synthfreek Posted September 7, 2010 Share Posted September 7, 2010 Just starting noticing this a few days ago. It seems to happen only with certain sounds(mid-bass?) and at slightly higher than "normal" listening levels. Is this the sign of a dying diaphragm or maybe the gasket seal gone bad? Maybe I'll throw a sound clip up on YouTube. Quote Link to comment Share on other sites More sharing options...
synthfreek Posted October 2, 2010 Author Share Posted October 2, 2010 bump... Quote Link to comment Share on other sites More sharing options...
synthfreek Posted October 2, 2010 Author Share Posted October 2, 2010 Here is a small clip of the sound it's making. http://www.youtube.com/watch?v=czzXtGeja-8 Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted October 2, 2010 Moderators Share Posted October 2, 2010 That's a strange sound. Is anything loose, crossover or bass driver, Just guessing I would think bass driver not midrange is where the problem is, if nothing is loose it might be the voice coil on the woofer. Unless it's higher in frequency than it sounds on that clip I would think not a midrange driver. Just a guess. [] Quote Link to comment Share on other sites More sharing options...
MechMan Posted October 2, 2010 Share Posted October 2, 2010 Sounds like the woofer to me as well...ouch! Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 2, 2010 Share Posted October 2, 2010 Thank for the YouTube. My guess is that it is the woofer bottoming out. I've written about this before. It is surprising, the first time encountered, to believe the woofer can make such a noise which seems to be in the midrange. I would say you should watch the woofer itself but I believe you can't take the grill off. You'd see gross motion. My thought is that the program material is down below the port tuning and thus is about 25 Hz or lower. As you may know, the port loads the woofer around the port tuning but then below that, it is free to move. A woofer in a sealed box (no port) is controlled by the sealed box. If this is from a CD, I'd try looking at the recording using Windows media player set to the "bars" display and see if there is some monster infrasonic shown on that spectrum analyzer. Am i correct that it only happens with that recordng? It seems to me that the speaker is being excited by specific (unheard) note in the passage. What we hear is going lower and lower for drama. Maybe near the end some subsonics are added. Something recorded for a synthfreek could do that. Wm McD Quote Link to comment Share on other sites More sharing options...
synthfreek Posted October 2, 2010 Author Share Posted October 2, 2010 It is the mid for sure. I have taken the back off to check for anything loose...zilch. I am using a synth to generate the notes so I could demonstrate as clearly as possible what it sounds like. Although the tone was certainly bass-heavy there are plenty of mids mixed in as well. It must be the bottom threshold of the mid's frequency response that causes the problem. After reading on the Crites site I began wondering if this is what a rotten gasket would sound like. Quote Link to comment Share on other sites More sharing options...
BEC Posted October 2, 2010 Share Posted October 2, 2010 Try tightening up the screws holding in the midrange horn. I heard a similar sound described here in this thread. The sound was the midrange horn not being tight enough which caused it to resonate when the woofer was at high volume at a specific frequency. http://forums.klipsch.com/forums/t/73587.aspx?PageIndex=3 Problem described on the 7th post on the page. Solution on the 13th post on the page. Bob Crites Quote Link to comment Share on other sites More sharing options...
synthfreek Posted October 3, 2010 Author Share Posted October 3, 2010 I tried that when I had the back off Bob. Think I'll actually open the driver today to inspect. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted October 3, 2010 Share Posted October 3, 2010 Maybe pull the diaphragm if you're up to it, and run some folded over masking tape in the gap. Debris could get in the gap and rub against the voice coil. I had a buzzing problem with a LaScala and noticed it was the midhorn. I noticed it while playing music. You'd hear this zzt, zzt, buzz, buzz, every once in awhile. I tore the driver down to inspect the unit, and not seeing anything out of the ordinary, cleaned the voice coil gap with double sided masking tape. It solved the buzz problem. I went ahead and did the other driver just for general purpose. It could have been something loose from the start. And tearing the driver down and reassembling/retightening may have fixed the issue...who knows... Quote Link to comment Share on other sites More sharing options...
djk Posted October 3, 2010 Share Posted October 3, 2010 "Debris could get in the gap and rub against the voice coil." It would have had to have been in there from the date of manufacture, there is no path into the gap from the outside of the driver. I would take the driver apart and examine the voice-coil for rub marks (both on the inside and outside of the coil former), clean the gap, and re-assemble. What is the exact frequency of the buzz? If it is at the impedance peak just below the crossover point you may be able to add a swamping resistor and increase the value of the crossover cap to compensate. 6dB crossovers are very hard on compression drivers. Quote Link to comment Share on other sites More sharing options...
fini Posted October 3, 2010 Share Posted October 3, 2010 I've had a flapping sound coming from my mid, too. Out the rear port, specifically. No debris in the gap, but I definitely detected some "rub marks." The frequency got so high it hertz. Serves me right, I haven't had a tight screw in years. Makes me question if I'm really cut out for this horny business. Quote Link to comment Share on other sites More sharing options...
Cal Blacksmith Posted October 4, 2010 Share Posted October 4, 2010 I only skimmed this thread and can not play your recording but when I bought my sons KG5.5s, there was a noise from the speakers that sounded like the woofers were going bad, it turned out that the glue holding the cabs together was starting to let go and the back of the speakers were vibrating with bass notes. A reglue with a good wood glue and glue blocks from the inside cured the problem and made the speakers much stronger than they were when we bought them. I may have missed the mark here entirely but that is my best guess for an answer on a thread where I couldn't hear the problem. Never mind if my answer does not apply[:$] Quote Link to comment Share on other sites More sharing options...
mark1101 Posted October 4, 2010 Share Posted October 4, 2010 You could temporarily disconect the mid range or woofer to test some of the theories here and be clear on exactly which driver it is. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted October 4, 2010 Moderators Share Posted October 4, 2010 You could temporarily disconect the mid range or woofer to test some of the theories here and be clear on exactly which driver it is. Darn mark, there you go inserting some common sense which will decide what driver is a problem, sounds simple now that YOU thought of it ! Quote Link to comment Share on other sites More sharing options...
MechMan Posted October 4, 2010 Share Posted October 4, 2010 You could temporarily disconect the mid range or woofer to test some of the theories here and be clear on exactly which driver it is. Darn mark, there you go inserting some common sense which will decide what driver is a problem, sounds simple now that YOU thought of it ! LOL [8-|] Quote Link to comment Share on other sites More sharing options...
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