Klipschorns with mud tweeters an zero grille cloth

[Erik Mandaville]

After removing the grille cloth, the baffle was spackled primed, and then repainted satin black. about 20 feet of the loop or soft, fuzzy side of velcro (self stick, black)was used to cover all contact areas between the front baffle and rest of the top enclosure. This filled the gap formerly occupied by the grille cloth, and also serves to help damp vibration. This fit is snug and works well!

With the new tweeter in, small details like valves on woodwind instruments have more of a pronounced 'click' when they open and close. Very realistic sounding. I tried this with my Kenwood solid state amp, and even that sounds good, but sounds from hi-hat or crash cymbals sound more like a high-pitched hiss than they do with my tube amps. I'm happy with the combination of alnico midrange and slightly higher output ceramic tweeter.

I want to start using an active crossover (when I can) with bi-amping, and the Kenwood will be used for the woofers, with the DRD parafeed 2A3s on the midrange and tweeter. Still, these amps sound very good running the Klipschorns (AL network) full range.

[Shock-Late]

Wanna hear the tweeters like you never did before?

If you have the AA network, try the following mods, recommended by Al K.:

1) remove zener diode (just put them out of circuit by unscrewing one of the two leads)

2) remove tweeter inductor screw (the screw that holds the inductor against the x-over board)

3) put 1uF polypropylene capacitor in parallel with the two 2uF in the tweeter circuit (not sure about the "parallel" thing, search on this BB you'll find the mod and some picts)

you won't believe your ears at how better your highs will sound. Absolutely stunning.

[Shock-Late]

Nevermind... you have the AL network... Ooops

[Erik Mandaville]

Thanks for posting that information, Shok-late. I appreciate the instructions, too. I have in fact listened with both the A, AA, and modified AA networks. I definitely preferred the AA with the bridging capacitor, since the stock version sounded really lifeless compared to the AA or AL networks. The A is wonderfully simple, and I might have another try at that using Hovland capacitors and a good air core inductor.

[Deang]

I don't understand your preference for the original AL network, as it supposedly has a pronounced "howl" at 300Hz. This has been verified by past users of the network, as well as Klipsch.

Shock-late, those "mods" for the AA network are suspect.

1) remove zener diode (just put them out of circuit by unscrewing one of the two leads).

The zeners are not in series with the tweeter, and do absolutely nothing except on those extremely rare occasions where power to the tweeter exceeds that which it was designed to handle. The zeners only conduct when the speaker is near the top of its operating limits. The only other time would be from a spike during equipment turn on/off, or from someone swapping cables around with the equipment on. The zeners are there for a reason -- and they should be left in.

"The diodes don't do anything until you exceed their breakdown voltage. Then they act like a variable resistor in parallel with the tweeter." -- DJK

2) remove tweeter inductor screw (the screw that holds the inductor against the x-over board)

Klipsch used both brass and steel screws. If the screw is brass, removing it does nothing, and if the screw is steel, it raises the inductance from 245uH to roughly 385uH. Leaving the steel screw in, or changing out a brass one in favor of steel is actually a pretty cool tweak -- as it lowers a known problematic spike at 6Khz. Hey, adding a steel screw is cheaper than using a bigger inductor -- maybe they changed out the brass screw for a steel one on purpose.

3) put a 1uF polypropylene capacitor "between" the two 2uF caps...

It might be a good mod, I really don't know. I guess I need to read through that thread again. OTOH, replacing the old motor runs with new capacitors will also restore the HF response (Yes, I know, everyone is tired of hearing it).

[Erik Mandaville]

"I don't understand your preference for the original AL network, as it supposedly has a pronounced "howl" at 300Hz. This has been verified by past users of the network, as well as Klipsch."

Hi, AK-4. I've known about the lack of popularity of the AL network, but usually tend to build my system around what sounds the best to me. I have never experienced the so-called "howl" or shout, but I am a little hard of hearing in my left ear anyway, which may in fact be the reason why I like this particular network. I've built both the A and AA network, and of the two I prefer the A.

Your reference to the bridging capacitor as being "between" the two other capacitors in the high pass branch of the network may be a little misleading for some. Those stock two capacitors are in series with one another, but the bridging capacitor is connected really rather to the outer ends of each of the other two: at the input end of the first in the series, but on the output of the second 2uf capacitor.

This modification provides a bit of an increase in tweeter output, but perhaps not as much as that of the A network.

The amps I built have an max output of around 3 watts or so. I removed the diodes, anyway. At some point I'm going to rebuild the AL with higher quality capacitors (both oil and film and foil)and air core inductors, which I've always preferred to iron core.

I use the AL network because it sounds better to me than the other two (actually three)I've built and auditioned.