User manual B&K AVR505 2

[. . . ] B & K Components, Ltd. AVR505 SERIES 2 AVR507 SERIES 2 User Manual Five or Seven Channel Surround A/V Processor Receiver 13791 1104 ii ACCESSORIES AND LIMITED WARRANTY USER MANUAL - AVR505 Series2, AVR507 Series2 © 2004 B & K Components Ltd. The information in this manual is copyright protected. No part of this manual may be copied or reproduced in any form without prior written consent from B & K Components, Ltd. SHALL NOT BE LIABLE FOR OPERATIONAL, TECHNICAL OR EDITORIAL ERRORS/OMISSIONS MADE IN THIS MANUAL. [. . . ] Continued on next page. . . 28 MENU SYSTEM SETUP The situation is different for large low-frequency peaks. These peaks are what tend to shake the knick-knacks off the shelves and result in an overall tubby sound to the bass. Fortunately, this CAN be remedied electronically. . . and without drastically altering the characteristic sound of your speakers. Typically a room will have 3 large peaks due to the distance between the front/back walls, left/right walls, and the floor/ceiling. B & K provides 3 notch filters to address each of these peaks. A test tone generator is provided to assist in the process of identifying the resonant peaks. The test tone generator will generate an adjustable frequency tone between 20-300Hz. The test tone generator can generate the test tone at -42dB, -36dB and -30dB. The -30dB setting matches the levels you set up in the speaker level menu assuming 75dB spkeaker calibration. Two lower level settings are provided if you wish to perform these tests at lower volumes. Initially, all filters are set to 0dB from the factory. Turn on the test tone generator at -30dB. Sweep the frequency range to locate the 3 highest peaks. Using an SPL meter, note the frequency and the level of these peaks. Also note the frequencies above and below the peak where the level is 3dB less than the peak. Adjust notch 1 frequency to the frequency of the first peak. Adjust the notch level to the difference between the peak level and the 75dB reference Room Response Example level. Adjust the notch width to the setting nearest those where the peak or peaks is 3dB lower. This Room Response Example illustrates the frequency spectrum and how notch filters and shelf equalization can be effective. Note the "problem" spikes in the room response curve in the diagram at right. By applying the notch filters and the shelving equalization, a flatter room response can be obtained. Once the notch filters are adjusted, they are applied to all inputs in all music modes. [. . . ] Poor ground connection in the interconnect cables. Batteries dead, missing, installed wrong. Speaker channels may not be turned on. POSSIBLE SOLUTION 1. Check AC line fuse, replace line fuse with . 12A 250V Slow Blow fuse. [. . . ]