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[Kevin Maxwell]

The point is that there's no such thing as "cold" in the first place.  Marginal cold or otherwise.  The term means nothing to a manufacturing engineer or a metallurgist.  By overheated I was referring to excess heat during the soldering.  This leaves a large grain structure that's easily fractured.  It looks like a piece of metal that's been bent back and forth and is about to crack.  Long term heating will cause a lesser degree of this but has more effect at the boundaries of the solder and termination where the metal gets brittle for metallurgical reasons.  Contaminated or oxidized terminations will cause various degrees of dewetting.  The closest you can get to "cold" would be a non-wetted joint where either things were too contaminated to wet at all or there wasn't sufficient thermal energy (time and or temperature) to get things to wet.  Typically one surface is less contaminated than the other so if it wets one but not the other it's a contamination issue, if neither wets then the process didn't have enough heat.

For people in the soldering industry, the term "cold solder" is roughly equivalent to "Can I get my mike to sound more lively?".   

I have been using the term “Cold solder joint” for a long time. I can see that technically that is incorrect. What would be a term that we could use without getting into proper analysis of what actually went wrong with the solder joint. How about “A bad solder joint”? Or a “Naughty solder joint” I’m sorry I couldn’t resist an attempt at a joke. But what do we call a solder joint that is no longer working properly, and usually re-soldering the joint fixes the problem. I have found a lot of equipment that fails after time and is fixed when you find the bad solder joint and fix it. A friend who has been a TV repairman for a long time has said that a majority of the fixes for TVs are solder joints.     

But from the description of the O.P. problem I would lean towards thinking that a good cleaning of the horns might fix a lot of his problems.

Bu this discussion got me thinking of all of the other terms that are improperly used in sound, like tuning a room. Should we start another thread where people can list the ones they feel are wrong.

[Richard Turner]

What does the crossover schematic look like? are there resistors or capacitors in parallel pairs in circuit? if there are that would be one place to check. a halving of capacitance or resistance would cause a tone shift EV uses good components but they aren't immune to being burned up. 300 shows 1500 hours doesn't seem excessive use.

IIRC they have a ceramic potted resistor in the HF section.

[Stephen Kirby]

I have been using the term “Cold solder joint” for a long time. I can see that technically that is incorrect. What would be a term that we could use without getting into proper analysis of what actually went wrong with the solder joint. How about “A bad solder joint”? Or a “Naughty solder joint” I’m sorry I couldn’t resist an attempt at a joke. But what do we call a solder joint that is no longer working properly, and usually re-soldering the joint fixes the problem. I have found a lot of equipment that fails after time and is fixed when you find the bad solder joint and fix it. A friend who has been a TV repairman for a long time has said that a majority of the fixes for TVs are solder joints.     

But from the description of the O.P. problem I would lean towards thinking that a good cleaning of the horns might fix a lot of his problems.

Bu this discussion got me thinking of all of the other terms that are improperly used in sound, like tuning a room. Should we start another thread where people can list the ones they feel are wrong.

If the solderjoint was good to begin with, and now fails conductivity, most likely it is cracked or fractured.  A touch of flux and reflowing it will usually restore operation.  Wicking or sucking off the solder and re-soldering with fresh solder it is better.  Reheating the same bit of metal increases the grain size on solidification, making it more prone to fatigue and subsequent failure.

[Kevin Maxwell]

If the solderjoint was good to begin with, and now fails conductivity, most likely it is cracked or fractured.  A touch of flux and reflowing it will usually restore operation.  Wicking or sucking off the solder and re-soldering with fresh solder it is better.  Reheating the same bit of metal increases the grain size on solidification, making it more prone to fatigue and subsequent failure.

When I say fix the solder joint I don’t heat up the joint without new solder. I use a very thin solder and am basically using a solder wetted iron and feeding new solder in while heating it up. And because I use such a thin solder I am not just globing on a bunch more solder.  Too much heat is required to melt the existing solder without doing this. I think people use the term cold solder joint because it seems like if you solder a connection without heating the 2 parts enough (cold) you might get the solder to flow enough to make an electrical contact but it usually doesn’t last very long. Is this because it is barely making contact and then it “easily fractures”?

[Stephen Kirby]

When I say fix the solder joint I don’t heat up the joint without new solder. I use a very thin solder and am basically using a solder wetted iron and feeding new solder in while heating it up. And because I use such a thin solder I am not just globing on a bunch more solder.  Too much heat is required to melt the existing solder without doing this. I think people use the term cold solder joint because it seems like if you solder a connection without heating the 2 parts enough (cold) you might get the solder to flow enough to make an electrical contact but it usually doesn’t last very long. Is this because it is barely making contact and then it “easily fractures”?

Kevin, when people don't provide enough thermal input and just melt a glob of solder into the area of a termination it doesn't "wet".  Like the old wax and water drops on a hood.  It gets into some complications of metallurgy and the physics of solidification of molten metals but basically when solder "wets", and gives a smooth contour, metals within the solder alloy with metals in the terminals in a thin layer between the two.  In a partially wetted joint, this layer isn't fully formed and the solder doesn't really "stick".  As you say, these connections are easily broken and unreliable.  A basic industry standard is that the angle formed from the solder and the termination surface should be less than 90 degrees.  Typically it is very shallow.  The 90 degree standard in IPC-610 comes from a diagram I made for military standards back in the '80s in the specific instance of wave soldering SMT resistors.  The dynamics of which tends to lump solder into that specific geometry.  More than 90 degrees and you don't know if it's wetted, so this was an acceptable compromise to the folks in the Naval Weapons Center who were writing the specs.

[Kevin Maxwell]

Kevin, when people don't provide enough thermal input and just melt a glob of solder into the area of a termination it doesn't "wet".  Like the old wax and water drops on a hood.  It gets into some complications of metallurgy and the physics of solidification of molten metals but basically when solder "wets", and gives a smooth contour, metals within the solder alloy with metals in the terminals in a thin layer between the two.  In a partially wetted joint, this layer isn't fully formed and the solder doesn't really "stick".  As you say, these connections are easily broken and unreliable.  A basic industry standard is that the angle formed from the solder and the termination surface should be less than 90 degrees.  Typically it is very shallow.  The 90 degree standard in IPC-610 comes from a diagram I made for military standards back in the '80s in the specific instance of wave soldering SMT resistors.  The dynamics of which tends to lump solder into that specific geometry.  More than 90 degrees and you don't know if it's wetted, so this was an acceptable compromise to the folks in the Naval Weapons Center who were writing the specs.

I was taught when soldering you are trying to get both components up to the same temperature and then flow the solder between them. This was especially painful when trying to hold a wire in place and not move it till the solder solidified when soldering some cables onto XLR connectors. The jacket on the individual wires wasn't thick enough to not transmit the heat. I tried to hold it back far enough so it wouldn’t get as hot back there. I just the other day was fixing a snake for a friends church and I couldn’t hold the wire back far enough to avoid the heat. It was a cheap snake that was built by the manufacturer with all press on junctions, no solder. Two of the chassis mounted type of XLRs physically broke off of their housing. I say type because they were just slipped into an extruded housing not fastened down in any way.

I would like to hear what the OP eventually finds as the cause of the monitors not sounding as good anymore. 

[Wes Garland]

This sounds counter-intuitive, Kevin, but I think you're either using an iron that isn't powerful enough, or has a dirty tip.  Soldering a connector like that should only take a second, not enough time to heat up the wire any distance from the termination like that.

[Kevin Maxwell]

This sounds counter-intuitive, Kevin, but I think you're either using an iron that isn't powerful enough, or has a dirty tip.  Soldering a connector like that should only take a second, not enough time to heat up the wire any distance from the termination like that.

Neither or those things. I was tough by NASA certified solderers. 

[Dave Garoutte]

Are you saying that soldering IS rocket science!?

[Tim McCulloch]

Neither or those things. I was tough by NASA certified solderers.

As was I.  A friendly neighbor worked at Rocketdyne (his wife worked with my mom) and he taught me to solder well.

Are you saying that soldering IS rocket science!?

It's "rocket surgery".

[ProSoundWeb Community]