8 | JL Audio - 300/4v3 Owner ’ s Manual
9
Bridged
Left Right
+12VDC Ground Remote Front F ilter Controls Front Input Section Front Speaker Outputs
Bridged
Left Right
Rear Speaker Outputs
Left Ch. Right Ch. Filter Fr eq. (Hz)
Filter Slope
Freq. Range
Input Voltage Input Sens. Input Mode
12dB
|
24dB
Filter Mode
Off
|
LP
|
HP
x1
|
x10 Low
|
High
Rear Input Section
Left Ch. Right Ch.
Input Voltage Input Sens.
Low
|
High 2ch
|
4ch
50
60
75
95
1 30
200
500
30 0 / 4v3
Four-Channel Full-Range Amplifier
Rear Filter Contr ols
Filter Fr eq. (Hz)
Filter Slope Freq. Range
12dB
|
24dB
Filter Mode
Off
|
LP
|
HP
x1
|
x10
50
60
75
95
1 30
200
500
IMPORT ANT
For opti mu m power output at a l l fou r cha n nel s,
con nec t t he sa me i mpe da nc e (b et ween 1. 5 - 4 Ω)
on a l l four ch a nne ls . On pa ges 16 and 17 are
cha r ts s how ing t he c onti nuous (R MS) power
output c apabi l it y of t he 30 0/4v3 i nto va riou s
combi nat ions of f ront a nd re ar i mpe da nc es
( opti mu m output is s hown i n bo ld t y pe). Pleas e
refer to t he se ch a rt s so you k now w hat to ex pe ct
in te rm s of power output .
IMPORT ANT
If you con ne ct a lo ad h ig her t ha n 4 Ω nomi na l
per c ha nne l in s tere o mode (or 8Ω i n brid ged
mode), power w il l d rop by h a lf w it h eve r y
doubl in g of imp ed anc e ab ove 4Ω st ereo / 8 Ω
mono. If you c onne c t a load lower t ha n 1. 5Ω
nomi na l p er ch an nel i n ste reo mo de (or 3Ω in
brid ged mo de , the a mpl i f ier prote ct ion
ci rcu it r y ac ti vate s a “sa fe” mod e wh ich re duce s
ampl i f ier power to prot ec t t he ci rcu it r y f rom
fa i lure (the yel low “L ow Ω” L E D li ght s to
ind ic ate t hat t h is ha s happ ened). S ee pa ge 10
for de ta i l s.
IMPORT ANT
Spe a ker lo ads b elow 1. 5Ω nom in a l per c ha nn el
in s tere o or 3Ω nomi na l i n br idge d mode a re
not rec omme nded a nd m ay cau se t he a mpli f ier
output to d i stor t ex ce ssi vely.
BRIDGING C ONSIDER A TIONS
Bri dg i ng is t h e prac t ice of c ombi ni ng t h e
out put of t wo a mpli f ie r cha n nel s to d ri ve a si ng le
load . W hen br id ged , ea ch ch a nne l produc es
sig na l s of equ a l ma g nit ud e, but opp osit e pola r it y.
Th e combi ned out put of t he t wo c ha n nel s
prov ide s t w ice t he out put volt a ge ava i la ble f rom a
si ng le cha n nel . T he 30 0/4v3 has b een d esi g ned for
brid g i ng of its c ha n nel pa i rs w it hout t he nee d for
input i nver sion ad aptor s.
Bridged
Left Right
+12VDC Ground Remote Front F ilter Controls Front Input Section
Front Speaker Outputs
Bridged
Left Right
Rear Speaker Outputs
Left Ch. Right Ch. Filter Fr eq. (Hz)
Filter Slope
Freq. Range
Input Voltage Input Sens. Input Mode
12dB
|
24dB
Filter Mode
Off
|
LP
|
HP
x1
|
x10 Low
|
High
Rear Input Section
Left Ch. Right Ch.
Input Voltage Input Sens.
Low
|
High 2ch
|
4ch
50
60
75
95
1 30
200
500
30 0 / 4v3
Four-Channel Full-Range Amplifier
Rear Filter Contr ols
Filter Fr eq. (Hz)
Filter Slope Freq. Range
12dB
|
24dB
Filter Mode
Off
|
LP
|
HP
x1
|
x10
50
60
75
95
1 30
200
500
T o bri dge a pair of channels, use the “L ef t + ”
a nd “R i g ht – ” sp ea k er c onne c tors on ly ( t h e “Lef t
–” and “ R ig ht +” rema i n u nuse d). The n con nec t
a mono sig na l t o bot h le f t a nd ri g ht RCA input s
for t hat ch a nne l pa i r. Thi s requ i re s an RC A
“Y - Adap tor” like the JLA udio ECS mod el
X D-C LR A ICY - 1F2M ( sold sepa rately) .
W hen br idge d, e ac h cha n nel p ai r w i l l
del iver o pt imu m power i nto a 3 -8 Ω load .
Op erat i ng br id ged ch a nne l pa i rs i nto a load
lower t ha n 3Ω i s not rec omm ended .
Be cau se a br id ged pa i r of ch a nne ls re qui re s
t hat b ot h cha n nel s rec eive i nput , you nee d to
con nec t bot h lef t a nd r ig ht RCA i nputs t o t he
brid ged c ha n nel pa i r’s inputs . C onne ct ion of
on ly one RCA i nput w i l l resu l t in re duce d power
out put, i nc rea se d di stor tion a nd c a n c aus e t he
a mpli f ie r to over heat . Do not do t h i s! In st ead , u se
a “Y -Adaptor ” to s plit t he mono s ig na l i nto b ot h
lef t a nd r ig ht RCA i nputs .
2) “ Fi lter S lope ” C ontr ol: T h is sw itc h
a l lows you to s ele ct f rom t wo f i lter
slop es for t hat c ha n nel s ec t ion.
“ 12d B ” : C onf ig u res t he f i lte r to at te nuate
f reque ncie s ab ove or below t he s ele ct ed
f i lter f re quenc y at a r ate of 12 d B pe r oc tave
(But ter wor t h a li gn ment).
“ 24dB ” : C onf ig u res t he f i lte r to at te nuate
f reque ncie s ab ove or below t he s ele ct ed
f i lter f re quenc y at a r ate of 2 4 d B per o ct ave
( Linkwi tz- Riley alignm en t ) .
Dep end i ng on t he spe a ke r sy st em a nd t he
veh icle , di f fer ent f i lter s lope s may be re qu ire d
to produc e a smo ot h t ra ns iti on bet we en t he
sou nd of d i f ferent sp ea k ers i n t he s ys tem.
Ex p er im ent to f i nd t he slop e wh ich b es t matc hes
t he acou st ic re qu ir ement s of t he sy ste m. T he
sha r p er “2 4dB ” set t i ng w i l l do a be t ter j ob of
prote ct i ng sm a l l spe a ke rs w it h l i mit ed power
ha nd l in g. T he s ha l lower “12 d B ” o ct ave s et t i ng
a l lows for g rea ter ene rg y over lap w it h t he re st of
t he sp ea ke r sy ste m. I n some c a se s, t h is re su lt s
in b et te r overa l l resp ons e a nd sou nd qu a l it y .
3) “ Freq. R an ge ” C ont rol: W hen t h row n to
t he r ig ht, t h is s w itch mu lt ipl ie s t he cut of f
freq uen c y se lect ed b y the ro ta ry “Filte r Freq .
( H z)” cont rol by a fac tor of 10. In t he “x1”
pos iti on, t he ra n ge of t he rot a r y cont rol i s
50 - 50 0 H z (as ma rke d). In t he “x10 ”
pos iti on, t he ra n ge of t he rot a r y cont rol i s
50 0 H z - 5 k Hz (50 0 0 H z ).
4) “ Fi lter Fre q. ( Hz) ” The f il ter f re quenc y
ma rk i ngs s ur rou nd i ng t h is rot a r y cont rol
a re for referenc e pu r pos es a nd a re gen era l l y
acc u rat e to w it h in 1/3 oc t ave or be t ter. If you
wou ld li k e to se lec t t he f i lt er cut of f f reque nc y
w it h a hi g her leve l of prec ision , con su lt t he
charts in A ppen dix D ( pag e 1 8 ) of this manual.
SPEAKER OUTPUTS
Even t hou gh you may h ave i ns ta l le d zi l l ions of
a mps i n your d ay, pleas e ta k e t he t ime t o rea d t hi s
se ct ion! The 30 0/4v3 is not a t y pic a l a mpl i f ier a nd
ca re mu st be t a ke n to ba l a nce t he f ront a nd re ar
cha n nel s pe a ker i mpe da nc es for op ti mu m out put
f rom a l l fou r cha n nel s.
Th e 30 0/4v3 employs J LAud io’ s exc lusive
Reg u l ated , I ntel l igent Power Supply (R . I. P . S .)
des ig n. T h is s ophi st ic ate d power suppl y a l lows
t he a mpli f i er to produ ce it s opt i mum p ower ( 3 0 0
wat t s ) over a w ide r a nge of sp ea k er i mped a nc es .
Unl i ke conve ntion a l a mpli f i ers t ha t requ i re a
spe ci f ic i mpe d an ce to pro duce opt i mu m power,
t he R .I .P . S.-e qu ippe d 30 0/4v3 give s you t he
f ree dom to us e a va r ie t y of spe a ke r con f ig u rat ion s
t hat ac hi eve f i na l imp ed a nce s be t ween 1. 5 – 4
Oh ms nom i na l pe r cha n nel (wit hout s ac ri f ic i ng
power out put or sou nd qu a l it y).
Th e oper at ion of t he R .I .P . S. c i rcu it r y i s
ent ire ly automat ic a nd a djus ts it se lf e ver y t i me
t he a mpli f i er is t u rn ed on ac cord i ng to t he
lowest i mp ed a nce pre sent at eit her f ront or rea r
cha n nel s. T here a re no u s er cont rol s to con f ig u re .
Th e sy ste m oper ate s t hrou g h t h ree st a ges of
imp ed a nce opt im i z at ion, cho osi ng t he st a ge
most a ppropr iate to t he ac tu a l i mpe da nc e of t he
spe a ke rs con nec t ed to it .
Be cau se t he 30 0/4v3 ut i li z es a si ng le power
supply, it wi l l s et it sel f up ba s ed on t he lowe st
imp ed a nce pre se nt at eit her t he f ront or re ar
a mpli f ie r cha n nel s. For e xa mple , i f you con nec t
a 2 oh m load to e ac h fr ont cha n nel a nd a 4 oh m
load t o eac h rea r ch a nne l, t he a mpl i f ier w i l l adju st
its el f to de li ver 75 wat t s x 2 to t he f ront 2 oh m
load s , but w i l l onl y del iver h a l f its opt i mu m power
( 37 . 5 wa tt s x 2) to th e rea r 4 oh m loa ds . If you
con nec t a 4 oh m loa d to a l l fou r cha n nel s or a 2
oh m load to a l l four c ha n nels , t he a mpl i f ier w i l l
del iver 75 w at ts x 4 . Se e, we t old you t h is a mp
wa s d if fe rent... R ead on , t here i s more i mpor t a nt
in for mat ion to fol low.