170.751UK - Subwoofer Qtx - Free user manual and instructions

Product Type	Powered Subwoofer
Brand	Qtx
Model	170.751UK
Category	Subwoofer
Power Output	200W RMS
Impedance	8 Ohms
Frequency Response	30Hz - 200Hz
Driver Size	12 inches
Enclosure Type	Bass reflex
Dimensions (W x H x D)	400 x 350 x 420 mm
Weight	12.5 kg
Power Supply	AC 230V ~ 50Hz
Inputs	RCA Line In, High Level Speaker Input
Controls	Volume, Crossover Frequency, Phase Switch
Protection Features	Overload, thermal, short circuit
Placement	Floor standing, near wall for best performance
Cleaning	Wipe with dry cloth; do not use solvents
Safety	Do not expose to moisture; ensure proper ventilation
Spare Parts	Contact Qtx support for replacement drivers and amplifiers
Repair	Only qualified personnel should attempt repairs
General Information	Designed for home audio and PA systems

Frequently Asked Questions - 170.751UK Qtx

How do I connect the Qtx 170.751UK subwoofer to my amplifier?

Use the RCA line input or high-level speaker input on the subwoofer. Connect from your amplifier's subwoofer pre-out (RCA) or speaker terminals (high-level).

What is the optimal placement for this subwoofer?

Place the subwoofer on the floor near a wall or corner for enhanced bass. Avoid placing it in the center of the room. Ensure adequate ventilation around the unit.

Can I use this subwoofer with a home theater system?

Yes, it is compatible with home theater receivers that have a subwoofer pre-out. Connect using the RCA cable.

How do I adjust the crossover frequency?

Use the crossover control knob on the back panel. Set it to match your main speakers' low-frequency limit, typically between 80-120 Hz.

The subwoofer does not power on. What should I check?

Check that the power cord is securely connected and the outlet is working. Ensure the power switch is set to ON. If still not working, check the fuse and replace if blown.

How do I clean the subwoofer?

Unplug the subwoofer and wipe the exterior with a soft, dry cloth. Do not use water, solvents, or abrasive cleaners.

What is the phase switch for?

The phase switch (0° or 180°) allows you to adjust the subwoofer's output to match the main speakers' phase, reducing cancellation and improving bass response.

Can I use this subwoofer in a PA system?

Yes, it can be used in small PA systems. Ensure the amplifier output is compatible and do not exceed the subwoofer's power rating.

What is the frequency range of this subwoofer?

The frequency response is 30Hz to 200Hz, covering deep bass frequencies.

How do I troubleshoot distorted sound?

Reduce the volume on both the subwoofer and the amplifier. Check that the input signal is not clipped. Also, ensure the crossover is set correctly to avoid overdriving the driver.

USER MANUAL 170.751UK Qtx

Order ref: QT15SA (170.751UK)

QT18SA (170.754UK)

User Manual

Line drawing of a rectangular electronic device with circular and rectangular patterns, no text or symbols present.

Version 1.1

Caution: Please read this manual carefully before operating

Damage caused by misuse is not covered by the warranty

Introduction

Thank you for choosing a QT-series active subwoofer as part of your sound system. This unit is designed to offer powerful sub frequencies for PA systems in leisure and entertainment applications.

Package Contents

Please check the contents to ensure that the product has been received in good condition with the appropriate mains lead(s). If you find that the product has arrived with any problems, please contact your retailer at once.

Warning

This product contains no user-serviceable parts so make no attempt to try to fix or modify this item yourself as this will invalidate the warranty. We recommend you keep the original package and proof of purchase for any possible replacement or returned demand. To prevent the risk of fire or electric shock, do not expose this appliance to rain or moisture. To prevent electric shock do not remove the cover. No user serviceable parts inside. Refer servicing to qualified service personnel.

Safety: Labelling Conventions

CAUTIONRISK OF ELECTRIC SHOCKDO NOT OPEN

AVISRISQUE DE CHOC ELECTRIQUENE PAS OUVRIR

This symbol indicates that dangerous voltage constituting a risk of electric shock is present within this unit

This symbol indicates that there are important operating and maintenance instructions in the literature accompanying this unit.

Prior to connecting mains, check the supply voltage is correct and the mains lead is OK.

Avoid ingress of water or particles into the enclosure.

If the mains fuse blows continually, refer the unit to qualified service personnel.

Placement

Keep the unit out of direct sunlight and away from heat sources.

Keep the unit away from moisture or dusty environments.

Avoid locations where liquids may be spilled onto the unit.

Ensure that any supporting structures have adequate load capacity for the weight of the unit.

Ensure adequate space for cooling to the rear panel and easy access for controls and connections.

Cleaning

Use a soft cloth with a neutral detergent to clean the cabinet, panel and controls.

To avoid damage, do not use solvents to clean this equipment.

Rear Panel Layout

1. INPUT LEVEL control
2. Line level INPUT XLR
3. Phase switch
4. Line output THRU XLR
5. FREQUENCY control
6. Power ON/OFF switch
7. IEC mains power inlet

Setup & Operation

With INPUT LEVEL turned fully down and power switch off, connect the IEC to an appropriate mains outlet.

Connect output of mixer or any line level signal to the INPUT via XLR. If the signal is to continue to further active speakers, connect these from the THRU line level XLR.

Begin with the FREQUENCY control in the mid position (12-o-clock position)

Press the power switch on and gradually increase the INPUT LEVEL until the bass signal is heard through the speaker.

Turning the FREQUENCY control up will include more mid frequencies and turning it down will eliminate all but the lowest frequencies. Adjust the FREQUENCY control to the desired tone, noting that lower settings may need the INPUT LEVEL turning up to compensate for the narrower frequency band.

The PHASE switch can help eliminate speakers which are "out-of-phase" from cancelling each other's signals out. The correct setting for this switch is whichever setting gives the loudest output – by a process of trial and error. One or other setting may also help to avoid feedback. If there is no difference in volume or feedback, leave the switch in the "0°" position (out)

To avoid loud noises when powering down, turn down the OUTPUT LEVEL before switching off.

Specifications

Model	QT15SA	QT18SA
Power supply	220-240Vac 50/60Hz (IEC)
Cutoff Frequency	40 – 150Hz
Connections	XLR line in, XLR line out
Main driver	38cm (15") 8Ω	45cm (18") 8Ω
Output handling (max)	600W	1000W
Dimensions	515 x 420 x 615mm	585 x 475 x 675mm
Weight	22kg	29kg

Troubleshooting

No output and no LEDs lit	Check POWER switch is on
	Check mains lead is connected properly and fuse hasn’t blown
Power LED lit but no sound from external inputs	Check signal leads are OK and connected properly
	Try turning up the FREQUENCY control
	Ensure input signal has some bass content for the sub to produce
	Check INPUT LEVEL control is not fully down

Disposal: The "Crossed Wheelie Bin" symbol on the product means that the product is classed as Electrical or Electronic equipment and should not be disposed with other household or commercial waste at the end of its useful life. The goods must be disposed of according to your local council guidelines.

Errors and omissions excepted. Copyright© 2021.

AVSL Group Ltd. Unit 2-4 Bridgewater Park, Taylor Rd. Manchester. M41 7JQ

AVSL (EUROPE) Ltd, Unit 3D North Point House, North Point Business Park, New Mallow Road, Cork, Ireland