User manual BOSTON ACOUSTICS GT50

[. . . ] The range of operation is 0. 7­1. 2. dB Q +1. 6dB 0dB -3dB . 707 . 95 1. 2 t (tuned crossover frequency) 7 6 8 2 6 REAR RCA Inputs RCA cables marked "REAR" from head unit or other line level device should be connected here. Use both inputs (L & R) for stereo. 7 REAR Input Switch In the left (STEREO L-R) position, the L & R inputs go to the REAR L & R channels of the amplifier. In the right (FRONT L-R) position, the inputs are derived from the FRONT channels and sent to the REAR L & R channels of the amplifier. STEREO REAR INPUT FRON T 8 SUBWOOFER RCA Inputs RCA cables marked "subwoofer" from head unit or other line level device should be connected here. Use both inputs (L & R) for dual subwoofer output from head unit. [. . . ] Wire runs should be kept to the minimum practical length. 10 Installation--Fuses and Wiring (cont. ) Power/B+ and Power/GND Connection Strip approximately 5/8" (16mm) of insulation. When using two (2) subwoofers, each subwoofer should be a minimum 4-ohm [or higher] impedance, (see System B, page 17). Subwoofer impedance must not fall below 2 ohms when in MONO mode. SU B WO O FER O U TPU T Setup Tuning--Full-Range Speakers 1) Music The material chosen for head unit/amplifier system setup must be both clear in recording quality and dynamic in amplitude. Many audiophile "test" discs have musical tracks with both of these characteristics and should be used. 2) FRONT, REAR, and SUBWOOFER Sensitivity Controls Turn controls all the way counterclockwise (minimum position). In this position, the amplifier will be less sensitive to the input signal from the head unit. 3) FRONT, REAR, and SUBWOOFER Crossover Controls Crossovers should be turned off during this phase of set-up. Move the HIGHPASS and FILTER switches to the "OFF" position--with these settings, full-range signal is sent to the FRONT & REAR speaker outputs. OFF OFF HIGHPASS ON ON L OW PA SS O F F 12d B 24d B SU B WO OF ER L EVEL 350 200 Hz 350 200 Hz 20 50 FRONT and REAR crossover controls 12 SUBWOOFER crossover control Setup Tuning--Full-Range Speakers (cont. ) 4) Head Unit The head unit should have all controls such as bass, treble, balance, and fader set to the flat or centered position. The volume control should be at the minimum setting. If the head unit has any equalization or bass management features such as boost, they should be defeated at this time. Turn head unit on and verify that the GREEN status LED is lit on the amplifier. 5) Volume With the chosen musical track playing, turn the head unit volume control up until the maximum level of undistorted signal is heard from the speakers. (For most head units, this will be near the end of the volume control range. ) WARNING!A distorted signal from the head unit sent to the amplifier can cause loudspeaker failure at higher listening levels! 6) FRONT and REAR Input Sensitivity Controls Slowly rotate control clockwise until maximum undistorted playing level is heard from the speakers. Listen closely for bottoming from the speakers. If detected, rotate FRONT Input Sensitivity counterclockwise until it is eliminated. 7) FRONT and REAR Crossover Controls To achieve higher undistorted playing levels from the front speakers, the FRONT crossover must be engaged. Rotate crossover control fully clockwise. The highpass crossover point is now set at 350Hz. Rotate FRONT "Q" Control fully counterclockwise. Move crossover switch to the right (ON) position. Slowly rotate FRONT input sensitivity control clockwise until maximum undistorted playing level is heard from the speakers. Listen closely for bottoming from the speakers. If detected, rotate FRONT input sensitivity control counterclockwise until it is eliminated. Slowly rotate FRONT highpass crossover control counterclockwise while listening for bottoming. You are lowering the crossover point, which means that more bass signal is being sent to the speakers. [. . . ] This warranty is void if the serial number has been removed or defaced. This warranty gives you specific legal rights, and you may also have other rights that vary from state to state. If Service Seems Necessary First, contact the dealer from whom you purchased the amplifier. If that is not possible, write to: Boston Acoustics, Inc. 300 Jubilee Drive Peabody, MA 01960 U. S. A. , or your authorized Boston Acoustics distributor We will promptly advise you of what action to take. [. . . ]