If 300 watts gives 112db of output at 37Hz, only 6 watts is being converted into sound pressure and 294 watts into heat.

If 600 watts gives 118db of output at 37Hz, only 12 watts is being converted into sound pressure and 588 watts is turned into heat!
For a doubling of sound pressure you would need to have 3000 watts which is 10 times more heat and 2970 watts in a single voice coil.

This is the main reason why voice coils are damaged.
Speakers only convert 1% to 3% of the power from the amplifier into sound and movement, the rest is wasted heat!

A second drive unit with only 300 watts input would give a doubling of sound pressure and a total system output of 600 watts is the best solution for more system output and sustained high power levels.

If you have ever touch a 100 watt light bulb when its on, you will know it can burn your fingers and light bulbs convert 10% of the wattage into light and the rest is wasted as heat. Now imagine a bulb rated a 300 Watts 3 X more power! this is how hot a voice coil can get, this makes the enamel or Teflon soft and fall apart and then the coil's tension or integrity is lost and falls apart, no more sound.

Shadow Works offers a one year limited warranty for all our subwoofers which covers manufacturing defects and workmanship. This does not include abuse or exceeding the subwoofers power rating. This kind of damage will leave clear evidence on the voice coil as a black burnt coil will remain that would have to be driven at 200+% over the rated capacity long term to inflict damage, Its the same as driving a new car engine into the red line and then slamming into a brick wall and then taking it back and saying it broke, this would be user error and not a defect in the woofer.

There will be a re-coning charge on such damaged units, which is fair practice. If used within the power rating we have recommended it will be impossible to damage a unit under normal conditions, so the unit will provide you with many years of high quality listening pleasure.

The laws of physics cannot be changed. If more output is required, add a second unit which can double the sound output. Putting twice the power through a single drive unit does not give you twice the output. For that effect, 10 times the amplifier output is needed.

Please use very high quality amplification, with clean honest power ratings, this gives the best sound quality and performance.

The cheapest amplifiers are typically the worst and always look at the fuse size as this tells us its true power rating.

Using an amplifier that is under powered is not ideal, because you will then over driving that amplifier and it will produce high levels of distortion and this can damaged the coil as distortion is typically pure voltage, it is better too have a higher powered amplifier than an under powered amplifier is the general rule.