User manual JBL SDEC 2500

[. . . ] DIGITAL ACOUSTIC CALIBRATION SYSTEM (DACS) INSTALLER'S MANUAL Table of Contents T ABLE O F FIG URES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 S E C T IIO N 1 -- IIIN T R O D U C T IIIO N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 SHIPPING TO THE NEXT DEALER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Th e k e y p r e m i s e o f r o o m e q u a l i z a t i o n a t l o w f r e q u e n c i e s i s t h a t t h e e q u a l i z a t i o n wi l l b e u s e d o n l y t o c o r r e c t r e s p o n s e e r r o r s c a u s e d b y r o o m r e s o n a n c e s . I t i s n o t u s e d t o c o r r e c t n a r r o w, d e e p , d i p s o r p e a k s c a u s e d b y d e s t r u c t i ve a c o u s t i c a l i n t e r f e r e n c e . A m e a s u r e m e n t m a d e a t a s i n g l e p o i n t c a n n o t d i s c r i m i n a t e b e t we e n r o o m m o d e r e s o n a n c e s a n d d e s t r u c t i v e i n t e r f e r e n c e . Th e o n l y e f f e c t i v e m e t h o d o f s e p a r a t i n g room resonances from interference is to sample the acoustic energy at several points in the room. ABOUT DATA ACQUISITION D A C S 4 e m p l o ys f i ve m i c r o p h o n e s , d i s t r i b u t e d t h r o u g h o u t t h e l i s t e n i n g a r e a . W h e n t h e d a t a a c q u i r e d f r o m t h e s e m i c r o p h o n e s i s s p a t i a l l y a v e r a g e d , t h e r e s u l t a n t c u r v e h a s e f f e c t i ve l y " a ve r a g e d o u t " m o s t o f t h e d e s t r u c t i v e i n t e r f e r e n c e c o m p o n e n t s wh i l e r e p o r t i n g r o o m m o d e s . Th i s i s b e c a u s e d e s t r u c t i ve i n t e r f e r e n c e p h e n o m e n a o c c u p y v e r y s m a l l s p a c e s wi t h i n t h e r o o m . Th e r e f o r e , i t ' s e f f e c t wi l l o n l y b e s e e n b y a s i n g l e m i c r o p h o n e . L o w f r e q u e n c y r e s o n a n c e s a r e q u i t e l a r g e a n d t h e i r e f f e c t wi l l b e wi l l b e r e a l i z e d b y s e v e r a l m i c r o p h o n e s . Figure 12: Sp at ially av erag ed syst em response. 3 ABOUT DATA PROCESSING Th e Mi c r o p h o n e Mu l t i p l e xe r ( S MM- 5 ) s c a n s t h e m i c r o p h o n e s s e q u e n t i a l l y a n d f o r wa r d s t h e d a t a t o t h e E xt e r n a l V e c t o r P r o c e s s o r ( E V P - 1 ) . Th e d a t a f r o m t h e m i c r o p h o n e s i s s p a t i a l l y a ve r a g e d i n t o a s i n g l e b l o c k o f d a t a . Th i s i n f o r m a t i o n i s d i s p l a y e d o n t h e c o m p u t e r s c r e e n . SDEC PROGRAMMING W hen you initialize DACS4, you are asked to input information about the Synthesis model being calibrated. W ith this information, DACS4 loads configuration information into the SDEC specifically for this installation and the speakers used. Concurrently, appropriate target c u r ve s a r e l o a d e d i n t o m e m o r y . About Target Curves By surveying many listening rooms over the years and applying proven engineering t e c h n i q u e s , J B L E n g i n e e r s h a ve e s t a b l i s h e d a f r e q u e n c y r e s p o n s e c h a r a c t e r i s t i c t h a t d e l i v e r s t h e m o s t c o n s i s t e n t l y s a t i s f a c t o r y r e s u l t s f o r a s y s t e m o f t h i s t y p e . Th i s " t a r g e t " c u r v e i s slightly different for each Synthesis model. F igure 13: T ypical t arget curv e Th e S yn t h e s i s t a r g e t c u r v e s r e p r e s e n t a t r e n d o f wh a t s h o u l d b e e xp e c t e d , n o t a s p e c i f i c s h a p e t h a t m u s t b e a c h i e v e d f o r g o o d s o u n d . Th e y a r e h e l p f u l i n t h e s e t t i n g o f o v e r a l l l e v e l s , a n d a r e u s e f u l f o r s ys t e m d i a g n o s t i c s . 3 CONNECTING DACS4 TO THE SYSTEM Th e s e i n s t r u c t i o n s a s s u m e t h a t t h e i n s t a l l a t i o n u s e s s t a n d a r d S y n t h e s i s c o m p o n e n t s i n a s t a n d a r d f i v e c h a n n e l + s u b wo o f e r c o n f i g u r a t i o n . I f t h i s i s n o t s o , p l e a s e r e f e r t o a l t e r n a t e configuration documentation or call your JBL Synthesis representative for specific instructions. Th e D A C S 4 s y s t e m a n d a l l S y n t h e s i s C o m p o n e n t s m u s t b e O F F wh e n m a k i n g t h e s e c o n n e c t i o n s . D o n o t a t t e m p t c o n n e c t i o n s wh i l e a n y t h i n g i s o n . U s e t h i s g u i d e d u r i n g h o o k u p o f t h e D A C S 4 h a r d wa r e . Figure 14: DACS4 hookup diagram 3 BEST LOCATION FOR THE DACS ANALYZER S ys t e m c a l i b r a t i o n m a y t a k e t wo t o t h r e e h o u r s , t h e r e f o r e , y o u s h o u l d g i v e t h e l o c a t i o n o f t h e t e s t e q u i p m e n t s o m e t h o u g h t . W h e n e v e r p o s s i b l e , s e t - u p D A C S 4 i n a l o c a t i o n wi t h c o m f o r t a b l e a c c e s s t o t h e c o m p u t e r . O p e r a t i n g f r o m wi t h i n t h e r o o m t o b e c a l i b r a t e d i s h i g h l y recommended though not absolutely necessary. Directly in front of any speaker In a high traffic lane A n y l o c a t i o n wh i c h p r e v e n t s y o u f r o m s e e i n g t h e S u r r o u n d P r o c e s s o r ' s f r o n t p a n e l d i s p l a y A n y l o c a t i o n wh i c h i n t e r f e r e s wi t h I R r e m o t e c o n t r o l o p e r a t i o n I n t h e m a i n s e a t i n g a r e a ( t h i s i s wh e r e t h e m i c r o p h o n e s wi l l b e ) On the floor W h a t e v e r l o c a t i o n yo u c h o o s e , u s e r e a s o n a b l e c a u t i o n wh e n r o u t i n g i n t e r c o n n e c t c a b l e s a r o u n d t h e r o o m . F o r e xa m p l e , c a b l e s c r o s s i n g t r a f f i c l a n e s s h o u l d b e t a p e d d o wn t o d i m i n i s h t h e t r i p p i n g h a z a r d l o o s e wi r e s r e p r e s e n t . Power Connections U s i n g t h e s a m e A C o u t l e t f o r a l l d e v i c e s wi l l m i n i m i z e g r o u n d c i r c u i t c u r r e n t , wh i c h manifests itself as audible hum in the speakers and/or popping noises during data t r a n s m i s s i o n f r o m t h e E V P - 1 t o t h e S D E C . I f yo u m u s t c o n n e c t t h e D A C S 4 h a r d wa r e t o m o r e t h a n o n e A C c i r c u i t , t h e p o t e n t i a l f o r h u m i s greatly increased. Powering-Up The DACS System A f t e r yo u h a ve c o m p l e t e d a l l c o n n e c t i o n s , y o u a r e r e a d y t o p o we r u p S y n t h e s i s a n d D A C S 4 . [. . . ] W h e n t r a n s m i s s i o n t o t h e S D E C i s c o m p l e t e a n d t h e s e t t i n g s h a v e b e e n b u r n e d i n t o m e m o r y , a " D O N E " d i a l o g b o x wi l l p o p - u p . R e m o ve t h e L o a d e r U t i l i t y D i s k f r o m D r i v e A : a n d r e t u r n i t t o s t o r a g e . Tu r n t h e S D E C o f f a n d r e m o v e t h e D B 9 c o m m u n i c a t i o n c a b l e . Th e n e w S D E C i s ready for installation. 3 SECTION 6 - DACS2 HOOKUP REFERENCE REFERENCE W h e n c a l i b r a t i n g a S y n t h e s i s s y s t e m wi t h a n S P P a n a l o g e q u a l i z e r , u s e t h e f o l l o wi n g g r a p h i c as a guide to connecting the DACS system to Synthesis Figure 45: DACS2 on screen w iring diag ram 3 AN A L O G E Q / C R O S S O V E R S Y S T E M S SYNTHESIS ONE FACTORY EQ SETTINGS Figure 46: Synthesis One fact ory EQ settings 3 SYNTHESIS ONE CROSSOVER FACTORY SETTINGS Cinema Mode INPUT LEVEL: 0dB (center detent) H I G H O U TP U T L E V E L : + 5 . [. . . ]