How subwoofer can handle over 200W

[DigiSoft]

Ok so I have 15 inch sum woofer and it is rated 2000W as I recall because the writing is blured.

I also have 200W amp. Yesterday I was testing it and I pushed the amplifier almost to the max.

The sound was very clear and loud but the membrane was jumping 1.5 inch in and out and I tough it might break so I turn it down.

Now my question is how some people run this woofers on 1000W amplifiers for example?

I am not scared from burning the coils on the woofer I am scared from ripping of the membrane because it jumps ALOT when I play some hard bass music.

[gearheaddruid]

Digisoft, the power rating is dependent on a lot of variables. You are seeing the woofer going beyond it's Xmax because the enclosure it is in does not have it loaded properly. Was the woofer in an enclosure when you did this? In a sealed enclosure, the air pressure inside the box will prevent massive excursions of the cone. In ported boxes, this will hold true until you get below the port's tuning and then the woofer might as well be in free air.
If you are right on the port's tuned frequency, the woofer will barely move due to resonant air pressure. Most of the pressure is going in and out of the port out of phase with the woofer so it appears to not move much. This is where you could really dump some power into it. Regards, Steve

[Dr.EM]

Are you running the woofers free, ie, outside of an exclosure? If so, they will move a lot less when used in an enclosure. If they are in a ported enclosure then you will also get excessive cone motion at frequencies below tuning. If in a sealed box which isn't significantly oversized, then you have maxed out the woofers (not entirely suprising, 200W IS a lot of power for even 15" woofers if RMS)

That said, I seriously doubt they'll handle 1 or 2KW! There are VERY few drivers which will have that kind of thermal handling.

[anickode]

To back up Gearhead's post, if the subwoofer was not in an enclosure, or not in the appropriate enclosure, there is no resistance to movement.

Another possibility is this: When amplifiers are pushed to their max, they begin to clip frequencies. The result of this is the output signal goes from a proper sine wave, to a clipped wave, or even pulsed direct current. This can cause speakers to blow out at lower than their rated wattages because the voice coil gets locked one way or the other. That's why it's important to match speakers to amplifiers. Underpowering a speaker with a maxed-out amplifier can in fact blow the speakers.

[DigiSoft]

Thank you both for your answers. Your answers really make sense.
I was testing the woofer in air without any enclosures.

I want to make box for this woofer and place it in my car. The biggest problem is that I don't know what kind of box should I build. cylinder? square?

And another problem is that the woofer specs are blured and impossible to read. so I don't know how to calculate the box. Is there something like standard woofer box for 15 inch driver?

THANK YOU VERY MUCH.

[gooki]

60 liters sealed, square is fine

[DigiSoft]

Originally Posted by gooki

60 liters sealed, square is fine

Shouldn't be vented? What box produces better lower tones, lets say from 20Hz and up, vented or sealed?

[Dr.EM]

It'll be harder to design a ported box for a driver with unknown parameters. A sealed box also is likely to perform better at frequencies as low as 20Hz since any ported box will unload the driver below tuning, which will typically be higher than 20Hz. The response of a sealed design is also generally flatter when you factor in the cabin gain of the car.

[DigiSoft]

Originally Posted by Dr.EM

It'll be harder to design a ported box for a driver with unknown parameters. A sealed box also is likely to perform better at frequencies as low as 20Hz since any ported box will unload the driver below tuning, which will typically be higher than 20Hz. The response of a sealed design is also generally flatter when you factor in the cabin gain of the car.

So we can say that sealed box is best for RNB/rap/hip-hop right?

Also should I use damping material for the box?

[gearheaddruid]

Also, shape is not so much concern as internal volume. Figuring the volume gets hard with strange shapes and construction gets a lot more complex. A square or rectangular box would be easiest. Make sure to seal all joints well, any leaks could be fatal to the driver if pushed real hard.