Voltage experts!! Help!!!

[mazzasec 5,000+ posts]

how many runs of 0/1 from batt to amp?

Correct me if im wrong but you cantreally do more thne 2 runs from the battery to the amp and positive run and a negative...

 

[IDSkoT 5,000+ posts]

Honestly I dont think you should drop that low even in the front. IMO But I really dont know how much current that amp pulls at .5.

I know that SD3000 is a BEAST, especially at .5 Ohm. That could be your "problem." Your amp is too beastly. If you have another amp that you can hook up to your subs at a higher resistance, you should try it.

Correct me if im wrong but you cantreally do more thne 2 runs from the battery to the amp and positive run and a negative...

Technically you can have more... but then it'd just siphon into whatever the max gauge your amp can hold so it's basically pointless... but possible!

 

[davidt487 10+ year member]

0/1 is only good for abot 300 amps so you need 2 run from batt to amp

 

[JBGabriel 10+ year member]

Correct me if im wrong but you cantreally do more thne 2 runs from the battery to the amp and positive run and a negative...

No you can do as many runs as you want. Your basically just making it easier for current to flow.

 

[IDSkoT 5,000+ posts]

0/1 is only good for abot 300 amps so you need 2 run from batt to amp

But if the amp only accepts 0/1 in, then it's pointless to have more than 1 run.

 

[JBGabriel 10+ year member]

But if the amp only accepts 0/1 in, then it's pointless to have more than 1 run.

But you can run as many as you want from front bat to back bat. And that will help because its a long run. The run from the back bat to the amp is so short that is shouldnt matter you wont loose much capacity.

 

[mazzasec 5,000+ posts]

Ive tried already I had 2 runs of positive from the front to the rear. That didnt help.

 

[davidt487 10+ year member]

do to runs use a dis block backwards and use a short piece of 0/1 to the amp them you wont lose so much voltage in wire because 0/1 over 20 ft you will prolly lose a .5 volt

 

[mazzasec 5,000+ posts]

Regardless of how many runs. I feel I should not have to do all that. I am only running 3000 watts with a 250 amp alternator. I know people running more power with smaller alternators and having voltage fine.

 

[cx-7heaven 10+ year member]

Pyramid 50 Amp Power Supply

8 AWG from supply to batteries

Kinetik 2400 Battery

Duralast 1000 CA Battery

2 AWG between batteries

4 AWG from batteries to amp

Fluke AC current / voltage meter

Sears DMM

Measurements:

65.8 volts

49.2 Amps

1.33 ohm calculated rise from 0.6 ohm DCR **

3237 Watts

14.4 volts rest dropping to 10.75 volts

** - Rise was higher than when I tested the 1500D, it was 1.08 ohms for that test. Presumably since my single run of 12 AWG speaker wire is heating up some much due to the extra power. I also did a few test runs at lower volume so the coils were warmer as well.

-----------

UPDATE ON AUGUST 26 2007:

Sean Belanger drove up from SC today with his O-Scope and a bunch of meters.

This setup was in my SPL truck with the engine OFF. At this time I have 2x Powermaster D3100s, 1x Kinetik 2400, and 1x DEKA Intimidator hooked up in the truck.

I had my trusty 50-amp pyramid supply hooked up to my batteries with 12 AWG wire just to keep them topped off, supply was set to charge at 12.8 volts and no higher.

Discovered the following from the testing:

1) Power output stays about the same as what I measured above even with a drop to around 11.8 volts.

2) Efficiency was high at 0.5 DCR with a rise to 1.32 ohms @ ~80% measured at 3030 watts of output.

3) At 0.5 DCR with a rise to 2.08 ohms we measured ~90% efficiency at 2572 watts of output.

4) When the amp was dropped down to 0.175 DCR with a rise to 0.82 ohms power only increased to 3450 watts. At this load we had to roll the volume to avoid protection so voltage was dropping to 11.2 volts by the time we got a reading. Efficiency dropped to around ~65 - 70% at this load.

5) We could have gotten more "output" from the amp but we stopped increase gain and volume when clipping made the wave-form ragged.

My conclusion for the SAZ-3000D is that, even for SPL competition, that dropping under 0.5 DCR won't gain very much. The power gain is small and results in a significant reduction in efficiency.

In a Street-A or similar one-battery limited vehicle the 3000D seems to work best for 0.5 DCR with a 2x - 4x impedance rise for maximum efficiency levels, especially if multiple amps were utilized and efficiency were key.

That is straight from Jacob. Note the batteries. You do not have enough battery to keep voltage up.

 

[mazzasec 5,000+ posts]

cx_7heaven that post was completely pointless. And I have 1 g34 and 2g31's and a 250 amp alt and your telling me I dont have enough eletrical to keep it higher?

 

[iamamp3pimp 5,000+ posts]

Alright so I am starting to get very pissed about my voltage. Before I was running a sundown 3000d @.5 with 1 g34 under the hood and 2 g31 in the rear. stock alt. Volts dropped to 11.4 full tilt. Now I got a Mechman 250amp alt thinking my voltage problems would be solved. But no. I get out my DMM. Full tilt idle battery under the hood reads 12.5 but then I DMM at the amp and I read 11.8 I have literally tried EVERYTHING. Switched grounds, grounded ALL batteries to chassis then grounded to each other. Ran a run of ground from the front Neg to the rear Neg. That didnt help so then I ran an UNFUSED run from the positive up front to the positive in the rear. STILL having problems. So as of right now this is the equipment and it cant be right.
Sundown 3000d @.5

1 G34 under hood, 2 G31 in the rear. 250 mechman alt.

At idle ALL batteries read 14.4. At full tilt front reads 12.5 at idle and the amp reads 11.8 When I rev up to 2000rpm amp reads 12.1.

My question is WHAT IS THE **** PROBLEM!!!!!!!!!!!!

heres the problem

H.O. alts are overrated.

nothing wrong with 11.8 v at full tilt...shit, mine used to drop down to 9.6 v and would still play

now it doesnt go below 12.2, and i have more power than you, and about 50 bucks worth of batteries in the back.

I picked up some duralasts off this guy for 10 bucks

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[JBGabriel 10+ year member]

All that testing is with the truck off though. THe amp is only running off the batteries.

 

[mazzasec 5,000+ posts]

heres the problem
H.O. alts are overrated.

nothing wrong with 11.8 v at full tilt...shit, mine used to drop down to 9.6 v and would still play

now it doesnt go below 12.2, and i have more power than you, and about 50 bucks worth of batteries in the back.

I picked up some duralasts off this guy for 10 bucks

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

So what ur saying is I basically wasted 300 bucks on an alternator? With my stock 105 amps I dropped to 11.4 full tilt at idle. With my new 250 amp alt I drop to 11.8 full tilt at idle. So my 300 dollar, 250 amp alt only helped me gain .4 of volts?

 

[chaunb3400 10+ year member]

cx_7heaven that post was completely pointless. And I have 1 g34 and 2g31's and a 250 amp alt and your telling me I dont have enough eletrical to keep it higher?

I think thats what that post said //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

The sundown appears to be a current hog...