question about ohms laws

[TheyDontWantMusic]

the "theydontwantmusic" Guy has been giving bad advise since he has gotten on this forum, he has been doing the same in some other threads too, Idk if he doesnt know better, or what, but he doesnt really seem to know what he is talking about

I'm sorry, what other posts did you have trouble comprehending?

[HHR Ed]

MOD POWERS ENGAGE!

that means stop bashing the dude and keep it to the topic please. Points were made, all is understood.

Now, anybody else have stories about Ohmy Ohm?

[TheyDontWantMusic]

MOD POWERS ENGAGE!

that means stop bashing the dude and keep it to the topic please. Points were made, all is understood.

Now, anybody else have stories about Ohmy Ohm?

I have one.... if you're like my friend, and wire at 0.25ohm, in a sealed box, and burp at 35Hz, and find it rises to 0.5ohm, and the amp handles it fine.

don't then play 20Hz, because the impedance rise in a sealed box decreases as the frequency does

[dereileak]

Also seems like each thread his words and usage of his words get more powerful. I swear he is sitting there looking up words. Knowing big words and how to use them does not mean you have great knowledge in amplifiers and how they work.

yea, I know, he think he must be mr. big shot, im not saying he doesnt know jack squat, but he seems to be a bit strongly worded and very opinionated, and much of the info he posts isnt quite right

[HHR Ed]

MOD POWERS ENGAGE!

that means stop bashing the dude and keep it to the topic please. Points were made, all is understood.

Now, anybody else have stories about Ohmy Ohm?

I have one.... if you're like my friend, and wire at 0.25ohm, in a sealed box, and burp at 35Hz, and find it rises to 0.5ohm, and the amp handles it fine.

don't then play 20Hz, because the impedance rise in a sealed box decreases as the frequency does

And in ported enclosures, there is something called "Unloading" This is when playing frequencies below the F3 point causes the woofer and enclosure to uncouple and impedance rise drops. This is very bad for the life span of a woofer.

[dereileak]

MOD POWERS ENGAGE!

that means stop bashing the dude and keep it to the topic please. Points were made, all is understood.

Now, anybody else have stories about Ohmy Ohm?

I have one.... if you're like my friend, and wire at 0.25ohm, in a sealed box, and burp at 35Hz, and find it rises to 0.5ohm, and the amp handles it fine.

don't then play 20Hz, because the impedance rise in a sealed box decreases as the frequency does

I believe the impedance rise is due to the wiring heating up in the voice coil causing it to be harder to push power through it, doesn't matter what frequency you are pushing through it, correct me if im wrong, but I believe that is the truth, if you push 1000 watts through a coil meant for 500, it will heat up, and will cause less power to go through it, v = amps * resistence, as the resistence rises, the voltage will go down, thus the amount of watts (at least I think this would be true for free air, as far as being in enclosures, I am not sure)

[Azagtoth502]

[TheyDontWantMusic]

I believe the impedance rise is due to the wiring heating up in the voice coil causing it to be harder to push power through it, doesn't matter what frequency you are pushing through it, correct me if im wrong, but I believe that is the truth, if you push 1000 watts through a coil meant for 500, it will heat up, and will cause less power to go through it, v = amps * resistence, as the resistence rises, the voltage will go down, thus the amount of watts (at least I think this would be true for free air, as far as being in enclosures, I am not sure)

you're wrong.

the impedance changes because of the movement of the voice coil in the voice coil gap.

different frequencies, and different boxes and tuning will result in the sub moving differently, so the impedance will vary.

edit: the impedance will vary regardless of the amount of power you're giving a woofer, whether it be 1 watt or 1000watts.

a lot of manufacturers will give an impedance and frequency graph in the datasheets for their drivers, which are measured free air, so there's no enclosure effecting the impedance.

for example, the peerless 850136 woofers:

http://www.d-s-t.com.au/data/Peerless/850136.pdf

the impedance is only 8ohms between 100 and 400Hz or so, and rises up to about 20ohm at the drivers resonant frequency of 28Hz.

if you connect an ohm meter to a sub, and push on the cone, the resistance will vary greatly.

[TeamHT]

MOD POWERS ENGAGE!

that means stop bashing the dude and keep it to the topic please. Points were made, all is understood.

Now, anybody else have stories about Ohmy Ohm?

Just basic points that have been made already, just hopefully in a more understanding format.

Impedance rise in my experience has NEVER been a good route to go when planning daily systems. Even if rise does occur, who is to say it will go above 1 ohm where the amp is stable at? It is true some amps have done well below recommended stability, but it is also true more than a handful of boards out there will not.

The issue I see is telling someone yes it can be done, without knowing any information which would even make the statement even CLOSE to accurate, intelligent, or safe for the OP. Yes, some amps can be run below recommended stability. Others won't.

[dereileak]

I believe the impedance rise is due to the wiring heating up in the voice coil causing it to be harder to push power through it, doesn't matter what frequency you are pushing through it, correct me if im wrong, but I believe that is the truth, if you push 1000 watts through a coil meant for 500, it will heat up, and will cause less power to go through it, v = amps * resistence, as the resistence rises, the voltage will go down, thus the amount of watts (at least I think this would be true for free air, as far as being in enclosures, I am not sure)

you're wrong.

the impedance changes because of the movement of the voice coil in the voice coil gap.

different frequencies, and different boxes and tuning will result in the sub moving differently, so the impedance will vary.

edit: the impedance will vary regardless of the amount of power you're giving a woofer, whether it be 1 watt or 1000watts.

a lot of manufacturers will give an impedance and frequency graph in the datasheets for their drivers, which are measured free air, so there's no enclosure effecting the impedance.

for example, the peerless 850136 woofers:

http://www.d-s-t.com...less/850136.pdf

the impedance is only 8ohms between 100 and 400Hz or so, and rises up to about 20ohm at the drivers resonant frequency of 28Hz.

if you connect an ohm meter to a sub, and push on the cone, the resistance will vary greatly.

Im not wrong, heat does play a role in the impedance of a subwoofer, there are many characteristics to calculate all of this, and is almost impossible to do, but increase in heat does infact change what the impedance will be