Jump to content

HiFi Heaven

Regulars
  • Posts

    276
  • Joined

  • Last visited

Posts posted by HiFi Heaven

  1. DC [Direct Current] can't produce Hiss, Hum, or ANY sound at all!

    Test this with a 1.5 V DC battery connected directly to your speaker.

    The woofer will move once and stay there until the battery is dead,

    turning the battery DC energy into HEAT, not SOUND.  Not a Peep!

     

    HUM is usually steady 60 or 120-Hz buzzing from AC power wiring

    sneaking into inadequately shielded patch cords, or faulty grounding.

    Ancient tube amplifiers with failing filter capacitors might go "Hmmm"

    as the owner tells you "It Hums because it doesn't know the Words!"

     

    HISS is thermal noise of random electrons partying inside your preamp,

    you have to turn the volume way up to hear them - they are very small.

    If you enjoy HISS like I do, get a Ham Radio and talk to me on the air!

    73, NØCRE  "Can't Remember Everything"  FCC Licensed since 1960

     

     

    • Like 3
    • Thanks 2
  2. Correct polarity can be heard as an increase in volume at crossover frequency on a noise signal,

    can be seen on an audio real-time spectrum analyzer like AudioTool on your phone or tablet.

    Out of phase produces a pronounced dip at crossover as opposing acoustic waves cancel.

     

  3. Hi MKAZ -  4Ω is normal DC terminal resistance for many Klipsch "8Ω" speakers.

    DCR at the input terminals = woofer DCR + negligible lowpass inductor resistance.

    Zero DC current flows through the crossover network to Mid, Tweeter, or Ground.

    Static 4Ω DCR rises to 6-8Ω AC in the bass musical range inside a tuned enclosure.

    Be aware a 3A fuse offers no protection for 1" voice coils - start with 1.25A fast blow.

    We used 3A fuses to protect commercial ALTEC 100-watt woofers with 3" voice coils.

    Music is dynamic.  Fuses are rated to blow within 10-30 seconds after 200% overload.

    Way too late for your charcoaled voice coil...

     

     

     

     

  4. Maybe some of our members could characterize the superiority of JEM capacitors vs. other brands

    on an objective basis with measurements of value, tolerance and ESR, rather than subjective jargon?

    I'm ready to recap 12 vintage Klipsch, looking for advice based on experience, not opinion.  Thanks!

  5. DC Ω resistance is ALWAYS less than AC impedance, sometimes a lot less.

     

    Quick test: swipe a 9-volt battery across the terminals, the cone should JUMP.

    Reverse the battery polarity, speaker cone should jump in the opposite direction.

     

    Use a 1.5 volt battery to test compression drivers - 9 volts might damage them.

  6. RF Skin effect, kids!  Frequencies over 200 MHz flow easier on the outside of the conductor!

    As we raise speaker cables off the floor, we reduce the probability of VHF harmonic absorption

    by nearby carpet fibers, vinyl polymers, wood resins, and damp concrete. 

    Never mind we can't even hear 20 KHz, much less the 100th harmonic!

    Learn the science, expose the grifters, enjoy your favorite music!

     

     

     

     

     

    • Like 5
    • Thanks 2
×
×
  • Create New...