Alternative to IKEA SYMFONISK speaker?

This post is also yours, but the two claims are at odds with each other:

Do you think there is a problem with the app (trying the same with a virtual device or another type you do have would be one way to test), or do you think there is a problem with this particular model of speaker or perhaps the driver? Replacing it as suggested here won't help if it's the former, but without narrowing it down, it's hard to know.