Open-back and closed-back headphones differ first in acoustic construction. This affects their relationship with the surroundings, but does not create an automatic ranking of sound quality. A model may suit a quiet private space while being inconvenient in a shared room. Begin with where you actually listen rather than a general promise of spacious or powerful sound.
Consider the everyday effect
Open designs allow more sound exchange between the earcup and its surroundings. Closed models typically provide greater separation and reduce outward leakage. Sennheiser's explanation relates this distinction to listening circumstances. The actual effect nevertheless depends on the model and fit; closed does not mean completely soundproof.
If someone works nearby, check what they can hear at your normal listening level. Conversely, notice how surrounding sounds affect your attention. Your own perception does not establish how much another person can hear close by. A brief shared check is more informative than an assumption based on the product name.
Separate enclosure from active cancellation
A closed construction is not the same feature as electronic noise cancellation. Check them independently in product information. Open or closed also does not determine whether the connection is wired or wireless. Keep these questions distinct when describing the intended use.
An open design may fit concentrated listening in a quiet room. Other needs may dominate when people share the space. This does not imply that distraction should simply be overcome by increasing volume. A more suitable environment or different listening arrangement may be the better first change.
Allow time to assess the fit
Notice pad contact, pressure and ear position when putting the headphones on. Glasses or changes of posture can affect the fit. Check again after a while for repeated adjustments or uncomfortable pressure. A striking first impression of sound does not replace that observation.
When comparing two models, keep volume reasonably similar and use the same short passages. Describe specific differences, such as how clearly a voice stands against its accompaniment. A claimed large soundstage should not displace every other requirement. Suitability combines the audible result, comfort and consideration for the actual surroundings. When those do not align, the construction label cannot resolve the problem by itself. Record which condition caused difficulty so that the next comparison addresses a real need rather than another vague promise.