What is the opinion of Reddit about the
TB Speaker D42-1 4″ – 2 Way Passive Radiator Design- Bookshelf Speaker- DIY Kit- Pair?

A total of 1 review of this product on Reddit.

11 points


2nd Oct 2018

Kinda want to put a damper on this thread a bit before it blows up and we look like fools. Well, more than the happy drunken fools we’re typically proud to be.

Logitechs are nearly always crap, and this is almost certainly not a very good speaker. But this is not fraud like their “fake tweeter” debacle — if Logitech wanted to fake a speaker driver to save a few pennies, this wouldn’t really be the cheapest way to do it. We already know the cheapest way to do it.

What you’re seeing on the bottom is a passive radiator: https://en.wikipedia.org/wiki/Passive_radiator_(speaker)

Logitech themselves say so, calling it a “four-driver (two active, two passive) design.”

A passive radiator provides the same function as a speaker port tube but it takes up less space than a port and allows the speaker to remain sealed, which is why just about every Bluetooth speaker over $20 uses them. The way a typical port works is it gives the driver juuuust the right amount of resistance; the air pressure gives the driver something to “push against” while still providing enough compliance for the driver to move freely. A passive radiator accomplishes the same thing except instead of being a tube filled with air, it’s basically just a speaker cone+foam surround.

As for the “fraud” aspect of making the passive driver resemble an active driver?

Well, it’s pretty standard practice for passive radiators to resemble regular old active speaker drivers; see ELAC’s tower speakers or these perfectly normal KEF tower speakers, or this wide selection of passive radiators over at Parts Express that look like regular old speaker drivers.

Admittedly, I guess that is potentially slightly misleading for novice buyers. On the other hand, the alternatives typically involve a weird asymmetrical passive driver on the side of the box or some other awkward arrangement so I dunno, I sort of like the aesthetics of having the passive radiators visually matched to the active ones.