Heresy upgrade with great imaging, smooth midrange and low-end SLAM!!

[Antone]

My 1981-vintage Heresy's were a graduation present (serial nos. 139X291 and 139X292), so I've owned them since they were brand new and used them continuously with no problems. Klipsch speakers are built to last! Their dynamic, open and direct sound has always endeared them to me, but the midrange drivers (squawkers) usually overbalanced the other drivers, rendering the sound peaky, midrangey and unsatisfying on some music. They never imaged very well, and my friends and I always wondered why those large (12") woofers sounded so wimpy. After much research and trial-and-error I have found a set of modifications (all reversible) that result in the sound I've always wanted from my beloved Heresy's.

I had the opportunity not long ago to repair some old Advent speakers which suffered from fried (first order) crossovers. In replacing the defective electrolytic tweeter capacitor (13 microFarads) I noticed that the enclosure was stuffed with foam-rubber padding. I discovered that this simple thing makes the box act acoustically like a much larger enclosure, deepening and tightening the low end significantly: with a smaller (10") woofer and smaller box the Advents have much deeper and louder bass than the Heresy's. I researched woofers and found some efficient (92 dB/W/m) 8-Ohm, large-excursion, 180 W RMS power-handling 12" drivers with a usable frequency response down to 25 Hz! Their spider and magnet-structure DWARF the original Klipsch K-22E. The new woofers reproduce mid-bass and lower midrange more quietly than the K-22Es, so I lowered the woofer low-pass coil's inductance to 3.8 mH in order to raise the top-end downpoint of the new woofers to compensate- by the way, there had been a 0.14 mH discrepancy between the left speaker's and the right speaker's woofer coils' inductances, which had audibly detracted from bass equality between L&R. Stuffing the boxes with polyester fiberfill, replacing the woofers and lowering the inductance of the woofer coils almost fixed the bass balance. I still needed to increase the woofer's overall output in order to balance the squawkers and tweeters. The solution was a more-efficient woofer coil. The old coils used 20-gauge wire wound on a cube-shaped transformer frame and had a Direct Current Resistance of about 0.5 Ohm. On the internet I found a toroidal, high-power inductor, wound with 14-gauge wire and yielding a DCR of only 0.072 Ohm, thus increasing the voltage--hence volume--to the woofer. I unwound a few turns of wire to lower the inductance to 3.71 mH (also reducing the DCR slightly). This inductance seems to be the right value for a seamless transition between bass and lower midrange. One last improvement to the bass was to replace the 18-gauge wires from the back of the cabinet to the crossover board and from the crossover to the woofer with 12-gauge wires for more efficient current flow.

The E2 balancing network utilizes three capacitors (one 33-microFarad electrolytic at the woofer output screws and 2 spam can-shaped, motor-run style 2-microFarad caps, one of which is connected to the tweeter minus output screw, the other connected to the plus input screw and the autotransformer) . I replaced the stale 20% tolerance, 33-muF electrolytic cap with a 33-muF, 5% metallized polypropylene cap and the non-tweeter 2-muF "spam can" with a 1%, 2-muF metallized polypropylene capacitor. With both speakers' crossovers out at once I could choose and combine cap values to minimize discrepancy between left and right speakers. The higher-quality caps resulted in crisper, cleaner, and more solid midrange with more presence (in a good way).

The tweeter horn driver has midrange and below blocked by the remaining 2-muF, spam-can cap (the one connected to the tweeter). First, I tried a 2-muF, 1% metallized polypropylene cap as I had used for the squawker, and the treble became clean, crystalline and sweet. But there seemed to be a peak around 6kHz right at the crossover point between midrange and tweeter; this over-emphasized sibilants slightly, so I tried a higher-quality, 1.8-muF, 2% metallized polypropylene cap from Denmark in order to raise the tweeter's crossover frequency slightly. Although it was rated at 2% tolerance, it actually measured at 1.800 muF; in fact both of the 1.8 caps measured 1.800muF for holographic imaging. Yes, Heresy's CAN image! Now my beloved Klipsches sound neutral, clean, and smooth--with plenty of bottom-octave slam!

[folkdeath95]

That looks pretty interesting. Do you have any clues to help us better understanding your work? Which woofer did you choose? Could you draw a schem of your crossover?

Thanks.[]

[Ironsave]

Welcome to The Forum.

I will ask you to post pictures and links to your updating/ upgrading.

I am interested in this post; but without sharing the detailed info; sharing the result has little merit.

Thanks.

[Marvel]

Yes, Heresy's CAN image! Now my beloved Klipsches sound neutral,

clean, and smooth, with plenty of bottom-octave slam!

They are no longer Klipsch speakers... sorry.

Bruce

[Olorin]

Really? He replaced the woofers, stuffed the cabinets, and modified the crossovers a bit. Are Khorns with ALK crossovers, or La Scalas with Dave's Tractrix horns in them, or Cornwalls with Crites tweeters also no longer Klipsch?

[Marvel]

Technically, yes... they are no longer Klipsch designs. Which means that my LS are really not Klipsch speakers anymore.

Bruce

[Antone]

This is a Heresy I upgrade. All components are available at parts-express.com .

Two Woofers part # 295-120

Two Tweeter Capacitors 1.8 muF part # 027-480

Four Squawker Capacitors: Two 33muF part # 027-592 and two 2muF part # 027-534

Two low-pass woofer inductors part # 255-820

Acoustic enclosure fiberfill part #260-330 (Divide evenly between the two speakers.)

It helps to be good at soldering, and it helps to have an LC meter part # 390-570 to fine tune the woofer inductors to 3.71mH and to measure the capacitance value of the Spam-can caps.

In each speaker there are two identical 2 muF spam cans, one being connected to the tweeter, and the other is connected to the plus input screw. The spam can whose terminals measure about 35 muF with an L/C meter is the squawker cap; the spam can that measures 2muF is the tweeter cap, which is to be replaced with the 1.8 muF Superior cap. Replace the 33muF electrolytic at the woofer output screws with the part # 027-592 . There are two open bracket choke-style inductors which look a lot like transformers; One is a low-pass inductor for the woofer, and the other is an autoformer that's used to decrease tweeter and squawker volume by 6 dB and 9dB, respectively. Just one of these has ONLY two leads coming out of it; one of which goes to a woofer terminal on the barrier strip. This is the woofer inductor to be replaced with part #255-820 unwound to yield an Inductance of 3.71mH. (Hot glue can keep the coil from further unraveling). One last step is to replace the two 18 AWG wires from the woofer with two 14 AWG wires of the same exact length.The same goes for the wires from the back of the enclosure to the crossover ("balancing network").

If you want to improve your Heresy's relatively cheaply, you might replace only (all) the capacitors and fill the enclosures with the poly stuffing. Stuffing the cabinets makes a NOTICEABLE difference in the bass depth and overall cleanness. The much better caps WILL sweeten, clean and solidify the midrange and treble without changing the Klipschness.

Happy listening!

Antone

[folkdeath95]

Thanks for the informations, parts ref, etc...

I made some quick simulations of the Dayton woofer with WinISD. It allows the Heresy to go a little deeper: 60Hz at -3dB versus 63Hz.

The efficiciency is lower than the K22, did you attenuate the squawker and the tweeter to match the woofer SPL?

[Ironsave]

Thank you for your interest; this is a Heresy I upgrade. All components are available at parts-express.com .

Two Woofers part # 295-120

Two Tweeter Capacitors 1.8 muF part # 027-480

Four Squawker Capacitors: Two 33muF part # 027-592 and two 2muF part # 027-534

Two low-pass woofer inductors part # 255-820

Acoustic enclosure fiberfill part #260-330 (Divide evenly between the two speakers.)

It helps to be good at soldering, and it helps to have an LC meter part # 390-570 to fine tune the woofer inductors to 3.71mH and to measure the capacitance value of the Spam-can caps.

In each speaker there are two identical 2 muF spam cans, one being the tweeter cap, and the other is in parallel with a (crappy) 33muF electrolytic and will yield a combined value of 35 muF. The spam can whose terminals yield a 35 muF capacitance is a squawker cap; the spam can that reads 2muF is the tweeter cap,which is to be replaced with the 1.8 muF Superior cap. Replace the 33muF electrolytic with the part # 027-592 . There are two open bracket choke-style inductors which look a lot like transformers; these are low-pass inductors for the woofer and squawker. Only one of these has ONLY two leads coming out of it; one of which goes to a woofer terminal on the barrier strip. This is the woofer inductor to be replaced with part #255-820 unwound to yield an Inductance of 3.71mH. (Hot glue can keep the coil from further unraveling). One last step is to replace the two 18 AWG wires from the woofer with two 14 AWG wires of the same exact length.The same goes for the wires from the back of the enclosure to the crossover ("balancing network").

If you want to improve your Heresy's relatively cheaply, you might replace only (all) the capacitors and fill the enclosures with the poly stuffing. Stuffing the cabinets makes a NOTICEABLE difference in the bass depth and overall cleanness. The much better caps WILL sweeten, clean and solidify the midrange and treble without changing the Klipschness.

Happy listening!

Antone

Thanks for clarifting your "upgrade" info.

Considering the woofers cost about the same as the Crites woofers; I am pretty sure the Crites woofers would probably be the better value..... (Can be found on Ebay for 2 for $200 vs. $93/ per at Parts Express)

I might be interested in trying this; perhaps down the line.......

[SilverSport]

Doesn't the Heresy go to about 50Hz +/- 5dB...???...it is the Heresy II that only goes to 63Hz+/- 3dB...

http://www.klipsch.com/na-en/products/heresy-specifications/

Bill

[folkdeath95]

Well, the curves I posted are only simulations made by a software using the Thiele/Small parameters of the drivers. Moreover, the volume of the box is only an approximation. I measured my Heresy to calculate the internal volume and found 54.5L. I wish to consider the volume of the braces, speakers, horns and crossover but I was to lazy to calculate it, so I set the volume at 50L in the software. I don't if this is more or less than the real internal volume of my cabinets.

My curves are certainly not as accurate as measurements in a anechoid room, but it's a good way to make some comparisons.

[SilverSport]

I have no issues with anything you posted...if the Dayton woofer goes to 60Hz and the Klipsch or Crites ones will do 50Hz or thereabouts...we have no improvement...adding in any slight margin for error...I see no reason that the Daytons should be an improvement...I just meant, it seems to me, you proved it is no improvement over stock...

Bill

[folkdeath95]

On the simulations with WinISD, the K22 goes to 63Hz at -3dB, the Dayton goes to 60Hz. I don't know how deep goes the Crites, but in a Heresy cab, when trying to keep good efficiency in mind, it's hard to go deep (the best result I had on WinISD was 55Hz at -3dB with a Focal Audiom 12, but the Heresy needed to be trnasformed in a bass-reflex enclosure).

If just looking the lowest frequency at -3dB, the Dayton could be considered as an improvement, even if I don't believe this 3 little Hz can be considered as an indication of sound quality.

[Antone]

Dear Klipsch Fans,

"Slam" means tight, fast and palpable very-bottom end, e.g. kick drum that hits you in the chest.

My Heresy's are no longer Klipsches only if a Shelby Cobra 350 is no longer a Mustang.

Regarding the woofer simulations, the Dayton Series Two woofer that I specify is efficient (92dB/W/m). Its output in the tubby, shallow midbass region is quieter than the Klipsch K22E's, but the Dayton has usable response down to 25 Hz (Fs=27 Hz) ! The K22E was basically inaudible below 50 Hz. To illustrate this, I could add 6 dB at 31 Hz with a graphic equalizer before I could hear a difference; now I can easily hear when I add 1 dB of 31 Hz! The Dayton woofer I specify has 275 W RMS power handling, a treated-paper cone, a large-excursion butyl rubber surround, a larger spider and a magnet twice as big as the K22E's. The old woofer ran out of gas long before the horns did; it no longer happens with the upgrade woofer. My speakers now simply give me another octave of bass.

With respect to output balancing, yes I did juggle slightly the relative outputs of the drivers (the old woofers never used to balance the horns in volume). The polypropylene capacitor upgrades just noticeably increased the squawker and tweeter volume, along with clarity. In repairing some Advent speakers, I had noticed a simple 1 Ohm, 10 W resistor being used to drop overall tweeter output by 3 dB. Hence, decreasing the resistance of the low-pass woofer inductor (originally 0.5 Ohm) would increase the woofer volume. (There was no way I was going to insert a resistor into the network.) The old coil was wound with 20 AWG wire to 3.9 mH. I found a really efficient toroidal inductor wound with 14 AWG wire, having a Direct Current Resistance of only 0.072 Ohm (almost seven times better!). This audibly increased woofer output. Since the new woofer is quieter in the upper end of its range, I lowered the Inductance of the new coil to 3.71 mH in order to raise the upper end roll-off point to transition to the squawker. By the way, the LC meter I have measured a "4.7 mH" coil at 3.9 mH. All my inductor values are based on my meter's readings. The original internal wiring was all 18 AWG, thick enough for the tweeter and squawker horns but not even close for the new woofer and coil. I replaced the leads from the woofer to the crossover and from the crossover to the input screws on the rear wooden panel with 12 AWG wire of the exact same lengths to give the woofer even more of an advantage. Also keep in mind that the new tweeter capacitors (1.8muF instead of the old 2muF) allow for less overlap at the squawker-tweeter transition, therefore producing less upper midrange output (!).

Thiele-Small parameters notwithstanding, I am a professional musician. I listen for a living, so I approached this project more empirically than some people. I stand by these upgrades as having all the euphonic effects I have described and as being worth the investment. What have always made these speakers, to which I've been listening critically for DECADES, so special, are still there: those great horns, the hand-crafted cabinets and the overall crossover network design. Upgrading the 30-year old electrolytic capacitors with polypropylene, higher power-handling, tighter-tolerance ones that never wear out is like replacing your project car's old Champion spark plugs with double-Iridium ones; it's still the same car, just better. As for the woofers, seeing and hearing are believing. Another octave. Definitely.

Antone

[willland]

I stand by these upgrades as having all the euphonic effects I have described and as being worth the investment. What have always made these speakers, to which I've been listening critically for DECADES, so special, are still there: those great horns, the hand-crafted cabinets and the overall crossover network design. Upgrading the 30-year old electrolytic capacitors with polypropylene, higher power-handling, tighter-tolerance ones that never wear out is like replacing your project car's old Champion spark plugs with double-Iridium ones; it's still the same car, just better. As for the woofers, seeing and hearing are believing. Another octave. Definitely.

Antone,

I respect your opinions and ability to transform your beloved Heresy's to the the more refined lower depth reaching speakers you desire. So they are not 100% factory originals you did enjoy for decades. So what? Now enjoy them for more decades in their much improved state.

My Heresy's are no longer Klipsches only if a Shelby Cobra 350 is no longer a Mustang.

One question, are you considering re-veneering them in some exotic wood that was not offered when they were built? If you are, then they will not be Klipsch anymore.[^o)] []

Bill

[Antone]

Let me reiterate: stuffed enclosures act acoustically like larger volumes than empty ones. The Dayton woofer that I specify has a much (2X) larger magnet and gives peak output at a lower frequency than the cheaper, smaller K22E. I wish that I could show the two drivers side-by-side; the Daytons just have a much bigger motor: more guts to overcome that too-small cabinet. More mods to improve bass include speaker-gasketing tape (part #260-542) for the back wooden panel to seal air-tight, making it an acoustic suspension system for flatter, lower bass. (Make sure the squawker driver is screwed tightly to its horn and that its rubber washer is undamaged.) The speakers still should go deep into corners without quite touching the walls, and I have found that the bass and midbass benefit greatly from having those angled, wooden plinths removed and placing the speakers around 18" off the floor. Try it.

You can convince yourself that my specified woofers are not much better, or you could try one. Parts-express has a great return policy; just don't scratch the trial woofer. When it arrives you will be surprised at how much bigger and how much higher in build quality the Dayton woofer is than the Klipsch K22. Without changing the low-pass woofer inductor you will still notice the very bottom being better represented, but it will be lean in the upper bass. The inductor makes a big difference in overall woofer output, so don't totally knock the woofer if it's too quiet; it is plenty loud with my specified Jantzen inductor adjusted to 3.71 mH. Feel free to try all my mods except the expensive woofer and inductor ($150 per speaker). Stuff the enclosures; seal the back panel; replace the capacitors (too old, anyway). Place the speakers on stands 18" off the floor in the corners. These things are all reversible. Save the parts; the spam can caps may be good still, but I bet they won't be within 0.1% of each other L to R. The old 33muF electrolytics had a 20% total tolerance (when new); my specified polypropylenes are well within 5%. Or just stuff the cabinets, and place them where I've indicated. That's cheap and easily reversed, and it will sound noticeably better. If you do go whole hog, matching the capacitance and inductance of the L and R crossovers within 1% or better of each other drastically improves imaging, so have both crossovers out at the same time and balance the values.

Happy Listening.

Antone

[greg928gts]

I think your speakers are still Klipsch Heresy speakers.

Greg

[Marvel]

I think your speakers are still Klipsch Heresy speakers.

Greg

[]

I should have put that in my first post....

[DrWho]

Let me reiterate: stuffed enclosures act acoustically like larger volumes than empty ones.

That gets thrown atound quite a bit, but it's not really true. A larger cabinet has more reactance, whereas a smaller cabinet with stuffing has less reactance and the remaining energy gets coverted to heat. No matter how you look at it, the smaller box will always be less efficient...no matter how much stuffing is added. Adding stuffing just changes (lowers) the Q of the low frequency corner. Making the box bigger will also lower the Q, but it will be more efficient.

So did you actually measure the final acoustic frequency response? Ithink it would be enlightening as to the merits of the mod.

[Antone]

"The K22E was basically inaudible below 50 Hz. To illustrate this, I could add 6 dB at 31 Hz with a graphic equalizer before I could hear a difference; now [with the DaytonST305] I can easily hear when I add 1 dB of 31 Hz! "

I do not have measuring instrumentation, so I cannot give out any numerical values (other than those I already supplied). I can affirm confidently that the Dayton puts out much more information in the bottom octave than the K22E. I used to need to add bass via tone knob or graphic equalizer to achieve a satisfying tonal balance (still lacking any of the bottom octave, though). Now bassy music sounds bassy with every control set 'flat'. Other people have auditioned my Heresy's as I added improvements, and all agree that it now is a much better loudspeaker. My brother used to call them 'kazoos', and he has provided strong testimony as to their drastic improvement since upgrading them.

"I had the opportunity not long ago to repair some old Advent speakers which suffered from fried (first order) crossovers. In replacing the defective electrolytic tweeter capacitor (13 micro Farad) I noticed that the enclosure was stuffed with foam rubber padding. I discovered that this simple thing makes the box act acoustically like a much larger enclosure, deepening and tightening the low end significantly: with a smaller (10") woofer and smaller box the Advents have much deeper and louder bass than the Heresy's." **

Even if I erred in claiming a large acoustic volume increase with stuffing, I can still hear the difference stuffing makes. The bass no longer sounds trapped in the cabinet; the stuffing pushes the bass out of the enclosure. With the stuffing the woofers project more like the horns. Also, even though I appreciate the beautiful cabinetry of the Klipsch enclosure, the plywood 'rings' more than MDF, and the stuffing helps to calm down the internal resonances. In regard to those Advents with smaller enclosures and smaller, less efficient woofers, their bass totally outclassed the Heresy's'. My goals were to take some of the good aspects of the Advent -extended, tight, strong bass and smooth upper midrange- and to combine them with the positives of the Klipsch. I firmly believe that I have accomplished this goal.

In my profession I have to make subtle changes to my reed, horn and air column to compensate for the numerous different acoustic environments of the various performance venues where I work. I'm used to tweaking and to evaluating sound on the fly; this makes for a self-critical attitude sometimes, but one benefit is that it is difficult to deceive myself. Seventy-five professional fellow musicians are listening to me critically, too, moment to moment. You don't last long in this career if you do not pay strict, unforgiving attention to sonic details. I have shared these modifications because they make real, significant improvements to the fidelity and 'listenability' of the Heresy loudspeaker. I don't claim that my modifications are the best ones, but they do yield the sonic benefits which I have detailed. It's a Buffet; take it or leave it.

** By the way, with the Advents I compared new, replacement bipolar electrolytic capacitors to polypropylenes. Polypropylenes sound less vague, less muddy, crisper and more solid than electrolytics, and I strongly recommend them over electrolytics in midrange and treble applications.

Happy Listening.

Antone