Takid455
01-05-2012, 11:17 AM
Issue: Sub is very low regarding sound with amp on full and head unit(HU) indicated to sub ON and max level.
Test performed:
Car A
HU, Amp & speakers installed
fronts & rears work well, sub is practically not working. Improved when amp is on 4ch, but it is a 5/6 ch system
Switched RCA cables around to test is one may be bad. no difference
RCA cables all have 0.4-0.5 ohms. used a jumper lead to test both ends at once since they were installed in car thus the added connect could have increased resistance, but it is very low as tested.
Hooked amp hook up/ signal wire the goes from HU to amp directly to 12v bat to amp. No difference.
HU appears to be functioning as is should otherwise which tells me the HU wiring is good or adequate at the moment.
Hooked up a ground from HU case to body. No difference.
Connections are all secure
Car B
F,R & sub w. amp installed & working properly
Installed RCA cables from Car B into amp/ sub combo & battery of Car A. In essence, Car B has a stand alone sub system & F&R system w/ common HU. All works fine. Tells me Amp, Sub and wires from bat to amp and wires amp to sub and battery in Car A are good.
Next step is to find another JVC HU (use same rear plug) and test for bad HU.
System components
Speakers: All CDT
Amp: JL 900/5
HU: JVC KD-R820BT
Any Thoughts or suggestions??
Test performed:
Car A
HU, Amp & speakers installed
fronts & rears work well, sub is practically not working. Improved when amp is on 4ch, but it is a 5/6 ch system
Switched RCA cables around to test is one may be bad. no difference
RCA cables all have 0.4-0.5 ohms. used a jumper lead to test both ends at once since they were installed in car thus the added connect could have increased resistance, but it is very low as tested.
Hooked amp hook up/ signal wire the goes from HU to amp directly to 12v bat to amp. No difference.
HU appears to be functioning as is should otherwise which tells me the HU wiring is good or adequate at the moment.
Hooked up a ground from HU case to body. No difference.
Connections are all secure
Car B
F,R & sub w. amp installed & working properly
Installed RCA cables from Car B into amp/ sub combo & battery of Car A. In essence, Car B has a stand alone sub system & F&R system w/ common HU. All works fine. Tells me Amp, Sub and wires from bat to amp and wires amp to sub and battery in Car A are good.
Next step is to find another JVC HU (use same rear plug) and test for bad HU.
System components
Speakers: All CDT
Amp: JL 900/5
HU: JVC KD-R820BT
Any Thoughts or suggestions??