DrTUBE

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 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... 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 !

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

Thanks @Ceptorman, These are DIY ones, 22L neat volume, low tuning damped Bass-Reflex, using vintage 1" PHILIPS tweeters (AD01631T8), "Teng-Hong" wide band 3" as midranges, Monacor 7" SPH-170 woofers, 715Hz/6KHz/12dB-oct. crossover, with variable L-pads on TW and MR : Cheers,

Remarkable work @yamahaSHO ! Congratulations... All this give me ideas for possibly improving my 1983 HERESY I HBR. Cheers,

I still have my pair of Klipsch Heresy I HBR from 1983 (IIRC) that I bought in 2004 : Cheers,

Hi KdAgain, 1/ The 12 ohms resistor can be 7W wirewound standard, or a 11 or 17W if you intend to often use your Heresy at maximum rating. On mine, I used 2 3W paralleled carbon resistor, and my tube amps are 70Wrms. If you have 20W resistor on hand, it's OK, of course. 2/ For the 15µF 250V capacitor : A/ use a polyester cap - from the Bennic (which I use satisfactorily), Visaton or Monacor brand, for example - rather than electrolytic of any kind. It's not a by-pass cap like the 33µF lo-pass filter of the woofer, where an electrolytic is convenient, because its high frequency losses have no influence. Here the highs pass through this 15µF, so it has to be from a better quality than electrolytic. B/ do not waste your money : standard grade like Bennic or Monacor are OK. Nothing critical here. C/ I use the Bennic brand because these caps are nice (yellow), well built, accurate in value and... cheap. When Bennic are not available, I switch to Monacor, which are the same good quality and price, but just less nice (grey), that's all... But you can find other good brands depending on your location (I am in France). A+! DrTUBE.

Hi Groomlakearea51, There is around a 10dB gap between the tweeter and the woofer when I RTA measured it, as I recall : this not harshness, but unbalanced frequency response. Well, you can change any cap or diaphragm, but I think you may waste your time and your money, I am afraid... A friend has a pair of 1984 Heresy I and the problem is the same. Is it a general consensus ? Anyone here has made frequency response measurements (1W/1m) ? It is said (but is it right ?) that the level of the squawker and tweeter were set to match as possible the level of a Cornwall, as the Heresy was intended at the start to be used as a center speaker between a Cornwall pair, and so the woofer was left "trying to do its best"... I seems strange to me but would be somewhat in accordance with my measurement. May be a Klipsch History Specialist from the forum could confirm or correct ? A+!

Hello all HERESY I owners, I have been recently asked again about a modification I have posted as far as 2006 about the modification of the E-2 Xover I have done on my Heresy I HBR, so I thought it would be interesting for some of you to see what it is. This mod is intended to smooth the impedance curve in the 3000-5000Hz region, in order to give an easier load to the amp, and regular frequency response, by removing the quite "squawky-trebly" tone often heard on the Heresy I. You will find all the information in attached file (.pdf) - as you will see, it is simple and the result makes it worthwhile to test... Best regards - DrTUBE. heresy F and Z curves 13-11-2005 .pdf heresy F and Z curves 13-11-2005 .pdf

Hello Wm McD, Care : unlike Bob's, my responses are for a K57+K601, not for K55+K400. Nonetheless, What is the "P-trap" you are speaking ? Have you got more info ? I Know nothing about that except its name, and I suppose that it applies to the K55+K400 but it may be of some interest to me for a K57+K601 application. If you are interested, I have other traces (response, impedance) about my DIY CW and its speakers : if it can help... I am searching by myself, taking in count informations coming from other users. (+

Your curves speaks for itself : I see the difference between the K-57 and K-55 on the K400, and I can mentally transpose them with a shorter K600/601 horn : the K-55 would reach a bit more linearly the 600Hz zone than the K-57, but I wonder if the shift is worth... Nonetheless, the CW1526C shows a good linearity until 600/700Hz when tested alone in my CW box, but when filtered, the result is altered, so I have to re-work on my Xover first... For info, here is a Xover comparison, near field (port not considered), sinus sweep, between : 1 - the CW1526C unfiltered / 2 - with a 3mH 0.07ohm 6dB/oct like B style / 3 - 3mH+22uF 12dB/oct 600Hz / 4 - 3mH+22uF 12dB/oct like B3 style, showing this alteration which directed me to look at the bass extension of the squawker. Thanks for your support, Bob.

In fact, my CW is a DIY proto (K-792-KP, K-57-K, CW1526C 15", AT-1) on which I experiment before final version. Nonetheless, the K-57 has difficulties to extend to 600Hz, as you can see it on my (I hope enclosed here) free-air response and, reading you advice, I suppose that the K-55 won't do much better, mainly because the horn size remains the same. And, in addition, I will have to correct the so-called-supposed default around 9KHz which doesn't exists with the K-57. But looking closely to the CW2 Xover schematic you've enclosed, I notice that the 3507 T-8A give -8dB attenuation to the K-57, instead of the -6dB found with the K-55 on other B Xovers fitted with the 3110A T-2A : this detail may be the cause of the "horny" sound of my K-57, by excess of level, because connected in the K-55 + T-2A way on my DIY CW Xover. Thanks for input, Bob.

Thanks Bob for the useful information. By the way, I tested the K-57 and also found the rapid falling below 600Hz - so I wonder if it is not responsible of a little "horny-duck" sound of the K-57 on male voice for example. Do you think that a K-55 would do better ?

I design, built and service tube amps for years... So needless to say that I am in accordance with this : You have heard 1 topology of tubes, there are several. I used to own Belles and use SET amps. Low Power, but for me provide the most enjoyable sound. So get yourself a SET amp, 300B, 2A3 or 45 amp to demo, before you decide. A 300B no FB single ended tube amp would be a good choice, since its damping factor is moderate, and you will have 6-8WRMS output, which is interesting. I use mine with my HERESY 1 with success and my DIY CW. Bear in mind that the damping factor is an important part of the sound in the amp-speaker combination : high damping factor amps (typically solid-state) gives tighter sound than moderate damping factor amps (mostly tube amps). But a Mc INTOSH 240 won't sound like a WE300B (on the same speaker) : both are tube-made, but the first is tighter than the second, thanks to its higher damping factor - so that's why there is a typology of tube amps. On some speakers, low DF will give heavy, lousy sound, and high DF will be suitable. On the contrary, the HERESY, which is a well damped speaker, will perform better, more "freely", on a low DF amp. It works well also with a friend's SCALA. You should try before you decide, but a DYNACO ST70 - in perfect working condition = serviced - would be a good alternative : less damping than the Mc240, more than the 300B... it's up to your taste ! About the preamp : tube is not compulsory, since it is less obvious than the DF of the amp, and it is mainly important for RIAA use. With a CD, you just need a pair of audio pots in a shielded box, that audiophiles call "passive preamp"...

Hello, Anyone knows the sensitivity of the K-57-K squawker as used in the CW2 (resin-molded K-601 horn version) ? In this forum, I read that it is + 3dB louder than the K-55, and also read that it has the same sensitivity as the K-55... Moreover, can I have a copy of the CW2 Xover schematic ?

Hello Tim, I had a pair of 1980 HBR HERESY 1 not very far from yours. These speakers work well with single ended no FB 300B tube amp on the 8 ohms tap, and also with OTL tube amp too. With a MARANTZ 2250B I have to increase a bit the bass level on the tone-corrector. Unlike any audiophile speaker, I suggest you to place them against a wall or an angle to have a correct bass extension, as it is recommended by Klipsch. Moreover, you have purchased for cheap one of the most sounding and indestructible speaker ever made in this size... Very truly yours,

I am on the verge of purchasing a pair of Heresy 1's and I am quite a large fan of clean sounding bass out of speakers. Now I know that the Heresy are not ported and also have a smaller woofer compared to some of the other speakers on the Heritage line. If you have a pair of Heresy's or have heard some it would be greatly appreciated what your opinion is of this area of these speakers. Thanks a lot! I have a pair of 1980 HBR HERESY 1, and they sound surprinsingly good in my small room (12sqmeter, slanted under-roof ceiling), when placed in "corner" position, and driven with a no-feedback tube amplifier. This special configuration enhances the bass level and give an extended, deep bass response, preserving the tonal qualities of the HERESY 1 : punch, tightness and speed, rather difficult to find in a bass-reflex cabinet... I tried the HERESYS in "normal audiophile" conditions (50sqmeter room, classical hi-grade transistor amps, speakers on stands, without corner placement) : the bass range had not a satisfactory level. Sincerely, DrTUBE.

Hi JK 6827, I own a pair of HERESY 1 HBR from 1983 these are fitted with the E-2 Xover If you can tell me how to include an attached Jpeg image to a post, I'll be pleased to give you all info about it, including an interesting and simple mod to make the HERESY 1 test AND sound better - to my personal taste, indeed. Every attachment trail I have made failed... Have you got THE right method ?

Hello I read quickly the suggestions of the specialists, and I agree : test your HERESY speakers "as is" before ! But I can give you some suggestions for an improvement of your HERESY 1, as I (and one of my friends) have got the same speakers. Personnally, I felt that tweeter and squawker (mid) were to high in level, even when placed in a corner or in a shed. Taking some measurements showed that the K77 and the K53 were about 10dB over the efficiency of the K22 (woofer). In addition, the impedance curve showed a huge bump to nearly 80 ohms between 3 and 5KHz. This doesn't work with my amps, and probably will not work very well with your amps too (heavily feedbacked I think). Please find the schematic of the Xover mod I have done on my and my friend's HERESY 1. I insist that this mod is EASILY installable and removable, without altering the original KLIPSCH components. If you are interested by the measurements, please let me know, I'll try to send it to you. This mod decreases the levels in a far more correct way, and make the impedance bump quasi-dissappear. And of course, tone is much better... But it's nevertheless a matter of personal taste !

Hello Just be careful to some details : power output rms Watts : 3W for a 2A3, 6-7W for a 300B, with REASONABLE life expectancy, that is to say : 300Vdc (2A3), 400Vdc (300B) plate voltages. You'll find amps claiming 12W output for a single ended 300B : this is not tube-wise... I have a 300B with switchable output power (4W/8W) : the 4W position is the one I use the most often, and it runs the tubes very cool (300Vdc on plate, 50madc plate current) and has no problem to drive my HERESY 1. I read that you have KLIPSCHORN... So you can be very tube-wise !

Thanks for these infos, Rick. Bruno.

good day to the specialists, I had a pair of K-792-KP horn tweeters they look like the K-79-K, except for the horn expansion, which seems more "incurved" - are they Klipsch tweeters? (no Klipsch brandname on them... only K-792-KP 9630) I measured them, and felt they were pretty good : 2 - 20Khz linearity (5db channel) @ 1m/axis/mls stimulus, efficiency around 100dB/w/m, Fs=1100Hz. - do you think I can use them instead of a pair of K-79-K, in order to build a home-made Cornwall enclosure? (I bought AT-1 Xformers from BEC to build the Xovers) - in fact, I haven't informations about the k-79-k to compare with : where can I find them? and I apologize for my "frenglish".

Good day to you specialists, I have a pair of "supposed" KLIPSCH horn-tweeters... these bears the following references: K-792-KP 9630 and they look like the K-79-K : same front dimensions and construction material, but apparently more "curved" horn profile. I measured them : linearity from 2 to 20KHz (6db channel) 1m/axis/mls, efficiency around 100db/w/m, Re=8,4ohms Question : are they KLIPSCH ? Do you have more info about these tweeters ? Have they similar performances as the K-79-K ? (I am planning to build a pair of DIY Cornwall enclosures) Thanks for your answers! Bruno

Good Day to the klipsch specialist I have myself some concerns with CORNWALL crossovers, as I am planning to build a Cornwall replica. My question is roughly the same : I know that there is different "type B" Cornwall Xovers, but I dont have any schematic nor performances for it to be studied. my speakers are : K-792-KP tweeter, K601+K57K squawker, HH1501 woofer, T2A replacement Xformers. Can you give me these informations ? May be my intervention in your conversation will seems a bit brutal to you , but I am brand new on this forum, and I apologize in advance. Thanks and very truly yours DrTUBE