I am considering using high quality spade lugs for connecting the drivers on my next build & wonder if anyone has any thoughts about this vs soldering the wire to the driver lugs. On my Sonus Faber Cremona speakers, the wires are soldered to the speaker lugs & just looking at them got me thinking. The wires used are maybe 10gauge & seeing the way they are soldered revealed what a small contact area there is. I am looking to use large wire & think I can get a better connection with a good quality spade lug. At least more contact area. It may sound like overkill, but I'm all about doing every little thing that I can if i think it will make a difference in the final product. BTW the lugs on my Scanspeak woofers are pretty broad, both of them.
Thanks,
Kev
Thanks,
Kev
Speakers are sometimes listened to at .5 vac or less, and that low energy signal can have trouble breaking through oxide on tin brass & copper surfaces.
The crimp end of spade terminals from AMP, T&B, Panduit, 3M, Ideal, is totally reliable, if it passes the pull test. The crimp excludes oxygen, making the copper wires a semi-solid mass. The other end? If you really mean spade or ring terminal, you can drill a hole through the driver blade & hold the terminal down with a #4 screw and nut. The screw pressure on the two surfaces also excluded oxygen. I supervised a test system in a factory that used 12 v signals to connect computers, and the crimp spade terminals under screws of barrier strips were totally reliable the decade I worked there. BTW on a vibrating driver, I'd use elastic stop nuts to prevent loosening. mcmaster.com grainger & fastenal are sources of boxes of 50 or 100.
If the terminal you are suggesting is actually a push on flag terminal, like .250" flag terminals, the the spring force of the female terminal is not high enough IMHO to exclude oxygen. Lots of drivers use push on terminals, usually .110" flags, and I've never had trouble with them. But in a car where those drivers were salvaged from, I never listen to the radio at a tenth watt.
The crimp end of spade terminals from AMP, T&B, Panduit, 3M, Ideal, is totally reliable, if it passes the pull test. The crimp excludes oxygen, making the copper wires a semi-solid mass. The other end? If you really mean spade or ring terminal, you can drill a hole through the driver blade & hold the terminal down with a #4 screw and nut. The screw pressure on the two surfaces also excluded oxygen. I supervised a test system in a factory that used 12 v signals to connect computers, and the crimp spade terminals under screws of barrier strips were totally reliable the decade I worked there. BTW on a vibrating driver, I'd use elastic stop nuts to prevent loosening. mcmaster.com grainger & fastenal are sources of boxes of 50 or 100.
If the terminal you are suggesting is actually a push on flag terminal, like .250" flag terminals, the the spring force of the female terminal is not high enough IMHO to exclude oxygen. Lots of drivers use push on terminals, usually .110" flags, and I've never had trouble with them. But in a car where those drivers were salvaged from, I never listen to the radio at a tenth watt.
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Some good input from indianajo, I agree it is about biting in for a gas-tight seal.
Even if it were about resistance, wire is not like a garden hose where a single point of restriction will reduce the entire flow.
How about adding some carbon conductive grease to the spade to exclude oxygen and improve contact.
Dielectric (non-conductive white silicone) grease (AKA heatsink grease) is also good for that provided the contact bites. It's commonly used for automotive contact corrosion protection. There's no need to improve conductivity, just maintain it.
Use Blackburn/Contax or similar Oxide inhibitor, it's been used for decades for the purpose of preventing oxidation in eletircal connections, and designed for that specific purpose.
A crimp only somewhat limits oxidation on the exct point it contacts the conductor and makes a mark in it. The best crimp connectors are meant to be used with octagonal crimp pliers, and not the usual plastic insulated ones.
Solder is not a ideal connection, it is good for sealing the conductor again to prevent oxidation, after you make a proper physical connection, and it is fairly easy to remove and redo if desired.
It is all very basic electircal connection logic, nothing new or special about it.
Crimp on connectors work fine, but they leave something to be desired when it comes to oxidation.
A crimp only somewhat limits oxidation on the exct point it contacts the conductor and makes a mark in it. The best crimp connectors are meant to be used with octagonal crimp pliers, and not the usual plastic insulated ones.
Solder is not a ideal connection, it is good for sealing the conductor again to prevent oxidation, after you make a proper physical connection, and it is fairly easy to remove and redo if desired.
It is all very basic electircal connection logic, nothing new or special about it.
Crimp on connectors work fine, but they leave something to be desired when it comes to oxidation.
A crimp holds the wire better than a soldered joint.
However if you solder it that is fine so long as the wire is supported so it cant move around and eventually fracture the joint.
However if you solder it that is fine so long as the wire is supported so it cant move around and eventually fracture the joint.
In military aircraft, rockets, space craft, submarines, and naval ships, the only place you will find a soldered connection is on a printed circuit board (except for a few rare exceptions). All other wire connections and joinings are of a crimp-type connection. This covers frequencies from DC to gHz, and current from micro-amps to 1000's of amps.
In military equipment, MTBF is low, they have to do the maintenance work very often, so crimping is convenient.
I remember the F16 radar maker advertising in Flight magazine that MTBF was now 60 hours. 1980s...
Atmospheric corrosion also affects the performance.
Use a good gas tight high quality crimp lug that will be of pure material, and hold its tension for decades.
Otherwise, solder it in, no chance of vibration induced loosening, which is going to happen in a speaker, if not very well done.
And of course, use some stress relief, so that pulled wires do not strain the joints, some sort of grommet, cable tie, whatever.
I remember the F16 radar maker advertising in Flight magazine that MTBF was now 60 hours. 1980s...
Atmospheric corrosion also affects the performance.
Use a good gas tight high quality crimp lug that will be of pure material, and hold its tension for decades.
Otherwise, solder it in, no chance of vibration induced loosening, which is going to happen in a speaker, if not very well done.
And of course, use some stress relief, so that pulled wires do not strain the joints, some sort of grommet, cable tie, whatever.
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Thanks for all the info. They are .25" flag terminals on my speakers. Are there any particularily superior push on connectors?
Kev
Not really other than sticking with industrial proven name brands [T&B, etc.]; with spade connectors it's normally better to seal them with a special conductive paste, though some folks feel it's sufficient to just use heat shrink tubing: CTB8 Thomas & Betts Contax Oxide Inhibiting Compound, 8-Oz
When I was trained to solder the traditional way. they weren't exclusive. You make your mechanical joint first then solder as additional protection. Modern automatic soldering methods are in violation of this.
+1 I've posted a number of times on similar threads that in UL/CSA testing of all size, manner of wire terminations that a proper crimp is superior and that connecting hardware be ring tongue with the appropriately torqued bolt size, flat, lock washer.
+1 and from habit started to post that the above spade connection be silver soldered for sealing, but in recent decades there's been such an increasing resistance to soldering in manufacturing due to cost, decided to post the mil-spec requirement.
Industrial brands flag terminals are in post 2. AMP is now TE Connectivity, if they haven't changed it again. it's been a whole year since the last change.
Dorman brand is pretty good, at auto supplies. IE they don't melt out at 30 amps the way radio shack & other ****ese brands do.
Dorman brand is pretty good, at auto supplies. IE they don't melt out at 30 amps the way radio shack & other ****ese brands do.
MTBR, not MTBF. But you can bet your sweet *** they aren't replacing wire connectors that often.
The humans seem to have gotten lost in this discussion. Not me to forget, that's what I've done for a living.
There are a whole bunch of ways an amateur can screw up spade lug work - including breaking the terminal block as the final step*. 63 years modifying motorcycles and cars... DAMHIK.
With soldering, when the connection looks right and seems shiny, I think you can be fairly confident it is just fine for connecting stuff in and around speakers.
B.
* or would you call mixing up the terminals in a dark speaker enclosure the last step?
There are a whole bunch of ways an amateur can screw up spade lug work - including breaking the terminal block as the final step*. 63 years modifying motorcycles and cars... DAMHIK.
With soldering, when the connection looks right and seems shiny, I think you can be fairly confident it is just fine for connecting stuff in and around speakers.
B.
* or would you call mixing up the terminals in a dark speaker enclosure the last step?
My point was that military equipment needs frequent maintenance, so connectors are easy to use, say to swap out parts, the bad ones go to repair.
That is done by trained specialists.
Soldering would take too much time, and risk damage if done frequently.
In a speaker, that does not happen.
So, if you can source really good connectors, go ahead.
But if you get poor ones, solder is better.
That is done by trained specialists.
Soldering would take too much time, and risk damage if done frequently.
In a speaker, that does not happen.
So, if you can source really good connectors, go ahead.
But if you get poor ones, solder is better.