Treble Loss..

[mtrycraft]

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.

[joel2762]

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.

[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!

[mtrycraft]

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.

[joel2762]

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?