gbyleveldt
AVForums Grandmaster
OK, so I've been messing around with SoundEasy up to a point where I can extract repeatable T&S measurements from a few drivers. The only difference is that, while the specs are the same for similar drivers, they are different to the published specs!
The CA18RLY drivers I'm using at this point have two sets of published specs available, both from Seas. One set is for Nov '03 and another set is for Aug '06 both being completely different. These are also different from my measurements (which might be flawed) and different still to the measurements that John (Zaph) has made (using SoundEasy)! What to do?!
This is what I'm doing: My driver is lying flat on my desk (cone facing up - is this wrong?) and then I do a simple Impedance measurement on it. I then add prestik (measured on a digital scale) to give me a 25% lower Fs and then, using a Delta Mass calculation, I can obtain the driver T&S. According to Zaph he believes that this method is incorrect and you should use the Delta Volume calculation. WHY?! Is this the reason why my measurements differ? There is no mention made of this in the SoundEasy guide. Timber suggested that I do the measurements in half space. Again, why? I'm not doing SPL measurements, I'm doing small signal analyses. I'm not trying to argue with any of the above statements, I'm just wondering if I'm doing something wrong. Any ideas?
Seas specs to follow
The CA18RLY drivers I'm using at this point have two sets of published specs available, both from Seas. One set is for Nov '03 and another set is for Aug '06 both being completely different. These are also different from my measurements (which might be flawed) and different still to the measurements that John (Zaph) has made (using SoundEasy)! What to do?!
This is what I'm doing: My driver is lying flat on my desk (cone facing up - is this wrong?) and then I do a simple Impedance measurement on it. I then add prestik (measured on a digital scale) to give me a 25% lower Fs and then, using a Delta Mass calculation, I can obtain the driver T&S. According to Zaph he believes that this method is incorrect and you should use the Delta Volume calculation. WHY?! Is this the reason why my measurements differ? There is no mention made of this in the SoundEasy guide. Timber suggested that I do the measurements in half space. Again, why? I'm not doing SPL measurements, I'm doing small signal analyses. I'm not trying to argue with any of the above statements, I'm just wondering if I'm doing something wrong. Any ideas?
Seas specs to follow
