hornej / beovox-poe

PoE power supply designed for B&O BeoVox CX50/CX100 passive bookshelf speakers

BEOVOX-POE

The beovox-poe project is an 80W PoE-PD PCB and panel mount for powering a HiFiBerry Beocreate 4 channel amplifier for upcycling B&O BeoVox CX50 and CX100 speakers.

The end result

• PoE-powered
• Data passthrough for Ethernet connection to Raspberry Pi
• Play audio over AirPlay, Bluetooth, etc.
• They look and sound awesome

How to build it

PCB

I designed the PCB to be ordered from JLCPCB. You should be able to get 2-5 boards fabricated and assembled for about $100 (not including the parts you will need to hand solder, see below).

1. Upload the zipped Gerber file "beovox-poe-mfg-rev2.zip" to JLCPCB
2. Select the silkscreen color you want. Green is usually the cheapest and fastest.
3. Select PCB Assembly and "Assemble top side". You can do both sides if you want them to solder on the threaded standoffs (MP1, MP2, MP3, MP4) but it will cost more.
4. Click NEXT
5. Upload BOM. pcb-files/Project Outputs for beovox-poe/BOM/Bill of Materials-beovox-poe(assembly).csv
6. Upload Pick and Place file. pcb-files/Project Outputs for beovox-poe/Pick Place/Pick Place for beovox-poe(assembly).csv *JLCPCB doesn't stock the AG5800 PD Module and the 1000 BaseT 4PPoE transformer so you will need to buy those separate from DigiKey or Mouser and hand assemble.
7. Click through placement preview (JLCPCB will likely contact you to confirm placement) and select application (I choose "DIY"), add to cart, and order!

Parts you may need to hand solder

• Silvertel AG5800
• Wurth Elektronic 7490220122
• YIYUAN SMTSOM380BTR. You can also get these ones (Keystone 24885) from DigiKey

Other Parts

• CX50 or CX100 speakers
• Hifiberry 4 channel beocreate amplifier
  • In the bundle you will want the 3D printed mount, Mini-XLR jack 4 pin x2, Mini-XLR cable 4 pin
• M3 x 4mm threaded inserts, 4pcs. I used this assorted pack from Amazon
• M3 x 10mm flat head screws, 6pcs. I used this assorted pack from Amazon
• CAT6 cable
• Ethernet switch with at least PoE+. You could also use a PoE injector if your switch doesn't have PoE.
• 3D printer filament. I used this matte white PLA

HiFiBerry Beocreate Amp installation

See the appropriate guide for your speakers on GitHub

Assembly

• 3D print from the 3d-files "beovox-panel-mount.step", "pcb-mount-left.step", and "pcb-mount-right.step".
• Use a soldering iron to install four M3 x 4mm threaded inserts into the pcb-mount-left and pcb-mount-right.
• Screw the pcb-mount-left and pcb-mount-right onto the PCB using the M3 x 10mm flat head screws
• Cut out a rectangular hole in the back of one of the speakers using your tool(s) of choice (drill, dremel, knife, file, whatever you have).

Repairing your speakers

Vintage speakers may need some TLC including refoaming the speakers, fixing the frames, and/or reclothing the frames.

Frames

You can 3D print frames for CX50/CX100 from Thingiverse. If you are in the US, I recommend this black speaker cloth from Joann. It is stretchy and thin which makes it easy to work with. I used this grey speaker cloth for the CX100 speakers. It is a little sturdier which I also like.

Speaker foams

I tested out some different speaker surrounds from Amazon and eBay and they didn't fit quite right for the CX50/CX100. I highly recommend these from Audiofriends. They also have this video on how to replace them.

Future iterations / improvements

• I don't see a huge need to have the diode ORing circuit and it also adds a bit of cost relative to the rest of the SMD components. It could just use a slide switch or something to switch between POE power and Barrel jack power.
• It would be fun to try out a USB-C PD version.