Farewell type 'AL' Hello type 'A-LPD'

[aviserated]

It would be cool if Klipsch installed some sort of tone adjustment device on their future model Klipschorn. I would love to have a new matching pair finished in Dark Walnut.

[3dzapper]

That is unlikely to happen. PWK was strongly opposed to "amatures" like us fiddling with the levels because we lack the proper measuring equipment. If you said it "sounded better", he'd say "BULLSH!T!"

Rick

[Erik Mandaville]

Hi, John:

You said, " just have to ask, .....

Eric, why are you using both an L-pad AND the Autoformer? Both do the same thing, so only one is needed."

Well, that is what I had been thinking, too. Since I am much more familiar with using series connected inductor and capacitor in the midrange branch of a network, I thought that the autoformer was acting exclusively as a voltage divider, sort of like a wire-wound potentiometer minus the shaft, but with various combination of input and output taps used to attenuate the driver. If all it was doing was reducing the voltage to the mid-horn, it seemed to me that an L-pad, matched to the impedance of the driver, would do exactly the same thing, with the added advantage of mainting an even impedance load to the amp.

If you see ALK's note on this in the technical forum, there is more to it than that -- I think...... He knows volumes more about crossover design than I (I have the Cliff's Notes version installed in my brain -- and probably even less than that!), and says that the autoformer should remain in place, and simply add the L-pad across the driver, and be done with it.

The whole thing has gotten sort of strange, and I'm tempted to just use what I calculated for in the way of a series L/C filter, without the autoformer (using the L-pad instead).

Your thinking was exactly the same as mine, but I may be wrong.

Erik

[Erik Mandaville]

I'm glad they are working Craig!

Rick: I think John wasn't question the use of the L-pad per se,' but rather the use of BOTH the L-pad AND autoformer. If both are used for the same purpose, I have discovered what (I think!) could be a disadvantage of using them together. The series capacitor into the autoformer needs to see an approximate 16 ohm load (to match that of the driver), but with the addition of the L-pad connected in series (also 16 ohms)the net impedance would be in the range of 32 ohms, or so. Since the capacitor must have 16 ohm, and the L-pad is provides that value of impedance, it just SEEMS to me that using one or the other is better than using them combined.

LOL! This is crazy!

[3dzapper]

Actually Erik I think the series and parrallel resistance of the L-pad across the driver is designed to minimize the effect on impedance seen by the network.

A 16 Ohm 3Db L pad would consist of a parrallel 39 Ohm and a series 5 Ohm resistor. 1/39+1/16=1/.088141=11.34Ohms {1/(1/R1+1/R2)} plus the 5 Ohm series resistor = 16.34Ohms.

Rick