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radiogram

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Posts posted by radiogram

  1. On June 24.2022 I asked @Chief bonehead permission to post CW III Schematics since CW III is no longer in production, and he gave me permission and directed me to the post the same in the Crossovers part of the forum. 

     

    In continuation of that permission, I posted the official Rev-A H3 schematics subsequent to @net-david posting official Rev-C of H3 schematics.

     

    I was not aware of the policy change until @Invidiosulus pointed out yesterday.

     

    Besides I do not understand how sharing schematics and that too what Klipsch Parts gave out, would violate the new policy. 

     

    Anyway I just want clarity as I respect this Forum and I do not want to violate anything in future.

     

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    • Thanks 1
  2. @net-davidWhat I am surprised is the amount of difference in the Mid Section particulalry between the between CW II and H III. They both use same drivers and same crossover points on either side. I thought only diff would be level matching L-Pad. But on my own experimentation with 3-dB L-Pad for CW III I could not get uniform 3dB attenuation in fact attenuation above 12Khz Started to increase and was about -4.5dB at 16Khz. So I am guessing that is why maybe Klipsch has different mid section network for H III vs CW III

  3. @net-davidAwesome. Thanks a Lot!. I just want you re-check this. Based on CWIII Xover it seems to me in the Woofer circuit, that the following 3 parallel caps C1, C2, C3 should be between L2 and R1 and C4 parallel to K28-E. If you look at the CW III Circuit I Posted in June 25th in Page 16, you will see why I am asking this.
     

    Thanks and I do appreciate the efforts.

     

    Cheers! 

  4. @net-davidI measured the inductors in my CW III network. Pretty straight forward. That is how I was able to post the CW III network. But just to be very sure I de-soldered one terminal of each inductor and then measured to avoid any interference from any component that me may be connected to the inductor in parallel.

     

    BTW, it seems to me in K53 circuit you posted, the three parallel caps should be in series between the inductor and resistor and the capacitor you have shown to be in series between the inductor and resistor should be parallel to the K53. Can you re-check this?

     

    Thanks

  5. @net-davidThanks for your post. I have been looking for H III schematic for quite some time. I am currently using CW III network for my H III upgrade from H 1.5 and bi-amping to reduce Mid & Tweeter level by 3 dB. I hope you get to measure the inductors and post a complete schematic so that I can mode my CW III network to be exact H III one.

     

    BTW, I thought the mid & high section will be identical (except for level matching resistor) between CW III & H III as they use same drivers and crossover points and I am surprised they are a bit different in terms of component values.

     

    Thanks

  6. @mboxlerI think I understand what you are driving at. Perhaps I did not communicate my expectations clearly. A properly implemented LPAD will give desired attenuation and yet make the network see the same load as before and thus without altering the frequency response that was there before the LAPD was inserted. A simple series resistor will not maintain the same freq response and so attenuation at different frequencies will be different. So I am not expecting same attenuation at all frequencies.

     

    What I am saying is the the insertion of 3 ohm resistor makes no real difference in output across tweeter (as compared to without 3 ohm)  in the tweeter's passband which is about 5.5K and up. Except for -1.9dB drop at 20K from 6K to 16K the final attenuation is not even -1 dB let alone -3 dB.  And the intent here was to lower the Tweeter output by 3 dB compared to the woofer.

     

    So with the amplifier giving the same voltage to the network, the insertion of 3 ohm has not shown any meaningful measured difference  in the tweeter's most of the passband.

    • Like 1
  7. @mboxlerThe attenuation we are looking at is after vs before inserting the resistor because that is the end result we want as Without changing the volume of my amplifier I want Tweeter attenuated. Yes if you just compare voltage across tweeter vs 3 ohm sure we get -2.27dB drop and the math is right. But this not the real attenuation we are looking for. .

     

    So, the real attenuation is 20 * LOG((Voltage Across Tweeter w/o 3 ohm series) / (Voltage across tweeter with 3 ohm series) ). So for say 4K Hz it is 20 * LOG(.094/.1020) = -0.709 dB Only.

     

     

  8. @mboxler- There are no other series resistors other than the 3 ohm I added. if we assume an average impredance of 8 ohm for the tweeter then the total load impedance has increased from 8 to 11 ohms. Then the volatge across the tweeter should be 72% (8/11) translates to power drop of about -2.7 dB (20 * LOG(8/11)). But my measured date shows at no frequency it is  not even -2dB. In fact at 8K and 10K it pretty much -0.3dB only.

     

    from My experiments I figure the mid driver K53 approximation of 16 Ohms hold good, but for the tweeter 8 ohm does not hold good. In 6K to 10K 10 ohm holds good. Beyond 12K Tweeter impedance increases as we up the frequency.

     

    Anyway I just got Hand held OWON oscilloscope and will re do my measurements as my Fluke multimeter readings above 1K are suspect and post my findings again.

     

    Also note that I just realised I replaced my Titatinum tweeter diaphragms with Bob Crite's diaphragms and they are no longer original Klipsch diaphragms.

  9. @mustang_flhtand others: 

     

    In my attempt to modify CW III Crossover to H III with LPAD attenuation to compensate 3db difference with CW III, I first tried to see what Klipsch did with Tweeter circuit by inserting a 3 ohm series resistor before Tweeter.

    I inserted 3 Ohm Series Resistor and I am surprised that measurements of voltages before and after 3 Ohm Series show not much difference at all. There is not even 1 dB attenuation in the tweeter pass band, let alone 3 dB. Here are my measurements. 

     

    Note -Please do not look at the Absolute voltage values, as my meter cannot measure full voltage beyond 1 KHz. Above 1 K its readings get tilted down as we go up in freq. But what we are interested is only the Delta not absolute value.

    What is wrong here? Also notice the Voltage across (3 Ohm + Tweeter) increased as opposed to Voltage across just Tweeter. Do not understand why Voltage is not same.

     

    What is wrong here? 

     

    image.png.28d9c52e0920fd63a530b69208123eb1.png

  10. @mustang_flht Thanks for the cooling tip.  I am India and have no access to 25 Watt resistors of decent quality easily. For now I am going to experiment with 10 Watt resistors and once I am satisfied I will probably get them from mouser/madisound etc when my sister comes here next month.

     

    BTW, I am now using Bi-Amping to make up for sensitivity difference between bass and mid-highs with the Integrated Amp driving the bass is boosted up. In this I actually find that I prefer the mid-highs 4db lower instead of 3db.

     

    I am also curious that a much less sensitive speaker (only 85 db) like JBL A130 I have, uses 1only 10 watt resistor when I would expect much more power going into this than the Heresy.

     

    Thanks

  11. Heresy III / CW III : 25 Watts Resistor really needed??

    Having recently figured out the resistor values in mid and tweeter section for H III Xover, now I am going to convert my CW III Xover to H III Xover by substituting the resistors. These resistors are all spec'ed at 25 Watts. Where I live I can only get 10 Watt Daytons. So only option is to buy two 10 watts resistors of half value and use them in series (to get up to 20 watts) which I rather not do as physical layout will not be a simple swap of resistors.

     

    Do I really need 25 Watts resistors for mid and highs? Can I get away with 10 Watts? 

     

    Thanks

  12. Having recently figured out the resistor values in mid and tweeter section for H III Xover, now I am going to convert my CW III Xover to H III Xover by substituting the resistors. These resistors are all spec'ed at 25 Watts. Where I live I can only get 10 Watt Daytons. So only option is to buy two 10 watts resistors of half value and use them in series (to get up to 20 watts) which I rather not do as physical layout will not be a simple swap of resistors.

     

    Do I really need 25 Watts resistors for mid and highs? Can I get away with 10 Watts? 

     

    Thanks

     

     

  13. @mustang_flht, @Donkeyshins, @CANT, @ccwarrior

     

    I have figured out the HIII mid and high section network. We already know from @CANTthere is a 20 Ohm resistor in HIII in place of the 50 Ohm resistor in CWIII. This is the mid section parallel resistor. With 20 ohm parallel, if I reverse calculate what should be the Series Resistance for 3 db lower, it comes to 51 ohms.

     

    So for HIII schematic, take the CWIII network and for mid section - simply swap out the 50 Ohm resistor with 20 ohm and swap out the 30 ohm series resistor with 50 ohms, and for high section just add the inline 3 ohm series resistor.

     

    It is possible bass section may be same because both the K33 and K28 are 4 ohm drivers. But I could be wrong here.

  14. @mustang_flhtbut won't that change the freq response? I believed That between CIII and HIII mid and High section the only difference will be around 3dB more attenuation compared with the CIII as HIII is 3db lower than CIII.  But if you have HIII Tweeter circuit with just a 3 Ohm Series Resistor then the freq response is not going the the same as CIII unless you do a proper L-Pad. I am confused.

  15. @mustang_flht

    @001

     The mid and tweeter sections between CIII and H111 should be identical except for Resistors' values. We know that the 50 ohm Parallel Resistor in mid section in CIII is 20 Ohm in HIII. Makes sense it is lower since HII needs more series attention so parallel value is Lower than the CIII.

     

    The Tweeter section, based on a past CANT's post, there is a series 3 ohm resistor which takes up the empty space marked R4 in the CIII network. But this does not make sense since we need L-Pad not just a series Resistor.

     

    Surprised HII Xover has not been really addressed in this forum in spite of it being out of production for a few years now.

     

    Do you think we could get Klipsch themselves to reveal the schematic in this forum?

     

    Cheers

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