I have a sony explode 52 x 4 head unit. The head unit powers 4 @ 6-1/2 door type speakers . I have one pioneer 300 watt mosfet amp powering a kenwood 8" in a small box. Then I have a pioneer 250w mosfet amp power two 240 watt 6x9s.
Sound great for heavy metal. Everything is fine going the interstate or just driving a good speed. But if your just idling or driving slow and you crank up the sound it can't handle the bass. The whole system just cuts off and then repeatedly try to come back on. If I turn it down a little it comes on okay.
What's going on. I recently bought a new battery with a lot of cranking amps and the problem went away for a while, but now it has returned. Its kind of embarrassing. Can someone help. In laymens terms.
Replies (7)
ryan on 03/29/2004 23:33:00
Can you find out how many amps your altenator is and how much current your amp draws (and the total of the fuses up)?
JWCCSNM on 03/30/2004 00:06:53
well, I have a100amp fuse at the battery and 20 amp fuse at each amplifier and a 20 at the head unit. So that's 160 amps. Not sure about the altenator or the current draw of the amps . I will find out tomorrow. So basically what may be wrong is I need a new altenator or just a altenator that has a higher output.
swez on 03/30/2004 05:30:25
What size power feed wires are you using from the BAT to amps? Should be at least #8 for this pair of amps. Same with grounds. That 100A fuse at the battery... too high for the wires and system needs noted. Drop to a 50 amp fuse for this. Should be fine if you don't have any shorts in the main power feed.
Also, double check your grounding of the amps and HU. They need to be solid connections to a bare metal grounding point in floor pan. If you read this FAQ, it explains the basics.
http://www.clubknowledge.com/Car_Audio_FAQ/?t4
Also, if your HU is not grounded to floor pan, do so. Factory harness grounds are often inadequate for aftermarket HU's. While you're at it, check the gain settings on your amps. They should match the HU RCA voltage ouput levels. Older HU's have a 2.0 volt output while newer HU's can provide 4.0 volts. If your gains are much below 2.0 volts... this can cause the amps to pull too much power and shut down as well.
Swez
PS You might want to have your charging system checked to be sure you have adequate ALT output to feed you electricals. If the ALT is weak, (below rated charging current/voltage) need to look into that too.
Auto Zone will test your ALT/BAT performance for free, right in the parking lot or thier garage. At low RPMs, output is low. But once the engine gets past ~1500 RPM, you should be getting full charge of 13.5 volts+ and maybe 80 amperes of current. If not, your ALT may need replacement. If weak, remanufactured ALTs are much cheaper than new. If you can get a higher output version that drops right in... go for it.
uochronos on 03/30/2004 05:35:17
if the amps are each fused at 20 then you shouldnt be pulling more then 50-60amp from the amps and head unit even at high volume... being a truck i would assume this has at least a 90amp alternator. which at idle would only put out around 40-50amps so if your always playing your system real loud and you have the headlights and say ac or heat on then when your idling your battery eventualy gets depleted. getting a larger alternator should fix this problem say 120-160amps. i would personaly first take it in and get it tested at a battery shop they can tell you exactly how much its putting out and if it and your battrery are in working order.
JWCCSNM on 03/30/2004 08:09:26
Swez, I believe I have a 2 ga wire from the battery to a distribution block that has two step down outlets for 8 ga which is what is going to the amps. I also have 8 ga ground wires. As for the HU, it is not grounded to the floor pan. Its grounded to its own frame. A frame that I'm sure evenually makes its way to the floor or firewall.
I'll ground it straight to the floor to see if that helps. I'll also run to Autozone and have that altenator checked out. Thanx guys. I'll let you know how it goes.
JWCCSNM on 03/30/2004 13:46:17
Grounded the HU to the floor and the problem went away. Thanx.
swez on 03/30/2004 14:15:44
Ahhhh, a living, breathing creature that now understands the value of grounding the HU to body pan.
Well done!
Swez
PS You were getting a "psudo-ground" via the RCA's and antenna feed. This proved inadequate as most will. Never assume the mounting bracket or stock wires are a good ground. They do have ground potential, but not enough to feed your amps well with a full, clean signal path.
Sound great for heavy metal. Everything is fine going the interstate or just driving a good speed. But if your just idling or driving slow and you crank up the sound it can't handle the bass. The whole system just cuts off and then repeatedly try to come back on. If I turn it down a little it comes on okay.
What's going on. I recently bought a new battery with a lot of cranking amps and the problem went away for a while, but now it has returned. Its kind of embarrassing. Can someone help. In laymens terms.
Replies (7)
ryan on 03/29/2004 23:33:00
Can you find out how many amps your altenator is and how much current your amp draws (and the total of the fuses up)?
JWCCSNM on 03/30/2004 00:06:53
well, I have a100amp fuse at the battery and 20 amp fuse at each amplifier and a 20 at the head unit. So that's 160 amps. Not sure about the altenator or the current draw of the amps . I will find out tomorrow. So basically what may be wrong is I need a new altenator or just a altenator that has a higher output.
swez on 03/30/2004 05:30:25
What size power feed wires are you using from the BAT to amps? Should be at least #8 for this pair of amps. Same with grounds. That 100A fuse at the battery... too high for the wires and system needs noted. Drop to a 50 amp fuse for this. Should be fine if you don't have any shorts in the main power feed.
Also, double check your grounding of the amps and HU. They need to be solid connections to a bare metal grounding point in floor pan. If you read this FAQ, it explains the basics.
http://www.clubknowledge.com/Car_Audio_FAQ/?t4
Also, if your HU is not grounded to floor pan, do so. Factory harness grounds are often inadequate for aftermarket HU's. While you're at it, check the gain settings on your amps. They should match the HU RCA voltage ouput levels. Older HU's have a 2.0 volt output while newer HU's can provide 4.0 volts. If your gains are much below 2.0 volts... this can cause the amps to pull too much power and shut down as well.
Swez
PS You might want to have your charging system checked to be sure you have adequate ALT output to feed you electricals. If the ALT is weak, (below rated charging current/voltage) need to look into that too.
Auto Zone will test your ALT/BAT performance for free, right in the parking lot or thier garage. At low RPMs, output is low. But once the engine gets past ~1500 RPM, you should be getting full charge of 13.5 volts+ and maybe 80 amperes of current. If not, your ALT may need replacement. If weak, remanufactured ALTs are much cheaper than new. If you can get a higher output version that drops right in... go for it.
uochronos on 03/30/2004 05:35:17
if the amps are each fused at 20 then you shouldnt be pulling more then 50-60amp from the amps and head unit even at high volume... being a truck i would assume this has at least a 90amp alternator. which at idle would only put out around 40-50amps so if your always playing your system real loud and you have the headlights and say ac or heat on then when your idling your battery eventualy gets depleted. getting a larger alternator should fix this problem say 120-160amps. i would personaly first take it in and get it tested at a battery shop they can tell you exactly how much its putting out and if it and your battrery are in working order.
JWCCSNM on 03/30/2004 08:09:26
Swez, I believe I have a 2 ga wire from the battery to a distribution block that has two step down outlets for 8 ga which is what is going to the amps. I also have 8 ga ground wires. As for the HU, it is not grounded to the floor pan. Its grounded to its own frame. A frame that I'm sure evenually makes its way to the floor or firewall.
I'll ground it straight to the floor to see if that helps. I'll also run to Autozone and have that altenator checked out. Thanx guys. I'll let you know how it goes.
JWCCSNM on 03/30/2004 13:46:17
Grounded the HU to the floor and the problem went away. Thanx.
swez on 03/30/2004 14:15:44
Ahhhh, a living, breathing creature that now understands the value of grounding the HU to body pan.
Well done!
Swez
PS You were getting a "psudo-ground" via the RCA's and antenna feed. This proved inadequate as most will. Never assume the mounting bracket or stock wires are a good ground. They do have ground potential, but not enough to feed your amps well with a full, clean signal path.
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