I haved owned a pair of Heresy IIs for over eight years. I agree with the previous reviewer that there is a lack of low bass with these speakers. I remedied that with a Velodyne subwoofer. Also, because of the horn tweeter in this speaker, extended listening was fatiguing which is why I replaced my Heresy IIs with a speaker with conventional drivers, first with Cambridge Soundworks then with B&W. At least these speakers are very efficient, 96 dB/watt, which were great for parties.

I owened Infinity Bata in Taiwan about 10 years ago.Since movied to U.S.A. too poor to buy a HI-FI system.
Bought a pair of Heresy (USED) one week ago, cost me $225.00
For the momey like $900.00 (NEW). Sound like this.
I would to give
5 Star

Over 20 years ago, I finally decided to look into some high-end stuff. I went to a store on Lover's Lane in Dallas that had a good reputation. After discussing speakers for awhile (the most important compenent of any system), the salesman/owner told me that in his 30-odd years in the business, 100% of his professional or serious pianist customers had bought Klipsch. Not 99.9% . . . 100%. I gave a listen and I understood why. I had never heard anything like them. Nothing in the room came close, regardless of size (except, of course, the Klipsh Horn). It is now over 20 years later, and my Heresy speakers look and sound EXACTLY like they did the day I bought them.
You hear people (especially the younger generation) complain that there is not enough bass. Who cares when they give you the most perfect highs and MID-RANGE you will ever hear? Except for the other Klipsch of the same generation (Cornwall, Klipsch Horn etc.), I have yet to hear a speaker with such perfect clarity and definition where it really counts. They are in a class by themselves when it comes to what I believe music is really all about . . . voices, guitars, trumpets, pianos, violins etc (highs and mid-range), and bass is plenty good enough! Add to that the fact that (1) they last forever and (2) they are so efficient you can damn near plug 'em in to a table radio and you have what I think are the best speakers, pound for pound and inch for inch, ever made. It's too bad the Heresy is no longer in Klipsch's regular product line. (I understand you can still special order them.) Imagine a home audio/visual system with two Klipsch Horns in the front, two Heresy's in the back and one of Klipsch's subs in the middle. I'll tell you flat out . . . with Klipsch Heresy speakers it DOES NOT matter what kind of amp/receiver you have as long as it sends a signal to them. I've never understood how they get so much our of such small and effecient speaker. It's gotta be the horns! Hey Klipsch, go back to the horn-loaded tweets and mids for us old farts!

I purchased my pair of Klipsch Heresys in December, 1978, in Dallas, TX. The salesman already had me sold on a pair of bookshelf speakers, but he said, "listen to this." He put on a vinyl LP of Sheffield Labs' King James Version (Harry James). I had never heard speakers sound so real. I do not hear the "cupped" sound that some claim about horn speakers. The Heresys are quick (drums sound great on them)and quite open to my ears. Hearing the Heresys from another room sounds quite like live music.
I still own the Heresys as my main speakers (now connected with Adcom electronics). I eventually plan to purchase some Magnepans, but will never get rid of my Heresys--they have been faithful friends for over twenty years. When I buy the Maggies, I think I might try some tube electronics with the Heresys.

Several years ago, I got involved in the single-ended amplifier scene through the purchase of the Audio Note Kit One. This is an excellent 300B based amplifier, and I was enjoying the sound quite a bit with a modified pair of Radio Shack Optimus LX4 pros (discontinued), but deep bass was seriously lacking. After a stint with Mission 371is (good, but a little too smooth), I ran across a pair of Heresy I's in a pawn shop for around $250.00.
I had read a good review of these in Sound Practices, so I was very excited to pick these up. When I got these home, I put them on the floor to test them out. Much bassier, but placement was not optimal. I was a little shocked at the difference in sound between these horns and dynamic speakers. To tell the truth, I was a little underwhelmed with the sound. Though dynamics were vastly superior, they seemed closed in and distant sounding. Also, the midrange/lower treble was edgy and hard. I placed these on stands so that the treble and mid horns were around ear level. The bass balance improved, but the hardness and closed-in sound were still there.

After a couple of weeks of listening, I opened up the back to examine the crossover. This is simply a matter of unfastening the eight screws that secure the back. The Heresy I's split the frequency spectrum using capacitors and inductors in it's network (don't ask me about the particulars of the circuit, I did't take time to trace out all the little jumper wires). Of particular interest were the capacitors. These speakers use two 2uF caps in each speaker. These can best be described as flat, hard, caps about 2" long with a squashed oval cross section (1/8" high) manufactured by Western Electric. I looked around to see what I had in by box. I replaced the input caps with one of the older TRT Infinicaps, and the tweeter caps with paralleled 1uF NOS Westcap oil caps. A lot of the hardenss was gone, and the sound was closer to what I had expected - dynamic and lively. However, the sound was still a little boxy and shut in.

I ordered a pair of round 13" Deflex subwoofer damping panels to tame the woofer's backwave. These are almost just the right size, however, I had to cut just a little bit (around 3/4") off of the very left, right, and bottom sides after I glued these on in order to close up the speaker. Also, I had to cut a rebate at the very top of the panel to accomodate the midrange driver, which just about contacts the back of the enclosure.

The results were mixed. The boxy coloration was significantly reduced and the sound was more natural, but the bass became a little heavy and puffy, with a bit of a "one note" quality. Deflex claims that these panels contribute to a more open and dynamic sound when applied to speakers. Remember, though, that in most instances, this gain in dynamics, liveliness, and volume is a result of removing the stuffing from the speaker. The Deflex panels are useful for vibration damping and, perhaps more importantly, controlling the internal reflections that contribute to that boxy sound.

Because the Heresy I's had no stuffing to begin with, the Deflex panels did reduce the boxiness, but also slowed down the bass. Please note that I only applied the panels behind the woofers, so I cannot speak for the full implementation of these panels.

Though much improved, further listening revealed a residual hardness in the midrange/lower treble. I considered packing modeling clay on the outside of the horns, but did not want to deal with the mess. I decided, instead, to apply damping sheets onto the outer surfaces of the metal horns. Opening the back of the enclosures, I went in and made templates of the flat outer horn surfaces (4 per horn) with paper. I then cut these out of a sheet of EAR Isodamp self adhesive damping material (obtainable from Michael Percy Audio, similar materials avaiable through The Parts Connection and elsewhere). When applied to the bottom and side flats of the midrange horn, the sound became smoother and richer. Very nice if your amp does not tend towards lushness. I did not damp the top of the midrange horn because of the raised lettering cast into this surface.

After this, I damped the treble horn. An intersting thing happened after the sheets were applied, though. The treble actually became edgier and much more irritating. After a week of further listening , I went in and wrapped the cylinder of the treble driver with damping material and, Voila!, smooth soft treble, at last! In fact, the effect of this damping may be too much if your amp is overly soft or smooth. When my Audio Note developed a hum, I pulled it out of circulation and substituted it with a Dynaco ST-35 (EL-84s). Too smooth. Nice sounding, but too smooth for these mods and not as detailed.

Another intersting thing happened after I damped the horns. The bass seemed to diminish, with the spectral balance tilting up towards the treble and midrange. This made the system sound anemic, with the bass lost somewhere in the distance. The middle and upper registers of the sound was getting really close, but the balance was way off! To fix this, I tried a couple of things. First, I applied damping strips to all the flat surfaces of the inductor U-frames. Interestingly, this brought a lot of the bass back, almost to a satisfying level. Then I applied damping strips to the arms of the woofer basket. Again, more bass. Alarmingly, however, the bass has more of a pronounced "one-note" quality. This isn't a terrible shortcoming, mind you, but undesireable if a tight, tuneful bass is one of your sonic priorities.

One thing about the damping sheets - I find that it takes about three days before the sheets sound the way they will sound. I speculate that the adhesive takes this long to fully set.

So where does that leave us? If you pick up a pair of the Heresy I's, I would recommend swapping out the caps, absolutely. To tame the horns a little, I would recommend the Audio Note (Jensen are the same) oil/paper/copper foil caps. These are the best affordable oil caps that I have tried. Hovland Musicaps are fine caps, but may be to detailed for these horns. I have heard good things about the new TRT Seti and Signature Infinicaps, but I have not tried these yet. Again, in all cases, replace the old caps.

If you are into rock, or raucous music, and don't mind sacrificing some boxy coloration for dynamic and livliness, change out the caps, and enjoy. If you want more refinement, you will have to work and experiment a little bit. The bass is the weakest part of this speaker design. One thing you might try that may solve this whole bass conundrum is this: the back panel of the Heresy I's is made out of a really flimsy 1/2" sheet of plywood. Replace this with a sheet that is at least 3/4" thick, apply the Deflex panel and the more rigid back may well ameliorate that "one-note" bass quality. With the 1/2" plywood and Deflex, a tap on the back will result in a springy thud, just the thing that may rob the bass of it's differentiation. Of course, you will have to drill new screw holes and remount the binding post (these should be changed, anyway).

Additionally, you may want to rewire the speaker with Kimber or Cardas or other wire and move the crossover to an enclousure outside the main box. The crossover itself is mounted on 3/4" thick plywood on which all inductors and caps are mounted. There is also a terminal strip to which all the inductors, caps, drivers, and jumpers connect. If you are ambitious and want to rework the crossover, you can eliminate all these spade-lug-to-screw-terminal connections, reducing an unbelievable number of solder joint and discontinuous metal connections. In my experience, this can have a major impact on the sound - for the better.

So how do I like the Heresy I's? I would not go back to those dynamic speakers I have tried, or most of those I have heard in the high-end salons. As stock speakers, the Heresys are good, but not that great. With some common sense mods, these can be great speakers. The dynamics of horns are breath-taking and cannot be matched by standard dynamic speaker. The clarity and detail of the midrange and treble are also unmatched by most speakers. What's nice is that with proper damping and cap choice, these horns can also be soft and rich. You must, of course, use an amp that suits the Heresy's characteristics - one that is clear, dynamic, but not edgy or too soft. Try a well designed single ended triode amp.

I am still not full satisfied with the bass. My next step is to change out the back panel, and then to rework the crossover. Otherwise, I have been very satisfied with my Herey I's.

Khoi Nguyen

OK, here is another one of those stories from 'ye-olde ancient days' at Audio Center (out of business decades ago)in Houston in 1963. I worked part time there in the early to mid 60's while attending U of H. The Klipsch line was very well represented there and the model H's (Heresy - $225.00 ea. in '63), were perched on top of a couple of Klipsch Cornwalls (some times referred to by Woody, our resident JBL and Marantz freak, as "Cornballs").
The components Klipsch used in those days were mostly made by other manufacturers. The woofer was an Electro Voice SP12 with a university 'SAHF' mid range driver with the back can removed, The EV woofer, with beatiful heavy chrome plated thick gauge stamped steel frame, had the round aluminum EV mfr. plate missing and with a cheap sticky label with a K-number listed in its place. The mid range was, I think, labled K-55. The tweeter was a beautiful brown phenolic diaphragm compresssion model with polished cast aluminum, radically flared horn, painted black inside made actually by Electro Voice (T-35), with real name plate also missing and 'K-77' (I-think) stuck on the back. The mid range horn (Klipsch K1000) was a really small dirt cheap aluminum sand casting with straight walled top and bottom plane but with a 'log'
or exponential horizontal flair rate, actually designed by Paul Klipsch. It had a very utilitarian look and finish typical of the stuff put out for high school metal shop projects in the 60's with a very rough body shop grinder surface on the front of the mouth with a 1" dia. thread ready for any cheap and dirty mid range PA driver that became available. The box was 3/4 inch fir plywood with a lacquered walnut veneer. The back might have been thinner maybe 5/8" or less. there was a reflex port about 2" X 6" in the front panel below the woofer. This woofer was of the (then) later varieties having am 'M' roll type of resin impregnated fabric suspension edge,(tanish brown in color), with a fairly thin black paper cone with a really enormous Alnico V magnet assembly about 7 1/2 inches in diameter X 6" deep. The mid range (Univ. SAHF) was the same unit (without the magnet cover) that was routinely bought at the time by the owners of the local Meyer Speedway to drive Univ. Cobraflex horns. This was the only cheapo mid-range that Meyer could find at the time that would be audible over the massive high SPL levels of a stock car race track. (this was in the day of the high performance muscle car high compression engines, 700 plus horsepower with double that on supercharged models and 105 octane gas with ignition timing at 14-15 degrees advance). It was V E R Y loud at 125 db+ all the time out there no matter where you sat or stood. The 60 watt commercial ampifiers they were using (big Dukane amps) were rattling the drivers apart all the time so we sold them replacements).

The modeil H crossover was all heavy commercial motor-run grade oil filled capacitors for high pass and superb inductors built on birch plywood cores (probably leftovers from the cabinet cuttings, but that is just a guess). This was far better then the typical cheasy NP electrolytic caps and iron core commercial grade inductors we were used to seeing in the acoustic suspension 'dog-house' boxes from his competitors. Bottom line: Klipsch's cost of these relatively beefy components was at least 2-3 times higher than his AR and KLH competitors costs and yet his sell price was about the same as top of the line AR-3's.

OK..now you have some idea what these drivers were originally intended to do. The EV woofer had a free air resonant frequency of around 42 HZ and sensitivity of 96-97 db at 1 meter. At the time if you contacted EV (Buchanan Mich.) and talked to anyone in engineering they would honestly and openly tell you that a 5 - 6 cubic foot box was strongly recommended as a minimum on this driver in order to get maximum performance and the most extended low end. I have a lot of respect for Paul Klipsch. His contributions to our understanding of horn technology were enormous. However the model H box is about 1/3-1/4 what is needed by this woofer.

At the time from about 1960 on Klipsch was under increasing market pressure to offer a bookshelf speaker system to compete with the masive onslaught of acoustic suspension designs like the AR-3 and the KLH 6's and 7's. This thing was break your arms off heavy for its rather smallish size. (mostly because of
the really hell-for-strong woofer.

All this said, how did they compare? Well, honestly, this was the only fairly cheap (sell price) item they (Klipsch) made and it was just a market stop-gap. Every time I saw him, Paul had always 'railed on' about all the shortcomings of ALL itty-bitty box speakers. Based on that I suppose he wouldn't be too upset if we look at the speakers rather obvious limitations. THE MAJOR PROBLEM with this system is really the low-end. The mid range and high end are the same componenents as used in the Cornwall at the time. The mid-range driver and tweeter are same as used in the legendary Klipschorn. (K-horn had a far bigger and better 500 HZ mid range horn as well as a folded bass horn. At the time the old fiberglass and wood K-500, on the K-horn, was a truly great design.)

OK...impressions...well...they are very bright and articulate. Now that we have some really fine subwoofers available maybe something really interesting could be done, but back in those days we didn't have these bandpass subs to play with. It would probably be hard to find one efficient enought to play as loud as the model H though. I think the previous reviewer who bought a pair for 50 bucks should get down on his knees. What a deal! I have no idea what Klipsch stuffed these with later on but they had some pretty impressive components in the early days. If you see a pair with a huge woofer with a monster Alnico magnet it is the old EV woofer. Buy 'em. The woofer is wonderful. These drivers would be excellent in a box just under the size of the 8 cu. foot Klipsch Cornwall. I am told that the later ones had a really cheasy CTS woofer with a molded ferrite "mud-magnet". Those wouldn't be quite as nice to play with. Comparisons? Of course, Far more 'dynamic range than an AR-3 with the typical 50-75 watt amp of the time. Despite what Paul always said though the AR-3's go down an amazing 1 1/2 octaves lower than the model H's rather meager 60-65 hz. This is a pretty dramatic difference and is painfully obvious on Poulenc and Bach Organ pieces with lot of sustained 32.7 HZ stuff which is completely missing on the Model H in this, way-too-small-for-the woofer, box Klipsch designed. Only the harmonics of the 32.7 HZ low C are reproduced by the model H. The fundamental frequecy is just not there at all. It's the box, it's the box, it's the box! It's too damn little for this conventional old timey high resonance woofer. OK......

I bought my set of Heresys in Boston 3 years ago, I didn't even intend to buy speakers when I went in. I was looking for a new turntable, but I asked the guy to play them for me just for the hell of it and I was hooked. These things are AWESOME!!! The only thing better are the Cornwalls. I would like to note that my Heresys are about 20 years old and still sound brand new.

I've had a pair of Heresy II's for a dozen years or so and couldn't be happier. They sound great and look great. Plus, they are made in America which always plays a factor in my personal buying decisions.

i paid $50 for a pair of these if you can believe it. A nice retired man in florida was moving and wanted someone to take them. I was just getting into hifi and wasn't familiar with klipsch. to be honest i liked the way they looked. I have had them for a year now...they sound open and true. i paired them with a rega elicit amplifier and a Sota Star turntable and the warmth and clarity of the sound stage is complimented by the horn setup of the heresys. i opened the speakers and lined the cabinet with insulation 3 inches thick and then applied 3/4 inch vinyl lining around the cabinet back to seal the air leaks and they sound twice as good. the bass is tight. i'll rewire them soon and get them up on some spikes and have a very nice speaker setup for around $100. only wish i could be so lucky with my other audio equipment purchases.
i am sure there are better out there, but these are in my home and work well with a warm sounding 70 dual mono integrated amp from england. they are very durable and classic...4 out of 5 because nothing is perfect even if you spend $5000

I bought Klipsch Heresy used about three years ago, on the reutation of the owning KG4 since 1987. They sound Great! I paid $300 used and am very happy. As far as the bass goes....When I can here it down the block thats more than enough. What is great about Klipsch speakers they are made for Rock and Classical Music. Very clear at low volume. If your not getting good bass out of them buy a better equipment.