Power requirement question

[DallasBass91]

I have 2 d4 subwoofers wired to 4 ohm final right now. They are powered by 2 massive drago 6k amplifiers (strapped) if I’m right this means the subs are getting 4 ohms each, and each amplifier is using the amperage required for a 2 ohm load (correct me if I’m wrong please). 
these amps say in the manual that when linked the min. Impedance is 2 ohms which I take that as they are only rated for 1ohm each and are not .5 stable. Being that I have 2 dvc 4 ohm subs I can only wire them to 4 ohm final and 1 ohm final. If I wire to 1 ohm final each sub would be running at 1 ohm but each amplifier would require the voltage for a .5 ohm load. If my thought process is correct what would my amperage requirements be to lessen the chance of failure here?

would I be ok with a 300amp alternator and 200 AH in batteries (agm) I can’t afford lithium atm. In the future I plan on doing 2 banks of roughly 24 headway lifepo4 cells each bank.

sorry for the long winded post 😢 

[Dafaseles]

I wouldn't play those amplifiers down to .5 ohm strapped, if that's what you're thinking. I haven't done it myself, but I would assume, regardless of how much electrical you have, it'll just throw them into protect. Though running each at .5 (separate) shouldn't be that much of an issue, so, like I said, I've never done it, so I don't know. 

As far as the electrical required for that goes, I couldn't find an amp dyno on that specific amplifier, but I assume at .5 ohm, at 14.7, you should get maybe a little over, a little under 4,500 watts, so strapped, let's say 9000 watts (just purely a guess). So, factoring in the 300 amp alternator, worse case scenario, you'll need an additional 764 AH of battery. 

Now factor in things like music being so dynamic, and those amplifiers being at least a little more than 70% efficient, to get by, you won't need quite so much. Though, my opinion being, you'd need more than 200 AH. 

That's my opinion anyway. Hope that helps

[DallasBass91]

20 hours ago, Dafaseles said:

I wouldn't play those amplifiers down to .5 ohm strapped, if that's what you're thinking. I haven't done it myself, but I would assume, regardless of how much electrical you have, it'll just throw them into protect. Though running each at .5 (separate) shouldn't be that much of an issue, so, like I said, I've never done it, so I don't know. 

As far as the electrical required for that goes, I couldn't find an amp dyno on that specific amplifier, but I assume at .5 ohm, at 14.7, you should get maybe a little over, a little under 4,500 watts, so strapped, let's say 9000 watts (just purely a guess). So, factoring in the 300 amp alternator, worse case scenario, you'll need an additional 764 AH of battery. 

Now factor in things like music being so dynamic, and those amplifiers being at least a little more than 70% efficient, to get by, you won't need quite so much. Though, my opinion being, you'd need more than 200 AH. 

That's my opinion anyway. Hope that helps

Thank you, it always helps to get insight from people especially ones who are more knowledgeable than me like yourself. I’m just wanting to have my subwoofers wired down to 1 ohm, which would mean the amps split the load so .5 each. So I guess that’s 1 ohm strapped? I’m not entirely sure but at 1 ohm w/14.7v they put out roughly 3409-3500 watts each but since they are splitting the load I believe they will need the voltage required for a .5 load even though they won’t be putting out .5ohm power. I know I would be much better off just getting one 6k rms amplifier and wiring the d4 subs to 1 ohm into the 1 amplifier since that would be a lot easier on the electrical, but the problem with that is I’m broke AF lol I’m just trying to make due with what I have. I know there is a lot more power I’m not currently using and as bad as it is to do I’m factoring in box rise which should be at least .3ohms which has me thinking it is possible for me to do without doing anything to crazy.

I would be happy with 13v and drops to 12.4 on music. Also my goal with this is to hit mid 150s I’d really like having a 155 sticker on my car 😂 

 

[Dafaseles]

So, strapping amps essentially makes it 1 amp, almost like bridging 2 channels on a 4 channel, making it one single channel with twice the power. Usually, when you bridge a 4 channel amp, you can't bridge at 2 ohm (the lowest impedance a single channel can handle) because the amp can't handle it. It'll either throw the amp into protect, or fry the amp. So usually it'll be 100 watts per channel at 2 ohm or 200 watts bridged at 4 ohm. Same deal with strapping amplifiers. It'll be 3000 watts at 1 ohm or 6000 watts at 2 ohm. So you wire your d4's to an 8 ohm final impedance each, so the monoblock sees 4 ohm because if you where to wire it down to 2 ohm each, then send a final 1 ohm to the strapped amplifiers, technically it should give you the power of 1 amp at .5 ohm ×2. Now, the company doesn't recommend this. You do this, you void the warrantee if something where to happen. 

As far as the being broke aspect goes, think about this. There's 2 things that can happen. One thing is you do it, you spend a twice as much on your electrical to support such a low impedance, and you fry your amps anyway and have no audio until you get the dough for a new amp. Or. You do it without upgrading your electrical and you fry your amps and your subs because the amp can't eat and is sending your subs a clipped to death signal. Now your out music, subs, and amp. 

Here's what I would do. You spend money once, therefore saving money in the long run. Run your system the way it is until you get enough money to upgrade your electrical to what you'll need (big alternator and I would recommend lithium). Install that. Then, get yourself a Sundown Audio SFB8000.1D for about $640. Full bridge amps are compact and very cost effective. Given the correct about of electrical for it to eat, it'll work awesome! And if there is a problem, Sundown has a reputation for good customer service. So now, if you choose, you don't need those Massive Audio amps anymore. Flip them for the cost of you SFB (or more) and essentially you just got a free amp. So instead of spending more than you wanted because you broke some stuff being impatient, you waited and did it right the first time. If I would have done that to begin with, it would have saved me $11,000 or more. 

As far as impedance rise goes, at times, your amp can see 6-7-8- maybe even 16 ohms. I don't know what exact subs you have, but if your willing to throw "6k" at them, what's another "1000 watts" per sub? Besides, you could always just set your gain conservatively and not worry about it. 

As always, that's just my opinion. I'm not going to tell you how to spend your money bro. 

 

[DallasBass91]

1 hour ago, Dafaseles said:

So, strapping amps essentially makes it 1 amp, almost like bridging 2 channels on a 4 channel, making it one single channel with twice the power. Usually, when you bridge a 4 channel amp, you can't bridge at 2 ohm (the lowest impedance a single channel can handle) because the amp can't handle it. It'll either throw the amp into protect, or fry the amp. So usually it'll be 100 watts per channel at 2 ohm or 200 watts bridged at 4 ohm. Same deal with strapping amplifiers. It'll be 3000 watts at 1 ohm or 6000 watts at 2 ohm. So you wire your d4's to an 8 ohm final impedance each, so the monoblock sees 4 ohm because if you where to wire it down to 2 ohm each, then send a final 1 ohm to the strapped amplifiers, technically it should give you the power of 1 amp at .5 ohm ×2. Now, the company doesn't recommend this. You do this, you void the warrantee if something where to happen. 

As far as the being broke aspect goes, think about this. There's 2 things that can happen. One thing is you do it, you spend a twice as much on your electrical to support such a low impedance, and you fry your amps anyway and have no audio until you get the dough for a new amp. Or. You do it without upgrading your electrical and you fry your amps and your subs because the amp can't eat and is sending your subs a clipped to death signal. Now your out music, subs, and amp. 

Here's what I would do. You spend money once, therefore saving money in the long run. Run your system the way it is until you get enough money to upgrade your electrical to what you'll need (big alternator and I would recommend lithium). Install that. Then, get yourself a Sundown Audio SFB8000.1D for about $640. Full bridge amps are compact and very cost effective. Given the correct about of electrical for it to eat, it'll work awesome! And if there is a problem, Sundown has a reputation for good customer service. So now, if you choose, you don't need those Massive Audio amps anymore. Flip them for the cost of you SFB (or more) and essentially you just got a free amp. So instead of spending more than you wanted because you broke some stuff being impatient, you waited and did it right the first time. If I would have done that to begin with, it would have saved me $11,000 or more. 

As far as impedance rise goes, at times, your amp can see 6-7-8- maybe even 16 ohms. I don't know what exact subs you have, but if your willing to throw "6k" at them, what's another "1000 watts" per sub? Besides, you could always just set your gain conservatively and not worry about it. 

As always, that's just my opinion. I'm not going to tell you how to spend your money bro. 

 

Solid advice there, sounds like if I wire it down I’m blowing something no matter what, I guess I’ll just have to save up for a new amp and run this setup until then, I have a 300amp alt on the way from js and a couple xs d3100 batteries, I’ll probably try the taramps bass 8k instead of the sfb line, hopefully it works out for me. I’m running 2 x18’s btw 

[Dafaseles]

What 18's? Not that it really matters, just curious. Sounds like a cool setup. You've probably said in another thread, but this last weekend was pretty hectic. Sorry I missed it. 

And Taramps is solid. 

I know you're not dumb, but I've heard this too many times for me not to say something as a warning. People say, "well, I don't understand why I need $2000 worth of electrical upgrades for a $300 amp. That's just stupid." Or something to that effect. Just because the amp is cheaper because of it being a full bridge amp, doesn't mean you need less electrical! 8000 watts is still 8000 watts! That's nothing to sneeze at. So electrical upgrades are a must! It seems like you've got a good plan though. Just figured I'd say something lol. 

 

[DallasBass91]

Just now, Dafaseles said:

What 18's? Not that it really matters, just curious. Sounds like a cool setup. You've probably said in another thread, but this last weekend was pretty hectic. Sorry I missed it. 

And Taramps is solid. 

I know you're not dumb, but I've heard this too many times for me not to say something as a warning. People say, "well, I don't understand why I need $2000 worth of electrical upgrades for a $300 amp. That's just stupid." Or something to that effect. Just because the amp is cheaper because of it being a full bridge amp, doesn't mean you need less electrical! 8000 watts is still 8000 watts! That's nothing to sneeze at. So electrical upgrades are a must! It seems like you've got a good plan though. Just figured I'd say something lol. 

 

Lol I appreciate the sound advice, never hurts to put it out there, I have the sundown x18’s v.1 d4 in a newly built flat wall in a 2015 Altima , I’m hoping to get the v2 recone when they come back. Also for power I have the 300amp js alternator on the way, xs power 3400r under the hood, d3100 in the back, big 3, all grounds are sanded, rear battery has a dedicated power run from the alternator as does the front battery. All cables is OFC. 1/0 except for the speaker cable which is 8ga I still still have to brace the inside of the port which is a slotted port along the top of the subs (adjustable port/removable). Wall is made of MDF and the port is made of birch with a MDF baffle. Lots of foam and every other part of the box has been braced

[DallasBass91]

6 minutes ago, Dafaseles said:

What 18's? Not that it really matters, just curious. Sounds like a cool setup. You've probably said in another thread, but this last weekend was pretty hectic. Sorry I missed it. 

And Taramps is solid. 

I know you're not dumb, but I've heard this too many times for me not to say something as a warning. People say, "well, I don't understand why I need $2000 worth of electrical upgrades for a $300 amp. That's just stupid." Or something to that effect. Just because the amp is cheaper because of it being a full bridge amp, doesn't mean you need less electrical! 8000 watts is still 8000 watts! That's nothing to sneeze at. So electrical upgrades are a must! It seems like you've got a good plan though. Just figured I'd say something lol. 

 

I do want to go lithium though I was thinking headway cells or something like that to save money instead of buying a built one. 

[Dafaseles]

51 minutes ago, DallasBass91 said:

I do want to go lithium though I was thinking headway cells or something like that to save money instead of buying a built one. 

Nice! 

On the FI website, right now they're having a sale on ying long cells. I don't know how much headway cells are. Just figured I'd throw that out there. 

 

[DallasBass91]

7 minutes ago, Dafaseles said:

Nice! 

On the FI website, right now they're having a sale on ying long cells. I don't know how much headway cells are. Just figured I'd throw that out there. 

 

I’ll check it out thanks for the heads up