Wharfedale super 3 tweeter issue

[ThachNguyen]

I have just bought pair of very old speaker Wharfedale W90. This model was found in 1962 the sound of these speakers is amazing I love them very much especially the super 3 tweeter make me surprise! As model W90 the Wharfedale designed 2 super 3 tweeter per each, it's mean one side there are 2 woofers,2 mid-ranges,2 super 3 tweeters. When I hook these speakers with my Mcintosh MAC 1900 one super 3 tweeter woks normally(sound is loud as usually) but another super 3 tweeter is quieter. I decided to pull them out and I use Ohm metter measure both of them. The result I have the quieter one is 62 ohms or 70 ohms but the normal is only 6.2 ohms. My question is anyone can let me know what happened with the quieter one? And how can I fix it? I brought them in a specialist repair speaker near my town and the technician told me he had never seen this issue before. Do you think this super 3 tweeter the manufacturing designed like that? I mean 60 or 70 ohms? Any one can give me any advise? Please see my pictures for your reference. Thank you very much.

 

[doctorolds]

My only suggestion would be to re-solder the connections and test again???

 

[VanArn]

The voice coil wire is aluminium and the connection to the flexible braids at the eyelets on the cone can corrode, causing a high resistance to be read on the ohmmeter range. Repair requires a solder formulated to suit aluminium or a special flux. It is a skilled operation and the chances of burning the cone are very high.

 

[ThachNguyen]

My only suggestion would be to re-solder the connections and test again???

Thanks for your advise the man who tried help me to repair also assume same as yours idea. He suspects one of contact point doesn’t good contact but he didn’t know where. Thank you very much I will do it and let you know.

 

[ThachNguyen]

The voice coil wire is aluminium and the connection to the flexible braids at the eyelets on the cone can corrode, causing a high resistance to be read on the ohmmeter range. Repair requires a solder formulated to suit aluminium or a special flux. It is a skilled operation and the chances of burning the cone are very high.

Hi,

Yes, the man who tried to help me fix it he said same as yours. After he was solder again the resistance reduce from 56 ohms to 54 or 52 ohms. I believe you’re right and I will contact the guy who help me fix these give him yours idea. Any way thank you very much. I will let everyone know the result after then. Thanks for yours idea.

 

[ThachNguyen]

Hi,

Yes, the man who tried to help me fix it he said same as yours. After he was solder again the resistance reduce from 56 ohms to 54 or 52 ohms. I believe you’re right and I will contact the guy who help me fix these give him yours idea. Any way thank you very much. I will let everyone know the result after then. Thanks for yours idea.

I mean the guy help me to fix these he still not sure that caused of issue and he still sway that the right way to go to. I will give him your idea. Thanks.

 

[ThachNguyen]

The voice coil wire is aluminium and the connection to the flexible braids at the eyelets on the cone can corrode, causing a high resistance to be read on the ohmmeter range. Repair requires a solder formulated to suit aluminium or a special flux. It is a skilled operation and the chances of burning the cone are very high.

Hi VanArn,

The technician did exactly as you advised and the job is well done.

@everyone,

If you have the same issued with W90 supper tweeter like this please do exactly as VanArn advised then your supper tweeter will works. Again Thank you VanArn!