Agent 99 Posted March 23, 2004 Share Posted March 23, 2004 Can anyone give me a little direction in tracking a noise in a 1991 klipsch cornerhorn. My brother left these in storage for a few years then asked me to look after them for awhile, he's a guest of the state for a dime. The problem is a low level humming sound , the humming is not source related. I've tryed switching amp channels and different amp . The sound always follows the same speaker regaurdless of source, inter-connect , speaker cable , A/C plug etc etc etc . I removed the woofer door and someone has replaced the bass driver at one time and done some real rookie soldering , it looks bad but appears to have good adheasion. I've hooked the speaker leads directly to the bass driver and directly to the HF leads and still get this noise . Can there be a problem in the crossover and if so then why am i getting the noise when going direct to the drivers them selves ? I may not have tested something correctly or you may need some more information. Any response would be of great assistance to an otherwise baffled and or uninformed klipsch owner. Thanks . Kerri lynn Quote Link to comment Share on other sites More sharing options...
ironwoods Posted March 23, 2004 Share Posted March 23, 2004 Hi and welcome to the forum, does it hum or buzz only when a source signal is applied? Or all the time? with no input selected? Does the speaker sound good, even with the hum? Is the replacement driver a klipsch? A buzz could be a wood panel vibrating. Problems can stem from light-switch dimmers and large motors such as those found in fridges, A/C-heating blower units and washer/dryers. Any of these in close proximity? Also high current wires running parallel with the speaker wire. I know the K-horns are heavy, but have you tried moving the problem child to a different location? One last thing, did you try tightening the mounting screws of all the drivers? If none of this works, we can start on a plan for a jail break. j/k Shhhhhhh, Max is still sleeping. Quote Link to comment Share on other sites More sharing options...
hoggy Posted March 23, 2004 Share Posted March 23, 2004 One Of my Khorns seemed to have a buzz like the one you descibe. It was a picture on the wall above the speaker. I would have sworn that it was the Khorn so check closely for that kind of stuff as was already suggested. Sound has a funny way of fooling you. hoggy Quote Link to comment Share on other sites More sharing options...
maxg Posted March 23, 2004 Share Posted March 23, 2004 Me? I aint sleeping (although the wife says sometimes it is hard to tell). Hmm...strange buzzing from a KHorn woofer (we think). Ah yes. no idea - sorry. Quote Link to comment Share on other sites More sharing options...
Parrot Posted March 23, 2004 Share Posted March 23, 2004 Max, Do you know the old TV show "Get Smart"? Two secret agents, Max and (female) Agent 99. http://www.fiftiesweb.com/tv/get-smart.htm Quote Link to comment Share on other sites More sharing options...
3dzapper Posted March 23, 2004 Share Posted March 23, 2004 If the wrong type replacement woofer was installed it is possible for the surround to contact the motor board and cause a noise. This would be with a foam surround with an outie curvature. Woofers in Khorns are heavy and hard to remove but it might be worth a look. A new replacement K-33 is availiable from Klipsch for a very reasonable price and would be a sound investment. Also you might be on the correct path looking for cold solder joints or corroded connections acting as a reciever for 60Hz radiation which is everywhere. Rick Quote Link to comment Share on other sites More sharing options...
maxg Posted March 23, 2004 Share Posted March 23, 2004 ---------------- On 3/23/2004 9:31:57 AM paulparrot wrote: Max, Do you know the old TV show "Get Smart"? Two secret agents, Max and (female) Agent 99. http://www.fiftiesweb.com/tv/get-smart.htm ---------------- I hada feeling it wasnt me he wanted....yes I think I did see that show as a child...cant remember much about it but "Agent 99" rings a bell. Quote Link to comment Share on other sites More sharing options...
Parrot Posted March 23, 2004 Share Posted March 23, 2004 Agent 99, Are you "down under" as in Australia? That's a long ways from home for a pair of Klipschorns. Quote Link to comment Share on other sites More sharing options...
Agent 99 Posted March 23, 2004 Author Share Posted March 23, 2004 Thank you for your replies gentlemen . Answers to the few questions are #1 the speaker in question is making a buzzing sound ( not a hiss ) the sound is at idle and is noticable at lower volume levels , the buzzing sound is there even when everything in the whole system is disconnected ( so that eliminates a ground loop ) except the amplifier to the speaker. The buzzing or humming i guess you could also call it has no relationship to the room as mentioned above it can be heard at idle but is taken over in level when source material is played , but between song tracks or a low listening levels you can hear this sound. The replacement driver has K-33 stamped on it but i do not know if it was installed correctly , My freind has a camera i could borrow and take pictures of the new driver and its poor soldering conections. With this new information do you gentlemen have any other suggestions ? PS. the down under comment is a female joke Max is also my brothers nickname , plus he's doing time in the max . You men don't have to tenderfoot your replies , i can follow along fairly well, i took electronics in high school so i know the terms ( but not all the curcuit paths ) I'm a welder by trade and i'm working on my pipefitter tickets right now. I went back and re-read ricks comments , what is 60hz radiation ? Quote Link to comment Share on other sites More sharing options...
hoggy Posted March 23, 2004 Share Posted March 23, 2004 Agent 99, Barbra Feldon. Think I spelled her name right. hoggy Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 23, 2004 Share Posted March 23, 2004 Hi, Keri Lynn, welcome. K-horn produce 104 dB for one watt and 1 meter. That's extreme and they will show up *every* problem with any electronics. So, only one channel makes the noise. The noise is constant and not related to the music, correct? It is a "hmmmmmmmmmmmmmmm" sound, correct? And it does it with all inputs disconnected from the power amp/reciever. This indicates only one of 2 problems. The amp is going bad or it is in a strong magnetic field that causes the hum (induced internally). If the noise was coming in on the powerline, it would be most likely in both channels. It is extremely unlikely that the hum is being induced in the speaker wires. Repeat your testing again, with the amp on and nothing but speaker wires connected. If you get a hum, move the amp several feet from it's location. If it still hums, reverse the polarity on the power plug, if you can. If you can't, get a 3 prong to 2 prong adapter the try it both ways. Note anything that changes the hum. If none of that eliminates the hum, get/borrow a known good quality, good condition amp and try it with no inputs. When you get a condition without hum, start plugging in sources. I'll bet the power supply of your amp is beginning to fail and the extreme efficiency of the K-horn shows it. If the hum does not vary with the music, it is not the speaker. I've had a LOT of trouble with hiss and ground loop buzzing with my La Scalas, all traceable to my preamp/processor. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted March 23, 2004 Share Posted March 23, 2004 Line voltage at 60 cycles per second puts a field out everywhere. In electronics did you ever look at an o-scope with nothing connected to the leads and see the jagged sine wave on the screen? That is radiated 60Hz from the wiring. A loose connection can pick up that hum and if it is amplified can be heard. Rick Quote Link to comment Share on other sites More sharing options...
BackBurner Posted March 23, 2004 Share Posted March 23, 2004 Barbara feldon & Don adams was a classic show . Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 23, 2004 Share Posted March 23, 2004 ---------------- It is extremely unlikely that the hum is being induced in the speaker wires. ---------------- However, I've had the recent experience of hum being directly induced in the woofer even without the speaker wires attached, by a strong electromagnetic field (from a variac) very close to the speaker. The bass horn's efficiency magnified it to audibility. Quote Link to comment Share on other sites More sharing options...
fini Posted March 23, 2004 Share Posted March 23, 2004 Are your "Domes of Silence" correctly installed? Is honey dripping from the bass bin? Thinkin' outside the hive here... Quote Link to comment Share on other sites More sharing options...
Agent 99 Posted March 23, 2004 Author Share Posted March 23, 2004 Are you guys implying the speaker may be picking up noise from elsewhere ? The one in question has a fridge sitting behind it in another room , there is also 2 A/C outlets within a foot of the speaker. The ST70 sits on a stand 2 feet off the ground and about 1 foot from the speaker in question. ( problem ? ) If i'm reading you gentlemen correctly then i should try addressing these issues first. I have tryed several differnet amps and always get this noise , so like you men say , it's airborne or it's the speaker itself. Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 23, 2004 Share Posted March 23, 2004 Regarding airborne hum possibilities, my suggestion is that you move some of those things away from the speaker, including the fridge (as well as stopping it) if it's immediately on the other side of the wall between them, and see if the hum decreases/stops. Moving my source of airborne hum away from the speaker reduced the hum and seemed to prove it was in fact the source. Quote Link to comment Share on other sites More sharing options...
jnorv Posted March 23, 2004 Share Posted March 23, 2004 I had a similar strange noise in one of my LS. Turns out the screws holding the woofer in place had come loose. Replaced them with allen head cap screws and the problem went away. Jim N Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 23, 2004 Share Posted March 23, 2004 I would have to go with a grounding issue or bad PS cap in the amp... However, I am not clear on the "buzzing" - that usually indicates a loose piece or something vibrating that should not be. A "hum" on the otherhand is a continuous tone (typically accociated with the 60 cycle AC supply). I would guess that if it happens at amplifier idle, it is not a "buzz" but is rather a "hum". A buzz would only happen with sonic activity, not at idle, when there is not supposed to be any... Here are the usual symtoms of a ground loop/PS cap problem: 1) incessant 60 cycle hum, does not get "amplified"; is always the same volume of hum regardless of signal being sent to speaker, i.e., amplifier volume does not effect hum volume. 2) if it ONLY occurs on one speaker, then it points to power supply problem in amp (with a stereo supply) or a channel specific problem (probably still with the supply). Grounding issue would be apparent on both speakers at the same time. This can be checked by switching the speaker cables between the 2 speakers and see if it moves with the amp channel or is on both channels. 3) it is unlikely that the crossover or any speaker driver has anything to do with the hum in question. Also, it is unlikely that the hum is introduced by AC line hash or EMI on the cabling. I would go with the bad amp channel power supply cap or a ground loop problem. Try a 2-prong AC adapter on the amp power cable and "float" your system; I have to that with my pre-amp. DM Quote Link to comment Share on other sites More sharing options...
ironwoods Posted March 23, 2004 Share Posted March 23, 2004 "PS. the down under comment is a female joke"- please elaborate on the jest. Pull the plug on the fridge, only after removing a cold brewski or two. Being a welder, all those juctions should be shiny bright by now. NP; Roger Waters > Radio *KAOS* > The powers that be. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.