Treble Loss..

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  • 11-28-2003, 12:39 PM
    joel2762
    Treble Loss..
    [COLOR=navy] When I listen to loud music for a long period of time, all of a sudden it sounds like someone turned a tone control all the way down on an old radio. All the highs just dissappear :mad: . When I turn the volume low it goes back to normal but when I raise the volume again, the same thing happens. It's like something is getting exhausted or something. I am using 2 ch mode with subwoofer. I'm running a Sony STR-DE585 reciever and Qest Q610's as mains. What's going on here? :eek: Is it the reciever or the speakers? How should I go about determening what is going wrong here? Maybe get another set of speakers and play those loud for a while and see what happens? Anyone have this experience before, or find a problem with the equipment..Anyone know what could be causing the problem? :confused: All help appreciated. Thanks in advance
  • 11-28-2003, 02:46 PM
    markw
    How loud is loud?
    Could it be your ears?
  • 11-28-2003, 05:39 PM
    mtrycraft
    Interesting indeed. Maybe the tweeters are getting too hot that is causing it to shut down, unlikely, or the impedance increases with that heat to negate the effect?
    I doubt it is the receiver but it may be. Or your hearing as a last resort?\
    Not much direct help :(
  • 11-28-2003, 06:14 PM
    joel2762
    Hmm.
    Nope, it's not my hearing I know that. I've checked. The tweeters are ferrofluid cooled but I guess they could still overheat. I'm going to try a different pair of speakers tomorrow, then i'll know if it's the speakers or not. Thanks for the help!
  • 11-28-2003, 06:20 PM
    joel2762
    Sorry. One more thing..
    To answer your question. Loud is when my reciever is on 60. It goes to 73. It needs to be this loud because i'm usually listening from a different room so to hear it good it needs to be at this level, however it is not at a level to damage ears in this room. The speakers don't distort or anything, they run fine. It's just after a while this happens with the tweeters.
  • 11-28-2003, 07:48 PM
    mtrycraft
    Quote:

    Originally Posted by joel2762
    To answer your question. Loud is when my reciever is on 60. It goes to 73. It needs to be this loud because i'm usually listening from a different room so to hear it good it needs to be at this level, however it is not at a level to damage ears in this room. The speakers don't distort or anything, they run fine. It's just after a while this happens with the tweeters.

    Could there be ferro fluid leakage problems?
    It does seem you ar eplaying it loud in order to hear it in other room. Maybe you should get a smaller system there, or move it there or ???
    It looks more like a speaker problem over heating. I just don't see why else it be missing the treble.
    Is the other speaker from a different maker?
  • 11-29-2003, 03:45 AM
    joel2762
    .....
    Quote:

    Originally Posted by mtrycraft
    Could there be ferro fluid leakage problems?
    It does seem you ar eplaying it loud in order to hear it in other room. Maybe you should get a smaller system there, or move it there or ???
    It looks more like a speaker problem over heating. I just don't see why else it be missing the treble.
    Is the other speaker from a different maker?

    Maybe it could be ferro fluid leakage. The two rooms are joined by a large double door. But the speakers are facing into the other room which is why it is not as loud out here. I listen to music when I am on my cpmputer usually. My computer is temporiraly in this room so it will be moved back into the other room, then I won't have to have it so loud. This problem also happens sometimes on lower volumes after a period of time..say around 50 on the reciever..Which is a comfortable listening level. I was thinking the same thing, It sounds like the treble is overheating. Yes, the other speaker I am going to try is one I built. If this problem doesn't occur when I try these speakers I will know what's causing the problem.
  • 11-29-2003, 04:32 PM
    Kursun
    possible cause...
    I think your loudspeaker may have some special high power protectors on its tweeter line. The simplest form could be an incadescent bulb wired in series with the tweeter. The filaments will get hot at high power levels, and the bulbs will actually glow... A hot filament has high resistance, so the output at the tweeter will drop. At the severest case the filament will act as a fuse to protect the tweeter.
    See the link:
    http://www.eden-electronics.com/tweeter.html
  • 11-29-2003, 05:17 PM
    mtrycraft
    Quote:

    Originally Posted by Kursun
    I think your loudspeaker may have some special high power protectors on its tweeter line. The simplest form could be an incadescent bulb wired in series with the tweeter. The filaments will get hot at high power levels, and the bulbs will actually glow... A hot filament has high resistance, so the output at the tweeter will drop. At the severest case the filament will act as a fuse to protect the tweeter.
    See the link:
    http://www.eden-electronics.com/tweeter.html


    That is a very good possibility too. Maybe he needs to call the speaker company to find out if in fact his speaker tweeters are so fused.
    And since the speaker does operate normally after the volume is reduced or turned off, more of an indication of this type of fusing, a no blow fuse may be used.
  • 11-30-2003, 05:09 AM
    joel2762
    Possibly...
    That could be what's happening because the problem does resolve as I lower the volume and it seems like I have to be listening for a while to cause this problem. Then after I turn it down for a few minutes,then turn it back to the same volume again, it happens within a shorter period of time..Like the fuse is still heated up. I think that's what is happening. Thanks for all help.
  • 12-08-2003, 04:20 PM
    joel2762
    Got it.
    Just recieved an e-mail from Quest. They informed me that these speakers do use speaker breaker tweeter protection. These are 120 watt speakers and I don't think that the tweeters should be cutting out like this. I'm glad they have this protection but maybe they should've used more powerful tweeters because I don't think that they should have to cut out at that level. Not even giving them 100 watts...Thanks for all the help everyone!
  • 12-08-2003, 09:07 PM
    mtrycraft
    Quote:

    Originally Posted by joel2762
    Just recieved an e-mail from Quest. They informed me that these speakers do use speaker breaker tweeter protection. These are 120 watt speakers and I don't think that the tweeters should be cutting out like this. I'm glad they have this protection but maybe they should've used more powerful tweeters because I don't think that they should have to cut out at that level. Not even giving them 100 watts...Thanks for all the help everyone!


    Well, that is good news to know :)
    However, your speakers overal are 120 watts, not individual drivers, especially the tweeter. I am certain that you are not pumping 100 watts to the tweeters or they would be up in smoke. Tweeters in home application is good to handle 20 watts of direct power.
    You may want to go back to Quest and see what their tweeters by itself will handle.
  • 12-09-2003, 03:14 AM
    joel2762
    You're Right...
    I see your point. I know tweeters can't handle much power, but couldn't they design one differently. I know it's complicated, but what's the point of using a 20 watt tweeter, rating the speaker 120 watts, then not being able to give the speaker near 100 watts and have the tweeter shutting off? Does anyone else have speakers that do this, or have experienced a problem like this?
  • 12-09-2003, 09:23 AM
    Quagmire
    One other possible cause for the condition you are describing is that at louder levels the amp section may be compressing the audio signal. When the amp starts to run out of steam it will create a condition where the signal begins to be compressed causing a loss in musical dynamics. To the furtherest extent, if the amp is driven into clipping, then the signal becomes completely compressed. Then of course, when you turn the volume down, the signal becomes less compressed and a return of normal musical dynamics results.

    Not saying this IS happening... only that this is a possibility.

    Q
  • 12-10-2003, 12:50 PM
    joel2762
    I was thinking....
    When this first came about I was also thinking the same thing, but now everything points to the speakers and I think that's the problem. I haven't driven the amp into clipping. I wouldn't be able to do that here, too hard on the ears :P. But 120 watt speakers should be able to be driven with a reasonable amount of power and not have to activate tweeter protection. They should put more powerful tweeters in, or simply lower the power level if they can't handle it...
  • 12-10-2003, 01:33 PM
    Kursun
    I don't agree on the probability of amplifier clipping. If you listen very carefully to an amp at the edge of clipping you'll notice slight brightening of sound . This is a very dependable clue to back off the volume and save the tweeter. At the later stage of clipping the sound will become excessively distorted, the treble will become metallic and piercing.

    In case of Joel, the problem is loss of treble, not brightening of sound.
  • 12-10-2003, 04:20 PM
    joel2762
    Yeah....
    Ya, the sound doesn't brighten. The amp isn't near clipping. I think the tweeter protection is too sensitive or the tweeters aren't powerful enough.
  • 12-10-2003, 04:45 PM
    Quagmire
    I'm not talking about amplifier clipping, but in the case of amp clipping, the piercing sound is a result of harmonics, not the output signal itself. The output signal when clipping resembles a square wave which by definition means that the clipped portion of the signal contains no dynamics.

    What I am really talking about is an amp compressing the signal before reaching clipping. I'm sure we've all had the experience of playing with the volume on a receiver and up to a certain point, the volume adjustment seems very linear - turn the knob and the music gets proportionately louder. But go beyond a certain point and the volume doesn't respond in such a linear manner any more - the music doesn't get proportionately louder, it just becomes less musical and compressed. Of course, if the volume is turned increasingly higher, the amp will eventually clip which has a completely different sound.

    Just posed this a possible cause of what he is hearing.

    Q
  • 12-10-2003, 09:14 PM
    mtrycraft
    Quote:

    Originally Posted by Quagmire
    I'm not talking about amplifier clipping, but in the case of amp clipping, the piercing sound is a result of harmonics, not the output signal itself. The output signal when clipping resembles a square wave which by definition means that the clipped portion of the signal contains no dynamics.

    What I am really talking about is an amp compressing the signal before reaching clipping. I'm sure we've all had the experience of playing with the volume on a receiver and up to a certain point, the volume adjustment seems very linear - turn the knob and the music gets proportionately louder. But go beyond a certain point and the volume doesn't respond in such a linear manner any more - the music doesn't get proportionately louder, it just becomes less musical and compressed. Of course, if the volume is turned increasingly higher, the amp will eventually clip which has a completely different sound.

    Just posed this a possible cause of what he is hearing.

    Q


    No. The amp is not compressing. It is the speaker that is compressing. That is the weak link. Never heard of an amp compressing.
    Volume controls are not linear throughout is range. And, if at high volume levels he is not getting more volume is certainly different from what he has reported of no volume at all.
  • 12-11-2003, 02:56 AM
    joel2762
    ....
    High volume levels get more volume, the speakers just can't handle it. They don't distort at all but the tweeter protection kicks in way too early I think. Or they just didn't use tweeters that could handle enough power.
  • 12-11-2003, 09:01 AM
    Kursun
    I think the tweeter protection kicks in way too early.
    As has been discussed earlier, average tweeter has a power handling capacity of about 20-30W.
    According to a popular site: http://sound.westhost.com/bi-amp.htm#hf_energy power distribution between drivers in a two way loudspeaker with a crossover at 3000Hz: %85 power to bass and %15 to tweeter.
    This means with an input of 100W average power the tweeter will receive only 15W of power assuming average program material. A tweeter can easily handle this much power.

    Your speakers seem to need a modification of its protection circuitry. If is the bulb type, simply wiring a second bulb parallel to the existing one will probably fix the situation.
  • 12-11-2003, 12:11 PM
    joel2762
    I was thinking the same thing....
    That very interresting. I was thinking that a little tweaking might do the trick. I might try that sometime. This wouldn't throw it off and then hark the tweeters would it?
  • 12-11-2003, 01:08 PM
    Kursun
    Needless to say less protection means more chance to get your tweeter fried! But nobody wants something that's so safe because it's not working at all! :)
  • 12-11-2003, 04:01 PM
    joel2762
    Exactly
    That's exactly it. The protector seems to cut in at loud volumes after say..10-15 mins. I guess when the elements heat up. The person I was talking to said they use "speaker breakers"
  • 12-11-2003, 10:29 PM
    mtrycraft
    Quote:

    Originally Posted by Kursun
    Needless to say less protection means more chance to get your tweeter fried! But nobody wants something that's so safe because it's not working at all! :)


    What he needs to do is move the speakers where he is, or he needs to move where the speakers are :)
    From his practice of loud volume, he will fry th espeaker for saure if he modifies his protection, guaranteed :)