Re: 4012HO vs TD12S [message #78969 is a reply to message #78967] |
Thu, 16 January 2014 12:47 ![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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The TD12S has excessive breakup above 800Hz.
When we first began using the the TD12S woofer, it did not exhibit this behavior. But last year, a customer came to me and showed me response of his speakers, which looked like what you see below. I then tested some other recent drivers and they had the same response. So we had to drop them.
To be honest, at first I thought it was a vendor problem at Acoustic Elegance, and that after bringing it to John's attention, he would get to the bottom of it. Either change cone vendors, or begin to advertise the speaker as recommended for use below 800Hz. Instead, I was surprised to see him deny this, and has even resorted to mudslinging.
So I'm here to respond to that right now. I encourage everyone to measure their own TD12S drivers. If you have sufficient resolution, and you have one of the "bad batch" of drivers, you'll see this kind of response in the far field, measured anechoic on a baffle:
Acoustic Elegance TD12S woofer amplitude response
Here is a close-up of the impedance curve, showing the impedance blips where the cone is resonant:
Acoustic Elegance TD12S woofer impedance, zoomed to show regions of cone breakup
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