HTS6 Operating Manual Genelec HTS6 Active Subwoofer HTS6 Active Subwoofer General description Genelec HTS6 is a powerful active subwoofer designed specially for high quality digital 5.1 channel Home Theater systems. Its 19 to 120 Hz (± 3 dB) frequency range and 124 dB sound pressure output capability are sufficient to handle the most demanding high SPL applications. High quality XLR and RCA line level input connectors and adjustable input sensitivity provide easy connection to all types of decoders. Bass roll-off rate and crossover phase can be adjusted to suit different acoustical environments and subwoofer positioning. A "LINK OUT" connector allows coupling two or more subwoofers together when very high sound pressure levels are required. The amplifiers are equipped with an "AUTOSTART" function for automatic switching between "STANDBY" and "ON" modes. Connectors for remote controlled power "ON/STANDBY" switches are also provided. unpacked, place the subwoofer in a suitable location (For more details see the `Positioning' section). Before connecting the audio signals, ensure that all equipment are switched off. Check that the subwoofer voltage selector switch is set to the correct voltage. Audio input to the subwoofer can be made via balanced XLR or unbalanced RCA connector. We recommend the use of balanced cables and connectors due to their better noise immunity. Do not use both inputs at the same time. The "LINK OUT" connector can be used for daisy-chaining several subwoofers together when high SPL is required. Simply connect a balanced XLR cable from the "LINK OUT" connector to the "XLR INPUT" connector of the next subwoofer. See section "Using multiple subwoofers". Once all connections have been made, the subwoofer and main speakers are ready to be powered up. low frequencies the effects of the room are strong. Even a slight change in the subwoofer's location can make a marked difference in the frequency balance and often patient and methodical experimentation and testing is needed to find the optimum placement. The placement will affect the phase difference between the main monitors and the subwoofer, and also the bass roll-off rate. These effects can be compensated by the use of the controls in the amplifier unit; but we recommend that at first you leave the switches untouched and concentrate on finding the position where the subwoofer gives the smoothest response, and only then use the controls to fine-tune the balance and phase alignment between the subwoofer and the main speakers. To begin with, place the subwoofer slightly offset from the center of the front wall. The recommended distance to the wall is less than 90 cm / 36" measured from the subwoofer's drivers. This position gives increased acoustic loading (and SPL) due to the proximity of the front wall and floor. Cancellations from the front wall and floor are also avoided. In a multichannel system the main speakers should ideally be positioned Installation Each subwoofer is supplied with a mains cable and an operating manual. Once Positioning in the room The placement of the subwoofer in the room affects the overall frequency response and sound level of the system dramatically, as at Figure 2. XLR to RCA connector for unbalanced operation. Subwoofer placement Near to a wall In a corner Flush mounted Figure 1. HTS6's connector panel, connectors and controls. Bass Roll-Off setting -2 dB -6 dB -2 dB Table 1. Suggested Bass Roll-Off settings symmetrically and at an equal distance from the listening position. If the frequency balance is not right, try moving the subwoofer slightly to the left or right so that different room modes are excited at different levels. Positioning the subwoofer close to a corner will boost the bass level at lower frequencies and may cause asymmetrical spatial imaging. If you are using two subwoofers, try placing them asymmetrically relative to the side walls. Sometimes moving the subwoofers apart into the front corners helps with problematic rear wall reflections and the loss of mutual coupling is compensated by the bass boost caused by corner positioning. Although the HTS6 subwoofer is magnetically shielded, they may cause some picture distortion if placed near very sensitive video monitors or computer displays. front of the grilles. The reflex port and connector panel should always have a clearance of at least 20 centimeters (8") to any objects to ensure proper function of the port and cooling for the electronics attached to the connector panel. subwoofer. An input voltage of -6 dBu with a -6 dBu input sensitivity setting will produce 100 dB SPL @ 1m in free field. To obtain a 110 dB SPL output an input voltage of +10 dBu is required when the input sensitivity is set to 0 dBu. Flush mounting the subwoofer If the subwoofer is flush mounted into a wall or a cabinet, it is important to ensure unrestricted airflow from the reflex port and cooling for the electronic components. This can be done by making the recess 20 centimeters (8") wider than the subwoofer. Place the subwoofer into the right end of the recess with the drivers' side facing the room. This leaves sufficient 20 centimeters (8") of free space on the connector panel and reflex port side. The height and depth of the recess should not be any bigger than those needed to fit the subwoofer flush with the wall surface. Setting the Bass Roll-Off switches The acoustic response of the subwoofer may have to be matched to the characteristics of the room and the positioning in which it will be used. To adjust the subwoofer to match these characteristics use the ''Bass Roll-Off' control switches located on the connector panel. Table 1 provides some suggestions for the "Bass Roll-Off" switch settings. When all roll-off switches are set to "OFF", a flat anechoic response is obtained. Minimum clearances to walls or other objects The power amplifiers are attached to the lower part of the aluminium grilles, which function as a heatsink. Do not cover the grilles or place the subwoofer so that there is less than 10 centimeters (4") of free space in Setting the phase control Incorrect phase alignment between main monitors and subwoofer causes a drop in the frequency response of the whole system at the crossover frequency. The graphs on the following page (Fig. 4) show the effect of phase difference to the frequency response. The phase difference between the main Setting the input sensitivity The subwoofer requires input sensitivity alignment to the source to obtain a correctly balanced system. The input sensitivity control is located on the connector panel of the Phase Difference: 0° Phase Difference: 90° 120 Hz 120 Hz Phase Difference: 180° Phase Difference: 270° Remote control type 12 V DC remote control Pole or contact + Contact 1 Contact 2 Connect to remote control input pin no. 1 2 3 4 120 Hz 120 Hz External switch or relay Figure 4. The effect of phase difference between the subwoofer and the main speakers Connect only one remote control unit at a time Table 2. Remote control connector pin sequence speakers and subwoofer at the listening position is dependent upon the position of the subwoofer, so the phase adjustment should be done only after the preferred position is found. Acoustic measuring equipment is required for accurate system alignment. If this equipment is not available, the following coarse phase matching can be applied. Toggle the -180° phase switch `ON' and `OFF' and set it to the position which gives the lowest sound level at the listening position. Next toggle the -90° phase switch `ON' and `OFF', and again set it to the position which gives the lowest sound level. Finally, set the -180° phase switch to the opposite setting. bass level increases by 6 dB. Three subwoofers give an bass SPL increase of 9,5 dB and four subwoofers 12 dB compared to a single subwoofer. Adjust the sensitivity control of all subwoofers in the group to match the SPL level with the main speakersystem. Note that the sensitivity setting must be the same on all subwoofers. Coarse phase adjustment method Configure the processor so that the main speakers (L, C, R) are set to "small" and check the subwoofer crossover frequency setting on your processor. This setting may be either fixed or variable, consult the operating manual of your processor. Connect an audio frequency signalgenerator to one of the front L, C or R input channels used in the system. Set the frequency generator to the same frequency as the subwoofer crossover frequency on your processor. If a signal generator is not available, you can use an audio test recording with a suitable range of test frequencies. Mute all other channels and perform the adjustment with only one of the front speakers playing. Autostart and remote control The HTS6 is equipped with an "AUTOSTART" function, which automatically turns the amplifier to "STANDBY" mode if an input signal has not been detected for approximately five minutes, and back to "ON" mode when the signal returns. The function can be deactivated by turning the "AUTOSTART" dip switch to "OFF". A two-colour LED on the connector panel indicates the amplifier status: green for "ON" and yellow for "STANDBY". The amplifier mode can also be switched by a remote control unit connected to the respective inputs on the amplifier. Two pairs of connectors are provided, 1 and 2 for a 12 V DC type remote control, and 3 and 4 for an external switch or relay type control. Do not connect two remote controls to the subwoofer at the same time. Remote control overrides the "AUTOSTART" function. Using multiple subwoofers The HTS6 is equipped with a "LINK OUT" connector to provide an easy way of coupling two or more subwoofers together in high SPL applications. Connect a XLR cable from the "LINK OUT" connector of the "master" HTS6 to which the main monitor channels are connected, to the "XLR IN" connector of the other, "slave" subwoofer. When two subwoofers connected in this way are positioned close to one another, 20 cm (8") GENELEC GENELEC GENELEC GENELEC Figure 6. Flush mounting the subwoofer. Note the clearance needed on the reflex port side. HEAVY WOODEN OR CONCRETE WALL ABSORBING MATERIAL HEAVY WOODEN OR CONCRETE WALL Figure 5. The curves above show the harmonic distortion analysis of the HTS6 in free field. In half space the SPL will be 6 dB higher. VIBRATION ISOLATORS f ~ 2-8 Hz VIBRATION ISOLATORS f ~ 2-8 Hz Figure 7. Flush mounting the subwoofer in a non-absorbing wall. Figure 8. Correct flush mounting in a semiabsorbing wall. ABSORBING MATERIAL Automatic protection circuits The HTS6 is equipped with protection circuits against speaker driver thermal overload and amplifier overheating. The protection system resets automatically so the user only has to turn the input level down to ensure that it does not reactivate. · Always use a mains power connection with protective earth. Failing to do · Note that the amplifier is not completely disconnected from the AC mains service unless the mains power cord is removed from the amplifier or the mains outlet VIBRATION ISOLATORS f ~ 2-8 Hz this may lead to personal injury. HEAVY WOODEN OR CONCRETE WALL Figure 9.Incorrect flush mounting in a semiabsorbing wall. Safety considerations The HTS6 subwoofer has been designed in accordance with international safety standards. However, to ensure safe operation and maintain the unit in safe operating condition, the following warnings and cautions must be observed: Warning! This equipment is capable of delivering sound pressure levels in excess of 85 dB, which may cause permanent hearing damage. Maintenance No user serviceable parts are inside the amplifier unit. Any maintenance of the unit must only be performed by qualified service personnel. · Do not expose the subwoofer to water or moisture. Do not place any objects filled with liquid, such as vases on the subwoofer or near it. · Servicing and adjustment must only be performed by qualified Guarantee This product is supplied with a two year guarantee against manufacturing faults or defects that might affect the performance of the unit. Refer to supplier for full sales and guarantee terms. · Opening the connector panel is strictly prohibited except by qualified service personnel. service personnel. HTS6 Operating Manual SYSTEM SPECIFICATIONS HTS6 Free field frequency response (+/- 3 dB) Maximum short term sine wave SPL output averaged from 30 to 85 Hz, measured in half space at 1 meter Maximum peak SPL output with random pink noise, measured in half space at 1 meter Self generated noise level in free field @ 1 m on axis (A-weighted) Harmonic distortion at @ 1 m on axis in half space 2nd 3rd Drivers Weight Dimensions Height Width Depth 19 Hz...120 Hz Short term amplifier output power (Long term output power is limited by driver unit protection circuitry) Amplifier system distortion at nominal output THD Mains voltage Power consumption ( ...