Unwanted Speaker Noise - How to Eliminate???

[lakehaus]

I am experimenting with different 12" speakers for a newly acquired Clark 5E3 18w combo.

I've tried:

* Fender labeled Emi ceramic
* Celestion G12M Greenback
* Celestion Alnico Blue
* Jensen Vibranto ('69) ceramic


So far, the Jensen is kickin' butt, but unlike the others (all newer), it's making an all too familiar noise - which none of the others make - like an insufficient ground noise. If I touch the guitar strings, the noise is diminished greatly but not completely.

When I was checking my connections on the speaker (old screw-on type), they were solid, but discovered that when I touched both + & - posts on the speaker simultaneously, that irritating noise completely disappeared - only to return once I removed contact (fingers) from one or both posts.

Any ideas of what I can do to eliminate the noise completely?

[billyz]

Older Jensens have the polarity reversed. So first check the polarity with a 9 v battery. Positive to positive will move the cone out. Secondly, It may be that the negative terminal is or is not grounded to the speaker frame. If it is not try grounding the frame. If it is try lifting the ground to the frame.

[lakehaus]

Thanks Billyz - I'll give your advice a shot and see what happens...