You can test a sub free-air with a cordless drill battery. If it moves and it doesn't scrape, it's good.
What you're probably hearing is your home receiver falling on its face when tasked with running a reactive load like the W7. Some amps just can't hang and don't have the current capabilities to run something like that woofer. What happens here is that the signal gets all screwy and causes the sub to make some really strange noises. This is different from straight up clipping/overdrive and will not sound the same.
To complicate matters even more; a poorly sealed box or improperly engineered vented box can exhibit the same symptoms.
What you're probably hearing is your home receiver falling on its face when tasked with running a reactive load like the W7. Some amps just can't hang and don't have the current capabilities to run something like that woofer. What happens here is that the signal gets all screwy and causes the sub to make some really strange noises. This is different from straight up clipping/overdrive and will not sound the same.
To complicate matters even more; a poorly sealed box or improperly engineered vented box can exhibit the same symptoms.
