There are 23 turns of wire on the after market one and 25 turns on the original, assuming I counted correctly.  Another after market coil (not shown) has 21 turns.

Admittedly, EV could have made these changes over the years but when purchasing an after market replacement, one has no idea of what they will receive.  Then there's the material from which the diaphragm is made.

While these differences may seem insignificant, the pair of T-350s I have, although they sound similar under most listening conditions, pink noise will reveal the sonic difference, not to mention a frequency response curve.

While the sonic difference is subtle to un-noticeable, it becomes tantamount to a nightmare to someone like me who likes to upset apple carts.  The caveat is that 'it's dangerous to be right when the established authorities are wrong' - VOLTAIRE.

The clamp is painted purple because it works better.  That claim is made without proof.

A brief description of the LMS is at the bottom of this page.

The stick on the floor next to the triangle is 1 meter long.

I realize this looks like a jumbled mess and one would be forever lost if it were a road map.  There are clearer curves below but it's a little less clear as to their relative  performance.

However, all vertical and horizontal scales are the same and the vertical scale had been stretched to separate the curves.  It looks a lot worse than it is.  Manufacturers sometimes compress the vertical scale to make the curve look flatter, like in the next piccy.  They do all sorts of things to make their product look better. One thing most don't do is specify the conditions under which the data was acquired.  Without the conditions, the data is essentially useless.

Another set of curves was run after writing this far and the difference with and without a flat baffle was negligible, about a 1.5dB variation around the band between 3khz and 9khz. but nothing that came close to the light green response.

I once asked Paul Klipsch about the 90 degree rotation of the T-35 and his reply was that it makes very little difference as high frequencies tend to beam anyway.

The above seems to verify the expression that states, "In theory, there's no difference between theory and practice.  In practice, there is."

That curve was run by the same methods always used, gated sweep.  This curve waas run with the speaker in chamber of the three way system.  In free air, then high frequency peaks were still evident with a low frequency roll-off due to no baffle.  When I compared this curve to that of the manufacturer, I concluded there was nothing wrong here.

The manufacturer's data sheet can be found here.

FW146

The product page is here.

Parts Express

This repetition was done to verify the unexpected results in horizontal dispersion versus horn orientation which I hope will be explained below.

The medium green & medium red are 23 & 46.

The lightest green & light pink are 25 & 47.

Ignore the crosshairs; I forgot to move it aside before capturing the screen.

The curves 45, 46 & 47 were run a day later than 21, 23 & 25.

The main oddity is the 23 & 46 pair compared to the 25 % 47 pair.  They show higher output in the octave between 5khz to 10 khz with the horn horizontal. This is contrary to theory.  However, in an attempt to explain this, the conclusion was decided that while the above may be true, the response is not very flat.  While the octave mentioned above may be only 3dB higher when the horn is horizontal, this will make the horn sound very bright due to the width of the passband, one full octave. The response is much flatter with the horn vertical.

This also shows that horizontal dispersion of this horn is essentially moot above about 12 khz.  Paul Klipsch was right when he told me in response to my asking about the horizontal orientation of the tweeter that high frequencies tend to beam and they surely do. I wonder how much, if any thought he gave to that 3dB rise in that 5khz to 10khz octave. 

Looking at the curves above 12 khz, 30 degrees off axis with the horn vertical versus horizontal shows no difference with the exception, especially with the horn vertical, of the drop of about 5 dB compared to the on axis response.  The pair of vertical orientation curves is extremely similar to that of the on axis response.  (Lightest green and light pink being close to parallel to dark green and dark red.)

The upper dark blue is 48, the lower not so dark blue is 49 and the light blue is 50.  The 3dB rise in the octave between 5khz and 10khz is also evident here.  

There are two sides to each data sheet.

FYI:  To convert the no longer used EIA sensitivity rating to the current RETMA, add 49dB.

The derivation of this is shown at the bottom of the page.