eastwood Posted April 16, 2015 Report Share Posted April 16, 2015 Somewhat of a noob so be gentle please. Had a couple questions I couldn't find a definitive answer on. Currently running 2 Wo12's on a jl jx500 mono amp. Now wanting a little more. Definitely going to get 2 sa-12's and a crescendo symphony 1500.1 or a sundown scv1500. Both amps are 1 ohm stable so should I get dvc 4ohm and go down to 1ohm, or get a different amp and go with dvc 2 ohm and run it at 2 ohm? Which is better/more efficient? Charging system is next. Currently stock 70amp alt and battery. Going to get a yellow top first and see what it can handle. My installer here thinks it should be enough for a 1500 watt system. What do y all think? Right now runs at 14.6 with nothing on, just the stereo at 14.38, then the stereo and lights, heater and wipers at 13.8. Thank you for any response. I know these questions have been asked before Link to comment Share on other sites More sharing options...
khinds94 Posted April 16, 2015 Report Share Posted April 16, 2015 I would get an AGM up front like a yellowtop and get another for the back. Reserve does you good with a small alt... And they aren't expensive. Edit: except when you have too many batteries and fuck up your alternator. But your alt should be able to charge 2 yellow tops 03 Sable LS AA mayhem 12" D2 Sundown ZV4 12" D1 Tantric HD 12" D2 Tantric SHD 12" D1 Sundown X12 V2 D2 2.5 cu net Sundown 2000d @ 1 ohm XS Power XP2000 Sky High Sound Deadener Sky High wire Stock alt Link to comment Share on other sites More sharing options...
SLYentist Posted April 16, 2015 Report Share Posted April 16, 2015 a single optima group 34 (arbitrary but common size) can likely handle about a 1000w system with a stock alt. Cables and wires almost never fail; the terminations do. Link to comment Share on other sites More sharing options...
Guest Posted April 17, 2015 Report Share Posted April 17, 2015 Just stick with the two 4ohm DVC subs to run at 1 ohm. Also, definitely just get a solid battery, I would recommend getting the largest XS Power battery you can fit under your hood. I would also recommend a second battery but your could try just one solid XS battery under the hood like a said and see if you can get away with it. Link to comment Share on other sites More sharing options...
SkarredSierra Posted April 17, 2015 Report Share Posted April 17, 2015 Welcome to the forum. Both of those amplifiers are good choices. Y not just get the sundown amp? That way it matches the subs. Yellowtops are ok but for just a little more you could have some xs power batts. An agm up front and an agm in back with 0 gauge big 3 and u should b good but a high output alt always helps. Link to comment Share on other sites More sharing options...
dbmode2 Posted April 17, 2015 Report Share Posted April 17, 2015 IDK about everybody else but I would play it safe on that 70amp stock alternator and stay on a 4 ohm load on the amp. The reason why you have to make sure all the other electronics in the car is getting enough amp's as well and plus you are looking at a huge voltage drop on current even with 2 batt's. Link to comment Share on other sites More sharing options...
Ahmed Johnson Posted April 17, 2015 Report Share Posted April 17, 2015 IDK about everybody else but I would play it safe on that 70amp stock alternator and stay on a 4 ohm load on the amp. The reason why you have to make sure all the other electronics in the car is getting enough amp's as well and plus you are looking at a huge voltage drop on current even with 2 batt's. Then he might as well turn the bass up on the HU and not even get an amp and sub. Link to comment Share on other sites More sharing options...
dbmode2 Posted April 17, 2015 Report Share Posted April 17, 2015 IDK about everybody else but I would play it safe on that 70amp stock alternator and stay on a 4 ohm load on the amp. The reason why you have to make sure all the other electronics in the car is getting enough amp's as well and plus you are looking at a huge voltage drop on current even with 2 batt's. Then he might as well turn the bass up on the HU and not even get an amp and sub. or just saved up for another high current alternator Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted April 17, 2015 Report Share Posted April 17, 2015 Somewhat of a noob so be gentle please. Had a couple questions I couldn't find a definitive answer on. Currently running 2 Wo12's on a jl jx500 mono amp. Now wanting a little more. Definitely going to get 2 sa-12's and a crescendo symphony 1500.1 or a sundown scv1500. Both amps are 1 ohm stable so should I get dvc 4ohm and go down to 1ohm, or get a different amp and go with dvc 2 ohm and run it at 2 ohm? Which is better/more efficient? Charging system is next. Currently stock 70amp alt and battery. Going to get a yellow top first and see what it can handle. My installer here thinks it should be enough for a 1500 watt system. What do y all think? Right now runs at 14.6 with nothing on, just the stereo at 14.38, then the stereo and lights, heater and wipers at 13.8. Thank you for any response. I know these questions have been asked before Welcome to the forum To touch on some of your questions, a given amp is more efficient at 2 ohms than it is 1. Because of that, you are going to pay more for 1500w @ 2 ohms as compared to 1 ohm. If you have no plans to upgrade your alt, the current demand of an amp trying to put out 1500W @ 1 ohm may be a bit much for your alternator, with or without an upgraded battery. That much power alone could demand more than your alt can supply. Make sure to read up on the big 3 and do it proper and set your gains very conservatively. The bug is going to bite and you are going to want more and more, I would suggest upgrading your alternator. To help you learn how to figure this on your own, take the RMS rating of your amp and multiply it by the efficiency rating at the given impedance level (impedance will change with music but it's a good starting point) and that will give you an idea of how much power your amp will draw to put out rated. So say 1500W /.7 = approx 2143. So far we are estimating your amp needs roughly 2143 watts in to put out 1500. Since we are probably talking about music, most likely at or below a 50% duty cycle (this is why a 1500W amp doesn't put out a continuous 1500w even if the electrical is there) so you can divide that 2143 in half and we end up with about 1072W. If you divide watts by volts, that will give you your current draw. You can figure 13.8 if you'd like, so 1072w/13.8v = about 78 amps. Your OEM alt is rated at 70, so your vehicle probably needs between 50 and 60 amps to keep everything going. See the problem? In your proposed scenario demand > supply, and thats when bad things happen. Voltage drops to unsafe levels, wires and components heat up, equipment blows fires start etc. Keep in mind music is dynamic and there many variables, but this helps you get close. I am not trying to scare you away from your build, but I definitely recommend you be very careful. Keep us posted. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
Ahmed Johnson Posted April 17, 2015 Report Share Posted April 17, 2015 IDK about everybody else but I would play it safe on that 70amp stock alternator and stay on a 4 ohm load on the amp. The reason why you have to make sure all the other electronics in the car is getting enough amp's as well and plus you are looking at a huge voltage drop on current even with 2 batt's. Then he might as well turn the bass up on the HU and not even get an amp and sub. or just saved up for another high current alternator He'll be OK with for a while as long as he doesn't turn it all the way up for a long time. My HO alt won't be in my truck until next week and I been riding with a bc3500 at .5 ohm for a couple weeks without a problem. He just had to watch his voltage and take it easy. Link to comment Share on other sites More sharing options...
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