound character

Answers on this topic

• What does Rob mean by 'starting and stopping of notes', timbre variation and 'sense of flow', and what causes them?

Everything he said on this topic (107)

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

• 2014-08-03Watts describes being astonished by the Hugo prototype versus his Qute: far more musical, no fatigue, revealing without forcing detail, fast rhythm, piano notes starting and stopping naturally. article, Aug 2014
• 2015-11-10Watts says Dave's key gain is timing: WTA filtering to 256FS reconstructs timing to 88 nS, improving starting and stopping of notes, while depth comes from the noise shapers. Head-Fi, Nov 2015
• 2016-01-29Watts says Hugo development has stopped because its FPGA is too small, and that after he improved DAVE's WTA filters it sounds faster, tighter, more dynamic, neutral and transparent. article, Jan 2016
• 2016-02-16Watts says Hugo's perception of timing, the starting and stopping of notes, surprised him, and Dave was about identifying and maximizing that factor, which he now understands technically. Head-Fi, Feb 2016
• 2016-06-02Watts says DAVE sounded too dark and soft late in development until a 256FS WTA stage improved perception of note starts and stops and restored balance. Head-Fi, Jun 2016
• 2016-07-24Watts says Hugo did things he had never heard from digital, especially on piano: each key being pressed and the timbre changing with touch, where before it sounded muddled. Hifistatement 2:46
• 2016-07-24Watts says Hugo's quality came from perceiving the starting and stopping of transients, not the WTA filter, since earlier 32,000-tap filters lacked it (Hugo had 26,000); DAVE gets bigger FPGAs. Hifistatement 3:31
• 2016-07-24Watts says timing accuracy is vital for bass and for hearing the starting and stopping of notes; timing uncertainty blurs the sound. Hifistatement 2:57
• 2016-07-24Watts says the DAVE filter took nine months to work on the FPGA, and was better but lacked Hugo's starting and stopping of notes, speed and timbre variation. Hifistatement 4:02
• 2016-07-24Watts says analog and noise shaper improvements made DAVE almost too rich and soft, lacking Hugo's immediacy, until improved WTA filters and other changes made it faster, tighter, more dynamic and more neutral. Hifistatement 11:45
• 2016-10-18Watts says he only appreciated hearing notes start and stop with Hugo three years earlier, and that accurate depth and sharp transients are key to approaching live sound. Head-Fi, Oct 2016
• 2016-10-20Watts lists the filter stages: Hugo and Mojo use WTA 16FS, linear interpolation to 2048FS and 260 kHz low-pass filters; DAVE adds a WTA stage to 256FS, nearer ideal sinc. Head-Fi, Oct 2016
• 2016-10-21Watts says adding the 256FS WTA filter turned DAVE from rich, dark and almost soft to sharper and tighter, improving starting and stopping of notes by nearing ideal sinc. Head-Fi, Oct 2016
• 2017-01-23Watts says the 256FS filter improves starts and stops of notes, Hugo cascaded two WTA stages while Dave uses one, and Dave remains well above Hugo 2. Head-Fi, Jan 2017
• 2017-04-07Watts says Hugo 2 is more incisive, transparent and refined than Hugo 1, crediting lower noise floor modulation, better noise shaping and truncation, and the 256FS WTA. Head-Fi, Apr 2017
• 2017-04-13Watts links 'strobing' impressions to hearing note starts and stops via the 256FS WTA, contrasting his son's live guitar with a soft CD playback, and wants both speed and warmth. Head-Fi, Apr 2017
• 2017-04-18Watts says closing the gap to live acoustic instruments is his main goal, notes electronica best reveals the stopping of notes as WTA improves, and says he enjoys all genres. Head-Fi, Apr 2017
• 2017-06-15Watts says Hugo 2's HF filter matters little at 44.1 kHz but more at 96 to 768 kHz, and the 256FS WTA stage audibly snaps note starts into focus. Head-Fi, Jun 2017
• 2017-06-26Watts recounts his DAC history since 1988 and how Hugo, from 2012, made poor recordings musically involving, which he attributes to the ear's sensitivity to reconstruction timing errors. Head-Fi, Jun 2017
• 2017-10-13Watts says timbre depends on transients, and that pitch, soundstage, timbre and the starting and stopping of notes all come from transients, which digital audio's frequency-response focus neglects. miceblue425 8:53
• 2017-10-13Watts says AAC sounds soft against 16-bit through a WTA filter because poorer transient timing blurs the starting and stopping of notes. miceblue425 58:36
• 2017-10-20Watts says interaural neurons have about 4 microseconds accuracy, far finer than CD, and that transient timing governs perceived starting and stopping of notes, timbre and bass pitch. Hifistatement 1:30
• 2017-10-20Watts lists WTA tap lengths (DAC64 a thousand, QBD76 18 thousand, Hugo 26,000, DAVE 164,000) and says each increase improved bass definition, timbre, staging precision and note starts and stops. Hifistatement 0
• 2017-10-20Watts says that improving timing lets you hear instruments starting and stopping better. Hifistatement 40
• 2017-10-20Watts says longer taps improved bass definition, timbre and pitch as usual, but the million-tap M Scaler also opened up depth and soundstage beyond DAVE's. Hifistatement 2:03
• 2018-02-23Watts says the brain reconstructs limited ear information into perception, judges bass pitch from the starting transient, and that without it a bass guitar's rhythm cannot be followed. MajorHiFi 6:28
• 2018-02-23Watts says wood blocks are hard to reproduce, an initial dynamic hit followed by timbre, which he notices when Dave drives efficient loudspeakers directly, plus a huge soundstage. Head-Fi, Feb 2018
• 2018-04-12Watts says the HF filter matters for 96k and 192k, the 256FS filter is easiest heard on piano over extended listening, and changing lights show the filters work. Head-Fi, Apr 2018
• 2018-04-13Watts says the level is the same; the new filter sounds smoother and warmer with better flow, which may give an impression of being quieter. needs context Head-Fi, Apr 2018
• 2018-04-27Watts responds to a review calling Hugo 2 merciless, contrasts live drums with reproduction, states Davina's goals of depth and speed, and says all design is his. Head-Fi, Apr 2018
• 2018-04-30Watts says white and green differ little without 96k or 192k files, he leaves it on green, and switching the 256FS filter is audible on fast transients. Head-Fi, Apr 2018
• 2018-07-21Watts says digital audio's principal problem is the timing of transients, from which we perceive pitch, left-right soundstage, timbre and the starting and stopping of notes. c w 7:49
• 2018-08-06Watts says the brain uses transient information for location, timbre and pitch, and recounts a listener saying the M Scaler made the tempo sound slower, which he relates to flow. Pursuit Perfect System 2:47
• 2018-08-06Watts says without the M Scaler musical flow sounds mechanical, jerky and disjointed, while with it you perceive the timing interplay between instruments that normal digital lacks. Pursuit Perfect System 3:35
• 2018-11-11Watts explains the M scaler's apparently slower tempo as reduced dominance effect, because 1M-tap WTA cuts program-dependent transient timing errors; 164,000 to 1M taps is very audible. Head-Fi, Nov 2018
• 2018-12-12Watts lists further variations to judge by: space, dynamics, pace and rhythm, instrument separation and power without cross modulation, and the starting and stopping of notes and sharp cracks. Pursuit Perfect System 7:30
• 2018-12-13Watts moves from noise floor modulation and small-signal accuracy to transients and the WTA filter, defining a transient as a sudden signal change and calling transients very important. Pursuit Perfect System 0
• 2018-12-13Watts says instrument separation, focus and timbre are better and note starting and stopping is perceived more accurately, because timing uncertainty is reduced. Pursuit Perfect System 9:54
• 2018-12-13Watts says he listens to more electronic music lately; its artificial depth still opens up, and its abrupt stops let the M Scaler show starting and stopping of notes clearly. Pursuit Perfect System 22:17
• 2018-12-13Watts says his phrase 'starting and stopping of notes' comes from electronica, where a bass drone stops sharply and the stop can be perceived. Pursuit Perfect System 23:08
• 2018-12-13Watts says amplified concerts blur left-right imaging and are poor for judging transparency, but convey immediacy, speed, separation and instrument power, which the M Scaler helps improve. Pursuit Perfect System 23:48
• 2019-08-01Watts says better transients make tempo seem faster while less dominance effect makes it seem slower; an M Scaler on Qutest mostly reduces dominance, sounding more measured. Head-Fi, Aug 2019
• 2019-12-14Watts tells a TT2 owner every DAC upsamples, the M scaler matches sinc to 16 bits for accurate transients, blind tests are insensitive, and he uses Aeon Closed on planes. Head-Fi, Dec 2019
• 2020-01-02Watts says people like MQA or minimum phase because their huge transient errors put sound out of focus, warmer and smoother, taming a DAC made bright by noise floor modulation. Passion for Sound 20:31
• 2020-01-28Watts says DSD adds softness because small-signal steps are delayed more than large ones, blurring transients, has poor depth from small-signal accuracy, and advises fixing hardness rather than using DSD. Head-Fi, Jan 2020
• 2020-03-27Watts says the M scaler gives a natural sense of flow and less fatigue because loud instruments no longer modulate transient timing, about 10 times more accurate than DAVE alone. Head-Fi, Mar 2020
• 2020-06-25Watts says replacing the conventional IR type filter with a WTA filter running to 88 nanoseconds was immediately audible in the starting and stopping of notes, such as piano attacks. Part-Time Audiophile 24:23
• 2020-06-25Watts says Class D cannot switch at 12 MHz; his designs ran at 800 kHz to 1.6 MHz, relying on output filters, so timing errors keep them below linear amplifiers. Part-Time Audiophile 25:19
• 2020-06-25Watts says fixing the 200 to 400 kHz noise shaper distortion was immediately audible, because very high order harmonics modulate transient timing, which can be perceived. Part-Time Audiophile 37:19
• 2020-06-25Watts says 200 kHz cannot be heard, but if it changes the timing of a transient it can be perceived because that effect is in-band. Part-Time Audiophile 38:02
• 2020-06-25Watts says 192 versus 48 kHz is subtle but 768 kHz is a massive change, and Hugo One's filtering to 104 MHz made piano notes' starts and stops audible. Part-Time Audiophile 41:12
• 2020-06-25Watts says he can now hear each piano note and the pianist's expression in the initial attack, so small timing accuracy brings big musical benefits. Part-Time Audiophile 41:58
• 2021-09-09Watts says the M Scaler improves tempo, pitch, timbre and separation, while WTA filtering above 16FS has so far only improved clarity, soundstage and starting and stopping of notes. Head-Fi, Sep 2021
• 2022-01-13Watts explains tempo perception depends on note starts and stops; timing modulation harms separation so the loudest instrument dominates; headphone sensitivity is rated at 1mW while volume is voltage. Head-Fi, Jan 2022
• 2022-03-19Watts says digital audio reproduces the starting and stopping of notes poorly, sounding hard or unnaturally soft, and that only true transparency, not a forced false transparency, gives these variations. MFG Audio Reviews 4:25
• 2022-03-19Watts says the brain perceives bass pitch, left-right location, timbre and note starts from transients, citing psychoacoustic tests where removing transients makes piano and trumpet indistinguishable. MFG Audio Reviews 16:12
• 2022-03-19Watts says more accurate transient reconstruction gives better bass pitch, location, timbre variation, separation and focus, and no listening fatigue, letting him listen for ten hours. MFG Audio Reviews 23:36
• 2022-04-26Watts says digital audio's primary problem is the timing of transients, defines a transient, and says the brain uses transient timing for lateral imaging and timbre. Audio Force 8:27
• 2022-04-26Watts says pitch, timbre variation, bass definition, instrument separation and focus depend on accurate transient timing, and timing errors confuse the brain and reduce emotional engagement. Audio Force 9:09
• 2022-08-19Watts says he tunes each variable listening for separation and focus, soundstage depth, timbre, bass pitch (dependent on transients), and the starting and stopping of notes. AVstore 18:29
• 2022-08-19Watts says digital makes a wood block crack sound softer, that note starts and stops depend on transients, and optimizing five interacting variables took thousands of listening tests. AVstore 19:17
• 2022-09-18Watts says the sharp sounds of real live music are being softened. The Source AV 20:08
• 2022-09-18Watts says you want things to be sharp, he knows what the issues are, and the softening is down to the A to D converter. The Source AV 20:22
• 2022-09-18Watts says that, strangely, digital softens leading edges; at least with his chain it is not hard and bright but too soft and too warm. The Source AV 21:22
• 2022-09-18Watts says TT2, DAVE and Hugo 2 have a WTA filter from 16FS to 256FS, unlike the 1FS to 16FS WTA, improving speed and the starting and stopping of notes. The Source AV 39:35
• 2022-09-18Watts says a piano key's sharp attack is easier to hear with the 256FS filter engaged, losing it adds softness, and technically you are better off with it. The Source AV 40:13
• 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
• 2023-01-24Watts says transducers change sound quantitatively but DAC/amps qualitatively, and musicality comes from portraying variation in dynamics, timbre, note starts and stops, and separation. Head-Fi, Jan 2023
• 2023-02-04Watts says bass pitch is perceived from the pluck transient, and going to 1000 taps improved bass pitch, timbre variation and the starting and stopping of notes. Dusty Audio 41:22
• 2023-02-04Watts says some like MQA's sound because losing transients impairs pitch perception, making bass fat, flabby and less tuneful with a bloom some enjoy. Dusty Audio 58:14
• 2023-03-26Watts says non-audiophiles found music slower with the M Scaler; he agrees, since removing mechanical, disjointed jerkiness restores natural flow that otherwise seems faster. Eric's Hi-Fi 38:17
• 2023-03-28Watts says degraded transient timing harms timbre variation, separation, focus, pitch and the starting and stopping of notes, noting he used PWM DACs in low-cost chip designs. The Headphone Show 32:45
• 2023-04-03Watts says it is more resolving, with timbre variation and sharp fast attacks as big gains; live unamplified sound can be explosively sharp, while digital and analog reproduction soften everything. needs context Amplify Audio 13:19
• 2023-04-03Watts says reproduced audio loses transparency and edge; the aim is sound that is fast, sharp and explosive, yet rich and warm when the occasion demands. Amplify Audio 13:58
• 2023-04-03Watts says his recent improvements make things sharper and faster with more weight and density, warmer and sharper at once, and that Ultima will be really interesting. Amplify Audio 14:13
• 2023-10-01Watts says reproduced audio is still not very good at speed: really sharp, fast sounds. The Source AV 30:40
• 2023-10-01Watts gives very fast rhythms in electronica as an example. The Source AV 30:53
• 2023-10-01Watts says an unmiked drum kit up close is very fast and sharp, reproduced audio softens transients, and both depth and speed/impact must be solved. The Source AV 31:05
• 2024-05-16Watts says with that separation powerful instruments hit hard, and a trumpet heard close up live should hit you like an axe. The Speaker Shack 7:14
• 2024-05-16Watts says reproduced audio is poor at instrument power and tracking quiet background players, and Quartet taught him how important timing information is for both. The Speaker Shack 7:31
• 2024-05-17Watts says reducing noise improves sound markedly, and that scaling is about transient timing, which the brain uses to separate instruments, perceive timbre and hear notes start and stop. AVstore 2:08
• 2024-05-17Watts says the result is blurred instruments, less timbre variation, poorer pitch especially in bass, and artificially soft starting and stopping of notes. needs context AVstore 3:43
• 2024-05-17Watts defines musicality as being emotional when listening and says it depends on pitch, starting and stopping of notes, and hearing each instrument separately and in focus. AVstore 4:02
• 2024-06-18Watts explains how interpolation modulates transient timing, harming separation, timbre, bass and fatigue, says any timing error is perceptible, and lists Quartet's five FPGAs, 2,500 components, 75-ampere supply and two million code lines. article, Jun 2024
• 2024-08-01Watts introduces the interpolation filter's transient accuracy and says the brain uses transient timing to locate and separate instruments, recognize timbre, and hear notes start and stop. Audiophilesdoteu 3:53
• 2025-01-08Watts says valve amps easily sound musical but bipolar can sound better, estimates 38 to 76 hours of Hugo M Scaler use per car battery, and says measurements ignore transients. Head-Fi, Jan 2025
• 2025-02-17Watts says filter errors make transients early or late, modulated by other instruments, confusing the brain so separation, timbral variation, location, bass pitch and note starts and stops suffer. audio-2G 6:13
• 2025-05-12Watts says very small timing errors substantially affect listening, and conventional DACs reconstruct transient timing poorly, making the sound muddled and confused and causing listening fatigue. Audiophile Junkie 4:18
• 2025-05-12Watts lists benefits of more taps and WTA tweaks (bass, staging, separation, fatigue, note starts and stops); at 1 million taps the Hugo M Scaler reaches identical sinc values. Audiophile Junkie 14:19
• 2025-09-14Watts says more accurate transient reproduction does two things: things sound richer, warmer and softer, yet hard, sharp transients sound sharper, harder and faster. needs context The Source AV 16:14
• 2025-09-14Watts says the other thing that changes is that the tempo gets slower. needs context The Source AV 16:35
• 2025-09-14Watts says the slower tempo is quite noticeable, particularly with rock or pop music. needs context The Source AV 16:42
• 2025-09-14Watts says accurate transients remove a mechanical quality and reveal musicians' timing interplay as instruments are better focused; some hear little difference with the M Scaler, others find it essential. The Source AV 16:52
• 2026-03-17Watts says no recording technique, tape or digital, captures sharp sounds such as a live rim shot properly; playback sounds softer and loses the fast edge. ecoustics 1:15:45
• 2026-03-24Watts says digital music can sound mechanical and jerky with rhythm that does not flow, and with Blackbird WTA things flow much more naturally. Audio Force 16:29
• 2026-10-02Watts says transient timing was the key factor: interaural delay was once said to resolve 4 microseconds, recent papers find no limit, and the brain uses timing for bass. HiFi Buys 17:47
• 2026-10-02Watts says clarity differs from transparency; he listens for variation in timbre, pitch and tempo, which digital can make sound mechanical and disjointed. HiFi Buys 47:22
• 2026-10-02Watts says improvements make music flow more naturally, sometimes sounding faster and sometimes slower, and following the beat is vital. HiFi Buys 48:07
• 2026-10-11Watts says the digital recording lost soundstage depth and was warmer than the original, partly from the ribbon mic, with much of the difference being speed, impact and power that Quartet brings out. Distorsiuni Interioare 11:17
• 2026-10-14Watts lists his criteria: greater timbre variation (warmer sax, brighter trumpet), more accurate starting and stopping of notes, consistent instrument separation, each attribute assessed independently. Part-Time Audiophile 8:21
• 2026-10-14Watts says all audio is poor at the shock of transients, and describes a first recording with his Tonmeister son: conventional ADCs, a ribbon mic, a small church orchestra. Part-Time Audiophile 13:38
• 2026-10-14Watts says the recording truncated depth by about 50 percent (a cello four metres away sounded two) and softened transient edges, a reason for his pulse array ADC work. Part-Time Audiophile 14:32
• 2026-10-14Watts says the pulse array ADC now yields 768 kHz recordings with immediate, fast transients and live-like power, with more test recordings planned over the coming months. Part-Time Audiophile 15:18
• 2026-10-14Watts defines a transient against steady state: the first pulse when a sine wave switches on, the starting or decline of a note, usually thought of as fast activity. Part-Time Audiophile 16:16
• 2026-10-14Watts describes a piano hammer's burst of white noise turning into string vibration as part of the transient, saying much timbre comes from transients, which are psychoacoustically essential. Part-Time Audiophile 17:02
• 2026-10-14Watts says degraded transient timing makes timbre, pitch, location and separation hard to perceive, causing listening fatigue and making emotional engagement harder. Part-Time Audiophile 20:12
• 2026-10-17Watts lists transient speed, instruments leaping from dense mixes, timbre variation, soundstage, unpicking many instruments, natural flow, and emotion as improvements, noting listener dependence. article, Oct 2026