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A couple of weeks ago I received an email from Tang Band touting their new W4-1757S planar coned full range driver. http://www.tb-speaker.com/detail/1230_04/w4-1757s.htm This interesting little neodymium driver purportedly uses an aluminum honeycomb sandwich construction planar cone and a large 1.5” voice coil diameter to help minimize cone flex. The moving mass of the 1857S is 25% greater than for instance, the W4-1337SA. This is to be expected as the flat panel will require additional material to exhibit anything like the rigidity of a conventional conical cone.
Their marketing blurb indicated it has very good off-axis response, but their response plots traditionally only show the on axis response. Curiosity getting the best of me, I emailed them asking for off-axis and HD plots.
Yesterday the response was received TB, and I was pleasantly surprised with what I saw. Not does the variation in off axis response rival or exceed many tweeter responses, but the HD plots look very good as well. Crossing them as low as 400 Hz 2nd order, or even 200 Hz 4th order acoustic appear possible. Forget using them as a woofer: The 2mm Xmax suggests midrange duty and up only. Note that in the HD plot the harmonic responses have been moved up 30 dB for clarity.
Now it’s not without its downsides: The response is pretty ragged above 2500 Hz, but still within +/- 5 dB or so overall, and the impedance curve is certainly not pretty, but the impedance ambiguities seem to translate into response variations rather than linear distortion.
Assuming they respond in real life as well as they do on paper, I could see these utilized in an MTM center channel with very acceptable off-axis response, and the potential for minimal lobing issues. :W
–Or, you could finally build that 12” 2 way you’ve always wanted! :rofl:
The rough top end probably could be massaged somewhat with notch filters, but it’s probably up high enough that it wouldn’t be too objectionable even left as is.
Flat cone drivers have been tried from time to time in the past with limited success. The 'cones' either flexed too much, or were so heavy that sensitivity suffered. It will be interesting to see if and when these will be made available to the DIY community.
C
Their marketing blurb indicated it has very good off-axis response, but their response plots traditionally only show the on axis response. Curiosity getting the best of me, I emailed them asking for off-axis and HD plots.
Yesterday the response was received TB, and I was pleasantly surprised with what I saw. Not does the variation in off axis response rival or exceed many tweeter responses, but the HD plots look very good as well. Crossing them as low as 400 Hz 2nd order, or even 200 Hz 4th order acoustic appear possible. Forget using them as a woofer: The 2mm Xmax suggests midrange duty and up only. Note that in the HD plot the harmonic responses have been moved up 30 dB for clarity.
Now it’s not without its downsides: The response is pretty ragged above 2500 Hz, but still within +/- 5 dB or so overall, and the impedance curve is certainly not pretty, but the impedance ambiguities seem to translate into response variations rather than linear distortion.
Assuming they respond in real life as well as they do on paper, I could see these utilized in an MTM center channel with very acceptable off-axis response, and the potential for minimal lobing issues. :W
–Or, you could finally build that 12” 2 way you’ve always wanted! :rofl:
The rough top end probably could be massaged somewhat with notch filters, but it’s probably up high enough that it wouldn’t be too objectionable even left as is.
Flat cone drivers have been tried from time to time in the past with limited success. The 'cones' either flexed too much, or were so heavy that sensitivity suffered. It will be interesting to see if and when these will be made available to the DIY community.
C
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I'm wondering how they sound though compared to my 1337SA's 
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