SA-3 Subwoofer Amplifier OWNER’S MANUAL Now Hear This 6400 Goodyear Road Benicia, CA 94510 800-NHT-9993
IMPORTANT SAFETY INSTRUCTIONS CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION: TO REDUCE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER (OR BACK). NO USER SERVICEABLE PARTS INSIDE. REFER TO QUALIFIED SERVICE PERSONNEL. The lightning flash with the arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.
Table of Contents I. Specifications Placement Front and Back Panel Diagrams General Connections Low-Pass Filter High-Pass Filter Subwoofer Phase Subwoofer Volume Control II. The SA-3 and SW3S: The SW3P Powered Subwoofer System Connection Methods Fine Tuning the Subwoofer Ill. The SA-3 and Biamplification Connection Methods Recommended Biamplification Settings Bass Tuning Methods lV. Operation Maintenance Changing the Line Voltage Setting Changing the Fuse Troubleshooting Glossary of Terms V.
SA-3 Amplifier Specifications · System Type: Monaural Class G subwoofer amplifier · Power Output: 250 watts RMS into 6 ohms · Frequency Response: 10Hz - 150Hz +/-3dB · Distortion: Less than 0.
Front and Back Panel Diagrams (A) Power Switch - Turns the unit on and off (B) Power / Status Light - Tri-color LED: Green (On), Orange (Standby), Red (Protect) (C) Volume Control - Adjusts the loudness of the subwoofer independently of the main speakers (D) Subwoofer Output Terminal - 5-way binding posts for connection to the subwoofer (E) High-Pass Filter (High Pass Fc) - 5-way selectable high-pass crossover for line out (F) Low-Pass Filter (Low Pass Fc) - Continuously variable low-pass crossover control
General Connections Caution: Prior to connecting the SA-3 to your system, it is important that all AC power connections to associated components (receivers, amplifiers, pre-amplifiers, processors, etc.) are either unplugged or turned off. Do not plug in or connect the SA-3 to AC power until all connections have been made. The SA-3 subwoofer amplifier is designed for use with passive subwoofers only.
phase settings on the same track. Do not attempt to evaluate the best sound while standing above the subwoofer or amplifier, as the sound at the listening position will be significantly different. Subwoofer Volume Control The SA-3’s front panel VOLUME CONTROL allows you to adjust the volume of the subwoofer relative to the rest of the system. Many listeners make the mistake of setting subwoofers too loud, which can cause excess bloat and loss of detail and musicality.
SW3P Connection Method #1 Connect the SA-3 from a receiver / preamplifier’s “Pre-Out”, “Line Out” or “Subwoofer Out,” with no high-pass filtering Use if: You wish to run your L & R speakers full-range You have a receiver with “Pre-Out” jacks but no “Main-In” jacks You have a receiver with “Subwoofer Out” jacks only You are using the subwoofer as the low frequency effects channel - sub out This method of connection allows your main speakers to receive the full-range audio signal (no high-pass filtering), and
SW3P Connection Method #2 Connect the SA-3 between a receiver’s “Pre-Out” and “Main-In”, with high-pass filter loop Use if: You wish to send your L & R speakers a high-pass filtered signal You have a receiver with “Pre-Out” and “Main-In” jacks You have a separate preamplifier and main amplifier 4) Connect the SA-3 SUBWOOFER OUTPUT to the SW3S input terminals with speaker cable.
Fine Tuning the Subwoofer The frequency chart below lists some terms commonly used to describe different bands of the frequency spectrum. The key to good subwoofer / speaker integration is repeated listening, followed by small re-adjustments of the subwoofer controls. The most important bass tuning functions you will control are the LOW-PASS FILTER, followed by the VOLUME CONTROL settings and then PHASE SELECTOR.
The SA-3 and Biamplification All NHT tower loudspeakers are designed with dual sets of binding posts to allow for biamplification. Biamplification is the use of two separate amplifiers, one to power the low frequency (subwoofer) drivers and one to power the upper frequency (midrange / tweeter) drivers. The advantages of biamplification include reduced distortion, increased dynamic range and power output.
Biamplification Method #1 (Most recommended) Line level connection in series, utilizing the SA-3’s high-pass filter. Use if: You have a receiver with “Pre-Out” and “Main-In” jacks You have a separate preamplifier and main amplifier This connection method routes the full-range line-level signal from the preamplifier through the SA-3, which passes on a high-pass filtered signal to the main amplifier and powers the subwoofer sections of the speakers directly with a low-pass filtered signal.
Biamplification Method #2 Line level connection in parallel, no high-pass filtering,with main amplifier and SA-3 connected from preamplifier Use if: You have a receiver with “Pre-Out” jacks but no “Main-In” jacks You have a separate preamplifier and main amplifier This connection method results in sending a full-range line-level signal to both the main amplifier and the SA-3. If you have a separate preamplifier that features two sets of line outputs, each set is connected to one amplifier.
Operation The SA-3 was designed to handle a wide range of listening levels, but every component has limits. It is important to use common sense and listen for signs of possible distress from the subwoofer. Noticeable distortion or harsh breakup is an indication that either the SA-3 or the subwoofer is running beyond its capacity, and the volume should be decreased. If you feel heat emanating from the front of the woofer, reduce the level immediately.
Glossary of Terms A c t i v e : Uses electrical power. A m p l i f i e r : An electronic device that increases the current of a signal, providing power to the loudspeakers (i.e. power amplifier, integrated amplifier, receiver). Bass: The range of audio frequencies below 160Hz, characterized by low pitch. Crossover: An electronic circuit that divides an audio signal into different frequency ranges. Distortion: Any deviation from the original signal, caused by any type of equipment.
Warranty (Valid Only in the U.S.A.
