[amit_mechengg]

gurus, i need a help. i have a JBL 75.4 amp and a gt5-12" sub along with JBL gto937 rear speakers. i have used a 8 core battery wire for the amp. also grounding is done with a 8 core wire.
i am facing a strange problem. i was testing my system with some heavy bass test tracks. i find that the head light dimms a bit and when the heavy note of bass is thrown out my alto jerks and i feel that it slows for a second or two and again regains its speed.
is the heavy bass altering either the sparkplug current or the ECU or the injectors or something related to electronics functioning of the car?

is this a common phenomenon? i am worried please help.

[abhibh]

Seems like alternator / battery issue but not sure.

[amit_mechengg]

Originally Posted by abhibh

Seems like alternator / battery issue but not sure.

battery is new. amaron. have u faced similar problem?

[iraghava]

Calling LBM, calling LBM! LBM ji please respond to cars jerking with heavy bass query!

[low_bass_makker]

Here I come..BOOM, BOOM,BOOM

Hmmm

I think your 8 core wire and its terminations might be the culprit

[amit_mechengg]

Originally Posted by low_bass_makker

Here I come..BOOM, BOOM,BOOM

Hmmm

I think your 8 core wire and its terminations might be the culprit

it has been connected from the battery directly to the amp via the fuse without any joints. there is no leakage and the wire is insulated with a tape where it connects to them amp.

[ramie2400]

Your amp is hungry for more power so when you put more volume it tries to pull more power from the battery resulting the lights getting dim.

You might have noticed it happenes only at night when you switch on the HL,it used to happen in my RnD Zen.

[redfire]

The amp is drawing too much power from your battery. The alternator may also suffer due to this. Try lowering the gain in amp and incresing the HU volume. Heard a mechanism of intsalling capacitors between battery power and amp, so that amp will get a constant good power. Search for it (google has many links) and try that. I am also planning this, though I have no issues with my amp + sub system.

[saintsinner]

Get a branded 8ga wire. maybe finolex.
heavy load on the battery might cause the car to act weird. my car's timing advancer went kaput due to low/high voltage which inturn blew the TPS. However i have a better TA and no problems.

Capacitors won't help you. your amp is on diet, the supply is strong enough but the connections are weak. so the chances are your cables are faulty. get scosche/monster cables. also, check if the ground connection is clean.

[vikram_d]

Me thinks it's an alternator problem or the headlight relays are not working. But headlight relays do not explain the sluggish response from the car.

Must be the alternator.

[panky12345]

step by step: upgrade the power & ground cables, BIG 3 and still if the problem persists (highly unlikely), please upgrade the battery.

[DerAlte]

The energy being pumped into the sub has to come from somewhere, right? In this case, it is the alternator. The more the current the amp circuit is drawing, the more mechanical load it is placing on the engine to cater to the electrical load.

The light Alto engine is unable to keep up (that's what you are sensing as 'slowing down'; happens also when the AC goes on). Also, since the electrical load is more than the alternator rating, the voltage regulator is unable to regulate the voltage - which you see as the 'headlight becoming dim'.

To get the same level of punch (your basic problem), you either need a more sensitive sub (one that produces louder sound with lesser electrical power), or change the alternator to a higher rating.

[amit_mechengg]

the light dimming is very less. its not that they go too much dim. but i was moving at very low rpm on 2nd gear while listening to heavy bass testers. i could feel that during the bass beat the car got sluggish and as soon as the beat goes my car moves as normal.
the power cable and ground cable are brand new and properly insulated. is it because of testing the heavy bass at loud volume?

[amit_mechengg]

Originally Posted by DerAlte

The energy being pumped into the sub has to come from somewhere, right? In this case, it is the alternator. The more the current the amp circuit is drawing, the more mechanical load it is placing on the engine to cater to the electrical load.

The light Alto engine is unable to keep up (that's what you are sensing as 'slowing down'; happens also when the AC goes on). Also, since the electrical load is more than the alternator rating, the voltage regulator is unable to regulate the voltage - which you see as the 'headlight becoming dim'.

To get the same level of punch (your basic problem), you either need a more sensitive sub (one that produces louder sound with lesser electrical power), or change the alternator to a higher rating.

that will be a costly affair . what if i reduce the gains on the amp and increase them on the HU ??

[DerAlte]

Originally Posted by amit_mechengg

...is it because of testing the heavy bass at loud volume?

Yes. The louder you play, more the electrical / mechanical demand.

Originally Posted by amit_mechengg

... what if i reduce the gains on the amp and increase them on the HU ??

The power requirement even in that case would be the same.