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JohnA

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Posts posted by JohnA

  1. DO NOT use a 9V battery to test a tweeter.  And when testing a tweeter, keep one lead moving so it never sees DC, but gets a series of pulses that cause a scratching sound.  Use only a 1.5V battery on tweeters and then, it's best only to test it in lieu of an ohm meter.  1.5V is also plenty to verify the polarity of a woofer. 

     

    9 volts across a tweeter is 10 watts, if the battery can supply the current.  Many tweeters cannot tolerate 10 watts. 

  2. I have several K-77s, $75 + shipping from 37343.  Assume 4 lbs and a 6" cube for each.

     

    I have 2 K-55-Vs, $100 each + shipping.  One is a spring terminal and the other is a solder terminal, but it has a rub/ring after having the diaphragm replaced.  Assume 6 lbs and an 8" cube for each.

     

    These were my back-ups that I'm sure I'll never need, now. 

  3. As in the old Type A Klipsch crossover, a 9 kHz theoretical crossover point is needed to protect the tweeter from low frequencies.  Don't change it.  What is the DCR of the tweeter?  What happens if you use a 1.5V battery across its leads, rubbing one lead?  Is its output similar to the woofer tested the same way? 

  4. On 5/6/2023 at 12:25 PM, Peter P. said:

    Thanks for the replies so far.

     

    Remember; this speaker was clearly not factory stock; the woofers are from Radio Shack and the tweeters are something other than OEM. I found aftermarket crimp connectors inside. That's why I suspect the fiberglass was added "after the fact". Besides, I would imagine most manufacturers would NOT use house fiberglass insulation for damping material.

     

    I haven't looked inside many speakers but in the couple I have peered inside there was substantially less damping material. In fact, compare my Heresy IIs, which only have a foam sheet curled around the woofer section of the cabinet.

     

     

    My VMPS subwoofers are tightly stuffed with fiberglass that looks like insulation grade fiberglass.  It's yellow. 

     

    https://www.audiokarma.org/forums/index.php?threads/avid-thread.116894/

     

    The OEM tweeter description sounds like the tweeter in Marantz Imperial 7s among others.  Not sure how to id the OEM CTS woofer, unless Eminence has old CTS data. 

  5. On 5/6/2023 at 9:31 AM, Coytee said:

    Ignorant side question....

     

    If his speaker is 'stuffed', why does the Cornwall only have damping material on (if I recall) one side and the bottom (or was it top?)  Either way, only has it on two surfaces, not "stuffed'????

     

     

     

    The woofer is modelled (or trial and error tested in the old days) for its frequency response with a certain amount of damping material.  The material makes the box volume behave as though it is different because it changes its "springiness".  As though it is larger, I believe. 

  6. Beautiful job on your SKs! 

     

    And, ... Great news about Gil!  I hear from him periodically, randomly.  I'm glad to get the new phone.  I'll call.  He had asked me to call, but I could not get an updated number when one of the old ones quit working. 

  7. You are reading through the crossover, so the capacitors make it read open.  You'll have to disconnect each driver from the crossover to measure it. 

     

    To measure impedance, you'll need a meter that can test at different AC frequencies.  Mine will, but at only 400 Hz, below the HF crossover point. 

  8. Cool!  I only have an HT, for now, and am finding more local repeater all the time.  We have over 30 repeaters in the area.  With so many, few are active.  The 8 or 10 GMRS repeaters are much more active. 

     

    I've already figured out an HF antenna will not work on my tiny lot, plus, no one else in the subdivision has an external antenna.  I have a CB antenna with sloping radials in the attic that works great.  The GRMS antenna up there, not so much.  I'm looking at a 6m/2m/70cm Comet, but it is over 8' tall plus tower.  Any suggestions are welcome.  The primary objective for 6m will be talking to the Nashville area. 

  9. On 3/21/2023 at 11:54 PM, sunburnwilly said:

    Well this is awkward .

     

    Wish me luck !   

     

    Don't feel awkward, many of us have gone through cancer.  I am a 2 time survivor.  One was prostate cancer, surgery 8 years ago this month; the year I turned 57.  I will pray for you, brother. 

    • Like 5
    • Thanks 1
  10. On 4/12/2023 at 11:36 PM, codewritinfool said:

    y'all are scaring the heck outta me.  i'll be 57 this year.

     

    Don't be afraid, start with a PSA test.  If you have a family history of prostate or breast cancer get at least annual PSAs.  The same gene mutation that "causes" breast cancer "causes" prostate cancer

    • Like 3
  11. 4 hours ago, JJkizak said:

    Some (most) people  give a crap less about quality. Label the products (Muntz for those people) and the good stuff (Western Electric quality for those that care).

     

    JJK

     

    THAT shows your age.  And I remember Muntz, sorta like another audio known for similar quality. 

  12. Schu, that sounds horrendously expensive and the panels' lifespan is 20 years. 

     

    I wish i'd seen this earlier.  I have a small system (240 panel watts) I built to teach myself how to build and operate PV systems.  I may use one on a mountain cabin.  One trick is to use Li batteries.  You can use a larger %-age of their capacity without causing damage. 

     

    At least in the SE US, electricity is cheap enough PVs can't compete unless you have a remote location with high cost to pull in grid power.  If you do it yourself, the right way (no batteries, thus no back-up power), you can make PVs pay for themselves. 

     

    I designed my system to power its inverter and loads for 3 days without sun and that was good for most years.  However, in the last 12 months, I have had at least 2 episodes when I got no appreciable PV generation for 4 and 5 days.  The reason I have LiFePO4 batteries is because one of those events happened when I was out of town and my PbSO4 batteries were pulled so low they were damaged.  I have even had to put an AC charger on the Li batteries twice to keep the voltage from going too low. 

     

    I have enjoyed building and upgrading my PV system and I love the idea that I have some power, no matter what happens, but the cost and poor, but improving, PV efficiency prevent it from being ready for prime time.  I would do it all over again, knowing what I learned, but as a hobby.  I now have a light over a work bench (1st objective) and can power 3 battery chargers, 3 lights, a receiver and speakers and two 2-way radios, all at once, for a while. 

  13. You do have room for Fortes.  I very much like the IVs; they have similar drivers to the Heresy IVs.  The distance to the wall is very flexible and room dependent.  You might find 150mm is good. 

     

    Your Reference center will not match the Heritage sound well, but you might not mind.  I did not dislike my old KLF-C7 between La Scalas.

     

    Heresy IVs do not need a subwoofer for music.  I recommend them wholeheartedly.  You will want to keep your subwoofers for the special effects channel.  The open E of a double bass/electric bass is down a little from the G, but you might think it was recorded that way.  H IVs are quite accurate and sound natural.  They will have the "size" and clarity you want, I believe.  Sound comes out of mine whole and there is no way to identify the location of the drivers, unlike my H Is. 

     

    I assume other members of the RF family do not meet your desires.   

    • Like 3
  14. 2 hours ago, KT88 said:

     

    Ok, then I don't know why EV recommends it the way they do. After all, when removing the horn, someone has the freedom to listen to the horn in vertical and horizontal orientation comparatively. I've also seen installations of the T35 without a baffle at all, but then I would suspect that the sound pressure might drop off at the lower crossover frequency. 

    Marvel, thank you for your objection, I am writing to help others and not to be necessarily right.

     

    If you look at earlier E-V data sheets, you'll find a dispersion graph.  Though you are correct that the T-35 is a diffraction horn, it's dispersion is wider above 6k Hz with mounted horizontally. 

     

    T-35_Disp.thumb.jpg.e0753835d556f9993c1654acc7964b5f.jpg

  15. Listening through my headphones, I hear a crackling that often indicates amplifier clipping (over-driving).  Your description of flub, flub, that i don't hear, could describe "port chuffing".  While normal, it *is* undesirable.  Your Cornwalls were not built with the massive lows special effects contain, so it it is port chuffing, all you can do is reduce the bass boost or the volume.  That will also reduce amp clipping.  If you have the bass boosted, reduce that the move them closer to corners and the walls to help recover that bass output. 

     

    It's easy enough to remove the backs and inspect the woofers.  If they are damaged, replacements are readily available and also recone kits. 

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