I did perform somewhat of a makeshift test on this sub with an enclosure that was smaller than the factory recommended size, and with only 75 watts of power going to the subwoofer. The subwoofer did not appear to have any noticeable rattles, and seemed to work well considering the subwoofer's 90's vintage age. However, please keep in mind that the subwoofer was not being pushed to it's maximum of 300 watts for an extended period of time, nor was the subwoofer in the factory recommended size enclosure, during the makeshift test. I also put a multimeter on each voice coil to show the readings of each voice coil. Unfortunately, with such limited time and limited resources available to me, these were the very best attempts, that I had at my disposal, that I could possibly do to test the subwoofer.
I should be getting some more of these and some JL Audio 8w6v1 vintage subwoofers also in the next few weeks. The item "Used JL Audio 10w6v1 Dual 6 Ohm 10 inch Old School/Vintage 90's Subwoofer #1" is in sale since Wednesday, November 20, 2019. This item is in the category "Consumer Electronics\Vehicle Electronics & GPS\Car Audio\Car Subwoofers".
The seller is "frankinhemi" and is located in Carnesville, Georgia. This item can be shipped to United States.