Why is my car still dropping RPM's when the bass hits?

[eric_marciniak]

So to start things off I have a 2008 Infiniti G35X with the stock head unit with an Alpine MRX-M100 mono amp hooked up using pre-amp the signal going to stock Bose amp, a Singer 200 amp alternator, AGM battery, DC Audio Level 2 wired at 2 ohms and 0 gauge Knukoncepts OFC power and ground.

I have been fighting RPM drop at idle when the bass hits even since I put the system in. I thought that going to 0 gauge along with the high output alternator would have solved the issue but it still the same as before.

I did the big 3 with 0 gauge as well and I have checked my ground for the amp and it's at 0.01 ohms of resistance and my voltage at is 14.1 the amp not under load and no lower than 13.04 at full blast.

I'm at a loss as to what to tackle next to fix this problem, is there anything else I can do to remedy this? I don't think I'm pushing enough watts for this to be a problem with the alt and wiring I have to back it up.

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[Popwarhomie 5,000+ posts]

The alternator is putting more load on the engine. Takes power to make power.

 

[Boomin_tahoe 5,000+ posts]

Who did the install?

 

[BCotrell]

So to start things off I have a 2008 Infiniti G35X with the stock head unit with an Alpine MRX-M100 mono amp hooked up using pre-amp the signal going to stock Bose amp, a Singer 200 amp alternator, AGM battery, DC Audio Level 2 wired at 2 ohms and 0 gauge Knukoncepts OFC power and ground.

I have been fighting RPM drop at idle when the bass hits even since I put the system in. I thought that going to 0 gauge along with the high output alternator would have solved the issue but it still the same as before.

I did the big 3 with 0 gauge as well and I have checked my ground for the amp and it's at 0.01 ohms of resistance and my voltage at is 14.1 the amp not under load and no lower than 13.04 at full blast.

I'm at a loss as to what to tackle next to fix this problem, is there anything else I can do to remedy this? I don't think I'm pushing enough watts for this to be a problem with the alt and wiring I have to back it up.

Does rpm drop matter?

 

[ThxOne Premium Member]

My 1995 Jeep Grand Cherokee was doing the same thing. I also did the big three (4). I was pushing two 12's on the same amp you mentioned at 2 ohms. At idle my engine RPM's would drop 200 RPM on long, low notes. I should also mention my voltage would drop down to between 9 and 11v. It was a ground issue at the battery (To the engine block and the chassis) once I made sure those were super tight... no more issues.

 

[Boomin_tahoe 5,000+ posts]

Alright so I would check connections and corrosion within the wiring.

 

[eric_marciniak]

Who did the install?

I put pretty much everything in myself except for the alternator that I had my mechanic buddy install. I made sure to run 0 gauge with a 200 amp fuse from the alternator + to the battery. I bought a hydraulic crimper and some nice thick lugs and made sure all of the wiring was done correctly.

Does rpm drop matter?

It might not but I'm not sure if it's too good for the car in the long run.

My 1995 Jeep Grand Cherokee was doing the same thing. I also did the big three (4). I was pushing two 12's on the same amp you mentioned at 2 ohms. At idle my engine RPM's would drop 200 RPM on long, low notes. I should also mention my voltage would drop down to between 9 and 11v. It was a ground issue at the battery (To the engine block and the chassis) once I made sure those were super tight... no more issues.

I'll double check everything.

Alright so I would check connections and corrosion within the wiring.

All of the wiring is pretty fresh and it's been having the issue since day 1.

 

[Boomin_tahoe 5,000+ posts]

This happened after you installed the audio?

 

[THATpurpleKUSH 5,000+ posts]

Alternators dont make full power until around 2k rpm- even high ouput alts. Turning the volume up at low rpm (idle) will put a heavy load on the electrical system and cause rpm and voltage drop.

 

[eric_marciniak]

This happened after you installed the audio?

Yup. On some really heavy bass songs it can start happening around around 60% volume while on most it will only happen at near full(a notch before distortion and clipping and not actually maxed out on the head unit).

Alternators dont make full power until around 2k rpm- even high ouput alts. Turning the volume up at low rpm (idle) will put a heavy load on the electrical system and cause rpm and voltage drop.

I've read that too but in my long email conversation with Michael Singer he said I would have no problem playing the system at full while the car was at idle with the 200 amp and that it was actually the best for low rpm output. He also could have just been trying to sell me an alternator haha.

I don't have any noticeable rmp drop while driving though which is good.

 

[ThxOne Premium Member]

Yup. On some really heavy bass songs it can start happening around around 60% volume while on most it will only happen at near full(a notch before distortion and clipping and not actually maxed out on the head unit).



I've read that too but in my long email conversation with Michael Singer he said I would have no problem playing the system at full while the car was at idle with the 200 amp and that it was actually the best for low rpm output. He also could have just been trying to sell me an alternator haha.

I don't have any noticeable rmp drop while driving though which is good.

An alternator is going to charge your batteries somewhat slowly. Up to 14.4v typically coming out of your alternator, that's all. The Alternator is not supplying the power to your amplifiers. Your amplifiers are getting their power from the battery. Which are typically 3 to 4 times the amp output of the alternator at near the same voltage. Buy a second AGM battery, put it in the back and wire it correctly... again, double check those grounds and you should be good. If that single AGM is 600cca and you add a second in parallel you should now have 1200cca to feed your amplifiers. You aftermarket alternator shouldn't have a problem charging the batteries while driving with the volume pretty low.