Buyer beware! NOT STEREO!!
Overpriced and under-featured!
Disappointing piece of shit IMHO!
So this line of the write-up is a lie?
*It lets you add an amp with wireless stereo Bluetooth audio reception to any professional audio system.
Here’s the info from Denon
It will receive stereo input from Bluetooth or via inputs, but sums it to a single speaker.
Look closely the output is Common, 4 Ohm , 70V, 100V.
It’s more of a muddle - as is this whole write-up.
Here’s the primary intended scenario for this – you own a restaurant (RIP) or other such venue where you already have a distributed music system (including a distributing power amplifier; these are generally mono or can be bridged to mono). You want to add Bluetooth capability (to treat the whole system like a big Bluetooth speaker).
The output port on this includes multiple signal options to match with the different input types for commercial music distribution systems – the terminal block provided lets you directly wire up to the correct output pin for your amplifier type. (All these output options are mono so the mention of “stereo” is misleading; as robins notes it will take a stereo Bluetooth signal – from your phone or whatnot – and sum it to a mono output). One of the pins is a “4 Ohm” output which is driven by the internal amplifier and could be connected directly to a single, “regular” unpowered speaker.
So the off-brand scenario for this goes something like: you’ve got ONE old hi-fi speaker in your garage; you buy this, connect some speaker wire to the common and 4-Ohm lugs on the terminal block, and you have turned it into a working Bluetooth speaker. (It’s mono, but so are most dedicated Bluetooth speakers). If this is your scenario and you understand the limitations $55 isn’t a bad price for what it is.
How well it works and how loud it can get depend on how efficient the speaker is and how much real power the amp has; 20W of clean class D power should in theory give you plenty of sound with most speakers, but power ratings are notoriously dodgy. On one hand Denon is normally pretty honest about specs; on the other hand anything powered by a wall-wart is unlikely to have any reserve power under stress.
Here’s a description about the 70v and 100v outputs. I had to search for a description. Typically, this signal would be split across multiple speakers wired in parallel. The high voltage output allows for low current so there is less loss on longer wires and thinner wire can be used. In turn, wiring the speakers in parallel means if one speaker fails, the other can continue to work. It also means there are no worries about matching the impedance. For the 4Ω connection, you would have to wire multiple speakers in a combination of parallel and serial to maintain the 4Ω impedance. So, this is really a PA amp that might be wired to multiple 70/100v ceiling speakers piping low volume muzak.