Thesis THX 2 II - Audio Electronics AUDISON - Free user manual and instructions

Product Type	2-Channel Car Audio Amplifier
THX Certification	Yes
Power Output (RMS @ 4 ohms)	2 x 200 W
Power Output (RMS @ 2 ohms)	2 x 400 W
Bridged Power (RMS @ 4 ohms)	1 x 800 W
Frequency Response	10 Hz - 50 kHz (±1 dB)
Total Harmonic Distortion (THD)	≤ 0.05%
Signal-to-Noise Ratio	≥ 100 dB (A-weighted)
Damping Factor	> 200 @ 4 ohms, 100 Hz
Input Sensitivity	0.2 V - 8 V
Input Impedance	47 kΩ
Crossover Type	Variable Low-Pass / High-Pass / Full Range
Crossover Slope	12 dB/octave (Butterworth)
Bass Boost	0 - 12 dB @ 45 Hz
Phase Shift	0° / 180°
Power Supply Voltage	11 - 15 V DC
Dimensions (W x H x D)	500 x 50 x 200 mm
Weight	3.5 kg
Protection Circuits	Thermal, Short Circuit, Overvoltage, Under Voltage
Recommended Fuse	60 A
Speaker Impedance	2 - 8 Ω (stereo), 4 - 8 Ω (bridged)
Audio Inputs	2 x RCA
Audio Outputs	2 x Speaker terminals
Remote Turn-On	Yes

Frequently Asked Questions - Thesis THX 2 II AUDISON

How do I connect the power wires to the amplifier?

Connect the 12V DC power wire to the amplifier's BATT+ terminal, the ground wire to GND, and the remote turn-on wire to REM. Use a fuse (60A recommended) on the power wire near the battery.

What is the minimum speaker impedance for bridged mode?

In bridged mode, the minimum recommended impedance is 4 ohms. Using a lower impedance may cause the amplifier to overheat or trigger protection.

How do I set the gain properly?

Set the gain using a multimeter or oscilloscope to match your head unit's output. Start with the gain at minimum, play a test tone at high volume, and adjust until the amplifier outputs the desired voltage (e.g., 28V for 200W @ 4 ohms).

Can I use this amplifier with aftermarket car stereos?

Yes, the amplifier accepts standard RCA inputs. It works with most aftermarket head units. Ensure the head unit's preamp output voltage is within the amplifier's input sensitivity range (0.2V-8V).

What does the THX certification mean for this amplifier?

THX certification ensures high-quality audio performance with low distortion, wide frequency response, and strict standards. It guarantees that the amplifier meets rigorous criteria for home theater-like sound in a car.

How do I adjust the crossover settings?

Use the crossover mode switch to select Low-Pass (LP), High-Pass (HP), or Full Range (FLAT). Then adjust the crossover frequency knob to the desired point (typically between 50 Hz and 5 kHz). The slope is fixed at 12 dB/octave.

What size power wire should I use?

For a total power draw (e.g., 800W RMS bridged), use 4 AWG or larger power wire for runs up to 15 feet. For smaller setups, 8 AWG may suffice. Always fuse appropriately.

Why does the amplifier go into protection mode?

Protection mode can be triggered by overheating, short circuit, impedance too low, or voltage issues. Check speaker wiring for shorts, ensure proper ventilation, and verify that the impedance load is within specification.

Can I bridge two channels to power a subwoofer?

Yes, bridge the left positive and right negative terminals. Connect the subwoofer's positive to the left channel positive and the subwoofer's negative to the right channel negative. Set the crossover to low-pass for subwoofer use.

How do I clean and maintain the amplifier?

Unplug the amplifier before cleaning. Use a dry soft cloth to wipe the exterior. Avoid liquids or solvents. Check connections periodically and ensure air vents are free from dust.

USER MANUAL Thesis THX 2 II AUDISON

THESIS

Index

02

THESIS - The project 03

Assembling and Cable connection 04

Size 05

THX 2

THX 2 Mono-Wiring connections 07

THX 2 Bi-Wiring connections 08

THX 2 Installation recommended with default set filter 09

THX 2 Installation with door mounted tweeter 10

THX 2 Tweeter Level Ajustment 11

THX 2 LFS (Low Frequency Shaping): Adjusting Low Frequency Response to eliminate resonances 12

THX 2 How to disassemble the circuit board "Step 1" "Step 2" 13

THX 2 How to disassemble the circuit board "Step 3" "Step 4" 14

THX 2 Modifications on the single components 15

THX mh

THX mh Mono-Wiring connections 17

THX mh Bi-Wiring connections 18

THX mh Installation recommended with default set filter 19

THX mh Installation with door mounted midrange 20

THX mh Tweeter Level Adjustment 21

THX mh Midrange Hi-pass: Activation of the High-pass filter for the midrange" 22

THX mh How to disassemble the circuit board "Step 1" "Step 2" 23

THX mh How to disassemble the circuit board "Step 3" "Step 4" 24

THX mh Modifications on the single components 25

THX 3

THX 3 Mono-Wiring connections 27

THX 3 Bi-Wiring connections 28

THX 3 Tri-Wiring connections 29

THX 3 Installation recommended with default set filter 30

THX 3 Installation with door mounted midrange 31

THX 3 Installation with door mounted double woofer 32

THX 3 Installation with door mounted double woofer and midrange 33

THX 3 Tweeter Level Adjustment 34

THX 3 Midrange Level Adjustment 35

THX 3 LFS (Low Frequency Shaping): Adjusting Low Frequency Response to eliminate resonances 36

THX 3 How to disassemble the circuit board "Step 1" "Step 2" 37

THX 3 How to disassemble the circuit board "Step 3" "Step 4" 38

THX 3 Modifications on the single components 39

Technical Specifications 40

THESIS

The Project

In order to create a system capable of reproducing amazing, first-class Sound, each acoustical component must abide to the most elevated standards of quality and design.

The Thesis amplifiers offer their best performance when used with speakers designed with the same philosophy. Throughout the years Thesis has represented a name referenced to the perfection of electronic design and performance. Today, technological development has enabled us to push the envelope in terms of the prestigious Thesis tradition. Creating a supreme product in amplification, the Audison development team has achieved their ambition of reproducing an unparalleled Sound.

Appropriate tuning

Assembling a speaker system imposes choices in which parameters such as personal taste, the physical installation limits and the acoustic environment of the vehicle itself have to be considered. Thesis speakers ensure the highest performance with both multi-amplified active systems and with systems using “passive” crossovers.

Pairing TH speakers with the TH amplifiers intensifies the synergy of products belonging to the same magnificent project. Therefore, choosing an active multi-amplified system or the use of passive crossovers is merely a question of personal taste.

The available crossover networks are:

THX 2, for a full range two-way system with TH 1.5 violino and TH 6.5 sax;

THX 3, for a full range three-way system with TH 1.5 violino, TH 3.0 voce and TH 6.5 sax;

THX mh, for a mid to high frequency system with TH 3.0 voce and TH 1.5 violino as part of a "mixed" multi-way system.

Open design

Each filter is, in actual fact, an “open” design which can be customised in order to obtain the best acoustic response in any environment.

Extreme customization

A mother board, designed for maximum versatile adaptation, provides the ability for anyone to customize their own THX crossover.

Designed as a continued project in-progress, it is possible to change and set:

• the power connection mode for BiWiring or when used as a passive multi-amplified system;
• the output level of every single speaker;
• the cut-off frequency of every single output;
• the filter cut-off slope;
• the Q (quality factor) at the crossover frequency;
• the use of notch filters to adjust the system to the vehicles acoustics.

Audison Thesis Advisor

The THX crossover default configuration has been designed to achieve the highest sound quality levels. This Advanced Manual offers complete information to fully enjoy their potential.

Each user has at his/her disposal the best support to make the most of the Thesis line expandability and customization possibilities. Through the “Support” area of the Audison website the user can interact with the Audison Thesis Advisor to be guided by a professional inside the Audison R&D Division who will provide him/her with the opportunity to further enhance their crossover.

A mother board, designed for maximum versatile adaptation, provides the ability for the users to customize their own THX crossover.

THESIS

Assembling

Cable connection

THESIS

Size

THX 2 THX mh THX 3

A B C D E
190 166 348 324 66,57"1/2 6"1/2 13"3/4
258 234 438 414 66,510"3/16 9"1/4 17"1/4
Misure espresse in millimetri e pollici / Measures in mm and inches

THX 2

PATTERNS

TUNING KIT (supplied)

N° 2 1Ω, 10W Resistors

N° 2 2,2Ω, 10W Resistors

N° 2 3,3Ω, 10W Resistors

N° 2 4,7Ω, 10W Resistors

N° 2 5,6Ω, 10W Resistors

N° 2 1μF, 330V Polypropylene capacitors

N° 4 4, 2 x 3 8 m m cross headed, self-tapping fixing screws

THX 2 Mono-Wiring connection

THX 2 Bi-Wiring connection

THX 2 Installation recommended with default set filter

THX 2 Installation with door mounted tweeter

Right Channel

Left Channel

WORK ON THESE COMPONENTS! (see page 13÷15)

THX 2 Tweeter Level Adjustment

THX 2 LFS (Low Frequency Shaping)

Adjusting Low Frequency Response to eliminate resonances

THX 2 How to disassemble the circuit board

Step 1: remove plexiglass cover (see page 4)

Step 2: remove the main screws (marked in blue)

Left Channel Right Channel

THESIS

THX 2 How to disassemble the circuit board

Step 3: remove the screws that secure the resistor blocks (marked in blue)

Step 4: remove the screws that secure the resistors with the clamps

THX 2 Modifications on the single components

Replace the 6,8Ω resistor originally mounted with a 5,6Ω one supplied with the product
Replace the supplied resistors originally mounted following the diagram on page 10

TUNING KIT (supplied)

N° 2 1.5 mH, ∅ 42 mm inductances

N° 2 1μF, 330V Polypropylene capacitors

N° 4 4 , 2 x 3 8 m m cross headed, self-tapping fixing screws

THX mh Mono-Wiring connection

THX mh Bi-Wiring connection

Left Channel Right Channel

THESIS

THX mh Installation recommended with default set filter

THX mh Installation with door mounted midrange

Left Channel
Right Channel

WORK ON THESE COMPONENTS! (see Page 23÷25)

THX mh Tweeter Level Adjustment

THX mh Midrange Hi-pass

Activation of the High-pass filter for the midrange

THX mh How to disassemble the circuit board

Step 1: remove plexiglass cover (see page 4)

Step 2: remove the main screws (marked in blue)

Left Channel Right Channel

THX mh How to disassemble the circuit board

Step 3: remove the screws that secure the resistor blocks (marked in blue)

Step 4: remove the screws that secure the resistors with the clamps

Left Channel Right Channel

THX mh Modifications on the single components

Insert the supplied 10 µ F capacitor
Insert the supplied 1,5 mH coil

THX 3

PATTERNS

TUNING KIT (supplied)

N° 2 1.5 mH, ∅ 42 mm inductances

N° 4 4 , 2 x 3 8 m m cross headed, self-tapping fixing screws

THX 3 Mono-Wiring connection

Left Channel Right Channel

THX 3 Bi-Wiring connection

Left Channel Right Channel

THX 3 Tri-Wiring connection

Left Channel Right Channel

THX 3 Installation recommended with default set filter

THX 3 Installation with door mounted midrange

WORK ON THESE COMPONENTS! (see page 37:39)

THX 3 Installation with door mounted double woofer

WORK ON THIS COMPONENT! (see page 37÷39)

THX 3 Installation with door mounted double woofer and midrange

WORK ON THESE COMPONENTS! (see page 37÷39)

THX 3 Tweeter Level Adjustment

THX 3 Midrange Level Adjustment

THX 3 LFS (Low Frequency Shaping)

Adjusting Low Frequency Response to eliminate resonances

THESIS

THX 3 How to disassemble the circuit board

Step 1: remove plexiglass cover (see page 4)

Step 2: remove the main screws (marked in blue)

THESIS

THX 3 How to disassemble the circuit board

Step 3: remove the screws that secure the resistor blocks (marked in blue)

Step 4: remove the screws that secure the resistors with the clamps

THESIS

THX 3 Modifications on the single components

1. Remove the screws securing the coil from the bottom of the PCB;
2. Unsolder the coil leads;
3. Unwind the coil with the help of an LCR meter until the value of 3,3 mH can be measured;
4. Refixe the coil.

capacitor
Insert the supplied 1,5 mH coil Insert the supplied 10g Supplied

resistors originally mounted

following the diagram

on page 31 or 33

Technical Specifications

		THX 2	THX 3	THX mh
Type		Stereo 2 wayPassive Crossover Network	Stereo 3 wayPassive Crossover Network	Stereo 2 way Mid-HighPassive Crossover Network
Size	mm / inch	348x190x66,5 133/4 × 71/2 × 25/8	438x258x66,5 171/4 × 101/4 × 25/8	348x190x66,5 133/4 × 71/2 × 25/8
Power	W peak	400	400	400
Handling	W continuous	200	200	200
Crossover frequency	LO/HI-pass	2.5 kHz	450 Hz / 3.5 kHz	280 Hz / 3.5 kHz
Slope	dB/Oct.	6/12	12/6-12/12	6 (ON-OFF) / 12 (default)12 (ON-OFF) / 12 (optional)
Thesis speaker set		TH 1.5 violino +TH 6.5 sax	TH 1.5 violino +TH 3.0 voce +TH 6.5 sax	TH 1.5 violino +TH 3.0 voce
Component Adjustment	TweeterMidrange	-2; 0; +2; +4 dB	-2; 0; +2; +4 dB-2; 0; +2 dB	-2; 0; +2 dBMD Hi-pass ON/OFF(280 Hz @ 6/12 dB/Oct.)
	Woofer	LFS 0; -2; -4 dB	LFS 0; -2; -4 dB
Sound Control		Low Frequency ShapingSpeaker Position ContourMulti-Amp ConfigurationAudison Thesis Advisor	Low Frequency ShapingSpeaker Position ContourMulti-Amp ConfigurationAudison Thesis Advisor	Low Frequency ShapingSpeaker Position ContourMulti-Amp ConfigurationAudison Thesis Advisor