Originally Posted by Ricci
Properly operating drivers fail for two reasons only. Mechanical damage and burning or overheating the voice coil.
You can cook any voice coil with far under rated power if you try. It is dependent on the signal, signal duration, box alignment, etc...I dont think there is a woofer out there that is impossible to cook with a real 1000w amp. Typical use and music signals are not going to cause it because the average power is far lower than the peaks and are usually not running the amp into heavy clipping (meaning not turned up all of the way effectively). Then there are 100% duty cycle signals like the 20+ second long sine sweeps I use for compression testing. These are 10x worse on the vc than anything that should typically be encountered in program material. Absolute worst case is you dump a pure sine tone into the system at a frequency corresponding to low impedance and minimal cone motion. It is only a matter of time for the heat to build up.
The SI I had survived one of the test sweeps at much more power than the Dayton amp can produce. This leads me to believe that either N8 was running a song with sine waves in it at full power for awhile while heat built up or there was something defective. (N8 I am labeling you a cranker from now on)
In any case this is the reason why generic power ratings are basically worthless because it varies so much. What might be safe on a 1500w amp for one person might get cooked on a 500w amp with another.
Well, I'll admit, I am a cranker lol but in this case, it was the same test I've done 100 times before. Before I ship out any of the subs, I put them through the test to make sure I'm not getting any mechanical noises and to make sure everything seems good to go. I do about 30 mins of free air at close to xmax with a few selected songs to give the drivers some action. I try not to give them anymore than half their power rating during free air testing as well. These 2 sub went at the exact same time with the same amps. The daytons are my usual testing amps and the boxes were 3CF. They weren't making any mechanical noise before the went. On the build up to the big bass note they both just popped and stopped lol. Like I said, I did the same test with the Dayton 18's and they did start to make mechanical noise but I turned it down before any damage. 2 different things. It's likely they were just overpowered, I was not using sine waves or anything else. Thats why i was like "WTF???" It's entirely possible that they may have been defective, I don't know. After ripping it apart, the coil had become completely unwound and was a mess, there were burn marks but it was hard to see with the coil in such a mess. I took my mal-x 21 out and did the same test at 10dB's over what I tested the dayton and SI at and it show no signs of distress or any audible distortion. I know they are not exactly the same quality of driver but I generally only build with top tier drivers.
My 2 new SI's will be here next week and I plan on doing the exact same tests. Though after these 2 sIO's are done, my focus will be shifted to my Gjallarhorn project and my 86 Regal T-Type needs some m ore go fast parts so I can get into the 10's this year