NHT S-20 Initial Control Settings, Subwoofer Placement, System Operation, System Maintenance

INITIAL CONTROL SETTINGS:

Input Sensitivity Selection:

This switch affects the input sensitivity of all three sets (XLR, TRS and RCA) of input jacks. When satellites are connected to the S-20, the subwoofer takes over as the master sensitivity control for the system.

IMPORTANT: Set the satellite speakers you're using to the +4 setting. Set the sensitivity on the S-20 to the appropriate setting for your source equipment.

HP Frequency Selection:

If you are using NHTPro M-00 monitors as satellites, set the HP FREQ to the 110Hz setting. If you use a different brand of powered satellites try setting the switch to 110 Hz when the satellite woofer size is 5” or smaller and 80Hz if larger than 5”.

Subwoofer Level Setting:

The level you select will depend largely on placement. We suggest you start with this control in the 12 o'clock position. Move the control in a clockwise direction to increase bass output and counterclockwise to decrease it. Adjust the level so that the S-20 seamlessly integrates with the satellites, ie. you can tell it's operating but can't “hear” it as a separate entity.

Low Pass Frequency Setting:

Getting this setting right may take a little time. Using a variety of demo material you are very familiar with, start with the control in the 12 o'clock position. If the bass sounds too “punchy”, turn the control counter clockwise towards 80Hz. If the bass sounds thin, turn the control clockwise towards 110Hz.

SUBWOOFER PLACEMENT:

Where you locate the S-20 subwoofer will have a pro- found effect on the system's performance. Unfortunately, there are no hard and fast rules to find the best location. If you have some flexibility, we encourage you to experi- ment. The following guidelines should help you in your placement decisions:

Placement near walls and corners will reinforce low fre- quencies; conversely, placement out into open space will add definition, but will reduce bass weight and extension.

Ideally, the subwoofer should be adjusted so that you hear the additional bass extension, but cannot localize the subwoofer itself. The subwoofer should be placed somewhere in the same plane as the left and right moni- tors. Listen as you go, using a wide variety of program material. Jazz recordings with acoustic bass and piano are particularly helpful in determining location, sub level and crossover settings. Transparency and integration are the goals.

The S-20 subwoofer amplifier has a number of controls which can help you determine optimal placement. A little time spent experimenting with these options should yield just the right solution for your installation.

TECH TIP: The bypass foot switch is very helpful when setting up and tuning the S-20 to your room. When switching the woofer in and out, no tonal difference should be noticeable, just bass or no bass.

SYSTEM OPERATION

The S-20 used in conjunction with good satellite monitors, like the M-00's, can play very loud with low distortion. Although designed to handle a wide range of listening levels, every speaker has its limits. Harsh breakup is an indication your monitors or the subwoofer have exceeded their output limits. Excessive boosting of bass, treble or equalizer controls can worsen the problem. If you hear continuous distortion or feel heat emanating from the drivers, reduce the level immediate- ly. Most speaker damage occurs from sustained high volume levels, not from transient sounds or brief musical peaks. Listening at high volume levels is potentially dan- gerous and can lead to permanent hearing loss, especially when listening in the near-field. Protect your ears and use common sense.

SYSTEM MAINTENANCE

Your S-20 subwoofer needs no regular maintenance. The S-20 cabinet is finished with a durable, powder-coat paint. Light dusting is usually sufficient, although the cabinet can be cleaned with a non-abrasive, water based, cleaner.

WARNING: To avoid risk of electrical shock, do not remove the amplifier from the rear of the cabinet. Refer all repairs to a qualified authorized service cen- ter. Always disconnect the S-20 from the AC power source prior to any maintenance.

TROUBLESHOOTING

If the S-20 fails to operate when the Power Switch is turned on, thoroughly check the power cord, input and output connections

If the S-20 turns on but the LED indicator fails to illumi- nate, mis-wiring or a power surge may have caused the amplifier to become damaged.

If the S-20 turns on but its status LED appears AMBER, the unit has gone into FAULT (protect mode), which could be caused by incorrect wiring, short circuits, or excessive volume. Turn off the Power Switch on the sub- woofer for two or more seconds to reset. If this doesn’t help, contact NHT customer service.

4