Newb needs help


New member
Username: Djbeanpole

Post Number: 1
Registered: Nov-05
Sorry if the following descriptions seems extremely vague... I barely have any idea what I'm talking about.

I own a 1999 Camry. Last summer a friend sold me a Alpine MRD-M500 amp w/ a Kappa Perfect 10.1D woofer. He and I both installed it and got it working. As for the gauge on the wiring I will have to ask him because I can't remember. He left me the receipts from all the stuff we used and all I can read off of it is "300W WAmp Kit." My deck is a Pioneer DEH-3700MP.

Lately I have noticed that my headlights are beginning to dim when I have the volume cranked up. And its starting to get annoying. I was thinking about getting a capacitor until I stumbled onto this website and read up about them. I don't think a capacitor is what I need anymore but instead I need a HO alternator.

My question is (unless I am wrong about what I've already said) is where would I look, and how do I know that I even need one and if so what type and where to buy?

Thanks ahead of time for your help. First post. Sorry if it sucked :-(

Silver Member
Username: Theelfkeeper

Stockbridge, GA USA

Post Number: 483
Registered: Feb-05

you'll want to keep the stock amperage (usually 50-75amps) plus whatever additional amperage you want for your system, leaving room for upgrades is always good. the RMS of that amp i think is 500 watts depending on load. so thats about 42 amps,
so 42 plus the stock output = HO alternator you need.
HO alternators are usually 150 amp, 175, 200 and 250. custom ones can be higher.

hope this helps, you'll prob get more replies too

Silver Member
Username: Theelfkeeper

Stockbridge, GA USA

Post Number: 484
Registered: Feb-05
oh, you will also want to look into a deep cycle battery, draining and recharging a normal stock battery will damage it. look at Optima yellow tops

New member
Username: Djbeanpole

Post Number: 2
Registered: Nov-05
I'm having a hard time figuring out what exactly my stock amperage is from the alternator I already have. I can't find the numbers online... where would I look in the car?

I am reading the specs off of the manual and Brandon I believe you are correct (although I might be reading this wrong) in regards to what you said about RMS of the amp. It says the following:

RMS @ 2OHMS is 500

There are a whole ton of numbers in the manual based on voltage, frequencies, channels, and ohms. What the hell does all of this stuff mean?

Silver Member
Username: Theelfkeeper

Stockbridge, GA USA

Post Number: 487
Registered: Feb-05
the alternator amperage should be on the alternator somewhere. don't know where you can find that info online.
all thoes numbers you are talking about tell you the rms wattage under different conditions. ohms is how the subs are wired to create a load on the amp. the lower the load, the more power the amp will give to the subs, but most amps cannot go below 2 ohms or you will blow the subs or the amp.
the voltage, 12.6 and 14.4, the more voltage the higher the output of the amp, nothing below or above these numbers though, below causes clipping and above (can't really do or you will fry the car) will burn up the amp. the car voltage sits somewhere between 12.6 and 14.4 when a load is present, so the amp output will be somewhere inbetween the numbers given.
don't know what the frequencies could be off the top of my head, can't see what your looking at either, lol.
channels should be one channel on a mono amp.

New member
Username: Djbeanpole

Post Number: 3
Registered: Nov-05
I looked in the car, and I read the manual and I didn't see anything that pointed to how many amps the alternator that I currently have gave out. From what I could find for just searching for "1999 Toyota Camry alternator" on I believe what is in there right now is around 80A.

I did talk to a guy at a local car audio shop here in Indianapolis. After speaking with him for a bit I am now aroused with the idea of upgrading what is already in my car. I was thinking of going from the dinky 10" Kappa Perfect to 2 12s. He recommended Memphis Audio. Apparently at this time a custom box they have that is vented down the middle is selling for what they buy at at $250. I'm not sure if this price is expensive or cheap in comparison as to what else it out there. As of yet I am still researching.

If I was planning this upgrade he told me that the amplifier I have now is adequate. I had him poke around in my car to tell me what was already in their. He told me that the wiring should probably be changed to 4 gauge down from 8. I asked him about the dimming headlights and that I thought a HO alternator was a good idea (seeing from what I had read, especially GlassWolf and some of the links he has posted in previous posts). I asked the associate about capacitors. He said they didn't even deal with them anymore and that a HO alternator might not be something I need. He pointed me to and said I would just need one of their batteries.

Now I am confused. What exactly should I do? New battery? HO alternator? Both? Is capacitor still even necessary? I have the means to buy all of this stuff. I do enjoy music quite a bit because I am in my car alot of the time.

Brandon these were some of the numbers I was looking at in the MRD-M500 manual:

Power Output: RMS Continuous Power (at 12.0V, 20Hz to 200Hz)
Per channel into 4 ohms (1% THD) ......... MRD-M500: 200Wx1
MRD-M300: 100Wx1
Per channel into 2 ohms (1% THD) ......... MRD-M500: 400Wx1
MRD-M300: 200Wx1
Power Output: RMS Continuous Power (at 14.4V, 20Hz to 200Hz)
Per channel into 4 ohms (1% THD) ......... MRD-M500: 250Wx1
MRD-M300: 150Wx1
Per channel into 2 ohms (1% THD) ......... MRD-M500: 500Wx1
MRD-M300: 300Wx1
Total Max. Power ............................................... MRD-M500: 900W
MRD-M300: 600W
Frequency Response .............................................. 20 Hz to 200 Hz
Signal-to-Noise Ratio
(referenced to rated power) ................................................. 90 dBA
Input Sensitivity (for rated power output)
MRD-M500 ............................................................ 0.5V to 8.5V

I understand now from what you have said about the voltages (14.4 and 12.6) and how all the electrial components work. Basically the headlights are dimming because the alternator isn't turning out the power fast enough so it sucks it out of the batteries draining power from other devices which is why I notice the dim (I hope thats correct). So what is my course of action?

Sorry for the long post and if this gets annoying that I don't know what I'm talking about :\


Silver Member
Username: Theelfkeeper

Stockbridge, GA USA

Post Number: 497
Registered: Feb-05
500 watts or more, you definally need a HO alternator. a new battery isn't gonna solve the problem, it may for a short ammount of time, but if your alternator can't keep it charged, the battery will go bad and you'll be back where you started again.
capacitors aren't needed unless you have excessive AC ripple in your DC lines. i doubt you'll have that problem.
you can check the battery with a meter with the system off, at idle the charge should be around 12.6 volts. when you rev the engine up, the voltage should increase to around 13.8 to 14.4. if you do this same thing with your system turned up and you get less voltage especially 12 volts or less, you definally need a HO alternator. if the battery isn't keeping 12.6 volts with everything off, its bad.
your pretty accurate with your last comments.

the frequencies from the amp info are the range the amp is capable of reproducing.
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