The Marshall Monitor III A.N.C. is the battery-life champion of premium headphones: 70 hours with ANC on, backed by drain testing, in a comfortable 250 g folding design with physical controls and strong calls. Sound is balanced and EQ-friendly, ANC good but behind Bose and Sony, no hi-res codecs. At the deal prices these hit, an easy pick for travelers.
— THE VERDICT · JUDGEANY EDITORSThe short version
The Marshall Monitor III A.N.C. is the battery-life champion of the premium headphone class: 70 hours with ANC on, 100 with it off, and TrustedReviews' drain testing suggests those numbers are conservative rather than optimistic. Sound is balanced and takes EQ well, the 250-gram frame folds into a hard case and wears comfortably for hours, and call quality is genuinely strong. The trade: noise cancelling sits a step behind Bose and Sony, and hi-res Bluetooth codecs are missing entirely. We don't run a test lab — the scores below are editorial judgments built on published evidence, not our own measurements.
Battery life: the headline, verified
Marshall's official figures are 70 hours of wireless playback with ANC on and 100 hours with it off, plus a 15-minute quick charge worth about 12 hours — a full recharge takes 2.5 hours. TrustedReviews tested the claim properly: a Spotify playlist at roughly 50% volume, tracked over months of use, losing just 1% in the first hour and 1% in the second. TechRadar's real-world take matches — about once a week on the charger with regular use, usually with plenty left in the tank. The Marshall app also carries over a Battery Preservation mode from the company's speakers, which caps the charge to protect long-term battery health.
Sound: balanced, EQ-friendly, and one dissenting voice
The 32 mm dynamic drivers (35 Ω, 20–20,000 Hz on Marshall's spec sheet) deliver a balanced, lively signature that plays to rock, pop, jazz and other instrument-forward music. TechRadar gave the sound 4/5 for its warm, well-separated presentation; Android Central, after nine months of regular use, couldn't find a deal-breaking flaw in the audio. The Marshall Bluetooth app offers a customizable EQ with bass boost, plus a Soundstage spatial-audio mode with adjustable room size — though reviewers agree it widens the stereo image without adding real immersion.
TrustedReviews disagrees, and it's the review worth taking seriously — months of testing, including a pink-noise ANC test and the battery-drain protocol above. Their verdict on the sound: "thin," "too tasteful" for Marshall's rock heritage, low-end impact that stays tame even with the bass boost on. The conclusion still holds because the dissent is about the default tuning, not the hardware: TechRadar, Android Central, Tom's Guide, Louder's five-star verdict and SoundGuys' 7.5/10 all rate the sound positively, the app's EQ and bass boost give owners a working fix (TrustedReviews concedes the boost "helps"), and RecordingNow — a professional audio engineer who bought the pair with his own money — scores them 8.8 overall with "great sound quality (after EQ)."
One thing every reviewer agrees on: SBC, AAC and Bluetooth LE Audio, nothing more. No aptX in any form, no LDAC. TrustedReviews notes that Marshall had said a hi-res codec update was coming in 2024 — by 2025, the headphones still ran SBC and AAC. If hi-res wireless is on your must-have list, this is a real deal-breaker.
Noise cancelling: good, not class-leading
Marshall's ANC continuously measures ambient noise and offers three adjustable levels — low, mid, high — plus transparency mode, all tunable in the app. In practice, most reviewers call it effective: Android Central lists "spectacular ANC" among its pros, and Tom's Guide calls it a solid step up from the Monitor II, especially against low-frequency rumble. The ceiling is consistent across reviews, though. TrustedReviews' pink-noise test showed only a minor improvement over the Monitor II, and on a plane the Marshalls let noticeably more cabin noise through than the Bose QuietComfort Ultra. Louder's expert verdict puts it bluntly: "not the last word in noise cancelling." Transparency is the weaker half — Tom's Guide found it lets in only marginally more sound than ANC-off, and the strong passive seal works against it.
Comfort, build and controls
At 250 grams the Monitor III is 70 grams lighter than its predecessor, and TrustedReviews credits the redesign — bigger earcups, plusher cushions, a headband that spreads weight better — for genuinely comfortable long sessions. It folds flat into a compact hard case with a velvet-style lining. The controls are physical, and reviewers keep praising that as a relief from touch panels: the signature multidirectional knob handles play/pause, volume, track skip, power and calls, with a dedicated ANC button and the customizable M-button (Spotify Tap, EQ presets or voice assistant) on the earcup linkages.
One practical gap: no built-in 3.5 mm jack. Cabled listening goes through the USB-C port with the included USB-C-to-3.5 mm cable — an annoyance TechRadar, Android Central and ServiceDig's review panel all flag for buyers who live on wired connections. Bluetooth 5.3 brings multipoint for two devices, LE Audio and Auracast readiness, and TrustedReviews reports a solid connection walking through busy London stations.
Price and value
The Monitor III A.N.C. launched in September 2024 at $349 — $30 up from the Monitor II — with a campaign fronted by Green Day's Billie Joe Armstrong. That launch price is rarely the real price anymore. SoundGuys reported Amazon cutting them to $229.99 in July 2026, a 39% discount from the $379.99 list price and an all-time low at the time, with the headphones holding a 4.5-star owner rating. Prices move constantly, so check the current price on Amazon before deciding: at deal pricing these are one of the easiest premium picks; at full list you're paying partly for the Marshall name over raw ANC performance.
Who should buy it
Buy the Monitor III A.N.C. for the longest battery life in the class, a comfortable folding design with real physical controls, multipoint and Auracast for travel, and Marshall's characterful looks. Skip them if your priority is the absolute best noise cancelling — Sony and Bose still lead — hi-res wireless codecs, or a built-in 3.5 mm jack. ServiceDig's aggregation of 16 expert reviews lands on the same line: choose them for battery, comfort and lively, rock-friendly sound; pass if you need elite ANC, hi-res codecs or wired simplicity.