|
Bronze Member Username: ArnotjiePost Number: 21 Registered: Apr-10 | Okay, So I'm in the final stages of planning my system. I have decided to go with: Sundown Audio SAZ-1000D Eclipse sw6210 custom box Either SAX-100.4D or AQ4x90 eclipse sc8365 for front eclipse sc6900 for rear I really have no idea about the electronics of the car itself. It is a 2003 toyota corolla. What will I need to do so I could run this system (alternator, Battery, capacitor, etc) ? please help |
|
Platinum Member Username: Insearchofbass2 hifonics 2607s, 2dcSounds12xls SPL\idmax12SQ Post Number: 14009 Registered: Jun-04 | I will sell you a pg xenon that puts out 200 rms x 4 it does the same power at 1-4 ohms 235 shipped brand new in box |
|
Platinum Member Username: GlasswolfLexington, SC USA Post Number: 13499 Registered: Dec-03 | try the system with stock electrical system first. see if voltages drop during use if yes, then: do the big 3 test again. if voltages still drop, it's time to look at a higher output alternator. I'd use 1/0 gauge wire for the amps you plan to use, with power distribution that could drop to 4awg close to the amplifiers. http://www.glasswolf.net/papers/charging.html http://www.glasswolf.net/papers/big3.htm |
|
Bronze Member Username: ArnotjiePost Number: 22 Registered: Apr-10 | Okay. thanks for all your help. I think I'll do the big 3 anyway to start with, just as a precaution. but that should be enough anyway. now, just want to make sure from the links... So does that mean that if the alternator does not put out enough current, even an extra battery would have very little effect, as it wont get charged properly? |
|
Bronze Member Username: ArnotjiePost Number: 23 Registered: Apr-10 | Oh, and also, when working out how much current is drawn: If I use the SAZ-1000d, running at 2ohms it only puts out about 600w rms. so will I then divide THAT by 12volts, or the 1000 rms @ 1ohm |
|
Platinum Member Username: GlasswolfPost Number: 13520 Registered: Dec-03 | "I think I'll do the big 3 anyway to start with, just as a precaution. but that should be enough anyway. " good plan. yes precisely correct on the second (isolated) battery. When you add a battery for an audio system it is best to isolate the battery so the starter battery is unaffected by the stereo. The issue with the alternator not being large enough, as you noted, is that the battery will then begin to drain as well, and once the battery's reserve is exceeded, your voltage rails will begin to sag and cause the amp(s) to clip anyway. The alternator, which above idle puts out more voltage than the battery, should be what generates and supplies any and all electrical current for the car when the engine is running. You use the amplifier's output @ the load presented, so if you are running @ 2 ohms, then you'd use 600 watts, which is about 60A of current at peak output (max volume on a resistive load with a pink noise tone generator, so ralistically if this isn't an SPL vehicle, you can be pretty conservative with that number and figure maybe 10-20% below that peak rating, so 54-48A. I should mention that in the notation on calculating alternator size. Thanks) |
|
Bronze Member Username: ArnotjiePost Number: 24 Registered: Apr-10 | Okay, thanks a lot for all the advice. I think I'll just start out with the big three, and see how it goes. If I do experience a big voltage drop, I'll get an alt with enough output to keep the battery from draining at all. This really helped, coz I found that some of the car audio shops are reaaly quite qlueless and really expensive. |
|
Platinum Member Username: GlasswolfPost Number: 13529 Registered: Dec-03 | yeah, sadly you don't really need to understand a lot about electricity to work in most car audio shops. This holds especially true for sales people. |
|
Bronze Member Username: ArnotjiePost Number: 25 Registered: Apr-10 | Apparently you don't even have to know a lot about the products either. The sales person told me to get an amp that puts out 500rms @ 4ohm, even though the sub has DUAL 4ohm voice coils. hahaha |
|
Platinum Member Username: GlasswolfPost Number: 13538 Registered: Dec-03 | yeah. that'd be 1Kw when the sub coils in parallel, since the amp will be (in the car audio world this is a constant) 2 ohm stable. Back in the day, all amps used to be rated @ 4 ohm power on the cases (IOrion, PPI, RF, etc) then companies started getting cheap and listing amps at their peak power and their lowest stable load power to make them sound more impressive to the uneducated. I liked Orion's approach, myself. List the amp at it's 4 ohm RMS output of 25 watts x 2 channels @ 4 ohms.. then just make it 0.5 ohm stable so it's a 400 watt amp. (This was done to mess with IASCA to show them how dumb their power classes were, and it worked.) It does remind me of a lot of people who come in here and state simply that they, "have a 4000 watt amp." 4000 watts... peak? RMS? (yeah RMS doesn't apply to power, only voltage. I know. "continuous") at what load? at how many volts? at a fixed tone or full band? burst or sustained signal measurements? This is what CEA2006 pwoer specs were designed for. They level the playing field for amplifier power specs between manufacturers by applying IEEE-like standards to the measurements. |