tcb Posted April 15, 2004 Share Posted April 15, 2004 /// Quote Link to comment Share on other sites More sharing options...
fini Posted April 15, 2004 Share Posted April 15, 2004 Mario, Do you have access to a digital camera? A photo would help. Perhaps re-routing the speaker cord would reduce the hum. Have you tried swapping wires at the amp? Quote Link to comment Share on other sites More sharing options...
tcb Posted April 15, 2004 Author Share Posted April 15, 2004 // Quote Link to comment Share on other sites More sharing options...
maxg Posted April 15, 2004 Share Posted April 15, 2004 So if I have understood correctly there must be a power line in there somewhere (under the floor or in the walls). Maybe its worth investigating getting that line moved - rather than bolting extras onto the cabling in the speaker.....obviously if it is not too costly (or disruptive) an option. Quote Link to comment Share on other sites More sharing options...
fini Posted April 15, 2004 Share Posted April 15, 2004 Would close AC lines affect the squawker driver? It seems it (and the wires to it and the woofer) are the only things close enough to the wall when the Khorn is in place. Mario, you have to get it a full 5 feet out of the corner for the buzz to stop? I.E. at 2 feet, the buzz remains? Quote Link to comment Share on other sites More sharing options...
artto Posted April 15, 2004 Share Posted April 15, 2004 Do you know approximately how old your room/building is, generally? Some older buildings were retro fitted for electric service after they were built. Also, many older buildings simply ran electrical service through exposed (not in a metal conduit pipe/tube) imbedded in the plaster wall lath. There are several ways you might test for this. Most metals will provide some amount of electrical shielding. Try sliding a thin sheet of steel behind the upper part of the Khorn & see if there is any improvement. You might also use a stud locator, usually used to find nails in walls to locate where the wall studs are. If there is a strong magnetic field emanating from in the wall, this should be able to detect it. A cheap metal detector should be able to do the same thing. Is this corner on an outside wall? Or inside? Is there any electrical equipment on the other side of the wall? Quote Link to comment Share on other sites More sharing options...
maxg Posted April 15, 2004 Share Posted April 15, 2004 fini, Its a bit strange I grant you - but I cant think of what else it might be - unless he has a long cable run to the speaker and that is running alongside a power cable. Quote Link to comment Share on other sites More sharing options...
fini Posted April 15, 2004 Share Posted April 15, 2004 Here's a handy device for finding live wires in walls. It's called a volt tick, and detects the magnetic field. You don't have to open up the wall or contact a wire. They're about $15 at Home Depot, etc. Quote Link to comment Share on other sites More sharing options...
ZAKO Posted April 15, 2004 Share Posted April 15, 2004 We could come over with crowbars & Hammers & help tear down that wall. A sheet of steel or aluminum might shield that wall from your speakers. If its large enough. Quote Link to comment Share on other sites More sharing options...
tcb Posted April 15, 2004 Author Share Posted April 15, 2004 [/// Quote Link to comment Share on other sites More sharing options...
tcb Posted April 15, 2004 Author Share Posted April 15, 2004 /// Quote Link to comment Share on other sites More sharing options...
Klipschfoot Posted April 15, 2004 Share Posted April 15, 2004 What is behind that bulkhead (the boxed in wall) in the corner? Do you live in an apartment? Quote Link to comment Share on other sites More sharing options...
tcb Posted April 15, 2004 Author Share Posted April 15, 2004 /// Quote Link to comment Share on other sites More sharing options...
maxg Posted April 15, 2004 Share Posted April 15, 2004 ---------------- On 4/15/2004 9:44:25 AM Klipschfoot wrote: What is behind that bulkhead (the boxed in wall) in the corner? Do you live in an apartment? ---------------- Yeah that does look suspicious doesnt it. I wonder what cables are hidden behind that? If you are in an appartment building there is a good chance they run straight down to lower levels. If not there is an equal chance they go directly under your floor. could be costly to sort out. Maybe consider a lead lining for the wall behind the speaker??? Quote Link to comment Share on other sites More sharing options...
maxg Posted April 15, 2004 Share Posted April 15, 2004 Posts are flying in and we are overlapping. So it is an appartment building. Are you on the ground floor - if not that looks very like it passes straight through. May be tricky to get it moved - but not impossible. Still a preferable option over trying to contain those electro magnetic fields though... Quote Link to comment Share on other sites More sharing options...
fini Posted April 15, 2004 Share Posted April 15, 2004 ---------------- On 4/15/2004 9:42:21 AM tcb wrote: Even if I removed the speaker cable,the buzz remains. The speaker is on air without any connection and still make that buzz noise. ---------------- Are you saying that without the speaker cable connected to the speaker (or to the amp?), you still hear a buzz coming from the speaker? In other words, the speaker alone with nothing connected is making a buzzing sound when within 5 feet of that corner? WOW! Thanks for the photo, BTW. I had pictured something completely different. The corner as-is is not properly shaped anyway (with that bump-out). I'd seriously consider a false wall using shielding material (if AC wires end up being the culprit). Also, consider asking the building owner (or builder) about that corner. Talk to your local building department, as they may have the plans for that building, or be able to point you in the right direction. An inspector might be able to come over and give an opinion, too. Talk to your neighbors, see if they have similar problems. Does the building have a manager or superintendant? Snoop around the basement or attic to see if you can figure out what's in there. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted April 15, 2004 Share Posted April 15, 2004 could be a transformer hidden somewhere in there as well...you could try listening for audible hum (telltale trannie sound) to the wall with a stethascope (sp?) or a paper or styrofoam cup. RF shielding will be the way to go here. let us know what you find out with the tick mentioned earlier and paper cup. regards, tony Quote Link to comment Share on other sites More sharing options...
tcb Posted April 15, 2004 Author Share Posted April 15, 2004 ///. Quote Link to comment Share on other sites More sharing options...
jnorv Posted April 15, 2004 Share Posted April 15, 2004 You might try probing the corner with an EMI (electromagnetic field meter). I picked one up for about $100 when I had a problem with interference withg a computer monitor. Jim N Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 15, 2004 Share Posted April 15, 2004 ---------------- On 4/15/2004 10:10:57 AM fini wrote: ---------------- On 4/15/2004 9:42:21 AM tcb wrote: Even if I removed the speaker cable,the buzz remains. The speaker is on air without any connection and still make that buzz noise. ---------------- Are you saying that without the speaker cable connected to the speaker (or to the amp?), you still hear a buzz coming from the speaker? In other words, the speaker alone with nothing connected is making a buzzing sound when within 5 feet of that corner? WOW! Thanks for the photo, BTW. I had pictured something completely different. The corner as-is is not properly shaped anyway (with that bump-out). I'd seriously consider a false wall using shielding material (if AC wires end up being the culprit). Also, consider asking the building owner (or builder) about that corner. Talk to your local building department, as they may have the plans for that building, or be able to point you in the right direction. An inspector might be able to come over and give an opinion, too. Talk to your neighbors, see if they have similar problems. Does the building have a manager or superintendant? Snoop around the basement or attic to see if you can figure out what's in there. ---------------- I don't have anything to add to the others, suggestion-wise, but that's gotta be one HELL of an electromagnetic field! I've had a lower level hum problem with a variac, which I understand is a sort of transformer, and, yes, it induced audible hum in the woofer and squawker without any speaker cables attached! The speakers probably pick up the field directly via the voice coil. The horns' efficiency apparently causes the hum to be audible; I'd guess nearly all others' speakers would not be efficient enough to make the hum audible. I've had many a power cable running behind and next to my K-horns without a trace of hum, so I think it has to be a lot stronger field than from simple 110-volt lines. I've heard that shielding for RF is different from that for EM -- aluminum vs. iron or steel, respectively. I hope the EM field can be stopped by a wall shield, and not travel around it. Larry Quote Link to comment Share on other sites More sharing options...
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