A little help for the lost?

Ok, here is the situation...

I have an Alpine CDA-9813 HU first off...and I'm ordering an Adire Brahma 12" subwoofer, powered by either a JBL1200.1 or a Better Audio1600, not sure which amp to go with?  Any recommendations between those two?

Second, I am not sure how I should go about building the box.  I have contacted Adire and they said I can build any size from 3.0 cu. ft. sealed to 8.0 cu. ft. ported?  How much of a difference will there be between a 3.0 cu. ft. sealed and the bigger ported box?  I would imagine the bigger ported box would be more guided toward SPL?

Third, I'd like to install this equipment(sub and amp) myself to save myself a little money.  Thing is, I have never installed any kind of stereo equipment.  What all would I need to get to install the sub and amp, and how would I go about doing it?

Finally, would 1200-1600 watts trash my alternator?  It's a 140 amp alternator.  I've been told/suggested to stay away from caps.

By the way, all this will be going in an Oldsmobile Aurora...batter is UNDER the backseat, so grounding it properly/good shouldn't be much of a problem.

Any help will be greatly appreciated!

Thanks!

Ok as for which amp.....I couldnt tell you because I have had no experience with either.  As for the box......usually (correct me if i am wrong someone) when tuned correctly the bigger the ported box the lower and louder the sub will be.  usually a mid range is suggested to get a balance between loud, low booms and tight response. 

the installation is easier than most actually believe.  the hardest thing i had to do in my civic was run the wiring so that it looked professional.  keep in mind that if you run into a snag....there are a lot of good people and good posts to find just about any information you need here.  

Last to figure if your alternator is ok here is the math.  take the rms rating of your amp (which ever one you choose) and devide it by 13.8 ( the general voltage assumption of most vehicles)  this will give you amperes used.  so for the jbl amp it woulld look like this 1200 / 13.8 = 87 amperes.  now assume that you have about 70-80% consumption of your OEM alternator which leaves you at 43 ampers to spare.  (at 70%) so you are basicly putting a 87 ampere draw on a system that has only 43 amperes to spare.  now keep in mind that this is just plain assumptions and actual calculations may vary but you might want to rethink the amp choice or get a slightly bigger alt.  Capacitors will help if you are only overdrawing the system by a few amperes but not 40 amperes. 

This is what I know.....please anyone correct me if i am wrong. 

thanks and you're welcome

~Q

i am just going by what most cars are built like.  you can add the amp that you want......just keep in mind that you may have problems with diming lights and other things.  if the draw is too much you could definatly hurt your car's electrical system. 

Like i said, i am just going on assumptions and who knows.....the alternator you have may only be used 40-50 percent leaving you enough room for what you want.  but if you do see dimming lights do something about your alt right away. 

best of luck. 

~Q

acq810z wrote:

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.  but if you do see dimming lights do something about your alt right away. 

best of luck. 

~Q

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That's the problem, I can't replace the alt. in the car right now,  It is waaaay too expensive in this car...$380.00 for the stock amp alt.  then close to $400.00 to install, that's the bottom end price I found around here. 

You have to either jack the engine up to get to the alternator on the Aurora, or you have to take the front half of the frame apart, neither of which is feasible, or cheap.

The problem is a bit complicated to explain but as a whole, I would say that as long as you understand the basic principles of the mobile electronics platform and how your sound system choices will impact it, you can do whatever you please. Let me explain.

The actual draw of your amplifier is normalized over time to a level much less than the listed max. The current will max out only during peak moments, such as when the bass hits. During those times, it's your battery that supplies the peak power while the alternator charges it back up. A strong battery makes all the difference. If your battery is weak or undersized, the sudden demand can overload and damage your vehicles wiring and alternator. Additionally and as a word of caution, some amplifiers (usually older units) can be damaged if the applied voltage drops below a certain point for even a moment. Ever heard Orion amps called O-fryin?

Whenever I install true-300 watt or larger systems, I talk to the customer and explain the need to "reinforce" the OEM electrical system and suggest some options. The first is to install a high demand battery such as the Optima (red top) which can be found for as little as $79. Most installers swear by them. The second is to upgrade the factory power cables, especially the chassi ground at the battery. Don't remove the factory ground strap but add another from the battery that's at least 25% larger than the max current of the sound system you plan to install. This site has calculators to help you determine the max current and wire gauge. On larger systems, I also suggest properly installed power caps. Caps help to smooth out the instantaneous demand spikes that can damage your alternator. Another option is to contact an alternator/starter repair shop to see if they can rewind your alternator for higher voltage and current output. If they can, be sure you DO NOT exceed 14.4 volts! Most mobile electronics can be damaged when run above 14.4 volts and the shop won't know that.

The dimming lights described by others is typically caused two ways. The most common is a weak or damaged battery. When a standard battery with stock wiring is used in a high-demand application, it develops internal defects that keep it from charging or supplying fully. When this happens, the additional current required by the sound system is sacraficed by the other electronics in the vehicle and drawn directly from the alternator. The other typical cause of dimming lights is the vehicle's wiring. In other words, the factory power cables can't support the extra load of the sound system. All vehicle electrical systems are designed to provide the stock components with adequate power and have a little extra capacity to allow for extreme conditions. If you plan on doubling the current load, you need to build that capacity into your vehicle. Options one and two above should take you where you want to go. Remember to have your battery load tested every year as a precaution.

Well, no worries about trashing my alt. as I've decided to slightly change my set up.

I am going with 1 12" Brahma, powered by the Planet Audio P850D which is     1 x 850 @ 1 ohm.