Q : Why do my woofers stink?
DD woofers use the highest temperature adhesives on the market. All our voice coils are baked to thermo-set the adhesives. When temperatures around 500 degrees F are seen by the coils, some outgassing from the adhesives will occur. This is a signal that your amplifier is being over-driven and sending a heavy clipped signal to the speaker(s). Immediately turn down the system to let the coils cool, if not, permanent damage will occur. Some outgassing is normal when peak temperatures are approached, the coil adhesive will re-set.
In all likelihood, the volume may only be a couple clicks too high where added sound volume was not increased but clipping amplifier outputs begin dumping heat to the coils. A good rule of thumb: stop turning up the volume as soon as noticeable increase of volume does not coincide with each volume click. In most cases 95% of the SPL can be retained without overdriving the amp.