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Bright Heresys? Dramatic, fix, for FREE.


Klipschguy

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Hello Solly,

Welcome to the Klipsch bulletin board.

Again, I have the same reaction. Interestingly, my Dad (now Grandad, too) was over last night and I asked him to listen to the modified Heresys. My Dad introduced me to audio over 30 years ago and has been into it himself since the late 50's - tons of knowledge about speakers, tubes, power supplies, et cetera. He has also owned and listened to many Klipsch speakers since the early 60's (currently owns Cornwall and Chorus).

Anyway, about 10 seconds into the first CD, he said "Oh yeah, I can hear it already" (said with a positive overtone). After a couple of songs he said "It's hard to believe speakers that size can sound SO GOOD."

Go Heresys!

Klipschguy

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Interesting post. I bought my Hereseys in 1983. I've replaced the caps with Northcreek Zen polyprops and rope caulked the horns. Both good tweeks. I'm interested in yours, but also curious if anyone knows where this rise in output around 9khz occurs with the K52H squawker. What's the diff between the K55 and the K52?

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well.

Paul

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well.

Paul

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well.

Paul

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well.

Paul

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well. Probably needed with the higher level of output in the 101db Cornwall's

Paul

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Wow:

I just saw Al K's schematic of the Cornwall B2 network and was surprised to see that 245uH choke across the tweeter poles. That has the effect of shunting off lower signal to ground and lowering some of the tweeter level. The choke is after the tweeter cap so the total signal resistance through the choke could be high and still reduce the tweeter level a significant percentage. Does anybody know the resistance of the choke?

Klipschguy, this could explain your Heresy's tweeter level being closer to your Cornwalls once they were reduced 3db.

What I'd really like to do is get a pair of chokes to play with. It will offer better tweeter protection with it's steeper cutoff slope as well. Probably needed with the higher level of output in the 101db Cornwall's

Paul

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Pkeller,

I saw that too. I also noticed the squawker and tweeter were hooked up to taps 3 and 4, respectively (Heresys are 2 and 3, respectively, from the factory). They both have the same staggered configuration.

Unlike the Heresy, the Cornwall has two components which offset the efficient highs of the K77 tweeter, relative to the midrange: 1) the larger, more efficient squawker horn lens (compared to the Heresys' lens), 2) the additional choke in the tweeter circuit - which was mentioned in your last post.

My Heresy modification of switching tap 2 to tap 3 in the negative leg of the tweeter circuit does a pretty admirable job (by my ears) of balancing out the tweeter and the squawker levels. But by looking at the Cornwall circuit, there may be another way to match the tweeter level - and that would be the addition of an appropriate choke in the tweeter leg of Heresy crossover while likely leaving the taps in their stock positions.

My only complaint (minor) of an additinal choke in lieu of the tap switching modification, is there would be one more filter in the circuit, which, as you know need to be kept to a minimum in the interest of a more pure sound. But it really depends on which one sounds better - which is the ultimate test and the right thing to do.

The choke would indeed attenuate the highs, but I don't know exactly how I would customize a Heresy network to make it function more like the Cornwall network - which in my opinion works quite well.

If you feel so inclined, investigate and try out a suitable choke value in the tweeter leg for the Heresy - I would definitely be open to trying it out and comparing it to my own modification to search for the best sound.

Again, I really do think a stock Heresy needs some attenation of the tweeter - the Cornwall circuit diagram also seems to suggest this and seems to provide an avenue of investigation. Like everybody else here, I just want the best sound from my speakers and enjoy sharing my findings/opinions with other Klipsch fans.

Great topic. Please keep us informed.

Klipschguy

P.S. I think the K-horn has a choke in its tweeter circuit too.

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Hey Klipschguy. Stumbled across this thread and read the whole thing with great curiosity.

I have a pair of Heresy I's (1978) that I have owned since new. Recently I moved into a new house and, for what ever reason (probably room acoustics), my Heresy's started sounding overly bright. I mean, over the years, they always sounded bright; sometimes to the point of almost being harsh. They've also seen various types of amplifiers from a cheap Sherwood reciever to a Crown (borrowed) to a NAD to my present Denon 3300.

Anyhow, for the last three months I've tried all kinds of things to quell this brightness - changing speaker location, making sure I didn't have the polarity wrong, boosting sub output, using the Denon tone control to cut treble 2db and/or boost bass by 3db...well, you get the picture. Nothing I've done has satisfied my ears.

Is it possible your tweek is what I'm looking for? I'm sure game to try except for one thing - I'm scared to death of poking around inside my speaker cabinet and I have no clue what I'm doing (ooops, that's two things smile.gif )

So, just how difficult would this be for a complete novice??

Tom Adams

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Tom,

I think this modification is just what your looking for because the story your telling about the room postions and the tone controls were exactly what I was doing - until recently.

The mod is very, very simple. All you have to do is: Note: This applys to the E Type crossover (not E-2 or others).

1)Remove the back - just take out the screws and don't overtighten on reassembly. The wires will still be attached to the back - just leave them alone.

2) Locate the T2A on the crossover. It looks like a transformer and has brown paper wrapped around the core. On CLOSE inspection of the brown paper you will see little numbers by the little taps (0,1,2,3,4,5).

3) The negative lead of the tweeter should be soldered to tap #3 (after it passes thru a 2uF oil filled metal-can capacitor). You'll see the number "3" on the brown paper.

4) Disconnect the #3 tap lead with a soldering iron (or, if you don't have a soldering iron, you can snip it, just leave about an inch of wire so you can reattach it if you don't like the mod).

5) Loosen the screw on the crossover which goes to the negative (white and black wire) side of the squawker (also makes it's way over to the T2A TAP 2) and put the wire under the screw and tighten it up (you will need to strip a little insulation off the wire to get good contact). Everything is clearly marked inside. Note: red is positive, black is negative. !!!Make sure you can trace your hook up wire back to TAP 2 on the T2A - you do not want a short! You can use a meter acoss the terminals to make sure you do not have a short, BEFORE listening tests.

6) Your done. Put the back on and listen to the results.

7) recap: Move tap #3 wire to negative side of midrange on the crossover (this will correspond to using tap #2 on the T2A - check it out when your inside the speaker). Make sure you can trace your hook up wire back to TAP 2 on the T2A! Use a meter across the inputs to make sure your not shorted.

8) post results here when done

9) VERY IMPORTANT: THESE INSTRUCTIONS APPLY TO THE E-TYPE BALANCING NETWORK. MAKE SURE THAT WHEN YOU HOOK THE TWEETER WIRE UP THAT IT IS EITHER DIRECTLY HOOKED TO THE T2A TAP 2, OR IF IT IS HOOKED TO THE CROSSOVER, MAKE SURE THE TWEETER WIRE CAN BE TRACED BACK TO THE T2A TAP2! IMPORTANT NOTE: The E-2 crossover has the POSITIVE side of the squawker going to the T2A, NOT THE NEGATIVE, so if you put the TAP 3 tweeter wire under the negative squawker screw with the E-2 network - YOU WILL BE SHORTED.

10) This modification is indeed simple, but requires some basic wiring knowledge and a little common sense. If you are unsure of what you are doing, DON'T do it, because I don't want anyone to short out their amplifier. Different crossover types are wired differently - so make sure (also somebody may have rewired something in the past - unknown to you). Before you hook your speaker up to an amplifier, use a meter to make sure your not getting a dead short - should be somewhere around 8 Ohms (I don't know the EXACT value, but it's NOWHERE near ZERO).

11) Make mod at YOUR OWN RISK, I am not responsible or liable for your actions.

Klipschguy

P.S. I have a feeling your speakers are going to sound a heck of a lot better.

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Thanks Klipschguy. I've printed out your instructions and will be making the mod shortly. I'm outta town for a few days, so it may be next week before I can post results.

BTW, last night I did what you suggested and put my ear to both the tweeter and the squawker. And sure enough, the output from the tweeter was much more overpowering than the squawker.

Thanks a bunch. smile.gif

Tom Adams

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Speaking of the heresy! What i would like to try with them is,,,,,,,,,,,,,

Take the backs off, cut a different piece of wood, for the backs, then cut 2 , 2inch, by 4inch vents on the bottoms, one on each side, and then create the same wood divider, just below the woofer frame, inside the box as the cornwalls, only out the backs!!

I have a funny feeling this might drop the db down to 38 or even lower!!

Just another crazy thought! Only if i did do this, id make sure not to damage anything, so i could put it back to original!!

Regards Jim

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I had thought the same thing. The problem is that the T/S perameters of the woofer are designed for a sealed enclosure. The balance of bass v/s mid would not have the same ratio of response. At higher volume levels, the sealed design of the Heresy depends on internal compression and rarification of internal atmosphere. It would be risky and non-linear to drive the woofer "unloaded" at such excursion levels. A tuned port might be used to augment the low response if the Thiel/Small measurments were known. This would limit low frequency excursion if the desired tuned frequency is close to the acceptable perameters of the woofer. Still, there would be all kinds of non-linearities in response. Better towork up a new crossover design using Klipsch tweeter and midrange and a more compliant "but efficent" woofer.

Good luck:

Paul

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I had thought the same thing. The problem is that the T/S perameters of the woofer are designed for a sealed enclosure. The balance of bass v/s mid would not have the same ratio of response. At higher volume levels, the sealed design of the Heresy depends on internal compression and rarification of internal atmosphere. It would be risky and non-linear to drive the woofer "unloaded" at such excursion levels. A tuned port might be used to augment the low response if the Thiel/Small measurments were known. This would limit low frequency excursion if the desired tuned frequency is close to the acceptable perameters of the woofer. Still, there would be all kinds of non-linearities in response. Better towork up a new crossover design using Klipsch tweeter and midrange and a more compliant "but efficent" woofer.

Good luck:

Paul

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Thought I'd share with you folks. Yesterday I was reading at PI loudspeakers, and they were discussing balancing the output from the drivers on the Heresy. To make long story short, I added a 22 ohm resistor in series to tweeter and 33 ohm resistor in series to squawker. The end result was a lot more power required to drive speaker to comparable levels and a generally dull sound. However, output from drivers was more equal in terms of db's. Somebody with more time and knowledge may be able to work this out.

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Not sure about the K-53 mid and the E-2 crossover. However, this tweak is more of a tweeter modification, not squawker. The mod specifically addresses the K77/K77-M tweeter output and attenuates it relative to the other drivers.

Somebody else out there may be able to tell you how similar the wiring of the E and E-2 crossovers are.

Anybody?

Klipschguy

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J Harris,

I did a search here on the E-2 crossover. I can tell you one difference already from reading the posts and that is the woofer X-over in the E-2 uses a 12dB/octave filter instead of a 6dB/octave like in the "E" (evidenced by the 33uF cap across the woofer leads).

You have obviously been tweaking your X-overs from the posts I've read.

A few questions. 1) what driver components do your Heresys have? 2) are your tweeters too bright? 3) does your X-over have a T2A?

Klipschguy

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