0 ohm load possible?

[qkassidyw 10+ year member]

I wear my sunglasses at night...

 

[Kyle_Keating 10+ year member]

which is why more voice coil is always better ! I'm sure you can attest that most drivers will have a minimum of 3db of power compression when given rated power for any extended period.


Also FYI to everyone... I believe if you are going to try cooling your sub motors with compressed gas you'd want to use nitrogen, which is inert...

Filling a sub box with nitrous oxide which is an oxident might not be a good idea since we are dealing with a significant amount of heat and enough voltage to create sparks.. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

actually more wire does not guarantee lower distortion, the properties dont change. Sure you can ultimately put more current into a larger mass of wire, but this leads to other complications, higher moving mass creates sensitivity losses and a moving coil can induce a magnetic charge inside the motor making it act as a loss inductor which causes frequency dependence sensitivity losses and also creates a flux modulation distortion at lower frequencies depending on the symmetry of the inductance with respect to displacement. More wire also does not get rid of the fundamental problem, even just a little current will cause a difference in temperature which then causes a difference in resistance in aluminum and copper. And arguably if you have more wire, you'll need more current to move it which is why more B is generally the sound quality approach to increasing BL. More B can also combat flux modulation and inductance by creating a saturated motor that is incapable of storing more charge in one direction due to saturation, and likewise it wont allow magnetic charge to be stored in the reverse direction (because the magnets keep it steady) its hard to get a motor to saturate in the right locations but non the less... more wire is not a sound quality catalyst.

 

[Haunz 10+ year member]

^ certainly you can't just add a larger coil to any given driver and not expect to effect it in multiple ways... but my line of thinking is more strait forward then all that, and I am sure you will agree...

If you have 500watts of power you are going to get less power compression (not to mention less distortion) feeding that power to a 1000 watt driver rather then a similar 500watt one...

 

[Pl8er 5,000+ posts]

Replacing oxygen with another gas in your sealed enclosure would be harder than trying to reach absolue zero with a blow torch and some gasoline.

HA HA HA HA HA HA!

I LOL'D!!

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

:ROFL:

 

[Pioneer~Saturn 5,000+ posts]

I wear my sunglasses at night...

Im going to have to agree here..

 

[djman37 5,000+ posts]

If you run 4 single vc 1 ohm subs in parallel you get a 0 ohm load?

you will never get to 0 Law of diminishing returns I believe? That load presented is only .25 ohms. 1 ohm divided by 4. And I'm not reading 3 pages of the flaming yet, I'll wait until I'm on the clock.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Ed Lester 10+ year member]

what school taught you about superconductors ? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

Ohms law works just fine.. you have zero voltage drop across zero resistance.. current transfer is almost instantaneous as the electrons flow @ 2.99X10^8 m/s (the speed of light).

Current flow is what it is, and the more current you can feed, the more current will pass untill a critical point in the magnetic field around the superconductor is reached and the meissner effect breaks down. At this point it is no longer a superconductor.

O.K. lets try a simple Ohm's Law equation using 0 ohms.

Lets find the current of a circuit which has 12v and 0 ohms of resistance.

Now Current equals voltage divided by resistance.

12v/0 ohms = ?????

alright, lets try to find wattage with that number.

we can use volts squared timer resitance.

12 x 12 x 0 = 0.

So I guess we have 0 wattage too.

Or we can use 100A as a figure and try and find voltage with 0 ohms.

We just have to multiply current times resistance. so we have.

100 x 0 = 0 and that means we have 0 volts.

Yes Ohm's law is working perfect with 0 ohm superconductors.

Thank you for clearing that up.

 

[ultimate157 5,000+ posts]

O.K. lets try a simple Ohm's Law equation using 0 ohms.
Lets find the current of a circuit which has 12v and 0 ohms of resistance.

Now Current equals voltage divided by resistance.

12v/0 ohms = ?????

alright, lets try to find wattage with that number.

we can use volts squared timer resitance.

12 x 12 x 0 = 0.

So I guess we have 0 wattage too.

Or we can use 100A as a figure and try and find voltage with 0 ohms.

We just have to multiply current times resistance. so we have.

100 x 0 = 0 and that means we have 0 volts.

Yes Ohm's law is working perfect with 0 ohm superconductors.

Thank you for clearing that up.

12v / 0 ohms = infinite current. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[Ed Lester 10+ year member]

12v / 0 ohms = infinite current. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

Is that even possible?

Read the paragraph with figure 7.

http://www.ornl.gov/info/reports/m/ornlm3063r1/pt3.html

 

[Rashaddd 5,000+ posts]

12v / 0 ohms = infinite current. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

How can you have infinite current? Jesus I can't believe people are still arguing its possible to have a 0 ohm load IN REAL LIFE. Obviously you "theoretically" could...just like "theoretically" you could have 100% efficiency..."theoretically" you could reach absolute zero...problem is in real life, its not possible. So in reality, it doesn't even exist, and never will exist, because its not possible.

 

[Ed Lester 10+ year member]

How can you have infinite current? Jesus I can't believe people are still arguing its possible to have a 0 ohm load IN REAL LIFE. Obviously you "theoretically" could...just like "theoretically" you could have 100% efficiency..."theoretically" you could reach absolute zero...problem is in real life, its not possible. So in reality, it doesn't even exist, and never will exist, because its not possible.

Good point.

Also, The OP asked if a 0 ohm "Load" is possible.

Just the fact that it is a "load" means that it will have some resistance.

 

[ngsm13 5,000+ posts]

Tards?

nG

 

[qkassidyw 10+ year member]

O.K. lets try a simple Ohm's Law equation using 0 ohms.
Lets find the current of a circuit which has 12v and 0 ohms of resistance.

Now Current equals voltage divided by resistance.

12v/0 ohms = ?????

alright, lets try to find wattage with that number.

we can use volts squared timer resitance.

12 x 12 x 0 = 0.

So I guess we have 0 wattage too.

Or we can use 100A as a figure and try and find voltage with 0 ohms.

We just have to multiply current times resistance. so we have.

100 x 0 = 0 and that means we have 0 volts.

Yes Ohm's law is working perfect with 0 ohm superconductors.

Thank you for clearing that up.

I was going to post this but I didn't want to get involved. This pretty much solves it.

When you get to higher speeds (500 mhz) though the equation changes because the behavior of current changes, as well as resistance. But that isn't relevant in this argument.

Any EE's on here that want to chime in?

 

[helotaxi 5,000+ posts]

Now when a driver moves, the movement as well as the passing current create great amounts of heat. This can greatly increase the resistance of a voice coil.

Care to explain what the movement has to do with coil heating? 100% of the coil heating has to do with the fact that only a very tiny amount of the current going through the coil creates any motion. All the rest is simply heating the coil. The movement of the coil creates air circulation around the coil and actually cools it.

In high power applications, coil heating can have a huge impact on the driver impedance. There are two parts to driver impedance, the resistance portion and the frequency variable portion based on the coil inductance and the movement of the coil in the magnetic gap. At certain freqs the resistance of the driver will make up the bulk of the driver impedance (right at resonance in a ported enclosure is a perfect example). At this freq, resistance rise due to coil heating is a big factor.

 

[Ed Lester 10+ year member]

movement can heat up the cone, and suspension. Certain types of foam rubber surrounds lose tension from the heat when moving, this changes driver characteristics.