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New member Username: ColoradoxcPost Number: 1 Registered: Jun-11 | Hello. In a couple months I want to retrofit my 1995 Jeep Grand Cherokee Laredo with a new sound system. (Brother broke it) The stock alternator that the car is fitted with produced 90 amps. I have no clue if the stat means 90 amps at idle or highway rpm. Anyway, I already know I need to get a more powerful alternator, but I want to make sure the brand and current produced will satisfy my system. Before I mention details on the system I want to make it apparent that by no means will I be listening to the system at full RMS ratings because I value my hearing. I'm not sure on the replacement main speakers but I purchased a below amp that can handle more than anything I would need. ( Im thinking less than 100 rms watts per speaker) Lanzar OptiDrive1222D -- 900 RMS watts Lanzar MAXP2051D--1,000 watts RMS into 4 ohms (class D) Lanzar HTG447 Heritage-- 4x250 RMS watts into 4 ohms (Class AB?) I'm not sure what the regulated voltage is (12V?) But calculating a 20% inefficiency and 40% for D, and AB respectively, I get a total current pull of 146.66 A at max RMS values.(If I use only 100 rms watt speakers for the mains). Since the stock amp was 90 A, does that mean I need a 236.6 A alternator?? I did some research and found the Fitzall-220 alternator in the link below( Powerbastards). I emailed the company and they said the alternator would be more than enough. It produces 110 A at idle and 220 + at 1200RPMs. It sounds doable to me. First, I will most likely never approach more than 3/4 volume level ever. I can turn to music down at lights/ idle speeds to the battery doesnt drain. Or, I could have a backup battery for the system itself for when the car is below 1200RPMS. Also, if the setup sounds feasible what do I need to do besides upgrade the wire gauge to handle to new larger current? I hope I don't have to replace any other parts of the electrical system. Thank you so much for the help and sorry for the long message. http://powerbastards.com/proddetail.asp?prod=Fitzall-220 |
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Gold Member Username: KaerfplSpencerport, NY USA Post Number: 1078 Registered: Jun-06 | In all honesty, if you are looking to just throw 300-500 Watts RMS at 4 Speakers for your vehicle, you may not even need to upgrade your alt. 90 Amps should be enough to handle that range without any issues. On a side note, did you already purchase one/all of those amplifiers or are you saying you are looking to purchase one/all of them? Those amplifiers you listed above are not that great. I personally would stay away from Lanzar all together. Before I even put my opinion onto whether you will need a HO Alt or not, we need to know what you actually plan on doing. Are you just replacing speakers, or are you installing subwoofers as well? Also, what is your budget on all of this? |
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New member Username: ColoradoxcPost Number: 2 Registered: Jun-11 | Wow I didn't know Lanzar had a bad reputation. I did buy all the things I mentioned already. I could return the items if the amps are legit crap. What negative traits come with lanzar amplifiers? I am running a sub like listed above. It has a RMS of 900 watts. I wanted to keep my budget of no more than $1200. I already spent 600. The HO would cost another 300. Leaving me around 300 for the 4 mains. |
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Bronze Member Username: Caraudio4lifeClovis, CA USA Post Number: 46 Registered: Nov-10 | my lanzar opti 1800d which powered 2 lanzar hrwdc12 dvc4ohm 1000wms a piece, died after about 2 months and i never had above half gain at a 1ohm load. also one of my subs surrond starting coming apart before the amp died. this was in 2006, my friends lanzar heritage 2600d died about 6 months later and he had at half gain as well at 1 ohm. powerng 2 15's same model as mine. but it was the cheapest yet loudest 2 12" system i ever had, ive had 2 jl w3, 2 mtx 3500, and 1 crunch and 1 sony xplod lol, crappy brands but you get idea. i heard opti line is suppose to be better, but if you could return i reccomend it, there are so many reliable/better brands out there. |
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Bronze Member Username: Caraudio4lifeClovis, CA USA Post Number: 47 Registered: Nov-10 | sorry meant my lanzar "VIBE" 1800d my mistake***** |
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New member Username: ColoradoxcPost Number: 3 Registered: Jun-11 | What about the MAX series. I won't be running any of the amps at 1 ohm. I heard running amps at low impedance can cause the amp to fail even if it is rated to work at that level. I'm going to run the sub amp at either 4 or 2 ohms. The mains at 4 ohms. It turns out that the seller's require 25% restocking fee and I have to pay shipping so looks like I am sticking with the brand for now. I purchased these in the first place because they are indeed cheap, and I have a very small budget. Anyway., back to my original question do I need to replace my alternator????} |
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Gold Member Username: KaerfplSpencerport, NY USA Post Number: 1081 Registered: Jun-06 | Ok, so you did purchase everything above already? Well, lets try to answer some of your questions then shall we? First off, the Lanzar OPTI 1222D you picked out is a 2 Ohm DVC Subwoofer that has a 600 Watt RMS rating, not 900 Watts RMS. With this said, you will need to look for an amplifier that can produce at least: A. 600 Watts RMS at 1 Ohm (Wired in Parallel) B. 600 Watts RMS at 4 Ohms (Wired in Series) The Lanzar MAXP2051D Amplifier you have chosen is way overrated however, you could use this amplifier to power that subwoofer in a 4 Ohm Load wired in Series. Even though it's rated for 1000 Watts RMS at 4 Ohms, I bet it's probably putting out more along the lines of anywhere from 400-700 Watts RMS. Maybe even less... One thing to keep in mind, this amplifier DOES NOT have any fuses built into the amplifier which is the main reason why these amplifiers fail often. Make sure all of your wiring is correct, fuses are in place, and the settings are set correctly on the amplifier to try and avoid damaging anything. As far as the Lanzar HTG447 Heritage amplifier goes, I would suggest looking into some Speakers that have RMS rating anywhere from 50-100 Watts RMS. The amplifier is rated for 250 Watts RMS at 4 Ohms, but once again, I highly doubt it's accurate. Here is a suggestion for some speakers you can look into: Kenwood eXcelon KFC-X173: http://www.sonicelectronix.com/item_22940_Kenwood-eXcelon-KFC-X173.html Infinity Kappa 652.9i: http://www.sonicelectronix.com/item_13454_Infinity-Kappa-652.9i.html Overall, I honestly don't think you will need to upgrade to an HO Alt with running less that 1000 Watts RMS through your Jeep. However, if you were really persistant on purchasing one, I would suggest talking to Nate at www.excessiveamperage.com. He is currently custom building me an HO Alt for my Nissan 300zx at a great price. |
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New member Username: ColoradoxcPost Number: 5 Registered: Jun-11 | Thanks Joe for your input. I'm not looking for any device that outputs 900 rms watts anyway. I just want a decent priced project to get my hands dirty on... I am a college student soo..... I can't buy top of the line gear quite yet, a.k.a expensive stuff. I appreciate the info on the "real" RMS values of the devices, and to be honest those values are more than anything i would ever need. What size fuse should I wire between the battery and the sub amp 50 A, and a 33 A fuse to the 4 channel amp? As for the alternator, I'll just wait till everything is connected to see if the car battery starts to drop below 12 V meaning the alt can't handle the load. |
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Gold Member Username: KaerfplSpencerport, NY USA Post Number: 1082 Registered: Jun-06 | Lets make things simple for you. Here are two amplifier wiring kits you can purchase. the first link will be for the MAXP2051D amplifier, and the second link will be for the HTG447 Heritage amplifier: Kicker CK4: http://www.sonicelectronix.com/item_3938_Kicker-CK4.html Kicker CK8: http://www.sonicelectronix.com/item_3936_Kicker-CK8.html |
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New member Username: ColoradoxcPost Number: 6 Registered: Jun-11 | Thanks Joe for the wire kits, I'll have to get them to make things easier. Since I'm stuck with the 2 Lanzar amps are there any other precautions I can take to prevent them from burning out. I would assume another reason the amps might burn out is because of poor heat sinks and bad ventilation installed compared to other higher end/standard products. Instead of sealing them under seats, ect. I could just leave them open to the air within the trunk. Anything else? Also, back to the alternator. If the system is around 1000 watts won't that pull over 83.3 A without effeciencies calculated. I don't know much about car electrical systems, but how many amps does a car require to function based off the stock item? If my jeep has a 90 A alternator with the system at peak performance won't that leave only 6.6 A for the primary electrical system, lights, AC, power stearing, ect... Sorry fora ll the questions. |
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Gold Member Username: KaerfplSpencerport, NY USA Post Number: 1086 Registered: Jun-06 | Never go by Peak or Max Watts when looking into car audio. Those are false numbers. The main ratings you want to pay attention to is the Watts RMS. As long as the amplifiers are in a well ventalated area, the settings are done correctly, and are not being pushed too hard, you should expect to get the full lifesppan out of these amplifiers. I don't have much time to explain amps, but here is a link where you can learn how to calculate how much amps your system will need: http://forum.realmofexcursion.com/accessories-electrical/3907-determine-amperage -draw-your-electrical-system.html |
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Gold Member Username: JbpittPittsburgh, Pa. Usa Post Number: 1225 Registered: Jul-09 | And on a side note... Im running around 1200wrms @ 1ohm on my 90 amp alt and my voltage never drops below 13.25. Get some good wire,do the big 3 and you should be fine. |
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New member Username: ColoradoxcPost Number: 7 Registered: Jun-11 | Thanks Art. It sounds like I won't have any issues with power since the lanzar amps are highly over-rated. Thanks everyone for clearing that mess up, because I would have blindly taken the RMS that lanzar puts out to calculate the required amps and buy a new alternator. How do companies get away with having RMS that are not accurate what so ever? |
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Gold Member Username: KaerfplSpencerport, NY USA Post Number: 1089 Registered: Jun-06 | It's all about advertising. Next time you go into a store, you will notice that a lot of Audio products have only the MAX rating on the label or the box. People see that, and then compair them with better products that typically display their RMS rating. In the end, people only see the numbers and don't even consider what MAX and RMS is until after they bought it. |
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Bronze Member Username: Caraudio4lifeClovis, CA USA Post Number: 49 Registered: Nov-10 | some are not cea compliant. thats how companies get away with it. some companies like joe said live off their max ratings, always go by rms ratings that you are most likely to experience, its unlikely you will ever get a 100% effienct amp, all output ratings are numbers right before fuses pop on amps!!!!! i beleive lol |
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Platinum Member Username: GlasswolfPost Number: 14289 Registered: Dec-03 | http://www.glasswolf.net/papers/index.html see the section below "Amplifiers" labeled "Electrical" |
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New member Username: BigbassPost Number: 3 Registered: Aug-11 | if any thing you could just take ur alt and have it upgraded to a higher voltage and also invest in a capacitor. i had an older kenwood 900wt amp running 2 jl 10's in my 1972 chevy pick up, the only problem was it drained my battery while the headlights wer on so i could never bump at night. it had the stock 60vlt alt in it. so i took it to a shop and had it upgraded to 100amp than bought a newer amp and capacitor, i never had a power problem after that, also if you have the money pick up a yellow top optima battery |
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Platinum Member Username: GlasswolfColumbia, South Carolina Post Number: 14442 Registered: Dec-03 | with the grand cherokee (I have owned 2 myself) if you want a high output system with the amps listed in the OP, you'll want to consider an alternator in the 150-200A range, preferably as a hot rating. That 90A alternator that comes stock, in large part, is used to power all of the electronics in the Jeep already. EFI and ignition system, power windows, HVAC, etc. do NTO buy a capacitor. complete waste of money. they do nothing for you to bolster your voltage rails. |