Sennheiser MOMENTUM 4 Wireless and BTD 700 Set (White) review

This review covers the White U.S. MOMENTUM 4 Wireless and BTD 700 Set, not an in-person listening or wear test. Sennheiser's U.S. bundle page pairs the White M4AEBT headset (the matching standalone White SKU is 509267) with a BTD 700 USB Bluetooth transmitter (SKU 700434). The public bundle record has a product ID and selected White variant ID 62239371952499, but no separate set SKU. That distinction matters when comparing listings: this is a particular package around the MOMENTUM 4, not a new headphone generation.

What the included transmitter changes

The BTD 700 gives a compatible USB host a Bluetooth audio path to the headset. Its manual describes USB-C connection to a mobile device or computer, or a connection to a PC or Mac's USB-A port using the supplied USB-A adapter. The transmitter is recognized as an external sound card without a separate driver installation, and the manual lists Windows 10 or later, Mac OS V11/V12, Android 13 or later, and iPhone or iPad with USB-C. It is not described as a TV or hi-fi transmitter. A raised dongle can also put mechanical strain on a phone port, so the manual recommends an extension cable when connecting to a mobile device.

This can be useful if the source lacks the Bluetooth behavior or codec path you want, but it is still an accessory-to-headphone link. If your computer already supports a satisfactory Bluetooth route, the BTD 700 may add little to your routine. The M4 headphones themselves also support direct Bluetooth, USB-C audio, and a 2.5 mm analog input; those are distinct arrangements, not benefits created by the transmitter. Sennheiser's selected White set page identifies the combination; its public product record does not provide a separate set SKU.

Codec claims need a compatible receiver

Sennheiser advertises aptX Lossless, aptX Adaptive and Auracast features for the BTD 700. Its BTD 700 manual says the dongle chooses a codec supported by both it and the paired headphones; in its Bluetooth Classic mode, the stated priority includes aptX Adaptive, aptX Lossless, aptX Classic and SBC. The MOMENTUM 4's current specification lists aptX, aptX Adaptive, SBC and AAC, while its instruction manual describes aptX Adaptive, AAC or SBC. The two components have a documented aptX Adaptive path. The available M4 documentation does not establish aptX Lossless, so the BTD 700's codec list alone is not proof of lossless transmission all the way to these headphones.

The same caution applies to the BTD 700's LC3/Unicast, Auracast and gaming claims. Its manual says those modes depend on the capabilities of the receiving headphones or audio device; the MOMENTUM 4 sources consulted here do not establish LC3/Unicast or Auracast reception, nor a specific BTD 700-plus-M4 gaming latency. The advertised transmitter capability should not be treated as an upgrade to unlisted headset features.

ANC and battery figures stay with their operating plan

The M4 headset has hybrid adaptive active noise cancellation. Sennheiser rates Bluetooth music playback with ANC on at up to 60 hours, under a stated iPhone-at-mid-volume condition. That is a manufacturer maximum, not a result measured for this review or a promise for a used battery, louder listening, calls, a different source, or every setting. This rating belongs to the documented direct M4 Bluetooth plan. The set page does not provide a separate ANC-on runtime test for playback through the BTD 700, so this assessment does not transfer the 60-hour figure to that transmitter arrangement.

The MOMENTUM 4 manual documents two active Bluetooth connections and up to six saved device profiles, with only one audio source playing at a time. This makes direct Bluetooth a documented phone-and-computer switching option; it does not mean both sources mix. The manuals do not establish that the two-device routine remains the same while the M4 is receiving audio from the BTD 700. They also do not say the 60-hour endurance test kept two Bluetooth links active at once, so treat 60 hours as the published direct Bluetooth/ANC maximum under its stated test condition—not a multipoint-specific result. Treat the transmitter route as a separate setup and check the exact host and pairing behavior you need.

Wired fallback is separate from the dongle

The M4's 2.5 mm headset input can accept an analog source through a 2.5 mm-to-3.5 mm cable. Its manual says ANC over that cable needs a charged headset and directs the listener to the cable when the battery is empty; Sennheiser's specification lists different active and passive speaker impedances. Together those sources support a powered wired ANC arrangement and a separate passive, power-off analog route. Passive playback is not ANC, and the product cannot receive USB audio through the BTD 700 when powered off.

One package detail remains open: the BTD 700 set page names the transmitter bundle but does not itemize the complete MOMENTUM 4 box contents. Do not infer from the standalone M4 package list or a product image that the set includes the same analog cable, case, or every paper insert. Check the exact seller's written bundle inventory before relying on the cable for passive backup. This assessment leaves the bundle's in-box analog cable field unknown rather than silently borrowing the standalone package list.

Exact finish images and offer checks

The selected White product image shows the White headset with a BTD 700 dongle and USB-A adapter. The U.S. set record also exposes Graphite, Black, Brown, Teal, Denim and Copper variants. Their manufacturer images are retained below as finish references; some images show the transmitter and adapter while others show only the headphones. A photograph does not settle box contents. The Black standalone M4 listing remains a separate identity gap: its selected U.S. store data says 800107, while the support specification names Black SKU 509266. The bundle's Black color choice has its own set variant ID but no separate component SKU in the public set JSON, so verify the Black headset code rather than assuming the White SKU applies.

The U.S. catalogue also lists a distinct MOMENTUM 4 Wireless and BTD 700 Refurbished Set product (Product ID 15610631258483) with six color variants, including White variant 67180764004723. Its page labels the combination Certified Refurbished and says the product was tested, checked and inspected; its public variant record has no bundle SKU, and the consulted page does not state a warranty term or complete box inventory. The White variant reuses Sennheiser's White M4-plus-transmitter image, which identifies the components but does not depict the condition of a particular refurbished unit. Functionally it is the same reviewed M4/BTD 700 combination; treat refurbishment, return terms, exact variant and seller condition as offer checks, not as a different ANC or runtime result.

For this White package, check that the offer is the M4-plus-BTD 700 set rather than the regular M4, a refurbished listing, or a different headset bundle. Confirm White and the component IDs, whether the host offers the required USB-C or USB-A connection, the supported host operating system, the included adapter, and the exact cable/case contents. Test physical fit and return terms for yourself; no personal comfort, clamp, sound, noise-reduction or ANC comparison is claimed here.

Other selected U.S. bundle finishes