identifying a speaker

Discussion in 'General Electronics Chat' started by maher471, Jul 13, 2012.

  1. maher471

    Thread Starter New Member

    Jul 6, 2012
    11
    0
    Hi, I was wondering if anyone know how I could do to know the power of an undefined speaker, just i know that is 8Ω.

    thanks in advance
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    Connect the speaker to a 1000W audio amplifier. Apply a 600Hz, 600mV rms sinewave to the input. Turn up the volume VERY slowly and measure the power delivered to the speaker. Keep increasing the power until the speaker stops working. At that point you know the maximum power the speaker can handle. Caution! Don't test ALL the speakers this way!
     
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    :eek: That test method would be destructive. You can get an approximation by comparing to others of similar size and construction.
     
  4. #12

    Expert

    Nov 30, 2010
    16,318
    6,818
    You could get better answers if you gave us ANY clue about the size.
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,025
    3,236
    One way, without destroying the speaker, is just to look up the power rating for speakers with similar diameter and weight (not counting any cabinet, of course). Your speaker will likely have a power rating close to that.
     
  6. maher471

    Thread Starter New Member

    Jul 6, 2012
    11
    0

    thanks for you MrChips and for all members, but what do you mean about "Don't test ALL the speakers this way", and if can I use a smaller audio amplifier to make the test, just around the 100w
     
  7. maher471

    Thread Starter New Member

    Jul 6, 2012
    11
    0
    can I determine the average power by measuring the displacement of the cone (center of the speaker) I think for 3mm speaker diaphragm movement(distance moved by the diaphragm relative to its resting position) but I don't know what frequency or power to apply

    is those links can help to solve the problem ?:
    http://www.df.uba.ar/users/sgil/physics_paper_doc/papers_phys/ondas_optics/doppler.pdf
    http://www.aes.org/tmpFiles/elib/20120714/3936.pdf
    http://www.diyaudioandvideo.com/Calculator/DriverDisplacement/Help.aspx
    http://www.diyaudioandvideo.com/Tutorial/SpeakerTesting/
     
  8. maher471

    Thread Starter New Member

    Jul 6, 2012
    11
    0
    I wondering for a standard method to apply for most speakers
     
  9. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    RadioShack sold the Minimus 7 speaker that had a 4" woofer, a 1" dome tweeter and a cast sealed aluminum enclosure. It sounded pretty good and had a low distortion response that was flat from about 80Hz to about 20kHz. It was rated at 40 Whats.

    The woofer had a real rubber surround (not cheap foam) and was stamped, "5W Korea". I played two of them pretty loud on my 70 Real Watts per channel amplifier and they lasted for many years.

    I think only ACID ROCK is played at full blast all the time. Real music or speech has momentary full power peaks but the average power is 1/10th or less.
     
  10. #12

    Expert

    Nov 30, 2010
    16,318
    6,818
    The only way to find the power rating of any speaker, no matter what size or who made it is, "Read the Label".
     
  11. DigitalReaper

    Member

    Aug 7, 2010
    70
    2
    Put a constant amount of power through the speaker and monitor its temperature. Increase the power slowly until the rear of the speaker is as hot as you're comfortable with. Don't forget there will be some delay between an increase in power and the temperature reaching a new stable level.
     
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