Crimp or solder (or both)

[mark1101]

Bob did two sets of networks for me.

When I got the first set back, the corns, I immediately noticed the fast-ons and no solder. I was a little surprised. But I pulled the fast-ons off and then pushed back on. They were very tight connections.

The performance certainly can not be faulted. They gave my corns new life. I think that for an audio speaker application, these type of connections function just fine. The comment about allowing easy trouble shooting would be a perfect reason not to use a solder joint in such an application.

To me the question becomes, how long does such a connection maintain good continuity.

[Erik Mandaville]

DJK:

The wire mentioned was not used because of some special sonic attributes. I used it because it's what I happened to have on hand at the time. I don't spend too much time worrying about wire types, since I've done that until I gotten sick of it. I've also used several different types of silver solder, which can make a harder joint. I just use 60/40 Kester or whatever Radio Shack happens to have on hand, as long as it's not an acid flux type of solder.

My point was simply that (I think and IMO)a strong mechanical connection should be held in place by well-soldered joint.

Erik

[markus111]

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And! I know people who rely on crimping only, and say that it works well for them!

Erik

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Erik,

They are very lucky people! One of the worst weeks I've ever spent was in an environmental test facility testing a new machine. We had a new tech who didn't know that he was supposed to solder every connection, as well as crimp. As soon as we got the machine on the vibration tester, it stopped working. For the next 12 hours we had to carefully solder every connection until we could get it working. While we were doing this, we were still paying $100 an hour for the testing! Even though speakers are not subject to harsh environments, they do get quite a bit of vibration. I think for as few connections as there are in a crossover, it's worth the time to solder up all the loose ends.

Mark

[dragonfyr]

With all due respects, I think this debate is akin to a debate over cables, but on a different level of abstraction.

Both connections can provide quality connects. And some excellent points have been presented by many.

After all, the issue at hand for a properly made connection, is not its continuity but its resistive integrity.

Depending upon the application, there are reasons for each. And various contributors have presented interesting and appropriate variations of both.

Personally, when I was involved in the design & development of laser systems for the Department of Energy and Navy, no crimp connections were allowed. And I have always been biased toward quality solder joints. But the circuits were also designated for potential exposure to corrosive environments. And this made sense, as the potential for additional oxidation at the joints was minimized by soldering. Simple mechanical crimp/compression connections exhibit the potential for oxidation to occur in highly corrosive environments. But that does not eliminate their consideration in other environments or in modified applications.

Does that mean that the connection will necessarily suffer? No. Does it mean that the potential for oxidation sufficient to prohibitively increase the resistance is possible. Perhaps. It is dependent upon too many variables.

There are many factors contributing to the decision of what constitutes an appropriate connection.

Note I mention an appropriate connection and not an ideal connection.

Perhaps the more important criterion is a risk-benefit model.

A properly made solder connection has many advantages. But what variables are present that may compromise a quality soilder joint? What is the potential for a cold solder joint in production? And how difficult would this be to remediate in the event it occurs. Are connections in the average home subject to corrosive environments? Are the connections such that they can be easily accessed or are subject to (relatively) frequent change? What is the guage of the wires? The practical concerns of soldering large guage wires are not insignificant.

What are the variables to be encountered? Vibration? Corrosive environments? Servicability? While many applications may share many variables, I would think that one environment could present significant differentiating variables potentially resulting in different methods being employed based upon failure analysis of the various manufacturing techniques, delivery methods, service environments. and servicability considerations (etc.). (for instance, space versus ocean deployment...)

Again, the criteria that must be assessed is 'risk' based. Where the benefits are weighed against the application, the potential for failure, the impact of this failure, and the ability to remediate subsequent problems.

But again, here we are dealing with 'hi-fi' connections. What variables are significant here? Perhaps those should be the determining criteria for the types of connections we utilize. And I dare say they can't be too extreme, when the %#$*! RCA connection has become dominant in the consumer audio industry!

[D-MAN]

A crimped-only connection is not as electrically conductive as a soldered one, all things being equal. Now whether that actually effects the application, I cannot speak to.

The contact points between the joined surfaces are reduced in area (volume, thread count, surface area, whatever) in a crimped connection, i.e., it depends on exactly what is touching what and the amount of air (a dialectric) defining the immediate area(s) of non-conductive contact.

Whereas solder flows around the threads (collectively and individually) providing more area-to-area surface physical contact with less air pockets. And that is a better electrical conducting joint.

DM

[WMcD]

I'll put my vote on the solder connection.

When putting spade lugs on zip cord, I crimp and then solder.

It is a little silly because the spades go to a screw down. I've also made up XLR's, RCA's, etc. These too are just mate to some spring contact connection in the long run.

OTOH, it is interesting how much of the a.c. power distribution system is made up of screw down connections. The tv cable distribution system has f-connectors (no soldering). The telephone systems has a fair number of wire wrap. Those choices may be due to time and skill level considerations. Still, these do work.

Take a look at our computers. There are thousand of surface mount devices which are soldered on (glued on) without any mechanical back up like the mentioned point to point soldered connections of the old days. But then we have many cable connections (USB, Firewire, parallel) which are just contact with some spring pressure.

I would add additional tribute to one of the foregoing posts about the beauty of point to point set up in the old days.

In high school a lot of us were building Heathkits. First efforts were ham handed. The moderator showed us the work of his dad. Dad was employed to build prototypes for a manufacturer, but he turned his talent to putting together a few Heathkits.

They were indeed Rembrants to our finger painting. The little old electrons probably didn't care. None the less, they had style and grace.

Gil

[BEC]

Well, back during my 10 years in the Air Force, we soldered everything. I was definitely in the "Let's solder it" camp back in those days. I even went to the Air Force High Value Soldering School.

After I got out of the Air Force, I went into commercial nuclear power. There, soldering was almost never allowed except on printed circuit cards. Everything else was either crimped or wire wrapped. I guess the reason for that is the inspection and proof difficulties of a solder joint at a nuclear plant. We tested and inspected everything over and over. You can always easily check out a crimp connection visually and you can even measure the deformation of the crimp.

I have, in almost 40 years of troubleshooting electronic circuits seen many problems caused by bad solder joints. A lot of those bad joints were not visually bad even under 10 power magnification.

I think you can make a good connection by soldering or by crimping. Soldering after the crimp would be fine also. Tinning the wire first would probably be the wrong way to do it because the solder could just cover up some insulating corrosion and prevent the crimp from breaking through the corrosion to make the best contact. Also, you would need to think about the fact that tinning the wire first might increase the size of the wire enough to cause a stress problem using a good ratchet crimper. That crimper deforms the barrel down to a certain size.

If you work in or live near a nuclear power plant, your safety depends on millions of crimps that are done on bare wire and hundreds of thousands of wire wraps. I can't ever recall a bad one being found. Of course they were all made with a calibrated ratchet crimper and that tool was calibrated before it went out each day and its calibration was checked at the end of each day.

I do still have a problem understanding how wire wraps can be so reliable, but I have never found a bad one.

Bob Crites

[scriven]

Bob,

As I remember it, the nice folks at Bell Labs came up with the wire wrap idea. In it's original form the peg being wrapped was a square with sharp edges. The wire was supposed to wrap around the peg tight enough to deform the peg along with the wire such that it made a very good airtight mechanical connection at each corner. Since each connection had about 40 of these contact points, assuming 10 wraps of the wire around the peg, it worked out to be a very good connection system. I don't think they ever intended it to be used in any type of hostile environment.

By the way, I love your Audiophile definitions!

[djk]

I have no problem with correctly done wire wrap.

I own a rachet-type crimping tool. I have no problem with correctly done crimps on ring and fork terminals.

I have a problem with faston terminals. They just don't sound good for audio, period.

I used to be a Klipsch dealer and at one time I would have as many as six identical speakers lined up, each with a different mod to the wiring and/or crossover so I could do side-by-side listening with some of the best electronics money could buy.

[BEC]

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On 5/21/2005 9:23:08 AM djk wrote:

I have a problem with faston terminals. They just don't sound good for audio, period.

I used to be a Klipsch dealer and at one time I would have as many as six identical speakers lined up, each with a different mod to the wiring and/or crossover so I could do side-by-side listening with some of the best electronics money could buy.

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Dennis,

What quality of a faston terminal makes it sound bad?

Bob Crites

[djk]

My idea is that the faston at the driver connections moves a minute amount due to speaker induced vibration, and that this produces the low level noise/'grunge' that I hear.

At the time I was listening to the Pines of Rome on Cornwall IIs and the image kept pulling to one side in the midrange, even when it didn't 'pull' it sounded a bit out-of-focus.

These were a brand new pair.

I stopped and cut off all the fastons, and soldered the stock KSC wiring harness direct to all the drivers in one cabinet.

It sounded quite different than the other cabinet.

I did the other one of the pair and went back to my Pines of Rome. I found the difference in imaging, depth, and low level detail to be quite amazing for a basically free mod. Skilled soldering was required to prevent damage to the faston connectors staked in the diaphragm, they melted if you were not careful (my dealer cost on a tweeter diaphragm at that time was only about $4 so it wasn't a big deal, just a hassle).

[BEC]

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On 5/21/2005 10:26:14 AM djk wrote:

I did the other one of the pair and went back to my Pines of Rome. I found the difference in imaging, depth, and low level detail to be quite amazing for a basically free mod. Skilled soldering was required to prevent damage to the faston connectors staked in the diaphragm, they melted if you were not careful (my dealer cost on a tweeter diaphragm at that time was only about $4 so it wasn't a big deal, just a hassle).

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Dennis,

I repair a lot of tweeters for customers. The diaphragm mount with diaphragm pre-installed is now $118.00 from Klipsch. My independent supply of those at a better price now is gone. Very often someone melts that plastic housing trying to get rid of the faston connector. Pretty often they do that same thing to the K-53-K or K-57-K diaphragm assembly (also plastic). I would disagree with soldering (especially for someone not very good at soldering) to terminals not built to be soldered. They usually end up with a cold solder joint on the 12 awg or larger wire that they decided to use and melted plastic on the driver.

Bob Crites

[WMcD]

BTW, this started as some sort of comment on crossovers using mechanical connections. Please know I've got no gripe with that and certainly do not mean to imply there is anything wrong.

It seems that any means of connection can develop a problem. Others here have more commercial experience and I have a fair amount in an amateur sense.

I had a very nice, early, Sony FM Walkman. (A gift from a generous friend.) The earphone connection went bad. I found the soldered connection at the pc board had cracked. A touch up with a soldering iron solved it.

It was something I would not have believed unless I saw it. Solder on the spool seems very malliable and flexible. Yet here it broke like a brittle metal.

I also had a car with the Lucas "Prince of Darkness" electrical system. It lived up to reputation. The ignition switch went bad. No lights.

The trouble was not with a switch wiper contact. Rather there was a spot where two pieces of brass were butted up against each other and connected with a brass rivet.

Visually, it looked good. It was almost impossible to believe the results of a voltmeter. One piece of brass read 12 volts, the other read zero. This was despite the fact they were in good physical contact with a rivet, to boot.

Obviously a corrosion or lack of clean surface issue. None of this obvious even when taken apart. The brass was just a little dull.

Yup, I cleaned up the brass, tinned both sides, replaced the rivet with a copper, small nut and bolt and soldered the joint.

All the above is just to say that any type of connection can go bad during service life even when it functions well at the beginning.

Gil

[djk]

"I repair a lot of tweeters for customers. The diaphragm mount with diaphragm pre-installed is now $118.00 from Klipsch. My independent supply of those at a better price now is gone. Very often someone melts that plastic housing trying to get rid of the faston connector. Pretty often they do that same thing to the K-53-K or K-57-K diaphragm assembly (also plastic). I would disagree with soldering (especially for someone not very good at soldering) to terminals not built to be soldered. They usually end up with a cold solder joint on the 12 awg or larger wire that they decided to use and melted plastic on the driver."

Bob, I was refering to the K79 type tweeter, not the more expensive K77. Have you talked to Bill at Great Plains Audio? I would buy the nude diaphragm from him and insist on the customer returning the old carrier with the lead wire still on it. Institute a core charge.

I strip and tin the wire, bend a hook in the end, flatten it slightly with a pair on needle nose, hook it through the opening in the terminal, squeeze it tight, and then solder with a 33W iron with an iron plated 1/8" screwdriver tip. I never use bigger than 16ga, I see no point in it. If the terminal looks dirty I polish it with a Scotchbrite pad befor soldering it. I have never had a failure with this method. $300 will buy you a Metcal, the Rolls-Royce of irons (I have one at work if I need it). I use a $20 Radio Shack/Ungar at home.

[michael hurd]

I like to crimp with a good set of crimpers, solder with 60/40 resin core solder, then a thin heatshrink to form a good mechanical connection. A good crimp alone, is much better than a poor solder joint.

If you have ever repaired wiring on a transport that spends 90% of it's time bashing over potholes in the bush, you quickly learn what will stand up. Soldering will create a stress point where the solder ends in the wire, without using a thin heatshrink as a stress relief will cause it to fail.

Also, where I live, salt is used on the highways, like it were going out of style. This causes ground wires to corrode like crazy in your vehicle. Just some additional things to think about, every different application requires different techniques.

Wire for anti-lock brake sensors must be extremely flexible, otherwise it would fatigue and brake from repeated flexing. The actual conductors are very fine, multiple strands, rather than a few thicker ones.

As far as connectors go, there are many different grades, from junk to excellent. Better connectors are more robust, and feature brazed seams. Heatshrink also comes in many flavors, from thin and flexible sleeving to thick, adhesive lined heatshrink for large battery cables.