Q ACOUSTICS 2070SI (01) PDF Document

Before making any connections to your loudspeakers, including the Q ACOUSTICS 2070SI, ensure that all active units in your system are switched off at the mains. When you switch on your sound system or change input sources, set the main volume control to a low level and turn it up gradually. Never play your sound system at full volume, as the position of the volume control does not directly indicate the power level and using very high volume settings can damage your hearing. Also, do not connect your loudspeaker terminals to the mains supply.

To unpack your Q ACOUSTICS 2070SI, follow these steps:

1. Unpack the speakers fully from their cartons.

2. Lift the speakers from the cartons by holding the cabinets. Do not use the protective bags to lift them.

3. The Q ACOUSTICS 2070SI is heavy; get assistance to lift it if necessary.

4. When maneuvering loudspeakers, do not drag them across the floor as this may cause damage. Always lift them before moving.

In the carton for your Q ACOUSTICS 2070SI, you will find the subwoofer, this product manual, a power cord suitable for your area, 2 x Right-angled RCA/Phono cables, and an AV Setup CD. Check the product carefully. If any items are damaged or missing, report this to your dealer as soon as possible.

For optimal performance of your Q ACOUSTICS 2070SI, follow these positioning guidelines:

General Placement: Bass frequencies are substantially omnidirectional, so you can position the subwoofer almost anywhere. However, the stereo image will benefit from positioning the subwoofer level with the front loudspeakers and as central to the listening position as possible.

Placement Near Walls: If you place the subwoofer close to a wall, the bass will be reinforced. In some locations, this may cause the bass to become boomy and indistinct.

Power Source: The subwoofer should be positioned close to a mains power source. Do not use extension cables; purchase a longer power cord if necessary.

Access: The mains ON/OFF switch is on the rear panel. Ensure there is ample free space behind the cabinet to allow free, unrestricted access to this switch.

Stability: Ensure the floor is sound with no loose floorboards. The air movement from the subwoofer at high volumes is substantial, so do not place it close to soft furnishings or objects that may rattle. Do not place objects of any kind on the unit.

Magnetic Sensitivity: The Q ACOUSTICS 2070SI should not be operated within 500mm of TV screens, monitors, or other magnetically sensitive equipment. Plasma and LCD screens are unaffected.

The Auto Power On feature on your Q ACOUSTICS 2070SI allows you to switch your main system on and off without needing to manually switch the subwoofer on and off as well.

If there is no signal input, the subwoofer will automatically power down into Standby mode after a few minutes, indicated by the POWER light on the rear panel changing to red.

As soon as the subwoofer senses an input, it will automatically switch into operational mode, and the power light will glow green again.

Some music or TV channels may have very little low-frequency information, which might prevent the subwoofer from automatically switching out of standby. If this happens, you can adjust the auto-on sensitivity to HIGH. However, this may cause the subwoofer to stay on at all times due to small amounts of noise from the main system amplifier. This noise should disappear when the main amplifier is in standby, allowing the subwoofer to turn off. If the subwoofer remains on even when the main amplifier is turned off, it is recommended to leave the sensitivity switch at MED.

If the level of noise from your amplifier is higher than normal, or if the connection cables are picking up hum from nearby power cables, the Q ACOUSTICS 2070SI subwoofer may remain on even when no sound is playing. If you notice a hum, try moving the cables to reduce the hum pick-up or try different cables. In circumstances where the problem cannot be easily remedied, we recommend trying the LOW setting of the sensitivity switch to see if that allows the subwoofer to enter standby mode.

Your Q ACOUSTICS 2070SI includes a Line output connection called “Chain out”. This feature allows you to daisy-chain the signal to one or more additional subwoofers. This is a convenience feature that serves as an alternative to using a “Y-Adaptor” at the amplifier output. Please note that the signal is a straight pass-through, so all subwoofers in the chain must be set up independently using their individual controls as normal.

To connect your Q ACOUSTICS 2070SI to an AV system, use a single RCA phono interconnect cable. Connect the SUBWOOFER OUTPUT on the AV amplifier to the L/Mono Line input on the subwoofer, pushing the plugs firmly home to ensure a good contact. Since this cable can be quite long, ensure you use a good quality, fully screened cable.

When setting up your Q ACOUSTICS 2070SI with a multi-channel AV system, start with the following default settings on the subwoofer’s rear panel:

Level: Approximately half

Crossover: Fully clockwise (AV setting)

Phase: Fully anti-clockwise (0° setting)

Sound Mode: AV

Phase invert: 0°

Auto on sensitivity: Med

Speaker type: No effect when crossover is set to AV, so either position is fine.

After connecting the power cord, switch the power on. The POWER light on the amplifier panel will glow, and the subwoofer will be operational. On your AV amplifier, ensure the subwoofer is set to ‘ON’ or YES, and the subwoofer level is at its default position or 0dB.

The AV Setup CD included with your Q ACOUSTICS 2070SI is designed to help you fine-tune the distance/time delay settings on your AV amplifier. The disc contains six tracks, each playing pink noise (20 Hz to 1000Hz) through a combination of one speaker and the subwoofer.

1. Choose whichever front speaker is closest to the subwoofer and play the corresponding track (e.g., track three for the front right speaker).

2. Adjust the amplifier’s distance/time delay setting for the subwoofer by the smallest amount possible (e.g., if the distance is 4m, change it to 4.1m or 3.9m).

3. Listen to see if the pink noise becomes warmer and fuller, or thinner in tone.

4. If the sound became fuller (e.g., at 4.1m), continue adjusting in that direction (e.g., to 4.2m) until the sound starts to become thinner again.

5. If the sound became thinner, adjust in the opposite direction (e.g., to 3.9m).

This process will help you find the optimum (warmest) setting. Do not adjust more than +/-0.5m from the original measured distance. Once the optimum setting is achieved, play track six to check the overall result. The sound should be full, warm, and integrated, with no individual speaker being dominant.

There are two connection options for your Q ACOUSTICS 2070SI in a stereo system:

Option 1 (Preferred – PRE-OUT Sockets): Use a stereo RCA phono cable from your amplifier’s PRE-OUT sockets to the L and R inputs on the 2070Si. The subwoofer will automatically add the L and R signals together.

Option 2 (HIGH LEVEL Inputs): If your amplifier does not have PRE-OUT sockets, use the HIGH LEVEL inputs. You will need two lengths of speaker cable to go from the 2070Si to the speaker terminals of your amplifier. Connect the two together, ensuring you keep the L and R channels correct and that the plus and minus connections are consistent at both ends.

When setting up your Q ACOUSTICS 2070SI with a stereo system, ensure all connections are secure and the subwoofer is switched off. Then, set the controls to the following default settings:

Level: Approximately half

Crossover: Minimum (50Hz) for large floorstanders; halfway (100Hz) for bookshelf or small speakers

Phase: Fully anti-clockwise (0° setting)

Sound Mode: Music

Phase invert: 0°

Auto on sensitivity: Med

Speaker type: Select ‘Sealed’ if your main speakers are of the sealed or closed-box type. Select ‘Ported’ if your main speakers have a port or vent in them.

After setting the controls, plug in the power cord and switch the subwoofer to ‘ON’. Play some familiar music and experiment with the Phase invert setting and level control until you hear a good blend between the front speakers and the subwoofer. If you can hear the subwoofer standing out, it’s too loud.

Fine-tuning the Q ACOUSTICS 2070SI can take many hours of listening as all controls interact.

Crossover Control: This determines the frequency at which the subwoofer’s output begins to diminish. It should be set to correspond with the frequency your main speakers begin to produce a strong output. You can find this frequency (the “-3dB point”) on your main speaker’s specification sheet under “Frequency response”. If the setting is too low, there will be a ‘hole’ in the sound; if too high, the bass will be overpowering. Room positioning also has a dramatic effect, so don’t worry if your required setting doesn’t match the specified frequency point.

Phase Control: Once you are close with the crossover setting, you can perfect the integration by adjusting the phase control. This control uses a pure delay via the Digital Signal Processor (DSP), providing a 0 – 180° phase shift at the chosen crossover frequency. It affects the bass level at the crossover frequency and the smoothness of the transition. This will interact with the crossover control, so fine adjustments of both may be necessary. You may also get a better result by flipping the phase invert switch and re-optimizing the controls. Experimentation is key to achieving perfect integration where you are not aware of any sound coming from the direction of the subwoofer itself.

Cabinet Care: Clean cabinets with a barely damp cloth. Do not use solvent-based cleaning materials. If the cabinets become stained, remove the stain with a cloth lightly moistened with water, white spirit, or isopropyl alcohol depending on the stain. Then lightly buff with a cloth to remove any residue. Never use abrasives of any kind.

Grilles: Lightly brush out grilles with a soft brush. Do not remove the speaker grilles unless absolutely necessary.

Drive Units: Drive units are best left untouched as they are easily damaged when exposed.

The appliance cord is terminated with a UK-approved mains plug fitted with a 3A fuse. If the fuse needs to be replaced, an ASTA or BSI approved BS1362 fuse rated at 3A must be used. To connect the mains plug, follow the color code for the wires in the mains lead:

Blue Wire (NEUTRAL): Must be connected to the terminal marked with the letter ‘N’ or colored BLUE or BLACK.

Brown Wire (LIVE): Must be connected to the terminal marked with the letter ‘L’ or colored BROWN or RED.