Practical testing …
Quickly to the right practical testing …
Test setup
Connect speakers
Bluetooth connection
RCA connection
Movies Sound Test
Games sound test
Music sound test
Power consumption
Heat generation
Test setup …
The Logitech Z333 2.1 system delivers a very strong bass due to the relatively large subwoofer with 13 cm speakers, which is why an increase in the bass control does not seem necessary. In general, the very clumsy controls do not seem sensible throughout. Exactly which frequency is adjusted in the treble or bass on the right side cannot be read on the device. The separate volume setting of the subwoofer, on the other hand, makes sense in order to weaken or strengthen its dominance over the tweeters and midrange speakers as desired. The Sub Freq control also allows adjusting the subwoofer frequency band from 0-300Hz. When starting up via the toggle switch, we first get a red LED for the RCA input. At this point, the leaflet clarified that we can only expect the blue LED display after a terminal device has successfully logged in via Bluetooth.
Connect speakers …
Up to three speakers can be connected to the Fosi Audio BT30D Pro amplifier: Left, right and the subwoofer. Those who do not need an active or passive subwoofer output can alternatively use the BT30D as a 2-channel amplifier. The speaker cables are optionally connected via banana plugs, which are officially called spring plugs. The sockets can also be used as screw terminals, but you have to be careful that no bare wires touch each other, so don’t strip the insulation too long. Hollow bananas would also be possible, but these can theoretically break in the socket. We recommend the use of conventional banana plugs, i.e. spring plugs, for speaker cables, as they are color-coded to prevent polarity reversal, provide excellent contact and can still be pulled off comfortably.
Bluetooth connection …
The recognition of the device via Bluetooth also ran without problems and as soon as a Bluetooth connection is established, the LED lights up blue, whereby the switch is noticed immediately anyway, since an integrated relay reveals the switch to the Bluetooth input with a quiet “click”. The Fosi Audio BT30D Pro is displayed as headphones under Windows 11 with the latest Bluetooth drivers, which isn’t a problem since the correct name is displayed for proper recognition. The usual extensions, such as Spatial Audio and audio enhancements from Microsoft, can also be activated on request.
However, a Bluetooth authentication query for possible security was not integrated via the Actions Semi ATS2853 Bluetooth chip.
For safety, you can only use the Bluetooth 5.3 device on one device for audio playback. That is, you can certainly pair the Bluetooth device with several end devices such as PC with BT module, TV, smartphone or tablet, but once playback via Bluetooth has been started, the amplifier cannot be taken over by another end device (ATS2853 without Bluetooth LE Audio).
This is helpful so far, so that no neighbor can disturb the Bluetooth music enjoyment. The only catch to this Bluetooth connection without authentication – if you only listen to music via the RCA input, anyone could establish a Bluetooth connection and thus disconnect the RCA connection! Thus, for example at a party, you should rather connect your device directly via Bluetooth. Unplugging the antenna does not help here either, since the range is still good even without a Bluetooth antenna.
Another indication of a rather rudimentary Bluetooth connection is the lack of support for aptX, aptX HD, aptX Low Latency or AAC – as you can see very nicely in the grayed out selection fields. SBC is not bad, but it could definitely be better.
RCA connection …
Now it was time to run the Logitech system via RCA connection compared to the direct connection to the computer via the BT30D Pro. Even if we cannot check the specific power specifications, the Logitech’s volume of 80 watts can be pushed into very listening-sensitive ranges and thus speaks highly for the external amplifier’s potency. There is no need to move the slider on the Logitech to the right side of the spectrum during movies and games. The low-noise power supply, which didn’t produce any audible electronic noise during operation, was very pleasing. Obviously, a good manufacturer was selected here.
Movies …
It crashes and screams when the guns speak in the Hollywood blockbuster Pirates of the Caribbean. For the first test, we followed the scene in the movie where Port Royal is attacked by the Black Pearl at night. At the beginning, two of the characters converse at a spatial distance on a battlements of the fortress, with the pair of speakers and amplifier perceptibly mapping the distance to the viewer. The slight reverberation of the spoken words is also believably conveyed. The brighter voice of the somewhat aging governor, on the other hand, can occasionally be a bit harsh, to which the amplifier in the background should hardly contribute. On the other hand, the macrodynamic contrast between moderately loud conversation and intense explosion was on full display when the first cannonball hit. Connected to the PC, this sudden volume change seemed a bit flatter, but this might have to do with slightly different volume settings. After all, the amplifier adds another control that has to be adjusted. It is not easy to precisely adjust the volume to the identical sound pressure level. The contrast between the background music and the chaos under cannon fire was very pleasing. In such hectic situations, being able to divide the soundscape into sound sources with some dimensions can go wrong with cheap speaker amplifier combinations. In the minimum case, the amplifier doesn’t distort the Logitech’s tonality; in the best case, the amplifier can still favor a bit more dynamics. Under no circumstances did the surface of the case get hot, which speaks for the efficiency of the device.
Games …
In order not to disturb the neighbors too much, Age of Empires 4 was then played at a low volume. In this context, the addition of the amplifier did not really seem necessary, since in principle nothing changed in the perception of the game. The warning of a wolf attack on the scout is very well sounded, just as in principle the entire game is well sounded. The Logitech alone can visibly portray that. It may be that the amplifier makes a change with larger speakers, which would be related to the pure performance increase in that case. In terms of noise or tonality, the amplifier does not seem to change anything.
Music …
Especially due to the strong lower frequency range of the Logitech solution, the sub-bass foundation of the song “Moondance” by Van Morrison seems very loud and rich. The higher-pitched male voice also appeared present, but not quite as superficial and full as on some headphone-amplifier combinations. As usual, the amplifier here did not change the tonality of the speaker in a good or bad direction. The subtle hi-hat attacks in particular can be located very well in the background either way.
Power consumption …
Of course, the power consumption of the devices also plays a role nowadays. Above all, it is also interesting to know how high the power consumption of the device is in idle mode when the power supply does not have a power switch. Here, the Fosi Audio BT30D Pro is content with just 0.2 watts in standby – so far away from the current EU rules of 0.5 watts and is even below the future EU requirements of less than 0.3 watts power consumption when turned off. No comparison to conventional devices. After switching on, the power consumption is around 6.4 watts and increases depending on the corresponding power output.
Heat generation …
As already mentioned in the technology section on the previous page, the two amplifier ICs in the thermally optimized TSSOP package are cooled via an aluminum heat sink as well as via the copper tracks of the PCB. The heat is transferred more or less directly to the aluminum package, as you can see very nicely on our thermal image. Overall, the temperature remained within limits even after longer use, but it is best not to place any other devices on the Fosi Audio aluminum case.
Fosi Audio BT30D Pro Speaker Amplifier Overall impression …