Review on 🔊 Fosi Audio BT30D: Bluetooth 5.0 Stereo Audio Receiver Amplifier for Home Outdoor Speakers & Subwoofer by Meghan Frye

Music is a big and daily part of our lives. Since we don't like to overload the system in the living room just to "brighten up" the sound in the kitchen area, I kept a small (homemade) 18+18W amplifier and Minimus 77 speakers on the fridge for years. . It was connected to the living room system via a stereo audio isolation transformer and a Bluetooth receiver with an audio switch. Ugly, but it worked and sounded good. After the recent renovation of the kitchen and living room, a nicer solution was required. With a 12x12 soffit positioned in an L-shape above all of the kitchen cabinets, in-wall speakers were the obvious choice. We ordered a set of Dayton Audio ME625W two-way in-wall units, and as I'll discuss later, we ended up adding a Dayton Audio DCS165 subwoofer and near-matching grille, all through Revain. The amps mentioned here were also purchased from Revain. My first choice for a new small amp was the Pyle PFA540BT with built in FM radio and Bluetooth functionality. This device was purchased in an open box from Revain. While it was loud enough, after warming up it had a subtle but noticeable squeaky midrange distortion that I didn't notice until it was outside the return window. My problem is that all of these new parts have been sitting idle while we have finished other repairs. We all agreed it was annoying, even my kids. Also, the switching power supply for this amplifier was so noisy (on HF) that the radio could only pick up a station with a local antenna only a few miles away. The rest of the group was completely submerged. (There is no FCC certification logo visible on the power supply, now we know why). My second amp was a FOSI audio device, BT30D, which is much better. There is no radio but there is BT and Line-In. On the plus side, it's a 2.1 system with a dedicated drive channel for the passive subwoofer. It is designed for 50 + 50 + 100 watts. It's quite noisy, but note that it comes with a switching power supply that can only deliver about half that power. (24V x 4A = 96W). Ah, marketing. Once the amp problem was fixed I was still disappointed that the wall basses didn't have the same bass as the little mini 77s we've been listening to for 10 years. Considering the large drivers and the amount of air left behind the walls, I was a bit surprised. Researching the FOSI website couldn't tell me whether or not the FOSI unit had a fixed high pass filter on the LR outputs, so I wasn't sure if they were speakers or a bass-limited amplifier. Everything below 120 Hz was missing. The Pyle amp, which doesn't have a subwoofer output, sounded similar in bass, and the third amp I plugged in also played with some bass. The conclusion is that they are speakers or installation environment, most likely speakers since they are separated by a large insulation that prevents any phase cancellation behind the wall. ordered and installed with a ¾" split baffle for support in the corner of the soffit for better loading. Once installed and set up we now have a system with decent expansion in the 50-100Hz range and more than enough volume to fill the kitchen area which gives a good stereo field to hear most of the room. I wish we had room for a larger subwoofer but with a surround behind a 12x12 soffit an 8" or 10" just wouldn't fit in fit a 6-1/2". Sub is respectable, but it's powered quite heavily to make up for the lack of piston area. A second identical block is being considered to double the cone area and improve efficiency, but at least for now it sounds good at reasonable levels. In general, the FOSI amp was ver. y is good and well behaved. It runs a little warmer, but for its size, it's well worth its weight, and the BT implementation sounds pretty good. It should have a decent SBC buffer layout as we don't encounter buffer leaks during long listening sessions with connected Apple, Android or Chromebooks. The Bluetooth range was also stable across the range. This is probably due to the external uncompromising BT antenna. The amp is small enough to be unnoticeable on the fridge and looks quite stylish. I would buy it again. I'll post the same review on the subwoofer and built-in speaker pages as it's sort of a system-level overview of all the details.