Fosi Audio BT30D Pro Review – Power For All Woofers
In this Article
INTRO
With the proliferation of mini-desktop sound systems tied to computers the Fosi Audio BT30D Pro plants itself front and center for this audio revolution. If you told me a few years ago I could have a legit 2.1 amp powerful enough to drive a pair of bookshelves PLUS a passive subwoofer in a box not much bigger than a deck of cards I would have said you are crazy.
Not to be confused with the lower powered BT30D, the Fosi Audio BT30D Pro is the $109 2.1 Bluetooth desktop amp that you did not know you needed. At time of this review it was on sale for $89. That small size however introduces some compromises that are minor annoyances.
BACKGROUND COMMENTARY
I was thoroughly impressed with the Fosi Audio TB10D (upgraded version) recently, that when they offered the 2.1 version using the same TPA3255 chip I was fully on board. So the TPA3255 is actually a 4 channel amp chip, but can be configured by the designer in 4 different numbers of channel arrangements. That does not mean, you get to configure it that way-it is designed for only one use so you have to pick the model that implements the usage case you need.
While the TB10D was an 80-100W 2 channel amp advertised as 300Wx2, it was still an impressively strong mini amp. The Fosi Audio BT30D Pro cuts down on that power output because two of the channels are un-bridged, the other two are bridged for a non-powered subwoofer. If you prefer to use a powered subwoofer, it accommodates with a 3.5mm pre-out connection instead. It does use the same 32V 5 amp power brick the Fosi Audio TB10D comes with.
The pre-out on the Fosi Audio BT30D Pro is not impacted or controlled by the low pass filtering, gain, or the bass adjustment. This is good news to avoid impacting the built in filtering of the powered subwoofer. Besides the volume knob, all the other knobs have no taper so adjusting is cramped unless you let your 3 year old wreck havoc.
I still wish Fosi Audio would have implemented a detent for the zero position on the tone controls, and markings for filter frequency would have been nice. Instead they opted for a simple, clean front panel free from distraction. All adjustments done by taste.
There is not a physical switch to toggle between analog input from the RCA’s and the Bluetooth input anywhere on the Fosi Audio BT30D Pro. Instead, when you connect or disconnect the Bluetooth it defaults to analog input. The Bluetooth has to always manually be connected each time you power up the Fosi Audio BT30D Pro. I am glad they chose this method, sometimes it is not necessary for Bluetooth to automatically connect and wonder why you cannot hear your phone calls when you answer.
Subjectively, the Fosi Audio BT30D tends to run warmer than the TB10D. I am not sure why this is the case, but maybe there is some heat loss due to the different filters required to run the TPA3255 as a 2.1 setup. It does not seem to matter if there is a subwoofer connected or not.
I noticed a small turn off click/pop when powering down. It is nothing that is even remotely close to speaker damaging levels, but I wanted to be clear it exists. It does not detract from the usability. My Lepai LP2020A+ and Ashly FTX1500 (rack mount professional amp) have way more turn off pop.
PACKAGE CONTENTS
Fosi Audio BT30D PRO
Bluetooth Antenna
32V 5A Power Supply
Operators Manual
SOUND
Tested with Behringer Truth B2031P and Aperion Audio 522D LR bookshelves mated to a Pioneer Venue 12 inch subwoofer (old sub amp kicked the bucket).
The Fosi Audio BT30D Pro cleanly provides around 40-50W of power to the bookshelves and the 100W to the Pioneer sub was enough to easily fill my office and small bedroom. In a larger room it provides plenty of room filling background music, but you are not going to knock your socks off at these levels.
I did notice though without the subwoofer, the Behringer Truth B2031P was missing the same bass impact the more powerful TB10D delivered. I attempted to level match so I was comparing correctly, and surprisingly the TB10D just has more kick.
I believe that it is acceptable considering the Fosi Audio BT30D Pro is meant to be used with a subwoofer anyway. It was harder to notice with the smaller 5.25 (130cm) woofer of the Aperion Audio, since they do not play lower frequencies.
Passive subwoofers are harder to find these days, so this amp might be aimed at hobbyist builders that frequent the pages of Parts Express, Madisound, or Meniscus Audio, (here in the States) or Solen for my northern neighbors. Or might I suggest browsing the local used market for blown powered subwoofers and pair this Fosi Audio BT30D Pro up to a set of bookshelf speakers for a garage, office desktop, or small bedroom setup.
COMPARISONS
Value wise the Fosi Audio BT30D Pro amp is exceptionally better than the Lepai LP2020A+ with only 2 channels of 20W, plus the Fosi Audio BT30D Pro offers bluetooth 5.0 and a subwoofer output. Compared to the Dayton Audio DT100A, it feels more powerful and gets louder. The Fosi Audio BT30D Pro also has a higher build quality, knobs are solid and it has 5 way binding posts for the speaker connections, although again a little cramped to use comfortably.
ENDING
The Fosi Audio BT30D Pro should lose the inflated power ratings and stick with truthful advertising. It fits my expectations and cozies up on the limited space of your desktop to provide just enough power to preserve your hearing, or run a background music machine in larger areas or apartment dwelling with maybe just enough sub thump to annoy your neighbors.
Disclaimer: Thanks for Fosi Audio for providing this free of charge so I could put more of my speaker collection to use as an excuse to my better half why I was hoarding them in a dark corner.
COMPROMISES
- Knob spacing
- Speaker Terminals are crammed
- Runs Warmer than TB10D
- Slight turn off noise
- No central stop point for 0db bass/treble boost
- No markings for the low pass filter to indicate what frequency it is set at
- Power brick only CE rated, missing NRTL certification
GOODIES
- Preout is unfiltered and unaffected by the gain knob.
- Solidly built and weighty
- Bluetooth built in
SPECIFICATIONS
- Output Power: 165W x2+350W@4Ω
- Terminating Impedance: 2-8Ohms
- Input Mode: Bluetooth + RCA
- Output Mode:Passive Speakers/Subwoofer + AUX
- Frequency Range: 20Hz – 20kHz
- THD: ≤0.03%
- SNR: 108dB
- Chip Set: TPA3255
- DC Input Range: 12 – 36V
- Bluetooth Transmission Distance: Up to 50 Ft
- Bluetooth Name: Fosi Audio BT30D PRO
- Device Dimension: 6 x 5 x 1 inches
- Power Supply: 32V 5A Power Supply
- Product Page
DISCLAIMER
Available directly for Fosi Audio or other retailers such as Amazon and Aliexpress.
Our generic standard disclaimer.
Hi. I have this Fosi and we have been using it for small dance parties. Does run hot.
A small correction. The 3255 will run two channels or bridge to one, but not four. The BT30D pro actually has TWO 3255 chips. One is running stereo and the other is bridged for the sub. Thus the sub can get roughly double the power depending on impedence.
Same with other brands and also builds that use the TI 3116. I have an Aiyima A03 with subwoofer power and it’s two 3116 chips running in the same configuration.
The preamp out on the BT30D pro is very nice. Can easily chain more amps and speakers as needed.