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Message: <blockquote data-quote="audioinformer" data-source="post: 6703814" data-attributes="member: 577879">The sub was a pro audio subwoofer and I was using the LMS program to perform the T/S parameters. Bl is the energy in the magnetic gap times the length of wire in the gap. As you heat up a coil of wire the inductance rises and creates an electrical loss. As a voice coil moves in the magnetic gap of a driver and the center of the voice coil moves from the center of the gap, you are having a loss of the Bl in the gap due to less wire that is effected by the gap. If part of the coil completely leaves the gap, your loss is increased greatly. If the coil of wire is effected by heat and it has an electrical loss, how does this not effect the X-max of a subwoofer? The Bl is being greatly effected by the electrical loss and X-max is the range of a driver with 70% loss of Bl but, X-max is the one variable that does not change? Since there is a possible Bl loss due to heat, then X-max can change and the length of a coil overhung from the top plate will not, voice coil length minus top plate height divided by two is a better and more permanent parameter for X-max since it can not change (unless the spider is sagging so bad that it is moving the voice coil too far out of the gap to be effective).Honestly I have spent too much time on this topic, I have to get back to work and get a project shipped out of China this week since Chinese New Years starts the 10th. and you are right if you like. X-max is what you want it to be and a single 15" nightshade has more displacement than a pair of 12" alphas because the nightshade has 23mm X-max (figured with maximum cone movement with 70% of total Bl) and the alphas X-max is 16mm (figured with coil length minus the top plate height divided by two for X-max) so what ever.... blah blah blah,./.,./.,      Ohh, and the nightshade is 102dB SPL (2.83 volts) and the alphas are 89dB (1 watt 1 meter) so the nightshade wins again,./.,./.,Ohh and Jacob I have nothing against you or your products. The sub that I re-coned seem to have bad glue joints or bad glue as that was the issue and the spiders, coil, cone, and the motor were all pretty close to IA DP but, I could be wrong. At the time i did not have the two subs side by side and i was going off of memory and I have been wrong many times beofre going off of memory so, maybe not. This was a while ago and there is nothing wrong with that and this was the only experience I have ever had with any of your subs. I have also heard that there is no issue with the glue or the joints at the present time. I know where your amps come from and they are a very good quality company. I know Mr. Park and Mr. Frank very well and I have been to their factor as well as meeting with them at CES many times and at the Hong Kong Electronics show once. (If you want to go to a great Korean restaurant in Vegas, go with Mr Frank to Seoul BBQ off of Sahara Ave., that is if you like Korean food.) I don't know either of you that well (Jacob or Electrodynamic) but I do know a lot of other people in the industry and I have been around a day or two my self.</blockquote>

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