Sennheiser MOMENTUM True Wireless 4: problems, parts and running costs

Checked: 2026-10-19

Summary

Owners report one earbud going silent, sometimes repeatedly on replacement units, and the microphones trail premium rivals in noisy calls. Running costs are low: no subscription, negligible electricity, and tips cost about $4.98 to $9.95 per year. At $99.95 manufacturer-certified refurbished (Sennheiser US, October 2026) it is a strong value; above $180-$200 for new old stock it is hard to justify against the $299.95 MTW5.

Common problems and fixes

One earbud goes silent — a July 24, 2026 r/sennheiser post described the right earbud lit and touch-responsive but producing no sound with something rattling inside, three months after an August 2025 purchase; the same channel failed again about eight months after the warranty replacement. Clean the charging contacts and reset first, but a touch-responsive yet silent bud after cleaning warrants an RMA. Covered under the 12-month US warranty for qualifying first purchasers with an authorized dealer receipt. [8][14][16]
Serial failures across multiple pairs — an August 30, 2026 owner reported three MTW4 pairs developing an inaudible or weak channel after about six months each, with prompt early replacements. This is one user’s experience, not a population failure rate. RMA is the practical route; repeated failures make the $99.95 refurbished set or the $299.95 MTW5 the safer buy. [18]
Charging contact dirt imitates failure — Sennheiser’s manual and FAQ instruct cleaning earbud and case contacts with a cotton swab and gently brushing the sound outlet without piercing the mesh. Intermittent charging or an unpaired bud can sometimes respond, but do not assume every silent unit only needs cleaning. Not a warranty item; owner maintenance. [3][14]
Non-replaceable battery aging — three sealed Li-ion cells lose capacity over years and the warranty treats batteries as consumables, excluding ordinary wear. No user-replaceable pack exists for the MTW4; the MTW5 added user-replaceable cells. [2][12][16]
Case is not weatherproof — IP54 covers the earbuds only; dry them before placing in the case and never charge wet. Water damage outside IP54 use is excluded from warranty. [15][16]

Parts and consumables

Silicone eartips (article 509283, size-dependent 509283-509286) — $9.95 for five pairs of one size (Sennheiser US, October 2026); sizes XS, S, M, L. Replace when torn, loose, unhygienic or no longer sealing; no official replacement interval. [10]
Stabilizer ear fins (article 509291) — $9.95 (Sennheiser US, October 2026). Replace if lost or stretched; no fixed interval. [17]
Charging case (article 700370, black-copper) — $119.95 (Sennheiser US, October 2026), case only with its built-in battery, no earbuds; color article numbers differ. Costs more than the $99.95 refurbished complete set, so ask service first. [11]
Earbud pair (L+R) — $199.95 (Sennheiser US, October 2026), no charging case included; no separately priced single left or right unit confirmed. [22]
Cleaning supplies — dry cotton swabs and soft cloth; no proprietary consumable cartridge or ear-wax guard sold for this model. [3][14]

Yearly running cost

No subscription or filter is required; normal playback, ANC, the app and firmware carry no verified recurring fee. Music streaming and phone hardware are outside earbud ownership cost. Electricity is negligible: Sennheiser lists 75 mAh per earbud and 820 mAh in the case, and an illustrative estimate assumes 5 Wh from the wall per complete charge cycle and 150 cycles per year, giving 0.75 kWh per year, or $0.19 per year at $0.25 per kWh; this is not measured consumption. Consumable tips: one $9.95 five-pair package every two assumed years is $4.98 per year, or $9.95 per year if replaced annually; a $9.95 fin set every three assumed years is $3.32 per year. Amortization examples: a $99.95 certified refurbished pair over an assumed three years is $33.32 per year, and a $249.95 new old-stock pair over the same span is $83.32 per year before shipping and tax. Loss scenario: a lost case out of warranty costs $119.95 and a lost earbud pair costs $199.95, more than the $99.95 refurbished complete set. [1][2][8][9][10][11][17][18][19][22]

When it is a good buy

US prices checked October 19, 2026, before tax and delivery: Sennheiser US new MTW4 is end of life and not available direct, with an old $299.95 list reference; Sennheiser US factory-certified refurbished MTW4 is $99.95 with a stated one-year warranty; Walmart marketplace (Buy Top Tech) lists new MTW4 at $249.95; Newegg marketplace lists new MTW4 Black Graphite at $249.95; Headphones.com lists new MTW4 at $349.95; Sennheiser US MTW5 is $299.95 new. Editorial thresholds: certified refurbished at $100-$120 delivered is good value if you accept warranty ambiguity and used-battery wear; new with an authorized original-purchaser receipt below $140-$160 can be attractive; above $180-$200 for brand-new old stock the age, warranty and failure reports make it hard to justify; at $250 or more prefer the $299.95 MTW5. Alternatives: MTW5 at $299.95 (October 2026) for buyers considering MTW4 new old stock above about $220, with user-replaceable batteries and Bluetooth 6.0; the $99.95 certified refurbished MTW4 for the same audio hardware at lower cost with warranty terms confirmed in writing; Sennheiser ACCENTUM True Wireless at $219.95 (Sennheiser US) for a simpler currently supported new product below MTW5 price. [1][8][9][12][13][16][18][19][20][21][23]