Trying to mellow out Klipsch KG 4.5 tractrix horn
I bought a pair of Klipsch KG4.5 speakers in good shape. I kind of like them (my first horn speakers), but they have a harshness in the treble that I'm trying to tame.
So far I've applied a layer of duct seal (a la Planet10) to both the tweeter horn and the woofer frame, which has helped gain clarity and smoothness. But the tweeter still has a little sizzle to the top end that bothers me.
A lot of people have said to replace the crossover capacitors, but they look like reasonable quality metallized Mylar film. How bad can those possibly be?
Here's the crossover schematic:
I was experimenting with putting a resistor across the + and - terminals of the tweeter. When I put a 50 ohm 10W wirewound there, the highs definitely get smoother and less brash, but maybe too 'dead.' When I put 100 ohm 10W it smooths the highs just a little tiny bit.
Here's what I've done to it:
Right now I'm listening with the 100 ohm there, and I think I want to try something like 82 ohms (split the difference between 50 and 100 ohms).
My question is -- Am I doing something incredibly stupid and wrong? I mean in general terms. I don't have the actual driver specs, so I understand that the crossover can't be properly analyzed from just the schematic. But in general terms, is putting a resistor across the tweeter likely to cause a problem?
Am I just attenuating the tweeter output by setting up a simple voltage divider between the series resettable fuse (that "polyswitch" thingie, which has 0.5 ohm internal resistance) and the parallel resistor?
BTW, I found this in the Multi-Way stickies...
Flattening the Tweeter's Impedance
That shows something like what I was thinking. But it also suggests that putting the resistor there changes the impedance of the tweeter, so changes the way the tweeter crossover components act on the tweeter (changes the -3dB point?).
It will likely make small reductions in output where there are currently impedance peaks, and also increase damping somewhat of the crossover. There will be some attenuation of the whole tweeter but it will most likely be insignificant. So...greatest effect nearer the crossover. No, no damage likely.
I also wonder whether someone else has had this exact problem and found a good fix?
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