Lucar connector or soldered joints for drivers

[LostForWords]

Fostex drivers seem to have very flimsy connectors that are designed to accept lucar connectors. There may be other names for these connectors that I do not know, but the contacts are not very substantial. The problem is that soldering wire to these terminals could easily cause damage to the voice coil connections and result in solder being absorbed by the flexible braided wire going to the voice coil. This would clearly have an impact on the driver's performance. What do the experts use, if they want a non-permanent connection and is there a suitable silver-plated connector out there?

[kevinkr]

I always solder.. Just be quick about it and use only enough to fill the joint. My latest speaker project is based on Fostex FE167, and those lugs are really flimsy.

I think soldering is preferable to relying on a physical connector to maintain signal integrity long term in an application where there will be significant vibration or in our corrosive, polluted atmosphere.. (One less joint to fail, develop a high contact resistance or non-linearities due to oxidization.)

[planet10]

I always solder. I have never had a problem soldering, cleaning, resoldering on any of the Fostex terminals, and i'm surely into the hundreds & hundreds. Granted almost exclusively with single strands of Cat 5 cable.

One should consider the thin metal of the terminals an asset.

[markaudio]

Hi guys,
I recommend solder. However, there is the downside depending on cable size. Some DIYers have a desire to use thick cables (over 1.5-mm) which can be tricky to connect properly. It's easy to over-heat the driver's connector plate and distort its flying leads if the cables are over 1.5-mm dia.

I've attached a pic of my solder method for smaller drivers. I usually run the cable the full length of the connector but lately, I've opted for trimming the soldered cable section to around 5 to 6-mm. This is usually more than enough requiring less solder and less heating.

Using a non-toxic flux and "pre soldering" both cable and the driver's connector before making the final soldering improves the joint.

I usually stick with 1.0-mm cable and 1.5-mm for the larger drivers. I'm sourcing cable (mostly high grade OFC copper) from Germany or Japan. Soldering these cables is easy as they require little heating.

Here's my tips for making a connection to a driver:
1 - Stay with high quality cable and avoid Dia.'s over 1.5-mm if possible.
2 - Make sure cable and connectors are 100% clean.
3 - Pre - solder both cable and connector. Using flux is useful.
4 - Don't make the joint too big. I've suggested around 6-mm is more than enough in most cases.
5 - Apply just enough heat to run the joint, and no more. Otherwise you risk damaging the driver.

Interestingly, some of my Japanese friends are using very nice gold plated push-fit connectors. I'm interested in trying these. I'll see if I have time to post a pic.

Cheers

Mark.

[planet10]

Mark's soldering technique is similar to what i do... the wire i use being 0.57mm diameter thou (still, riding on the backs of billions of miles made for the computer industry, very pure copper)

dave

[markaudio]

Hi Dave,
Yes, even better. Any source for well insulated ultra-high grade OFC copper or silver cable (for those who like this alternative) that's 0.5 to 1.0-mm Dia should be an excellent choice.

There's been allot of recent chat on other threads about cable qualities and types. There's many choices which is nice.

I more keen to encourage DIYer's to stick with cable diameters less than 1.5-mm. I've witnessed too many damaged driver connector plates and buckled flying leads. Sad to see a nice driver ruined due to inappropriate cable size selection.

Cheers

Mark.