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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 files

Compare uploaded measurements across the full system and individual channels.

Measurement setup

Equipment and conditions used for these measurements.

Date
Environment
Car interior
Position
Driver seat
Microphone
miniDSP UMIK-1
Calibration
Individual calibration file
Whole build
Jl Audio CS112LG-TW3
JL Audio 6W3v3-4
JL Audio C3-650
JL Audio C3-650
One Audio WB3.e
One Audio WB3.e
Measurement details Log sweep · REW
Method
Log sweep
Software
REW
Export processing
1/48 octave
Original measurement data Distortion.txt

System diagram

15 nodes 19 connections

Signal and power routing, as wired. Open a node for the part behind it.

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Bluetooth adapter Audison B-Con II Trunk
B+ GND Bluetooth
Optical
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
Ground Ground
GND
Power Car Battery 13.5 Volt
PWR OUT GRN
Fuse holder Eton PCC 20
PWR IN
160 A
Distribution block HIMOZEAN Mini ANL Fuse Holder
PWR IN
1 2 3
  • Power
  • Ground
  • Speaker-level audio
  • Analog audio
  • Digital audio

Build parts

10 unique parts 13 units

Parts used in this build. Open a part for specifications and other documented uses.

Competition history

3 events

Events this build was entered in, and where it placed each time.

2nd

EMMA Sound Off 2026 Horsch & Guck

Leipzig July 18, 2026
Official results
Category
SQ Entry Unlimited
Points
279
Organized by EMMA
6th

FinAYAle 2025 Germany Finals

Bad Salzuflen October 11, 2025
Official results
Category
Einsteiger
Points
154
Organized by AYA

Updates

9 updates

Changes, fixes, and progress logged after publishing. Newest first.

  1. Still continuing with the sound deadening

    Edited
    Still continuing with the sound deadening photo 1
    Still continuing with the sound deadening photo 2
    Still continuing with the sound deadening photo 3

  2. 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.

    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. photo 1

  3. Trying to connect stuff, the problem is - Car wont give any signal on stock sub

    Trying to connect stuff, the problem is - Car wont give any signal on stock sub photo 1

  4. Kinda insane extra work, but should be worth it

    Kinda insane extra work, but should be worth it photo 1

  5. Had to find out cables myself and create this diagram

    Had to find out cables myself and create this diagram photo 1
    Had to find out cables myself and create this diagram photo 2
View build log

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