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SA-2
Subwoofer Amplifier
OWNER’S MANUAL
Now Hear This
535 Getty Court
Benicia, CA 94510
800-NHT-9993
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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.
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Table of Contents I.Specifications 2 Placement 2 Front and Back Panel Diagrams 3 General Connections 4 Low-Pass Filter 4 High-Pass Filter 4 Subwoofer Phase 4 Subwoofer Volume Control 5 II. The SA-2 and SW2Si: The SW2Pi Powered Subwoofer System Connection Methods 5 Fine Tuning the Subwoofer 10 III. Multiple Subwoofer Configurations: Using two SW2Si subwoofers 11 Connection Method 11 IV. The SA-2 and Biamplification 11 Connection Methods 12 Recommended Biamplification Settings 15 Bass Tuning Metho
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SA-2 Amplifier Specifications · System Type: Monaural Class G subwoofer amplifier · Power Output: 120 watts RMS into 8 ohms, 165 watts into 4 ohms · Frequency Response: 25Hz - 150Hz +/-3dB · Distortion: Less than 0.03% at full power · Crossover: Low-pass continuously variable between 35-150Hz, 18dB/octave Selectable high-pass at 50, 75, and 110Hz, 12dB/octave (line-level) Fixed high-pass at 100Hz (8 ohms), 6dB/octave (high-level) · Input Connectors: Gold plated RCA jacks for line level input Gol
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Front and Back Panel Diagram (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 Level Output Barrier Strips - Speaker level connection to satellite speakers (F) High Level Input Barrier Strips - Speaker level connection from amplifi
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General Connections Caution: Prior to connecting the SA-2 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-2 to AC power until all connections have been made. The SA-2 subwoofer amplifier is designed for use with passive subwoofers only. As it is not a full-range amplifier, it will not function satisfactorily if used to power ful
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tings 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-2’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. A properly cal- ibrated subwoofe
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SW2Pi Connection Method #1 Connect the SA-2 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 This method of connection allows your main speakers to receive the full-range audio signal (no high-pass filtering), and the subwoofer to be utilized for low bass extension only. 1) Your
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SW2Pi Connection Method #2 Connect the SA-2 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 This method allows your main speakers to receive a high-pass filtered signal (not full range), and the subwoofer to be utilized for low- to mid-bass reproduction. The full-range line-level signal coming
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SW2Pi Connection Method #3 Connect the SA-2 at speaker level from the receiver’s speaker outputs, with fixed high-pass filter Use if: You wish to send your L & R speakers a high-pass filtered signal Your receiver has no “Pre-Out”, “Line Out” or “Subwoofer Out” jacks This method of connection is recommended if you have a receiver with no line level preamplifier output of any sort and you want your L & R speakers to receive a high-pass filtered signal. The SA-2 may be connected to the system at s
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SW2Pi Connection Method #4 Connect the SA-2 at speaker level from the receiver’s speaker outputs, with no high-pass filter Use if: You wish to send your L & R speakers a full range signal Your receiver has no “Pre-Out”, “Line Out” or “Subwoofer Out” jacks Your receiver has two sets of speaker output terminals: “Speaker A” and “Speaker B” This method of connection is recommended when you have a receiver with no line level preamplifier output of any sort and you want to run your speakers full rang
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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. Frequency Chart Low Bass Mid Bass Upper Bass Lower Mid Mid Upp
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Multiple Subwoofer Configurations: Using two SW2Si subwoofers While the addition of a powered subwoofer system results in significant improvements to an audio or home theater system, there are some potential drawbacks to the use of a single subwoofer in certain rooms. A single subwoofer tends to excite the resonant frequen- cies of a room, inevitably causing peaks and dips in the room response within a certain range of low frequencies. To help counteract some inherent low frequency colorations
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Biamplification Method #1 (Most recommended) Line level connection in series, utilizing the SA-2’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-2, 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. Do not
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Biamplification Method #2 Line level connection in parallel, no high-pass filtering,with main amplifier and SA-2 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-2. If you have a separate preamplifier that features two sets of line outputs, each set is connected to one amplifier. If
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Biamplification Method #3 Speaker-level connection in parallel, no high-pass filtering, with SA-2 connected from the main amplifier’s speaker output Use if: You have a receiver with no “Pre-Out” jacks You do not have a separate preamplifier and main amplifier This connection method may be employed if your receiver has no line-level preamplifier output. The speakers and the SA-2 are con- nected in parallel off the receiver’s speaker output terminals. If your receiver has two sets of speaker ou
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Recommended biamplification settings: 1) SUBWOOFER PHASE: 0°. If the main amplifier inverts phase, use 180°. If you are unsure about this, select the setting that results in higher bass output with the volume control unchanged. 2) SUBWOOFER VOLUME: Adjust for accuracy, listening for seamless blending between upper and lower frequency ranges. When changing electronics, it may become necessary to re-adjust the SA-2’s volume level, since the correct volume setting depends on the sensitivity of
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Troubleshooting If the amplifier fails to operate when the Power Switch is turned on, check the power cord and all the input and output connections thoroughly. If the front panel status LED is red, the unit is in “protect” mode. This could be caused by incorrect wiring, short circuits, or excessive volume. Turn off the Power Switch on the front panel for two or more seconds to reset. Double check all speaker cables to be sure that no small strands are extruding. If the front panel LED indic
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Warranty (Valid Only in the U.S.A.) Warranty Period: For the period of 5 years for parts and 5 years for labor for loudspeaker products and 1 year for parts and 1 year for labor for electronic components from date of original purchase (the warranty period) from an authorized NHT dealer, NHT warrants that if our product fails to function prop- erly under normal use due to a manufacturing defect when installed and operated according to the owner’s manual instructions enclosed with the unit, it wi
