Help! with adding new tweeter caps to Heresys

[J Harris]

Please advise me.

I just got 4 Jensen PIO capacitors to put across my Heresy tweeters to smooth them out.

I was under the impression that there would already be caps on the crossover which I would simply exchange with new ones! Instead, there is only one cap on the crossover -- on the woofer. There are also two little plastic boxes screwed onto the crossover panel, but I'm assuming they're inductors of some kind, not caps.

I have a 1985 Heresy with an Type E-2 network.

Did the model simply come with no caps on the tweeter? Can I simply add my new ones to smooth the treble? And if so, where do I put them, where should the negative and positive leads go, etc.??

Thanks in advance for all your help! I'd like to do this tonight if possible...

J

[JohnA]

The black plastic boxes are 2 uF capacitors. Klipsch had to change to them when the 2 uF Aerovox caps were no longer made.

John

[J Harris]

Aha! I thought I was losing my mind. I've never seen caps that look like that.

So will I still an improvement from putting in the Jensens?

Do you know how I should wire them -- positive to where, negative to where? (Sorry for the dumb questions -- I'm just starting out in the electronics hobby.)

Thanks!

J

[DokSoul]

I installed the Northcreek "Zen" polyprop caps with grey leads towards source for both the squawker and tweeter on my 1983 hereseys, E-2 xovers. The change has been in effect 2 weeks. I have difficulty in discussing the subjective qualities of the change. For myself I listened individually to musical instruments for the change. For the tweeters, I checked the cymbals and triangles. They are clearer and more pronounced...they stand out more. I believe the new caps opened up the top end. The squawker is more difficult to tell. I do notice that on acoustic guitar music that the harmonics of the strings and sliding on the frets is more present. Also with piano music I can hear the attack on the keys more. In general, I would sum up that there is faster response to the music that adds a clarity that wasn't there before. Somewhat subtle but definitely better.

One question I have for you fellow tweakers is the electrolytics (33 uf, 100v) across the woofer in the E-2 xover. I don't see anyone discussing those. In general electrolytics tend to degrade over time...I'm not sure if that's only in higher voltage applications or not. I there a need to replace these high frequency bypass caps? If so, what have others done?

[J Harris]

I finally replaced the tweeter and squawker caps with the Jensens, and the change has been pronounced, especially in the highs. Much smoother and less piercing. This gives the entire frequency range more clarity, since there's less distorted high-end tizz competing with the rest of the music.

To answer your question about the 33uf cap: on the advice of an Audio Asylum poster, I'm replacing them with Solen metallized polypropyplene. I have them on order -- can't wait to try them out. If you decide to do this, I'll be looking forward to hearing your results.

Have you tried upgrading the internal wiring? or front mounting the drivers? These are both options I'm considering for future mods, and I'd love to hear how they've helped other posters. (I've long-since damped my horns.)

J!

[Malcolm]

Electrolytics can definitely degrade over time. I have replaced electrolytics in crossovers from the 50s and 60s where corrosion has eaten away the connection between the foil and the wires. I have fixed unusable TVs and avionics by doing no more than replacing the electrolytics in the unit. Voltage rating doesn't seem to have much to do with how long they last. The environment they live in, operating and non-operating, can have a big affect on their life.

The electrolytics I have replaced in Heresys with E2 crossovers were all probably in good condition because the speakers lived in temperature controlled environments and were never abused. But degradation is not the sole reason for replacing them. Bipolar electrolytics are basically a compromise in a crossover. They aren't as good for the application as some other types, but they are a lot cheaper. And the quality of the 33uF caps in the E2 network is probably much less critical than the quality of the 2uF caps. Klipsch made a decision to use a "good enough" part for the circuit to keep the cost of the Heresy reasonable. You, as an audiophile, can use whatever you can afford and tweak to your heart's content.

[DokSoul]

I have now had an extensive time to listen to and "burn-in" the new Zen Caps, and I am quite pleased at the results. Their is much more clarity from the tweeter...can't say I hear that much difference from the mid horn, but I figure the improvement to the sound as experience in the tweeter probably carried over to it also - just harder to distinguish. J Harris>the only other mod I did was to rope caulk both horns. That was an excellent improvement. I haven't replaced the electrolytic yet, based on what Malcom (thanks for your post, it was excellent!), I'm really not sure that's worthwhile right now. At present my electrolytic are in great shape, no leaks. I believe as others that many mods have diminishing returns. Therefore there are some I have no intention of doing. Ex: Moving the horns to the front of the baffle board seems like alot of work and I'm not convinced that there is much if any improvement. I'd like to thank both Malcom and J Harris for their excellent posts. Let me know if you find something good to tweak.