I have a somewhat general question about L-Pads with fixed resistors. I am still working on my LE14A/LE85 project. I measured the relative sensitivity of the two drivers and find the LE85 about 19dB higher than the LE1`4A (no fixed L-Pad, 16 ohm variable L-Pad set @ 12 o'clock). The JBL L200B network (which I am using as a starting point) uses an L-Pad composed of 2.5 ohm series and 5 ohm parellel. This does not provide enough attenuation for my horn. In researching options, I have found two resources with different options:

I tried the L-pad as calculated in the cookbook and the attenuation seems about right, but I am wondering what advantages there might be to using the pi speaker approach (they claim increased damping of the horn) and how one might calculate values. Also I wonder that JBL uses a small series resistor and larger parellel resistor in most of their designs.

- The pi speakers article on cross-overs which was excellent http://www.pispeakers.com/Speaker_Crossover.doc shows the 'L' backwards from the JBL (which I believe is standard) version with the series resistor coming AFTER the parellel. It also tends to have a series resistor larger than the parellel one. Unfortunately, they do not give formulae to calculate values.
- Vanc Dickerson's Cookbook gives the formula for a fixed L-pad. Unless the labels of R1, R2 are swapped (which is why I refer to parellel and series rather than 1-2), the series resistor comes out much larger than the parellel one. (For 16 ohm, 16dB attenuation, the numbers are sereis= 13, parellel = 3)

Finally, pi speakers bypasses their series resistor with a small cap (which varies between 0.47 and 5 uF). Not sure how this value is calculated. The L200B accomplishes this bypass with 1 uF cap and 0.16mH coil and a fixed 5 ohm resistor. Does anyone really understand how this circuit works or how the values are calculated? I would like to add a little more high end boost (above 10k) but at this point it would be blind guessing at alternative values.

Thanks for all your help. This forum is really great!