How to figure out OHM load?

[HHR Ed]

Looks like they are running 10's in the car now. Last time I was at hughes house, they where testing with 12s. Didnt know they changed it up.

They are running 1 NSB75 with drop to 10.3 volts, and 4900watts.

http://audioforum.termpro.com/topic/4/20431/2.html

I didnt say that all tested at higher frequancys. Just a thing Ive noticed with some companies. I was trying to find the exact post on Termpro that I seen it, and the freq was 100hz. It was just used as an example. Not something to base every amplifier off of.

ahh, I C. Yeah I remember seeing a test Murilo did on a SD12k and it was a 100hz tone I believe.

And I think he is only getting 6K out of his 12Ks in his Street B Panda.

Those tiny boxes have a big impedance rise.

[Nova]

Bangin caddy, thanks for the great info. That's exactly what I wanted to know. But in a simple dummy form for me, if I'm running more than one sub and I wire in parallel I would do the equation like this: 2 dual 8 ohm subs, take the 8 ohm then divide 4, I would be running at 2 ohms. If I wired them in series it would be: 2 dual 8 ohm subs, take the 8 ohm and multiply it by 4, I would be running at 32 ohms. Yes?

4 dual 2 ohm subs in parallel would be 2 ohm/8 = .25 ohm series would be 2 ohm(= 16 ohm

Edited October 6, 2009 by Nova

[audiofanaticz]

Ive searched thru 12 or so pages in the amp section on termpro to try and find it, but it was a while ago. So its prob deep in the forums now and the search feature sucks so bad imo. LOL

All I could find was dante vs SD ego trips.... LOL

Dante: sd amps make dc current, 5 year warranty wont make the company last.

Murilo: our amps are lifetime warranty.

dante: sd amps go poof unlike stetsom.

Murilo: we have 10 stetsoms fixing for customers now.

Or something simular to that... LoL

All you see is fried this or fried that from Brazil for the most part.

[audiofanaticz]

Bangin caddy, thanks for the great info. That's exactly what I wanted to know. But in a simple dummy form for me, if I'm running more than one sub and I wire in parallel I would do the equation like this: 2 dual 8 ohm subs, take the 8 ohm then divide 4, I would be running at 2 ohms. If I wired them in series it would be: 2 dual 8 ohm subs, take the 8 ohm and multiply it by 4, I would be running at 32 ohms. Yes?

4 dual 2 ohm subs in parallel would be 2 ohm/8 = .25 ohm series would be 2 ohm(= 16 ohm

Correct.

[HHR Ed]

Bangin caddy, thanks for the great info. That's exactly what I wanted to know. But in a simple dummy form for me, if I'm running more than one sub and I wire in parallel I would do the equation like this: 2 dual 8 ohm subs, take the 8 ohm then divide 4, I would be running at 2 ohms. If I wired them in series it would be: 2 dual 8 ohm subs, take the 8 ohm and multiply it by 4, I would be running at 32 ohms. Yes?

for 2) dual 8 ohm subs

If you are running in series just add up all the ohm loads. so 8+8+8+8=32 ohms.

for parallel

1/coil1 + 1/coil2 + 1/coil3 + 1/coil4 = 1/total = 2 ohms

Edited October 6, 2009 by HHR Ed

[Hotdog]

How do you find out what your impedance Rise is?

Play at close to full volume with ohm meter on speaker wires at amp?

Now my setup is kinda weird because I have 4 dual coil 4ohm subs... 2 subs are wired to 4ohms then wired together to 1ohm. The other 2 are wired to 8ohm then wired together to 4ohm then the 4ohm and 1ohm wires are wired together to get .8ohm but what I am actually seeing at the speaker wire is 1.1ohm

[Nova]

Correct.

Thank you.

[audiofanaticz]

How do you find out what your impedance Rise is?

Play at close to full volume with ohm meter on speaker wires at amp?

Now my setup is kinda weird because I have 4 dual coil 4ohm subs... 2 subs are wired to 4ohms then wired together to 1ohm. The other 2 are wired to 8ohm then wired together to 4ohm then the 4ohm and 1ohm wires are wired together to get .8ohm but what I am actually seeing at the speaker wire is 1.1ohm

You have your stereo wired up bad.

I have a feeling one set of woofers is seeing more power then the other set.

What you should do is series all the coils together on all 4 subs, then with the remaining 2 wires from each sub parallel together.

However your amp will be played at 2 ohms.

But the result of how you have your setup wired is proboly the difference in your actualy reading at the speaker wires.

As for calculating impdance rise, burp your vehicle at a said frequancy measure AC voltage and current then use ohms law find the actual impedance at said freq.

[Hotdog]

You have your stereo wired up bad.

I have a feeling one set of woofers is seeing more power then the other set.

What you should do is series all the coils together on all 4 subs, then with the remaining 2 wires from each sub parallel together.

However your amp will be played at 2 ohms.

But the result of how you have your setup wired is proboly the difference in your actualy reading at the speaker wires.

As for calculating impdance rise, burp your vehicle at a said frequancy measure AC voltage and current then use ohms law find the actual impedance at said freq.

Would the speaker wire at the amp reading be correct?

[Boon]

The most power I have seen out of an amp in a street class setup is about 7000w. and thats on a 12K

Off topic but I was reading some euro stuff recently and they reckon they've reached the conclusion that ~8000w is pretty much the absolute maximum you can get from a single battery.

So with all these monster amps available now you're better off running at 1 ohm nominal or more and not thrashing the amp