Jump to content

Bright Heresys? Dramatic, fix, for FREE.


Recommended Posts

Background: I have been enjoying Klipsch speakers since I heard my first pair of K-horns back in the 70's (instant addiction). However, until a year ago I had only had experience with the large Heritage Klipsch speakers and had never owned or listened to a pair of Heresys, so I bought a pair off Ebay.

They are 1980 Heresy I's with a K22-E woofer, K55-V squawker, K77-M tweeter, and a Type E balancing network.

I have owned and been listening to a pair of Cornwall I's (100% stock) for years and I am in love with the sound - I expected the same for my Heresy's. However, when I heard the Heresys, I didn't want to admit it, but they were just too bright and sounded to me nothing like the K-horns, Cornwalls, or La Scalas (lots of listening experience with each). The Heresy tweeters were just screaming loud compared to the squawker. In my Cornwalls, the tweeter plays at about the same level as the squawker when you put your ear by each one. This is also true of the K-horns and the La Scalas. I was contemplating getting rid of them and dismissing them as "not real Klipsch speakers." This sentiment was coming from one die-hard Klipsch fan too. My feeling was that the Herseys sounded decent, but not great. With all the Heresy modification posts here, I assume there are many who feel like I do.

Anyway, enough background, on to the good stuff, read: solution. After careful listening, I decided that the problem was definitely a tweeter problem, not a squawker problem, no need for a P-trap, or some caulking dope. After a quick search, I found a schematic for the Type E network on this BB and copied it down (search T2A, then read "The great inductor face-off"). The T2a transformer provides the attenuation for both the squawker and the tweeter. Each tap (six of them in all) is a 3dB increment. Note: the tap #'s on this BB's schematic is hard to read, the numbers should be 0,1,2,3,4,5 for the bottom tap to the top tap.

Anyway I figured "Hey why don't I just change the attenuation by trying different taps?" So I opened up a Heresy and unsoldered the wire from the #3 tap on the T2A (which goes through a 2uF cap then on to the negative terminal of the tweeter on the crossover). And here's what I found. (A copy of the schematic will greatly help you follow what's going on, even though it's quite simple.) Also, the #'s of the taps is written right on the T2A, so there is really no chance of making a mistake.

1. First I tried tap #4, which is unused. This brightened the tweeter up a lot (by 3dB, I guess). No dice.

2. Next, I tried tap #1, which is also unused. Dramatic attenuation of the tweeter, however, 6dB was too much attenuation. By the way, I'm using alligator leads for the tests. Also, I'm doing A/B comparisons with my vintage Alnico Cornwall I's for reference.

3. Finally I tried tap #2 which is the same tap used by the squawker's negative lead (so basically I just loosened the screw on the negative terminal of the squawker on the crossover, put the bare wire under it, and tightened the screw - piece of cake). This lowered the output of the tweeter by 3dB and was perfect! The voicing of these Heresys now very closely match the sound of my Cornwalls and other big Klipsch (less some low bass) and I must say I am thrilled with the results. These speakers now sound like "real Klipsch" to me. The Heresys also sound way better loud than they used to - they sound more like a big speaker. The bass and midrange are greatly improved because they are not being drowned out by the overzealous tweeter. My goodness, now THESE speakers have beautiful midrange too! Hail Klipsch!

I hate modifying anything from the original, but this was an exception. The results from this are also very apparent, none of that "deepened the sound stage" or "fuller bouquet" stuff - we're talking real results. Somebody else please try this modification and write back to this BB and post your opinion/findings.

Couple other things. 1) this modification is easy, FREE, and 100% reversible. I printed my modification on a piece of masking tape and taped it to the T2A for future reference (Although I'll never change it back, unless deep shag rugs come back in style and rob 3dB of my highs). You may or not like the mod as much as I do, but it sure is an easy way to change the tweeter attenuation, in both directions. Another benefit is that with 3dB of attenuation, you cut 1/2 of the power going to the tweeter (but with only a perceptable difference in loudness) thus protecting it from burnout.

One last point. I also tried stuffing one cabinet loosely with some damping material and compared it to the other speaker. The damping material definitely robbed some punchyness from the woofer and, in my opinion, was not an improvement - I removed it instantly. Also, any thoughts on my modification would be appreciated - I haven't read of anybody trying this, have you?

I LOVE my Heresys.


Link to comment
Share on other sites

  • Replies 92
  • Created
  • Last Reply

Top Posters In This Topic

I agree that the Heresy is the poor little brother of the other Heritage speakers. In fact I believe that in the early days of the Heresy, the need for cashflow was paramount. PWK designed this speaker to have an entry in the lower buck market.

The Reference RP-3s that I now have do not match the wall of sound the Heresy's could produce. The smoothness of the RP3s is much better. Also, the clarity of the sound is better than the old Heresy's as is the extended bass. Not sure why Klipsch chose to rid themselves of the Cornwall and not the Heresy.

I am ready to do modifications to my Heresy's to improve their sound. Surely the replacement of the capacitors in the E network is high on my list (along with new diaphrams for the tweeter and squawker, and something to improve the bass). Prior starting the renovation, I will try your upgrade. I too have noticed that my Heresy's (that I bought brand new from an authorized Klipsch dealer in June 1981) are balanced to have a lot of sound coming from the tweeter. I do not remember this as being true when these speakers were younger, which makes me think that there is some degradation in the network (after all, I'm told a good capacitor starts degrading after seven to ten years).

Link to comment
Share on other sites

I really depends on the construction of the cap. Electrolytics, for instance, change the most with time due to degredation of the one molecule thick conductive film electroplated to the dielectric.

Heresy 1's with the "E" network use sealed paper in oil caps that are very stable and change "very" slowly. They have, however, been surpassed by the sonic character of some more modern caps.

Recently, I have been evaluating an "E" crossover network for the Heresy 1's that uses close to stock layout and component values, but has upgraded parts. While not yet perfect, the result has much more high frequency extension, imaging, soundstage, and transparency. This netework depends heavily on the use of bypass caps across the base film caps. It also depends on the "P-Trap" notch filter needed for the K55-V Atlas mid driver used in series 1 Heresy's.

I'm still not convinced my mid horn cap combination is optimal, but it's very very close now. Different brands and bypass values have yet to be tried though. It is significantly better than the stock network at this point. I have detailed much of the parts used in the basic rebuild in other posts on this forum. What remains is fine tuning that has yet to be perfected, but presently, it's close.

The bass is forever limited by the Heresy woofer design required to blend with the mid horn, sealed cabinet, and high efficiency at upper bass frequencies. I'll eventually use hidden powered subs to fill in frequencies below The Heresy's reach.

Paul Keller

Link to comment
Share on other sites

Hello CC1091,

It's been about five days since I tried the T2A tap modification and I've spent a lot of time listening to the speakers since.

So far I am quite happy with the modification. My Heresys are hooked to the same system as my Cornwalls, but are in different rooms, so A/B comparisons have been easy. I must say with a wide variety of music, from new age to classical, these speakers sound way more like the Cornwalls than they ever did - the level of brightness is very close. The speakers sound "bigger" than they used to, (albeit not bigger than the Cornwalls).

I'm probably wrong, but my guess is that Heresy speakers were probably voiced brighter by Klipsch to cope with the deficiencies in the LP (no offense to any vinyl people out there) and maybe heavy carpeting because the tweeter is closer to the floor when compared to its big brothers. Or maybe to give them a "flashy" sound to boost sales. I do remember an old ad for the Heresys (around 1980) where some guy stated his Heresys "sounded brighter" than some other big pair of speakers he had bought and they were "definitely not for sale." So it seems Klipsch had some idea these speakers were bright and maybe wanted to make it seem like an attribute. Heck, who knows?

After listening to these speakers, I'm really wondering why Klipsch didn't choose tap 2 instead of tap 3 for the tweeter level.

I may also try a P-trap, or other modifications, but they really sound like they don't need it - I'm pretty happy with the sound - unmistakably Klipsch.


Link to comment
Share on other sites

Hello Pkeller,

I have read that oil filled caps are quite good for horn networks. How long do you think those Aerovox 2uF caps will last in my Heresy's? Also, can you still get these same oil filled caps? My Cornwalls do not appear to have any degradation of sound after many years of use (1975). I would be open to changing my caps - just want to be careful not to lose that "Klipsch sound."


Link to comment
Share on other sites

I doubt the Aerovox caps have changed much over their 26 years of life. I don't know of any source for them presently. Even if you could find NOS Aerovox caps, their age alone will make them close to what you already have. The miniscule current used by the mid and tweeter in 101db speakers is really not a degrading factor. The big reason to use premium modern film caps is to attain superior detail and extension in the high tones. There is no question that the Northcreek Zen 2.0uf caps have greater transparency than the stock caps. This comes at the loss of some smoothness that the mid squawker requires. For this reason, I bypassed both the 2.0's with .1uf Northcreek Crescendo caps. This smoothed things out a great deal without loss of the transparency or extension.

The P-Trap also requires some modification. I used Zen 3.0uf but found that

it too needed bypassing. I only had a Harmony (again Northcreek) .22uf at hand, so I used it with good results. I'm going to try Crescendo caps for the P-Trap in both base and bypass mode. I hope this adds to the transparency even more, but at this point I'm fishing for even better results.

I should say that Northcreek caps behave much differently than most all other caps on the market. Normal metal film caps will become bright and hissy when used in bypass mode. This is not at all what Klipsch networks need. Not so with the three lines of Northcreek caps.

There is also concern regarding the addition of capacitance value when bypassing. Making a 2.0 into a 2.1uf is only a 5% change for the mid horn and 10% for the tweeter and not noticable given the gradual 3db design slope of the stock "E" network.

As for moving the mid and high frequency taps on the autoformer, I have avoided trying this as it changes the impedance of the system a slight bit, but probably not a significant amount. This network sounds well balanced with the stock locations used. If anything, I would lower the squawker 3db, but that might be a bit too much, so for now it will stay. You do have my curiosity tweeked, though.

My Heresy's still sound like Klipsch designed, but with a higher livel of surrounding ambiance and detail.

All of the above has been done without tearing into the stock Klipsch networks. I can reinstall the stock boards in a few minutes if I desire. This is only insurance should I decide to sell the Heresy's some day. But I don't see that happening any time soon.

Paul Keller

Link to comment
Share on other sites

I've been thinking that the bright voicing of the Heresy's might be due to amplification.

Heresy's were designed when tube amplifiers were the standard. Tubes have a softer cleaner high frequency presentation ("generaly speaking", no flames needed) and a more pronounced mid response. I am using tube amplification for evaluation and testing. This might explain our difference in tap location needed.

Especially if you using solid state equipment more than about 15 years old. SS equipment, including pre-amps were pretty bright back then.

What are your driving components?

Paul Keller

Link to comment
Share on other sites

Hello again Pkeller,

I've tried various amplification with my Herseys, but nothing truely "high end." For a while I used a piece of Carver equipment with a high voltage magnetic field amplifier.

The Carver had a lacking, tinny sound with no bass - even my wife could hear it. Mediocre with Cornwalls, unaccepable with the Heresys - way to bright. (No offense to Carver fans out there, it could be the electrolytics in the solid state amp were beginning to leak a little DC voltage after 15 years of use.)

Next I used a Fisher 500c tube receiver that I rebuilt (you know, high quality film and foil bypass caps, bulletproof the grid bias circuit, etc). Good results with this push-pull Williamson type amplifier. Smooth sound, with slightly rolled off highs which were indeed more compatible with the Heresys' proclivity towards bright sound (lends to your said theory about tube amps). Bass decent, for Heresys.

Anyway, I really wanted a remote (technolgy knocking at my door) which was making me tired of the Fisher 500c (now being used with some big, vintage Bozaks - sweet).

On to my latest aquisition: the Yamaha Natural Sound RX-596 Stereo receiver (also hooked up to my Cornwalls). Lovely, smooth sound much like the old Fisher Tubes, but with deeper bass and better woofer control (the 240+ damping factor helps control those big 15" Cornwall woofer cones). Amp also has a high current design: 80 wpc into 8 Ohms/ 200 wpc into 2 ohms. Nice detail, and a little cleaner on the highs than the Fisher, especially with the "CD Direct" engaged, which employs a dedicated CD amplifier and bypasses the tone controls, loudness, balance, and selector switch. Way better than the Carver, albeit I realize it's still not a MacIntosh stack. Still the same thing though - SMOOTH and clean on the Cornwalls, BRIGHT and clean on the Heresys (pre-modification).

Just listening to my Heresys again late this afternoon - they really sound great, I can't believe I was going to get rid of them.

One last thing. I originally attributed the excessive brightness of my Heresys to the K77-M ceramic magnet tweeter. My Cornwalls have the round magnet Alnicos and sound smooth, so I figured that the K77-M was junk and Klipsch had screwed up the tweeter on the redesign - I was pretty mad. Anyway, with the tweeters turned down a notch, they sound almost exactly like the Alnicos. The K77-M IS a good tweeter.

I've been thinking about building a tube amp one of these days, we'll see how that one does.


Link to comment
Share on other sites

Thanks Klipschguy and Pkeller. Someday I will get off the computer long enough to make the simple modifications talked about here <grin>. The dialogue on the oil filled caps is helpful, also the changes in impedance values concerned me with the modification that Klipschguy was talking about (although I do agree that it is probably inconsequential).

My 2 cents on the tube vs solid state discussion: Yes perhaps the bright sound design was intended for the tube amps. I have only used solid state amps (actually receivers)with my Heresys since I purchased them. I feel they are brighter and less dynamic than they used to be.

Original receiver was a Sony STR-V25 25 wpc receiver. Heresys sounded very sweet with this extra budget unit. Not much bass though. It died an early death months after the warranty ran out.

Next was an NAD 7130 35wpc (with huge dynamic headroom). Silky bass on this unit helped the lack of bass on the heresys, though not as detailed on the high end. I still have this unit, although the tuner section is dying slowly. I would blame it for the somewhat frayed sound that comes from my Heresys except that my newest Receiver also produces this sound when played through the Heresys (nope, diaphrams have all been replaced).

Latest Receiver is a Denon AVR-2700 5 channel 85 wpc amp. Heresy's really sucked with this amp. My new RP-3s sound great though (even better since I borrowed a friend's Marantz monoblocks and found they actually made these speakers sound less dynamic).

I want to try the Heresy's again with a good quality (tube??) 20 watt (or less??)amp. I wonder if that will help eliminate the distortion I hear, and perhaps bring the drivers back into sonic alignment??

Link to comment
Share on other sites

A comment on "bright sound",

Klipsch in the past produced his speakers to be flat across the spectrum.

Because of the high efficiency, his heritage line generally sounded bright because the bass was allowed naturally to drop off. Over the years many people have commented that it was better to have a balanced system staying within it's natural limits rather than forcing bass response via tuning, etc. I tend to agree.

So the bright sound is largely the lack of low bass, which can be restored with a good subwoofer these days. I do not believe that whether the electronics was tube or solid state went into the design (although only tubes were available when Klipsch started making speakers).

Also over the years the stereo dealers and people I knew back when all stated that it was Paul's contention that if the speakers sounded too bright, then fix the room because the speakers were acoustically correct by design. Also something I have tended to agree with. BTW Klipsch used to set the treble down about 3 to 6 db relative to the bass horn of the Khorn. Don't know if they still do that today.

I hope these little tid bits help in understanding the sound you hear. My LaScalas tend to sound a little bright by themselves but with my subwoofer they sound "perfect" to me. I have not modified my LaScalas in any way. As far as I am concerned they sound just fine. So I just listen to them.


John P

St Paul, MN

Link to comment
Share on other sites

Hello Klipsch fans. I do sincerely appreciate all who have contibuted to this thread - it's been a good exchange.

Anyway, concerning the brightness of the Heresys. I really do not think they are "balanced" BY DESIGN - that's kind of my point and why I am a little baffled by the design - make no mistake, Klewless, I do certainly agree with your premise about speaker designs and "fixing the room" - been there done that, willing to do it again.

However, as stated earlier, the tweeers in my Herseys, before the modification, were TWICE as loud as the squawker when putting my ear alternately from driver to driver (on any decent recording, and this fact is independent of the room acoustics). Also, they sounded too bright in the same room with with my lovely sounding Cornwalls - so I really don't think it's a room problem.

With my Cornwalls, and friends La Scalas and K-horns, the tweeter and squawkers both play about the same level, the squawker may even be a little louder - try it for yourself, you'll say "dang he's right!" (Also I have access to three different pairs of Cornwalls and they all sound just like mine).

With my mod, the tweeter now plays about the same level as the squawker and sounds a heck of a lot better, loud or quiet. I am a devoted PWK fan, and really believe in his designs, but I know a brightly voiced speaker when I hear one.

By doing a Heresy search on this BB, a trend can clearly be seen that there is a problem with the high frequency balance in these speakers (P-traps, crossover upgrades, horn damping, felt around the mouth of the horns, et cetera). One will rarely see threads about too bright Cornwalls, La Scalas, or K-horns. Most people want to keep every Heritage Klipsch bone stock, except for the Heresys - including myself.

If you have the means to try it, put your ear by the tweeters and squawkers in various Heritage Klipsch speakers - you'll see what I mean. Then try tap 2 instead of tap 3 with your Heresys, you'll be amazed how much more they sound like their big brothers. If you don't like it, it's 100% reversible, free, and only takes about 10 minutes per speaker - including taking the back off. Anyway, Pkeller has experimented with some other crossover modifications which sound impressive and are worth checking out. But the point is still the same - there is some high frequency imbalance in the Heresys.

Thanks again,


Link to comment
Share on other sites


I'm really at a loss as to why your tweeters are excessively bright. Most of the modifications you site are for the "mid" horn in the Heresy's. My K77's being alnico, and yours ceramic may explain part of the difference, but not to the extent you describe. I was thinking that possibly you have mid drivers that have an extreemly agressive 9khz return resonance. Since the tweeter takes over at 6khz, this would add substantially to the perceived tweeter level.

A large 9k spike in response from a non-linear region of the mid driver could introduce a secondary harmonic that feels like your sticking a pencil in your ear. Not every Atlas mid driver resonates at 9khz, so it stands to reason that some may resonate a "great deal" at 9khz. When you reduced the tweeter level, it could have brought the overall 9khz region more into balance.

I am not at all confident that this is what happend. It's only a theory.

In any case, you may want to try the P-Trap before any further crossover mod. I know that my Heresy's became a lot more civilized when I added the P-Trap.

It could be that the return resonance at 9khz is at a fixed volume and becomes less of a factor in the more efficient Klipsch designs

using the Atlas mid driver.

Dang I hate to be baffled like this.

Keep us posted.


Link to comment
Share on other sites

Thanks for your thoughts Pkeller,

I'm not sure why my tweeters are bright either. But, I must say the mid sounds quite good, maybe even a little subdued (for a horn), when you put your ear by the squawker.

So I really think is is the tweeter.

I may try a P-trap, hook the tweeter back to tap #3 and check out the difference. I just want to be careful to not put too many filters in the circuit which, as you know, can also degrade the sound. That's one of the reasons I like the tap mod, because you are only attenuating the tweeter a little bit more by using the original design components, and this helps minimize other unwanted ramifications which may steer a speaker towards a "non-Klipsch sound" - which would be a real heresy.

You know it may be the alnico vs. ceramic issue. Klipsch did say in a memo that they incresed the output at 12KHz when redesigning the tweeter. Maybe it's a little more efficient too? Anyway, I guess you could say that in all these posts I am talking specifically about the "Heresy I's with the K22-E, K55-V, K77-M and E-type network."

Note: my friend has a pair of 1980 Cornwalls with the K77-M, and the highs, to me, sound pretty much the same and balanced as my alnico Cornwalls - this tends to refute the alnico/ceramic theory (although maybe the crossovers compensate for the newer tweeter - like using "tap 2 in lieu of tap 3 - just kidding).

Anyway, whatever the case, I am listening to my Heresys now and they sound balanced and lovely. Also, don't get me wrong, my Heresys sounded good before, certainly listenable, just too bright.

Maybe somebody out there could put their ear next to their Heresy tweeter and squawker, alternately, and let me know if the tweeter is perceptably louder than the squawker. Or is it about the same?

Thanks again for all your input.


Link to comment
Share on other sites

recently purchased a set of used heresey's & decided to try the modifications, rebuilt the cross-overs used jensen copper foil in oil caps & solen inductors, rewired with some dh labs wire i had, damped the tweeter with rope caulk & the midrange horn with some black hole 5, lined the inside of the cabinet with 3/4" fiberglass, finally replaced the back's with 3/4" mdf with new binding posts. ok spent some bucks & while the changes were noticeable, i was expecting a drastic improvement, sorry it didn't happen, a definite improvement but not for the bucks i spent! then came this post & i figured, what the heck, nothing to loose, well i gotta admit, this seems to be the cure i was looking for! immediate improvement, the harsh glare from the tweeters was gone, did not seem to effect volume in any way, just eliminated the listener fatigue associated with the heresey, some may not agree but thanks for the post, i'm impressed with the results. was thinking about selling the heresey's but now i'll rethink that decision.



Link to comment
Share on other sites

Hello Mike,

I had the same reaction. I cannot belive how much better my Heresy's sound now. I used to almost never listen to them and defered to my Cornwalls. Now, I seek them out (they're playing right now - lovely). I actually think they sound a little better than my Cornwalls with piano music - really quite amazing. They sound way better lound AND quiet - which a real test of a modification.


Link to comment
Share on other sites

Hey Mike,

I answered your last post but both question and reply seemed to have disappeared. Anyway your speakers are 1976, and are basically the same as my 1980 Heresys, except yours have the alnico K77 tweeter and mine have the K77-M with the ceramic magnet. By the way HWO stands for "Heresy, Walnut, Oil finish.


Link to comment
Share on other sites

Hi, first post, so bear with me. I have been following this discussion and decided to make the modification (move wire from 3 to 2) to my Heresy I's. First reaction was "Did I screw up!" But like all tweeks, I decided to give it some time. After a couple of hours, it really started sounding better. I found that I needed to back down on my sub-woofer, a lot! The Heresy's really came into their own after about five hours. They now sound like big speakers, separation is greatly improved, their image width is huge and the treble is still there, only more clear. And the bass, wow, never expected to have to back down my sub level. Very pleased with change, Thanks a lot.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...