quick question about bower compression..

[shadyJ]

How long does it typically take for power compression to drop the sensitivity of a driver? Is it gradual or can it happen within seconds? I don't know how fast the VC will heat up. My guess is it would take a minute or so of hard use to significantly raise its temperature. Also, how long does it take for the VC to cool down, or how long does it take for the driver to regain its sensitivity after it has dropped?

crap, another question, how do I change a typo in the title of a post, lol

 

[fuzz092888]

Hot Stuff: Loudspeaker Voice-Coil Temperatures | Stereophile.com

I think this may help.

 

[shadyJ]

Thanks for the link, it seems to suggest that it does take a few minutes of heavy use for resistance to rise.

 

[Steve81]

I would think it depends on a few factors: actual amount of energy being dissipated as heat in the VC (factor of power levels and driver efficiency), driver design (VC heat sinking & venting), the cabinet (I would imagine that a sealed cabinet might allow for greater heat build up than a vented cabinet), etc.

 

[TLS Guy]

How long does it typically take for power compression to drop the sensitivity of a driver? Is it gradual or can it happen within seconds? I don't know how fast the VC will heat up. My guess is it would take a minute or so of hard use to significantly raise its temperature. Also, how long does it take for the VC to cool down, or how long does it take for the driver to regain its sensitivity after it has dropped?

crap, another question, how do I change a typo in the title of a post, lol

It happens within seconds. Just think how quickly a 40 watt, 60 watt and 100 watt light bulbs heat up.

If we get to really high power, think of it in terms of a toaster or electric fire.

Getting the heat away fast is a huge challenge. There are no cheap drivers that achieve this.

How long recovery takes, is dependent on program and driver design.

 

[shadyJ]

Thanks for the info guys!

 

[Grador]

I think the question has been answered quite well already, but to give you a good analogy: you can think of the Voice Coil like a pot of water on a stove. Some voice coils take more energy to heat up [think of this like the amount of water in the pot], some are better at giving off this heat than others [think of the pot being shorter and wider like a saute pan].

Now you can think about the volume you're on your system [energy] as the exact same thing as how high you turn up the stove [...also energy]. At a certain point the water will start to steam just like at a certain point you will start to get some thermal compression. At a certain point no matter you hit a limit, the water will boil, and the resistance of the VC will increase to a point where it limits power.

Given that power compress [thermal compression] is directly dependent upon temperature, how quickly it goes away is a variable of the factors listed above.