Klipsch Heresy “Type E” Capacitor Replacement

Eight years ago I picked up a beautiful set of Klipsch Heresy speakers.  My dad used to sell hi-fi in the 80s and one day an old friend and former customer called him up to say he was moving to Florida and letting go of his stereo (apparently they don’t allow nice stereos there).  We went over to his house and auditioned what he had, which included this first generation Klipsch Heresy pair.  After a brief listening session I couldn’t help but take the speakers home with me.

There are some fairly heated debates among hi-fi buffs over whether or not the Heresys are worth a damn. Some listeners hate them, some love them.   I happen to be in the latter camp, so I’ve toted them along from place to place, most recently in my cross-country move to Montana.  They always manage to find their place in my primary listening system, driven by a Kenwood M2A at 220 watts/ch.

With a manufacture date of sometime in 1980, these particular speakers are now 33 years old.  They have been well cared for throughout their lives.  The cabinets are in excellent condition and all the drivers are original, with the exception of diaphragm replacements in both K-77 tweeters.  I had one die on me a couple years ago and opted to replace the HF diaphragms in both speakers for sonic consistency, with genuine Klipsch parts, of course.

Even when well cared for and used properly, the capacitors in the crossover network are bound to fail to some extent over time.  The “Type E” crossover network found in Klipsch Heresy speakers up to 1982 consists of two capacitors, two transformers and a wiring block.  All capacitors have a lifespan.  While in a few rare instances they die suddenly when overdriven, they usually tend to drift off spec with age.  Of course, as the caps drift off spec, so does the sonic character of your speakers.

Mine seemed to sound fine, but I figured they deserved some maintenance after several years of faithful service.  I’m a bit of a novice when it comes to replacement of electronic parts such as this, so I didn’t feel comfortable sourcing my own capacitors.  Luckily, a gentleman by the name of Bob Crites has replacement kits available on his website.  Within a few days I had four caps and a wiring diagram on my doorstep.  Time for some fun.

It’s pretty easy to remove the crossover, or “balancing network,” as Klipsch calls it.  Loosen the screws on the wiring block for the three pair of driver leads and the rear panel input, remove two screws for board the x-over components are mounted to, and the whole network comes right out.

Isn’t that steel label plate cool?  The two old capacitors are those oil-can looking things, located top center-ish on the board.  Note the rust starting to build up on the outside–yeah, pretty old.  Just clip the leads, unscrew them from the mounting plate and you’re ready to install the new caps.  Along with new Sonicap capacitors (rated at twice the voltage of the original caps), Bob also includes mounting blocks and zip ties, leaving you with everything you need to complete the task minus some solder and an iron.  Mount the new caps, consult Bob’s included wiring diagram (or take detailed pictures of the crossover before you remove anything), sling some solder and there you have it.

It took less than an hour to pull and update and reinstall the crossovers for both speakers.  Not a bad Saturday project–plenty of time left over for a bike ride, a drink or an extended listening session with your refreshed speakers–or all of the above.

Let me take a step back and say that I had no proof my old capacitors were “bad.”  Again, bad caps can continue to work, just not to their original specifications, so even though my speakers seemed fine, they may very well have strayed from their original sonic signature.  My personal stash of electronic testing tools is limited to a couple of multi-meters, so there was no scoping to be had.  However, I do own a cheap Dayton EMM-6 measurement microphone, a USB audio interface and a computer.

Before I even unhooked the speakers for their surgery, I downloaded a trial version of FuzzMeasure and set up a little measurement rig.

While the angle of the photo is a little misleading, I placed the microphone so its capsule was one foot off the grill, pointing about halfway between the tweeter and woofer–pretty much right at the K-55 midrange driver Klipsch lovingly named the “squaker.”  I put some tape on the floor to make sure got things back in the same place for my post-installation measurement.  I measured the speaker, swapped the caps as described above, then measured again.  Below are the two measurements overlayed.

As you can see the response stayed more or less the same.  A slight gain in HF output and a little change in the transition zone between the LF and MF drivers.  Of course these measurements aren’t perfect, but it is nice to have a visual representation.  But do they actually “sound” better?

Verdict: Experiments like this are often hard to judge.  You’ll read all sorts of ambiguous adjectives when looking at others’ accounts of capacitor replacement.  “The soundstage was vastly improved.”  “A sparkle was restored that I hadn’t heard in years.” “I discovered a 4th dimension after replacement.”  Yadda, yadda, yadda.  While I cannot say right off the bat this “upgrade” drastically changed my speakers’ sound, I can say the project was greatly rewarding.  These speakers have been with me for many years and have never let me down.  Day after day, night after night they enable me to listen to music.  If nothing else, this endeavour is an insurance policy that our relationship will last many years more.

Community XLT41 & XP502 Woofer Replacement

Once upon a time there was a dealer that loved selling Community loudspeakers to MSU Bozeman.  Long throw, 3-way mid/hi horns, “full-range” weatherproof public address units, portable monitor/utility speakers… the university bought them all.

The latter units still see regular use.  My department owns a pair of XLT41 12″ 2-way boxes and a pair of XP502s, also 12″ 2-way boxes (though I’ve only seen one of them, the other is still exists only in legend).

Both models are very similar, featuring bi-amp capability, NL4 interconnects, black carpet finish, pole-mount sockets and a form factor that allows them to be used as stage wedges.  The main difference upon visual inspection is the HF section.  The XLT41 features a “rotatable” (see also: square) 90×60 degree horn while the XP502’s horn is a rectangular, 90×40 degree.

In my last post, I mentioned my ongoing quest of testing the department’s tech inventory to get a better handle on what we have to work with.  Well, I already knew one of the XLT41 boxes had a non-functioning woofer.  Funny story, during my interview, they staged a small “practical” for me to participate in, which consisted of setting up a portable PA system in a presentation scenario with laptop, microphone and projector.  After completing the task and firing up the system, I noticed the woofer was out and informed those overseeing.

Now that I have the job and the woofer is still not functioning, I pulled it out, took a meter to it and lo and behold I metered nothing–an open circuit.  I took the woofer back to the office and started looking for a recone kit or replacement driver.  After typing in the numbers listed on the magnet, I realized the XLT41 and XP502 share the same woofer–which would explain why their performance is so similar on paper.

Given the XP502 is currently missing its significant other, I opted to pull the working woofer from it and drop it in the XLT to give us a matching, working pair.  Now, one detail confused me a little.  While looking at the spec sheets for each box, the nominal LF impedance was listed as 8 ohms.  However, the sticker on the woofer says 4 ohms.  This was discrepancy consistent between all woofers.

Here are the boxes next to one another, woofers out.  XP502 on left, XLT41 on right.

While I had the grille off, I figured I’d go ahead and use that “rotatable horn” feature of the XLT41.  The horn had been set up so that the wide dispersion was in the horizontal plane when being used as stage monitor, on its side.  I’d say 95 percent of the time it’s getting used on a speaker stand, so I turned the horn to get that 90 degrees of horizontal dispersion when upright.

By this time, I’d spent enough time with these speakers that they were growing on me.  Yes, they’re cheap boxes in the scheme of things, but they’ve obviously served their purpose over the years, fulfilling the needs of many, many events, all the while holding up to the abuse of tired student workers packing them up after long Friday night shifts.  Though, I will say I discovered a new level of cheap manufacturing when I pulled out that horn.

Notice the horn doesn’t actually have bolt holes for the driver.  Instead they opted to glue some pieces of fiber board to the horn, staple on a baffle and bolt the horn to it.  The staples were starting to pull loose, so it was only a matter of time before the driver fell off on one of those late-night strikes.  I grabbed some wood screws and secured the baffle back to its counterparts.

The XLT41 now has a working woofer.  Though I should still pull the horn out of the other box and reinforce it, as well.  Now regarding the empty hole in the XP502.  It seems Community no longer has parts for this 11-year-old box, but I do know from the sticker on the magnet the speaker is 4 ohms and was manufactured by Eminence.  Perhaps this replacement will do the trick.  Edit: I had inferred parts were unavailable judging by info from Community dealers on the web, however a quick call to Community support revealed that parts are indeed still obtainable.  A replacement woofer is $141–a bit pricey in my mind, but at least I know I’m getting the real deal.

Infinity Qb EMIT Tweeter Repair

Lots and lots of shows at the Gillioz these days, but I’m still finding time to take on a few personal projects here and there.  When I saw a set of Infinity Qb speakers on Craigslist for $50 I couldn’t pass them up.  As seen in an earlier post, I restored a set of Infinity RS5b speakers and fell in love with their sound.  The Qbs are essentially the grandparents of the RS5b.

However when I arrived to buy the speakers, a quick visual inspection (and subsequent listening) revealed both EMIT planar tweeters where non-functional.  You could easily see a tear in each of the drivers, so I talked the guy in to letting me take them home for half his asking price, which seemed fair for both of us as the woofers and mids were working just fine.  If nothing else I could always part the speakers out, though I really hate promoting that practice.

I did a little research online and read about a guy who fixed some EMIT tweeters with this conductive paint used for repair automobile rear-window defrosters.  My local auto parts supplier had some for about $10 a bottle.  An additional trip to Hobby Lobby to find the smallest paint brush I could (the one included with the paint was too wide) and I had everything I needed to tackle the project.

The whole task was a little daunting, as the line I had to paint to restore the circuit was so very small, but it’s hard to break a tweeter that’s already broken so I just dove right in.  I filled in the missing gaps and let the tweeters sit overnight before running audio through them (though I did confirm I had completed the circuit with a volt/ohm meter).

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Low and behold, it actually worked.  I’m still in disbelief, but both tweeters work and sound just as they should.  One of the two tweeters quit working after a few seconds, but a second coat of conductive paint resolved the issue.  We’ll see how they hold up after additional hours of play time, but I’m really happy about how things turned out.

Now I’ve got a (second) cool set of vintage Infinity speakers and am only out about $37.50.  Let the listening commence!