How We Built It. How You Can Too.
Hudson was 11. Huxley was 8. Neither of them had built anything with electronics before. This is exactly what we did, in order, with no shortcuts and no soldering iron.
A Bluetooth speaker built inside a PVC pipe. Real drivers. Real amplifier board. Real battery. Bluetooth 5.0. Charges with USB-C. Sounds better than half the speakers on Amazon. We know because we tested them.
This guide covers all three Pup Audio models:
1. The Driver. The actual speaker cone. Turns electricity into sound β a magnet, a coil, and a cone that vibrates. We buy them loose and mount them ourselves.
2. The Amplifier Board. Music from your phone is a tiny signal. The amp board makes it big enough to push the cone. Ours also handles the Bluetooth connection β one board, both jobs.
3. The Battery. 18650 lithium cells. 3.7V each. The XY-P15W amp board wants 8β24V, so we either boost the voltage up or wire two cells in series for 7.4V.
4. The Enclosure. The PVC pipe. Not just a housing β a sealed cylinder creates back pressure that improves bass. Bigger pipe = more air = more bass.
Your Phone (Bluetooth)
β
Amp Board receives signal wirelessly
β
Amp Board amplifies it
β
Wires carry it to the Driver
β
Driver cone vibrates
β
Sound18650 cells = 3.7V each. Two in series = 7.4V. Two in series with a boost converter = adjustable up to 12V+.
The XY-P15W runs best at 12V. At 7.4V it works but loses headroom. For The Pup (small, bedroom use) 7.4V is fine. For The Forge and The Howler, use the boost converter set to 12V.
πΎ No soldering iron required. Every connection uses screw terminals. Strip the wire, insert it, tighten the screw. That's it.
| Part | Model | Use | Cost |
|---|---|---|---|
| Bluetooth Amp Board | XY-P15W | Forge + Howler | ~$10 |
| Small Amp Board | PAM8406 | The Pup | ~$7 |
| 3" Driver (pair) | 3" 4Ξ© 20W full range | The Pup | ~$10/pair |
| 4" Driver (pair) | 4" 4Ξ© 30W full range | Forge + Howler | ~$18/pair |
| USB-C Charge Board | TP4056 Type-C | All models | ~$10/12-pack |
| 18650 Battery Holder | 2-slot with switch | All models | ~$8 |
| 18650 Batteries | EBL 3000mAh | All models | ~$20/4-pack |
| DC Boost Converter | MT3608 | Forge + Howler | ~$7/5-pack |
| Hookup Wire | 22 AWG red/black | All models | ~$9 |
| Part | Size | Use |
|---|---|---|
| PVC Pipe | 3" | The Pup |
| PVC Pipe | 4" | The Forge |
| PVC Pipe | 6" | The Howler |
| PVC End Caps | Match pipe | All |
| PVC Primer + Cement | One kit | All |
| Rubber feet | Adhesive | All |
| Paracord | Any color | Handle/strap |
3" PVC Β· Single Driver Β· PAM8406 Β· 6hr Battery
Pipe length: 8 inches.
Parts: 1Γ 3" PVC pipe (8" long), 2Γ 3" end caps, 1Γ 3" driver, 1Γ PAM8406, 1Γ TP4056, 1Γ 2-slot battery holder (parallel), 2Γ 18650, wire, hot glue.
Mark 8" from one end. Cut with a pipe cutter or hacksaw. Sand both ends smooth with 120 grit. Run your finger around β no sharp spots. Huxley's job was sanding. He was thorough.
On one end cap, find center by drawing diagonals corner to corner. Drill with a 2.75" hole saw. Dry fit the driver β it should drop in with the flange resting on the cap. Do not cement anything yet.
Same end cap: one 3/8" hole for USB-C, one 1/4" hole for the power switch. Back end cap stays sealed for bass.
The TP4056 has four pads: IN+/IN- (USB-C in, pre-wired), B+/B- (to battery), OUT+/OUT- (to amp). Red from holder β B+. Black β B-.
PAM8406 terminals: VCC, GND, L+, L-, R+, R-. Connect OUT+ β VCC, OUT- β GND. For mono: tie L+ and R+ together to driver positive; L- and R- together to driver negative.
Strip 1/2" of insulation. Driver + (red dot) β combined L+/R+. Driver - β combined L-/R-. Tighten screws. Tug each wire β shouldn't pull out.
Install batteries β switch ON β pair "PAM8406" on your phone β play. If sound: good. If not: check polarity and terminals.
Thread the USB-C through its hole. Hot glue the TP4056 inside the end cap. Seat the driver and glue the flange. Coil amp + battery inside the pipe. Route the switch wire to its hole. Primer + cement the speaker end cap to the pipe. Leave the back cap friction-fit until final test.
Power on. Full volume 60 seconds. Listen for rattling (re-glue), distortion at max (back off 10%), crackling (loose wire β re-check). When clean: cement back cap. Add rubber feet. Drill two 1/4" paracord holes near the top for a handle.
The Pup is done.
4" PVC Β· Dual Drivers Β· XY-P15W Β· Stereo Β· 8hr Battery
Pipe length: 12 inches.
Parts: 1Γ 4" pipe (12"), 2Γ 4" end caps, 2Γ 4" drivers, 1Γ XY-P15W, 1Γ TP4056, 1Γ MT3608 boost, 1Γ 2-slot holder (series, 7.4V), 2Γ 18650.
XY-P15W needs at least 8V and sounds best at 12V. Two cells in series gives 7.4V β close but not enough. The MT3608 steps that up to 12V.
Batteries (series, 7.4V)
β
Boost Converter (set to 12V output)
β
XY-P15W Power Input (VIN)
For charging:
TP4056 USB-C connected in parallel to batteries
(B+ to battery+, B- to battery-)Setting the boost output: The MT3608 has a small blue trim pot. With batteries installed and the converter powered, put a multimeter on the output and turn the pot with a small flathead until you read 12.0V. Lock it. Don't touch it again.
One driver per end cap. XY-P15W has labeled L/R outputs β match them to the physical ends. Held horizontally you get real stereo spread.
Follow the same drilling, wiring, test, and assembly steps as The Pup. The Forge is identical β just two drivers, boost converter added, and 12" pipe.
6" PVC Β· Dual 4" Drivers Β· 30W Β· Party-Grade
Pipe length: 16 inches.
Parts: 1Γ 6" pipe (16"), 2Γ 6" end caps, 2Γ 4" 30W drivers, 1Γ XY-P15W, 1Γ TP4056, 1Γ MT3608 (12V), 2Γ 2-slot holders (4 cells, two series pairs in parallel), 4Γ 18650.
Battery note: Four cells. Two in series = 7.4V. Wire those two pairs in parallel = still 7.4V but double capacity. Into the boost converter β 12V to the amp.
Same build process as The Forge. Bigger pipe, bigger drivers, 4-cell pack. More air in the 6" pipe = significantly more bass with no tuning.
We only build two or three at a time. Each one takes longer. Each one sounds a little different. That's the point.
For The Forge and The Howler:
[18650 x2 series]ββ[Boost MT3608]ββ[XY-P15W VIN]
β β
[TP4056 B+ B-] [LEFT OUT+/-]ββ[Left Driver]
[USB-C port] [RIGHT OUT+/-]ββ[Right Driver]
β
[Switch]ββ[Battery negative]
For The Pup:
[18650 x2 parallel]ββ[TP4056 B+/B-]ββ[PAM8406 VCC/GND]
β β
[USB-C port] [L+R+ combined]ββ[Driver +]
[L-R- combined]ββ[Driver -]Check polarity (red to +, black to -). Check batteries are charged (TP4056 red LED = charging, blue/green = full). Confirm Bluetooth is paired.
Batteries may be low. Boost converter may be drifting β check output voltage. Normal at absolute max on small drivers.
Ground loop β make sure all GND connections share one common ground point. Driver not fully seated β re-glue flange.
Something loose inside β open back cap, check mounting. Driver flange not fully glued β add hot glue.
Board not powered β verify power LED. Too many saved devices β hold pairing button 5 seconds to clear memory.
Hudson learned what voltage means. Not from a book β from watching a speaker refuse to play loud until the boost converter was set right. That stuck in a way a textbook never would.
Huxley learned that sanding matters. First pipe he rushed it. Driver sat crooked. Had to redo it. He didn't rush the second one.
Both of them learned that something can come from nothing if you follow a process and don't skip steps.
That's the whole point of GoToddy. Build something real.
Pup Audio started as an idea on the GoToddy platform. Hudson went through the six-step wizard, figured out his costs, set his prices, and wrote a real plan before he cut a single piece of pipe.
START YOUR BUSINESS PLAN βPup Audio β Powered by GoToddy πΎ Β· Build Guide v1.0