Bluetooth adapter Audison B-Con II Trunk B+ GND Bluetooth
Optical
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Description
CarSQ is an actively amplified sound-quality system built into a Renault Megane E-Tech while retaining the factory interior, infotainment system, and everyday usability of the car.
The system combines dedicated door mid-bass drivers, sealed wideband speakers in custom sail-panel enclosures, a front-mounted subwoofer, and a separate trunk subwoofer. Signal processing, amplification, crossover design, time alignment, and equalization are handled through a fully active DSP-based setup.
This is not a finished one-time installation, but an evolving long-term project. The build documents the complete development process: OEM integration, custom fabrication, driver testing, acoustic measurements, tuning experiments, competition results, problems, failed ideas, and later system revisions. The goal is to achieve accurate tonality, a stable front soundstage, strong low-frequency integration, and high output without sacrificing the practicality of the vehicle.
Measurements
8 filesREW RTA 1/48 octave, 64k FFT, Forever averaging stopped at 100 averages, Rectangular window, no smoothing, mono Pink Periodic Noise, UMIK-1 with 90° calibration file, moving microphone method. Exported with no additional smoothing.
Measurement Setup
26 Jul 2026 Context Car interior Driver Position
Equipment miniDSP UMIC-1 REW
Method RTA · Moving microphone / MMM Pink noise mono 64 FTP
System Diagram
15 nodes 19 connectionsSignal and power routing, as wired. Open a node for the part behind it.
Bluetooth adapter Audison B-Con II Trunk 
Phone / tablet Google Pixel 8 Pro Middle console Phone holder Bluetooth
Subwoofer JL Audio 6W3v3-4 Front subwoofer SPK IN
Multi-channel DSP amplifier JL Audio VX700/5I Trunk B+ GND Optical S/PDIF · S/PDIF
1 2 3 4 SUB OUT PRE OUT 1
Full-range driver One Audio WB3.e Right Sail Panel SPK IN
Full-range driver One Audio WB3.e Left Sail Panel SPK IN
Other speaker driver JL Audio C3-650 Left Door SPK IN
Other speaker driver JL Audio C3-650 Right Door SPK IN
Passive subwoofer Jl Audio CS112LG-TW3 Trunk Subwoofer SPK IN
Distribution block HIMOZEAN Mini ANL Fuse Holder Trunk PWR IN
160 A 260 A 320 A
Mono amplifier JL Audio RD500/1 Trunk B+ GND RCA 1
SPK OUT
GND
PWR OUT GRN
Fuse holder Eton PCC 20 PWR IN
160 A
Distribution block HIMOZEAN Mini ANL Fuse Holder PWR IN
1 2 3
Audison B-Con II
Part details
- Manufacturer
- Audison
- Model
- B-Con II
Key specifications
- Active or passive
- Active
Diagram ports
- B+Input
- GNDInput
- BluetoothInput
- OpticalOutput
Google Pixel 8 Pro
Part details
- Manufacturer
- Model
- Pixel 8 Pro
Key specifications
- Supported audio formats
- MP3, FLAC
- Streaming protocols
- Tidal Connect, Bluetooth
- Bluetooth version
- Bluetooth 5.2
- Network connections
- Wi-Fi
Diagram ports
- BluetoothOutput
JL Audio 6W3v3-4
Part details
- Manufacturer
- Jl Audio
- Model
- 6W3v3-4
Key specifications
- Nominal size
- 16.5 cm
- Nominal impedance
- 4 Ω
Diagram ports
- SPK INInput
JL Audio VX700/5I
Part details
- Manufacturer
- Jl Audio
- Model
- VX700/5I
Key specifications
- Amplifier class
- Other
- DSP sample rate
- 192002 kHz
- DSP bit depth
- 24 bit
Diagram ports
- SPK OUT 1Output
- SPK OUT 2Output
- SPK OUT 3Output
- SPK OUT 4Output
- SUB OUTOutput
- B+Input
- GNDInput
- PRE OUT 1Output
- Optical S/PDIF · S/PDIFInput
One Audio WB3.e
Part details
- Manufacturer
- One Audio
- Model
- WB3.e
In this build
- Quantity
- 2
Diagram ports
- SPK INInput
One Audio WB3.e
Part details
- Manufacturer
- One Audio
- Model
- WB3.e
In this build
- Quantity
- 2
Diagram ports
- SPK INInput
JL Audio C3-650
Part details
- Manufacturer
- Jl Audio
- Model
- C3-650
In this build
- Quantity
- 2
Key specifications
- Nominal size
- 16.5 cm
- Nominal impedance
- 4 Ω
Diagram ports
- SPK INInput
JL Audio C3-650
Part details
- Manufacturer
- Jl Audio
- Model
- C3-650
In this build
- Quantity
- 2
Key specifications
- Nominal size
- 16.5 cm
- Nominal impedance
- 4 Ω
Diagram ports
- SPK INInput
Jl Audio CS112LG-TW3
Part details
- Manufacturer
- Jl Audio
- Model
- CS112LG-TW3
Key specifications
- Enclosure type
- Sealed
- Nominal impedance
- 2 Ω
Diagram ports
- SPK INInput
HIMOZEAN Mini ANL Fuse Holder
Part details
- Manufacturer
- HIMOZEAN
- Model
- Mini ANL Fuse Holder
In this build
- Quantity
- 2
Key specifications
- Input count
- 1
- Output count
- 3
- Number of fuse slots
- 3
- Negative or positive distribution
- Both
Installed fuses
- Fuse 2
- 60 A
- Fuse 3
- 20 A
- Fuse 1
- 60 A
Diagram ports
- PWR INInput
- FUSE OUT 1 · 60 AOutput
- FUSE OUT 2 · 60 AOutput
- FUSE OUT 3 · 20 AOutput
JL Audio RD500/1
Part details
- Manufacturer
- Jl Audio
- Model
- RD500/1
Diagram ports
- SPK OUTOutput
- B+Input
- GNDInput
- RCA 1Input
Ground
Diagram ports
- GNDBoth
Car Battery 13.5 Volt
Diagram ports
- PWR OUTOutput
- GRNOutput
Eton PCC 20
Part details
- Manufacturer
- Eton
- Model
- PCC 20
Key specifications
- Number of fuse slots
- 1
- Fuse type
- Mini ANL
Installed fuses
- Fuse 1
- 60 A
Diagram ports
- PWR INInput
- FUSE OUT 1 · 60 AOutput
HIMOZEAN Mini ANL Fuse Holder
Part details
- Manufacturer
- HIMOZEAN
- Model
- Mini ANL Fuse Holder
In this build
- Quantity
- 2
Key specifications
- Input count
- 1
- Output count
- 3
- Number of fuse slots
- 3
- Negative or positive distribution
- Both
Diagram ports
- PWR INInput
- FUSE OUT 1Output
- FUSE OUT 2Output
- FUSE OUT 3Output
Front Sub
- Source port
- SUB OUT
- Target port
- SPK IN
- Wiring
- Normal
Speaker level
- Source port
- SPK OUT 1
- Target port
- SPK IN
Speaker level
- Source port
- SPK OUT 2
- Target port
- SPK IN
Speaker level
- Source port
- SPK OUT 3
- Target port
- SPK IN
Speaker level
- Source port
- SPK OUT 4
- Target port
- SPK IN
Trunk Sub
- Source port
- SPK OUT
- Target port
- SPK IN
- Purpose
- Speaker audio
- Interface
- Bare wire
- Transmission
- Copper
- Direction
- One-way
20 mm²
- Source port
- GRN
- Target port
- GND
- Purpose
- Ground
- Interface
- Terminal
- Transmission
- Copper
- Direction
- Non-directional
- Polarity
- Ground
S/PDIF Optical IN
- Source port
- Optical
- Target port
- Optical S/PDIF · S/PDIF
- Purpose
- Digital audio
- Interface
- TOSLINK
- Transmission
- Optical
- Direction
- One-way
BT 5.2 LDAC
- Source port
- Bluetooth
- Target port
- Bluetooth
- Purpose
- Digital audio
- Interface
- Bluetooth
- Transmission
- Wireless
- Direction
- One-way
20 mm² - 15 cm
- Source port
- PWR OUT
- Target port
- PWR IN
- Purpose
- Power
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
20 mm²
- Source port
- FUSE OUT 1 · 60 A
- Target port
- PWR IN
- Purpose
- Power
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
20 mm²
- Source port
- FUSE OUT 1 · 60 A
- Target port
- B+
- Purpose
- Power
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
20 mm²
- Source port
- FUSE OUT 2 · 60 A
- Target port
- B+
- Purpose
- Power
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
5 mm²
- Source port
- FUSE OUT 3 · 20 A
- Target port
- B+
- Purpose
- Power
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
Analog audio
- Source port
- PRE OUT 1
- Target port
- RCA 1
- Purpose
- Analog audio
Ground
- Source port
- GND
- Target port
- PWR IN
- Purpose
- Ground
- Interface
- Terminal
- Transmission
- Copper
- Direction
- Non-directional
- Polarity
- Ground
Ground
- Source port
- FUSE OUT 1
- Target port
- GND
- Purpose
- Ground
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
Ground
- Source port
- FUSE OUT 2
- Target port
- GND
- Purpose
- Ground
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
Ground
- Source port
- FUSE OUT 3
- Target port
- GND
- Purpose
- Ground
- Interface
- Terminal
- Transmission
- Copper
- Direction
- One-way
- Power
- Ground
- Speaker-level audio
- Analog audio
- Digital audio
Build parts
10 unique parts 13 unitsCatalogue parts used here, with roles. Part pages carry the full specs.
-
Audison B-Con II
Bluetooth adapter
-
Google Pixel 8 Pro
Phone / tablet
-
JL Audio 6W3v3-4
Subwoofer
-
JL Audio VX700/5I
Multi-channel DSP amplifier
-
One Audio WB3.e
Full-range driver
-
JL Audio C3-650
Other speaker driver
-
JL Audio RD500/1
Mono amplifier
-
Jl Audio CS112LG-TW3
Passive subwoofer
-
HIMOZEAN Mini ANL Fuse Holder
Distribution block
-
Eton PCC 20
Fuse holder
Competition history
3 eventsEvents this build was entered in, and where it placed each time.
2nd
EMMA Sound Off 2026 Horsch & Guck
- Category
- SQ Entry Unlimited
- Points
- 279
Organized by EMMA
3rd
ToN Hauptstadt AYA
- Category
- Einsteiger
- Points
- 140,5
Organized by AYA
6th
FinAYAle 2025 Germany Finals
- Category
- Einsteiger
- Points
- 154
Organized by AYA
Updates
9 logsChanges, fixes, and progress logged after publishing. Newest first.
-
Still continuing with the sound deadening edited
-
We've been trying to figure out what's going on for over a month now; the usual ways to trick the system aren't working.
-
Trying to connect stuff, the problem is - Car wont give any signal on stock sub
-
Kinda insane extra work, but should be worth it
-
Had to find out cables myself and create this diagram
Discussion
Forum threads linked to this build, covering questions and fixes.
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