Re: 4012HO vs TD12S [message #78976 is a reply to message #78975] |
Fri, 17 January 2014 08:32 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to previous message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18753 Registered: January 2001
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Illuminati (33rd Degree) |
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I agree with you. Older model drivers are perfect, and I used them for years without issues. But four samples of recent drivers all measured as shown in the charts I posted above. My suspicion is that AE got a batch of cone assemblies that were different than what they used in the past, and exhibit the breakup we see above.
I'm not sure when this new cone batch first appeared on the scene, and John has not been forthcoming, so there's no really way for me to know how to identify versions of the TD12S driver by way of something like serial number or build date. It may not even be as simple as a "bad batch" of cones. It might be something else, altogether. All I know is my early measurements of TD12S drivers were good, but this last year, I measured four that were as shown above, and therefore best used below 800Hz.
Hey, just for reference, what does your driver's amplitude response look like? You remember the response charts of my three π speakers with TD12S drivers manufactured a few years back: Nice and smooth, nothing like the ones I measured last year. Are all of yours like that?
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