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Stuffing an Heresy I ? :/


DrTUBE

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Hello All,

 

A few days ago, I re-opened my beloved Klipsch Heresy I HBR from 1983 in order to... Stuff them...

 

When I bought my pair of Heresy in 2004, I noticed that there were no stuffing inside, and I was told by a friend - who owned a pair of HBR too and recommended me to buy one pair also - that this was factory stock. So OK...

 

In 2005, I modified the E-2 crossover (removable, harmless mod) to tame the loudness (to my ears) of the Tweeter K-77-M + Squawker K-53-K/K-701 versus the woofer : I made a measurement which showed at least a 10dB excess in favor of the TW and SQ... I described this little mod somewhere on the forum, AFAIR, but where ?... Since it was in 2005, I repost it here, just for the occasion :

 

sPnnLb-heresy-F-and-Z-curves-13-11-2005-

 

In 2005, I also put a little mattress of natural wool on the back panel of the cabinets :

 

qGnnLb-P1110667.jpg

 

I don't know if it has a great effect for taming the cabinet resonances, but since the original didn't had any damping at all by construction, well... OK.

 

Then I recently decided to go further, and test a "full, 100%" stuffing of the cabinet, using 50mm thick cotton wool mattress (material used for home thermal and acoustic insulation) :

 

aKnnLb-Heresy-I-stuffed.jpg

 

boAnLb-P1110682.jpg

 

This appeared to be efficient - at least at my ears - for taming low-mid and mid resonances, dampening the resonant peak of the box Fb, and extending the bass response thanks to the increase of acoustical volume due to Qtc lowering... Well, I did not made any measurements yet, but it seems that it followed the descriptions about stuffing sealed enclosures given by Vance Dickason and Joseph d'Appolito in their books.

 

Since it's an experimentation, my questions are :

 

- Did some of you followed that stuffing route ? (or is it considered a Sacrilège)

- Did you noticed bad or good results ?

- Pros and Cons of doing this on an Heresy ? (which is not the average enclosure, right ?)

- What were/are your alternatives ? Or better ideas ?

 

Thanks to let me know :)

 

Cheers,

 

 

 

 

 

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9 hours ago, DrTUBE said:

Since it's an experimentation, my questions are :

 

- Did some of you followed that stuffing route ? (or is it considered a Sacrilège)

- Did you noticed bad or good results ?

- Pros and Cons of doing this on an Heresy ? (which is not the average enclosure, right ?)

- What were/are your alternatives ? Or better ideas ?

 

Thanks to let me know

 

It's a sacrilege:lol:

  • I've never tried it, but I remember a caution in the old Martin Mayer book (1958!) to not "overdamp" a speaker enclosure with too much glass wool or cotton wool.  I have no idea whether this is :pwk_bs: or not.  By the way, until Star Trek misused it in the series beginning in 1966 (and ever after), it was "damping," not "dampening."  It is still "damping" in orthodox circles.  For instance, a power amplifier doesn't have a "dampening" factor, unless it is incontinent.
  • Given the small panels, I wouldn't expect much in the way of resonances.  Did you hear resonances before stuffing it?
  • Call me naive, but I would think PWK would have added an inexpensive item like stuffing, if it would have helped.  1983 was late in the Heresy I's history, so there would have plenty of time (26 years) to discover and remedy an inexpensive limitation.  The Heresy I's were discontinued 2 years later.
  • Weren't the midrange drivers labeled or stamped PWK in 1983?  Given no stamp/label, and the huge (10 dB) elevation of the mid and tweet (before you corrected it), I can't help but wonder if they are stock Heresy, or modified by the former owner.
  • If it were me, I'd consider leaving the stuffing in just one Heresy, take it out of the other, and AB them (with the preamp switched to mono) with rambunctious, bass heavy music, followed by pipe organ, and seeing which sounded better, while noting any resonances.  Or, use a frequency sweep for the woofer only.  Then, for the sake of counterbalancing to eliminate order effect, switch the wool to the other enclosure, and AB them again.

Good Luck!  Be Safe!  😷

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Thanks @garyrc for your insight,  :)

 

  • I've never tried it, but I remember a caution in the old Martin Mayer book (1958!) to not "overdamp" a speaker enclosure with too much glass wool or cotton wool.  I have no idea whether this is :pwk_bs: or not.  By the way, until Star Trek misused it in the series beginning in 1966 (and ever after), it was "damping," not "dampening."  It is still "damping" in orthodox circles.  For instance, a power amplifier doesn't have a "dampening" factor, unless it is incontinent.

 

Ah, my apologies for the words confusion :( I was unsure of the exact term when I wrote this... I'm not English language native. Yes, there's always a discussion about with how much damping material (matériau absorbant ou amortissant in French) you are advised to fill a sealed, and even a Bass-Reflex enclosure. I don't think there's a definitive answer on the subject...

 

Moreover, can you tell me more about that " old Martin Mayer book" from 1958 ? Maybe I can find a copy ? 

 

  • Given the small panels, I wouldn't expect much in the way of resonances.  Did you hear resonances before stuffing it?

 

Well, the back panel vibrates under your fingers at loud volume, but this is not surprising in any way. In fact, it's rather internal resonances tied to the reflections of sound on the bare panels, if I can say so. Yes, I heard those reflections - even at low volume level - coming through the speaker, or intermodulating with it, and the stuffing provided neutrality in the mid and mid-bass range of the K-22-K. I'm not sure that stuffing is a better or worse option, but it proves to be efficient as expected.

 

  • Call me naive, but I would think PWK would have added an inexpensive item like stuffing, if it would have helped.  1983 was late in the Heresy I's history, so there would have plenty of time (26 years) to discover and remedy an inexpensive limitation.  The Heresy I's were discontinued 2 years later.

 

I agree : If there was no stuffing put in the Heresy I, it was certainly a tonal choice (center stereo speaker ?), and not an economical matter.

 

  • Weren't the midrange drivers labeled or stamped PWK in 1983?  Given no stamp/label, and the huge (10 dB) elevation of the mid and tweet (before you corrected it), I can't help but wonder if they are stock Heresy, or modified by the former owner.

 

Well, I think that they are factory stock... Here are some pictures of the inside to let you judge the original condition - or not. Discard the 15µ yellow cap and resistors that you see on the E-2 crossovers, since they are my added Z modification. Also discard the color dots put on the speakers to note the polarities : it's me again... :)

 

VFnnLb-Heresy-I-unstuffed.jpg

 

k0LnLb-P1110656.jpg

 

k0LnLb-P1110657.jpg

 

k0LnLb-P1110658.jpg

 

  • If it were me, I'd consider leaving the stuffing in just one Heresy, take it out of the other, and AB them (with the preamp switched to mono) with rambunctious, bass heavy music, followed by pipe organ, and seeing which sounded better, while noting any resonances.  Or, use a frequency sweep for the woofer only.  Then, for the sake of counterbalancing to eliminate order effect, switch the wool to the other enclosure, and AB them again.

 

Yes, you are right. This is the next step : A/B comparison of one stuffed vs. one unstuffed Heresy, and measurements. Maybe there's a compromise to find ? Or no compromise at all !

 

Good Luck!  Be Safe!  😷

 

Thanks again & Cheers !

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8 minutes ago, DrTUBE said:

Well, the back panel vibrates under your fingers at loud volume, but this is not surprising in any way.

I own a pair of Heresy Is as well. I did some reading and one advice that came up was, since the cabinets are quite small, Heresy does not need bracing in general. The exception beeing the back-panel, as You mentioned. That could be fixed with a simple 4x4, screwed diagonaly to the panel from the inside, thus not visible and easily reversible if one wants to go back to stock.

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1 hour ago, AndreG. said:

I own a pair of Heresy Is as well. I did some reading and one advice that came up was, since the cabinets are quite small, Heresy does not need bracing in general. The exception beeing the back-panel, as You mentioned. That could be fixed with a simple 4x4, screwed diagonaly to the panel from the inside, thus not visible and easily reversible if one wants to go back to stock.

 

Thanks @AndreG. !

 

Yes indeed, bracing the back panel itself is easy, and I'll plan to do it also. Maybe by building a special braced panel...

 

In the early 2000, I quiclky experimented a Bass-Reflex transformation of my Heresy I, by building a special ported back-panel :

 

NUMnLb-ESSAI-HERESY-BG-EN-BR.jpg

 

The performances obtained by software simulation were interesting, but proved not to be so convincing finally... It was a quick test that I did not dig further at that time - I should !

 

Cheers,

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I like the experimentation. I always thought the mids and tweets were a bit hot in my ‘78 Heresys too. Mine are definitely not 10db too hot though. Sure that’s the stock woofer?  There is a thread around here describing moving the squawker and tweet down a tap (-3db) along with the corresponding cap change that always sounded interesting. An l-pad might be easier for experimentation I guess. 
Keep up the good work. 

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On 2/21/2021 at 6:23 AM, DrTUBE said:

 

Thanks @AndreG. !

 

Yes indeed, bracing the back panel itself is easy, and I'll plan to do it also. Maybe by building a special braced panel...

 

In the early 2000, I quiclky experimented a Bass-Reflex transformation of my Heresy I, by building a special ported back-panel :

 

NUMnLb-ESSAI-HERESY-BG-EN-BR.jpg

 

The performances obtained by software simulation were interesting, but proved not to be so convincing finally... It was a quick test that I did not dig further at that time - I should !

 

Cheers,

You need to have a K-42 woofer or Delta Pro 12a to have the port work well. Then you don't need the Xover mod. It's called a Super Heresy 3.0 as done by Fido.

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On 2/21/2021 at 2:04 AM, DrTUBE said:

Moreover, can you tell me more about that " old Martin Mayer book" from 1958 ? Maybe I can find a copy ? 

 

I think it was Hi Fi Revised 1958 edition by Martin Mayer.  As I remember, it was a paperback with good photos and illustrations, very clearly written and fully understandable to me as a school kid, providing some technical background and history, and presenting what Mayer thought of as the best choices at various prices, but my memory is a bit rusty when it has to reach back 63 years!

 

It mentioned the Klipschorn (ingenious, but "too efficient" ??? -- another vague memory), JBL Altec, Marantz, McIntosh, H. H. Scott, Bozak, Leopold Stokowski, Perry Como, etc.  I rediscovered the book decades later -- it had been relegated to my parents' basement and looked remarkably like the Dead Sea Scrolls, so I discarded it. 

 

It's fun to remember The Way We Were.  I maintain that if 15 ips, half track stereo tape was the source, the best sound of then was about the same fidelity as now, making some "audiophile" sound in ultra snooty high end stores sound pale, dead, and un-dynamic.  As the late Art Dudley put it, " ... what did we give up to gain such easy access to [the virtues of modern equipment]?  Natural-sounding dynamics. Impact. Pluck. Snap. Body—especially body.  And soul."

 

Martin Mayer was a man of (popular) letters.  He wrote many, many books.  In the introduction to one, he stands in front of a mirror and addresses himself as Fyodor.  Need I say more?

 

 

Here is Amazon's offering.  No your eyes are not deceiving you; the new hardbound choice is $920.99

Hi-Fi, New Revised Edition Hardcover – January 1, 1958

by Martin Mayer (Author)


See all formats and editions

Here he is in his writing room; it looks like mine.

Martin Mayer in 1988. In his books and articles he took readers on behind-the-scene tours of Wall Street, Madison Avenue, the practice of law, the solemn delights of a Spanish guitar and the tangles of a racially divisive New York City teachers strike.

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On 2/21/2021 at 3:35 AM, garyrc said:

 

It's a sacrilege:lol:

😷

no argument  , it's  a true Heresy  , to stuff a klipsch  Heresy like a Chicken   -I think PWK would have wanted that  beautiful  drivers and horns be visible to the eye

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On 2/20/2021 at 5:05 PM, DrTUBE said:

Hello All,

 

A few days ago, I re-opened my beloved Klipsch Heresy I HBR from 1983 in order to... Stuff them...

you can put a 1/2 inch  thick section of sound insulation foam around the woofer -------such as in the Heresy III ,  and that is all that is needed in the Heresy 1  --basically . this  separates the bass frequencies from bouncing on the mids horn  and the  tweeter horn  -

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7 hours ago, ClaudeJ1 said:

You need to have a K-42 woofer or Delta Pro 12a to have the port work well. Then you don't need the Xover mod. It's called a Super Heresy 3.0 as done by Fido.

 

@ClaudeJ1 : I attempted to search on the forum but found no traces of those Super Heresy 3.0 by Fido... :( Can you point me to the link ?

 

Thanks & Cheers,

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6 hours ago, DrTUBE said:

 

@ClaudeJ1 : I attempted to search on the forum but found no traces of those Super Heresy 3.0 by Fido... :( Can you point me to the link ?

 

Thanks & Cheers,

sorry, I didn't know what to call them. It's just that he got a pair of K-42's from me, did the port, and nothing else. My Super Heresy 1.0 has been built by dozens of people as a mod to an original cab, or some have built cabinets from scratch using Klipsch components from that were parted out on Ebay. Fido is the only one that didn't INCREASE the output of the mid and tweeter horns by changing the E network in his, he just left it alone per my suggestion and just did the port and woofer swap. You have already done the port so all you need is the woofer and your are done!

 

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40 minutes ago, ClaudeJ1 said:

sorry, I didn't know what to call them. It's just that he got a pair of K-42's from me, did the port, and nothing else. My Super Heresy 1.0 has been built by dozens of people as a mod to an original cab, or some have built cabinets from scratch using Klipsch components from that were parted out on Ebay. Fido is the only one that didn't INCREASE the output of the mid and tweeter horns by changing the E network in his, he just left it alone per my suggestion and just did the port and woofer swap. You have already done the port so all you need is the woofer and your are done!

 

So I guess I haven't been paying attention.....so now the recommendation is to use an "E" network as is, rather than the "B"?

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36 minutes ago, DrTUBE said:

Ah, OK @ClaudeJ1 - I see,... Thanks !

 

Cheers,

The Delta Pro 12a woofer @8ohms is 3 db louder than the Klipsch K-22 woofer, which is really 11 ohms, so it, effectively, puts out about 4 db less than the K-42/DeltaPro 12a when you add the extra impedance in the mix. So for the extra bass you were looking for, you simply need to buy the right woofer for that box/port/absorption combination and NOT use the K-22. Like all the rest who have done this, you will be amazed at the difference.

 

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9 hours ago, ClaudeJ1 said:

The Delta Pro 12a woofer @8ohms is 3 db louder than the Klipsch K-22 woofer, which is really 11 ohms, so it, effectively, puts out about 4 db less than the K-42/DeltaPro 12a when you add the extra impedance in the mix. So for the extra bass you were looking for, you simply need to buy the right woofer for that box/port/absorption combination and NOT use the K-22. Like all the rest who have done this, you will be amazed at the difference.

 

I have used the Delta Pro 12LFA several times with good results using both a 4" round rear port or a 1" x 14" front slot port (HIP).

I don't have a lot to compare it to other than a stock set of Heresy with the K-22 and the bass response is night and day different (better) IMHO

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OK - I see @ClaudeJ1 and @MookieStl !

 

In fact, "Bass-Reflex-ing" my Heresy I was just an experimentation I did in the mid-2000s... Today, I consider letting them in Sealed enclosure operation definetly. For a Bass-Reflex, I would go differently. :) 

 

By the way, I have read somewhere that Klipsch "recommends the K-24-E as the replacement woofer for the K-22-K" that I have in my Heresy I. Is that a true statement ? To your knowledge, Is there other alternatives ?

 

Cheers,

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6 hours ago, DrTUBE said:

OK - I see @ClaudeJ1 and @MookieStl !

 

In fact, "Bass-Reflex-ing" my Heresy I was just an experimentation I did in the mid-2000s... Today, I consider letting them in Sealed enclosure operation definetly. For a Bass-Reflex, I would go differently. :) 

 

By the way, I have read somewhere that Klipsch "recommends the K-24-E as the replacement woofer for the K-22-K" that I have in my Heresy I. Is that a true statement ? To your knowledge, Is there other alternatives ?

 

Cheers,

The K-24, as far as I can recall from my meeting with Jim Hunter in 1985 was to squeeze a teeny bit more bass out of the sealed Heresy box. Mostly a slight tweak to go with the new plastic tweeter he designed for the Heresy (cheaper to make than buying K-77's from Electro Voice, which were reserved for the LaScala, Belle, and Khorn with higher price tags.

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