Can you damage a speaker by feeding it frequencies lower than its rating?

Discussion in 'Archived Threads 2001-2004' started by altan, Dec 4, 2002.

  1. altan

    altan Stunt Coordinator

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    Can I damage a speaker by feeding it frequencies that are lower (or higher) than its rating?

    For example, if I have a speaker rated from 50Hz to 20,000kHz, can I damage it by playing content with a 15Hz tone?

    Thanks in advance...

    ... Altan
     
  2. EdwinL

    EdwinL Stunt Coordinator

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    Hmm... I don't think so, it's like asking you to blink your third eye..... you can't because you don't have a third eye... your incapable....

    just like we can't hear above 20kHz

    I may be wrong though...
     
  3. RussKon

    RussKon Stunt Coordinator

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    the speaker will not respond...it will not even realize that it is receiving a signal that low...
     
  4. altan

    altan Stunt Coordinator

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    Is it not possible the speaker will simply do a relly stinky job of reproducing the sound. So poorly, in fact, that the driver cannot move far enough to reproduce the sound, which would effectively cause the speaker to clip itself and break?

    (I don't know what I'm talking about, just proposing a "what if...")

    Thanks for the responses guys...

    ... Altan
     
  5. Neil Joseph

    Neil Joseph Lead Actor

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    I suppose if you crank up the amplitude (volume) and assuming the speaker does not have a high pass (subsonic) filter, then yes, of course you could. I should do a search for you on damaged subs.
     
  6. Neil Joseph

    Neil Joseph Lead Actor

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  7. pete sterna

    pete sterna Auditioning

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    go to http://www.nch.com.au/tonegen/ and download the cute little program for free that generates tones, and save them as wave files. Then create a test audio CD and check out your speakers. I discovered that my Missions which are rated to 38hz will do 30hz nicely. I also discovered that I can't hear much over 16k, and my wife goes to 17k. I'm sure my speakers are doing it, but I think old age and a noisy job has done me in.[​IMG]
     
  8. Geoff L

    Geoff L Screenwriter

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    Assuming clean power, dirty is worse, any speaker will play what it can play frequecy wise. Say your speaker measures flat to 50hz and begins to roll off. Your playing a movie or music and a note centered at 23-hz blows in, the speaker will try to reproduce it but it can't.

    But as you turn the volume up your asking the speaker to continue to play what it can & can't reproduce, at a louder and louder spl till eventually the driver will reach it limits of travel, and poof.... Speaking of the woofer in this case, asked to produce both midrange and bass in a 2-way. Still applys to basicly any none full range speaker.

    But this would be much more aparent in example above.

    A very generalized answer and not very well put,sorry..
    Short answer is YES, you can and will damage any speaker feeding it signals below it's playable responce and at increasing volumes. Thats why there are subwoofers and also receivers with large small and crossover settings.

    Play a 20hz note at 60-db threw that speaker and it will probley/might survive, though you would hear nothing. Play the same 20hz note threw it at 100-db and you hear nothing for about a 1/2-second or so, then a god awfull racket will be aparent. Ported speakers being worse (no driver protection under tuning) than sealed, as sealed offers the driver more protection and a nice much longer roll off.

    Your 50hz and rolling off sealed, or ported speaker is now toast!

    Hopefully, someone will come in and explain this in a much clearer way than I....
     
  9. Todd Beachler

    Todd Beachler Stunt Coordinator

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    alright, I'll ask a dumb question: wouldn't you still be able to hear the harmonics associated with the fundemental frequency?
     
  10. pete sterna

    pete sterna Auditioning

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    In response to Geoff, I think the main question was with a normal level in mind. My missions are rated to 38hz, but in stereo mode with a CD playing some music with loud bass at 25hz, I wouldn't expect them to blow.
     
  11. Geoff L

    Geoff L Screenwriter

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    Pete
    Correct, clean power and sain levels is key.
    Also your speakers dig much deep naturaly than the example I pointed out.
    But still could be toasted with enough spl and deep freqs.
    =======>
    I think common sence plays a big role when using any speaker and playing it full range. You just don't ask your typical bookshelf speaker to produce 20-hz at 100-db...Well dah right, you'd be surprised what I've seen people do and they wonder what happened!
    =======>
    Todd
    Yes, port noise, harmonics, distortion, certainly. This when not even pushing the speaker (in my poor example above to blowing) and using clean power.
    I was trying to keep it simple and I am not good at explaining things clearly & understanding like others here are able to do! [​IMG]
    Regards
    Geoff
     
  12. mark alan

    mark alan Supporting Actor

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    go to http://www.nch.com.au/tonegen/ and download the cute little program for free that generates tones, and save them as wave files. Then create a test audio CD and check out your speakers. I discovered that my Missions which are rated to 38hz will do 30hz nicely. I also discovered that I can't hear much over 16k, and my wife goes to 17k. I'm sure my speakers are doing it, but I think old age and a noisy job has done me in.
    It sounds like people are stealing my idea[​IMG] . As a followup to this question, if you have your speakers set to small, with the bass sent to subwoofer via LFE, I would think that you couldn't send enough power at low frequencies to damage your speakers, correct?
    Also, as a followup to my earlier post. http://www.hometheaterforum.com/htfo...hreadid=110475 I stuffed my sub with polyfill and it now does a much better job of reproducing the low frequencies.
     
  13. Geoff L

    Geoff L Screenwriter

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    For the average receiver yes your correct.

    But distortion from under powering a speaker when set to small, can fry things to.
    One would be much less apt to fry a bookshelf when set to small. But when you got 5 to 6 speaker playing at once and had a few beers the volume goes up and you might not notice the distortion coming from any of your speaks with all that sound and a sub pounding away at you. Thats why finding what your receiver can do safely with ones type/size speakers is a good idea.

    Buying a test disc or burning one as you have done and running tests to see what your speaks are capable of freq wise is a good idea.
    Makes it allot easier to figure out where to cross them and at what slope if you have the means. Also once thats done running test for spl to see where the volume knob should stop and never go past!

    Pumping out 105-db peeks to the speaks & 120-db peeks to the sub during (movies) in an average room cleanly, takes more than what the average (Joe six-pack) has in CC or Best Buy equipment. Speakers set to small and sub doing double duty picking up the rest.
    Not saying that it can't be done, but true referance from 20-Hz to 20kHz is something only a few systems I've seen & heard are capable of. Certainly a small closed in room dose make this much easier.
    The rooms and system I've personaly seen/heard are med to large rooms and only 2 out of 8 of them can do it cleanly top to bottom.
    And good God it's SCARY LOUD...Crap falling off the walls, looking for something to crawl under!

    Not bashing anybodys CC or BB stuff or any equipment sold their!!!!!
    Please no flames, ouch hot....

    Ok, I'm seeing cross eyed, time to hit the sack.
    Buy the way Pete nice speaks, I am sucker for the Britt sound.

    Cheers
    Geoff
     
  14. pete sterna

    pete sterna Auditioning

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    Hey Mark, I wasn't stealing your idea. I came up with it on my own. I didn't know you posted a similar one before.

    Pete
     
  15. pete sterna

    pete sterna Auditioning

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    PS. I did take some advice from some people here who's names I don't recall, and bought a sound meter from radio shack. I think if I combine my test CD and the meter, I might be able to tune my system to produce a reasonably flat response in my room. Not bad thinking for a "Joe six-pack".[​IMG]
     
  16. mark alan

    mark alan Supporting Actor

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    I was just joking around pete. I getting a sound meter tomorrow also to play around with my system.

    I just happened to download the same tone program. I guess great minds think alike.
     
  17. pete sterna

    pete sterna Auditioning

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    Hey Mark, let me know if you find some trick to make it easier. I made sure I burned my test CD with a setting checked that insures equal volume for all the tracks. (tones)

    Pete
     

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