Heresy Type E crossover mod

[jimjimbo]

While "trolling" some of the deep, dark secrets of crossover mods past, I came across this (partial) post, (attributed to DeanG and/or John Albright) that sounds good, and am wondering if it still holds true for both the E and E2 networks.  Also, here is the closest resistor I found, seems to be the proper values...

 

http://www.parts-express.com/15-ohm-10w-resistor-wire-wound-5-tolerance--016-15

 

(or is there a "better" resistor, or different type that should be used?)

 

 

"I've tried all of the different network mods and networks for the Heresy. Keep it simple; the top is too hot in relationship to the bottom (a common complaint). So, put a 15 ohm resistor in parallel with squawker, you can screw it right to the + - spots on barrier strip for the squawker. Then move the tweeter from tap 2 to tap 1, and the squawker from tap 3 to tap 2. This lowers the midrange and treble by 3dB which brings the bass up and makes the speaker sound much more balanced. The 15 ohm resistor means you don't have to change the primary capacitor value. IOW's, it keeps the crossover points the same. I suggest you try it, you probably won't feel the need to do anything else."

 

 

 

[jason str]

Parts Express sells Mills resistors as well.

 

Probably cost more.

[Bossman]

 Also, here is the closest resistor I found, seems to be the proper values...   http://www.parts-exp...lerance--016-15   (or is there a "better" resistor, or different type that should be used?)  

 

I would not use that $0.78 resistor in a E or E2 network. They impose their own sonic characteristics which takes away all the subtle details. They will make a good speaker system sound like clock radio speakers. I recommend Mills or a higher quality resistor. 

Edited July 13, 2016 by Bossman

[avguytx]

Mills and Mundorf are definitely the resistors I would personally use. Mills has always been my "go to" as are Solen caps.

Edited July 13, 2016 by avguytx

[jimjimbo]

You guys are great, thank you!

[The Dude]

I am curious to your finding.

[mwhitwo3]

Jim

I tried this mod on my Heresy E 2´s and it helped balance the speaker some, but then i tried Claudes Super Heresy, Baby Cornwall mod  .

As you know the Super Heresy is something totally different and a lot more exspensive, than adding a resistor to the barrier strip. 

Adding the resistor and lowering the taps does help , but is nowhere near the Super Heresy mod.

[Deang]

What we "know" is nothing - since you really didn't tell us anything.

[jimjimbo]

Jim

I tried this mod on my Heresy E 2´s and it helped balance the speaker some, but then i tried Claudes Super Heresy, Baby Cornwall mod  .

As you know the Super Heresy is something totally different and a lot more exspensive, than adding a resistor to the barrier strip. 

Adding the resistor and lowering the taps does help , but is nowhere near the Super Heresy mod.

Yes, I have Claude's very first pair of Super Heresy's....love them, if they are placed in the right spot, which fortunately, I have...

 

I'm just doing this on a "normal" pair of H1's I recently got pretty cheap, so going to try it out.

[jimjimbo]

What we "know" is nothing - since you really didn't tell us anything.

Not quite sure what you mean here Dean.

[Deang]

I didn't know what he was talking about. And he didn't provide any details. Maybe at one time I knew, and just no longer remember. Otoh, he was addressing you directly.

Did the Hollywood Vampires show last night, and I'm going on about three hours sleep - just ignore me. :-)

[jimjimbo]

OK, take a nap.

 

I asked a question on the AA build thread regarding adding a resistor as well, if you want to take a look.

[mboxler]

I've been thinking about a different solution.  Replace the 2.5 mH inductor to the K-22-E with a 1.3 mH, then adding an autoformer between the new inductor and the driver.  Input 0 - 4, output 0 - 5.  This would double the power to the driver...a 3db increase.  Not sure if the autoformer would handle the current.

[Marvel]

The mod for the Heresy works great and is not expensive. I have HIIs, but my son did this on his originals and it helped a lot. I Mills non inductive would be my choice.

Bruce

[rtaylor76]

So i just purchased a pair of HBR's and did this mod and it did help, but all the high end details went away too. So I started look and asked why is there a 16 ohm resistor on the mid and not anything for the tweeter?

 

By my values, here a are the calculations for where the crossover frequency is stock:

 

    Mid horn: 16 ohm x 8 (pin 2) = 128 ohms + 2uf cap = 621 hz (depending on calculation)

    Treble horn: 8ohm x 4 (pin 3) = 32 ohms + 1 uf cap (two 2uf caps in series) = 4973 hz

 

Now with this mod:

 

      Mid horn: 8 ohm (two 16 ohm in parallel) x 16 = 128 ohms + 2uf cap = 621 hz (same as before)

      Treble horn: 8 ohm x 8 (pin 2) = 64 + 1 uf cap = 2486 hz (not the same)

 

You could add a parallel resistor to the tweeter to move it to mach exactly. I don't even think this is necessary. 

 

Unmodded they have a mid hump, and doing the mid mod (moving the mid to pin 1 and adding 16 ohm resistor in parallel) does the trick. Leaving the high end intact keeps it's efficiency up and likely a flatter response. The top end may still sound a slight bit bright, but I think it is much more balanced and has a fuller range now. 

 

So my thinking is to do the mod to the mid horn and just leave the treble where it is.  

 

Thoughts?

[JohnA]

On 7/13/2016 at 9:25 AM, jimjimbo said:

While "trolling" some of the deep, dark secrets of crossover mods past, I came across this (partial) post, (attributed to DeanG and/or John Albright) that sounds good, and am wondering if it still holds true for both the E and E2 networks.  Also, here is the closest resistor I found, seems to be the proper values...

 

http://www.parts-express.com/15-ohm-10w-resistor-wire-wound-5-tolerance--016-15

 

(or is there a "better" resistor, or different type that should be used?)

 

 

"I've tried all of the different network mods and networks for the Heresy. Keep it simple; the top is too hot in relationship to the bottom (a common complaint). So, put a 15 ohm resistor in parallel with squawker, you can screw it right to the + - spots on barrier strip for the squawker. Then move the tweeter from tap 2 to tap 1, and the squawker from tap 3 to tap 2. This lowers the midrange and treble by 3dB which brings the bass up and makes the speaker sound much more balanced. The 15 ohm resistor means you don't have to change the primary capacitor value. IOW's, it keeps the crossover points the same. I suggest you try it, you probably won't feel the need to do anything else."

 

 

 

 

As this was just to be an experiment, that PE resistor is just fine.  If you like the balance, there is a better way, with the benefit of being kinder to SET amps. If you don't like it, you've spent a pittance. 

 

[JohnA]

18 hours ago, rtaylor76 said:

So i just purchased a pair of HBR's and did this mod and it did help, but all the high end details went away too. So I started look and asked why is there a 16 ohm resistor on the mid and not anything for the tweeter?

 

By my values, here a are the calculations for where the crossover frequency is stock:

 

    Mid horn: 16 ohm x 8 (pin 2) = 128 ohms + 2uf cap = 621 hz (depending on calculation)

    Treble horn: 8ohm x 4 (pin 3) = 32 ohms + 1 uf cap (two 2uf caps in series) = 4973 hz

 

Now with this mod:

 

      Mid horn: 8 ohm (two 16 ohm in parallel) x 16 = 128 ohms + 2uf cap = 621 hz (same as before)

      Treble horn: 8 ohm x 8 (pin 2) = 64 + 1 uf cap = 2486 hz (not the same)

 

You could add a parallel resistor to the tweeter to move it to mach exactly. I don't even think this is necessary. 

 

Unmodded they have a mid hump, and doing the mid mod (moving the mid to pin 1 and adding 16 ohm resistor in parallel) does the trick. Leaving the high end intact keeps it's efficiency up and likely a flatter response. The top end may still sound a slight bit bright, but I think it is much more balanced and has a fuller range now. 

 

So my thinking is to do the mod to the mid horn and just leave the treble where it is.  

 

Thoughts?

 

Well, first, the tweeter cap is downstream of the autoformer and is not affected by changing the tap.  The tweeter is actually 8 ohms, so the 2 uF cap is correct, allowing for the hump in the K-77-Ms response.  As produced, the woofer runs at 94 dB, the squawker at 98 and the tweeter at 99 dB.  Cutting the squawker and tweeter 3 dB improves the balance, but it still has a climbing response curve. 

 

The parallel resistor is ONLY for experimental use.  It will absorb some power meant for the squawker.  If you like the effect, there is a better way. 

 

[Deang]

What John said. :-)

[rtaylor76]

I returned the tweeter back to position #2 on the transformer after noticing some really lacking mids. I had to do an A/B comparison with my KEF's to really hear how mids sucked out.

I want to try the other mod of the resistor and cap change before the transformer instead of the parallel resistor on the squawker.

I will also add that it might have taken the Dayton caps to settle in. At first trey sounded very much warm, and now they sound much more balanced. Anyone else have this experience with Dayton MKP caps?


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