dshoaf
That high voltage buzz
Been this this mountain a couple of times with some SMG 2s and 3's. Had all of Bighahuna's experiences. What help me was to use some large diameter fender washers to hold the ends of the bass panel wires down as I was gluing them into place. This was after the cleaning of the old glue material had been completed. I, too, initially didn't clean enough of the old glue first and had it mixing in with the new glue.
Fender washers should be steel so they'll use the magnets behind the panel to be pulled down onto the mylar panels. This keeps the end of the wires held down while the new glue dries. Once they're in place, remove the washers and apply glue to the empty spots so the wires don't buzz. Once the ends were re-glued back down, I went through the middle bass sections to be sure the wires didn't have gaps. Before I buttoned them up, I also ran a frequency sweep with an audio signal generator driving a power amp. This allowed me to find any specific frequency where a partially delaminated wire would start vibrating.
On the tweeter wires, I used the same fender washers as the new wires went back down. This allowed me to keep the wires in place as I strung them back and forth on the panels. I could keep the wires taught and positioned over the magnets. When gluing them up, I started in the middle of the panels and worked my way to the outside edges to keep those itty bitty wires from bunching up and causing the same buzzing problem.
Lastly, with all the fumes, I did all my work outside the garage door. Here the problem was debris from a tree and some wayward insects caused a bit of problem during the gluing process.
All the speakers were reworked with new crossover caps and socks. They're now residing somewhere in the SF Bay Area with happy owners. Agreed, add lots of power and they will stand up and sing. I used 250 wpc Hafler amps to get that job done.
Enjoy! Its a fun, somewhat messy but satisfying project and the factory is just excellent for support for 40 year old speakers.
Cheers,
David
Fender washers should be steel so they'll use the magnets behind the panel to be pulled down onto the mylar panels. This keeps the end of the wires held down while the new glue dries. Once they're in place, remove the washers and apply glue to the empty spots so the wires don't buzz. Once the ends were re-glued back down, I went through the middle bass sections to be sure the wires didn't have gaps. Before I buttoned them up, I also ran a frequency sweep with an audio signal generator driving a power amp. This allowed me to find any specific frequency where a partially delaminated wire would start vibrating.
On the tweeter wires, I used the same fender washers as the new wires went back down. This allowed me to keep the wires in place as I strung them back and forth on the panels. I could keep the wires taught and positioned over the magnets. When gluing them up, I started in the middle of the panels and worked my way to the outside edges to keep those itty bitty wires from bunching up and causing the same buzzing problem.
Lastly, with all the fumes, I did all my work outside the garage door. Here the problem was debris from a tree and some wayward insects caused a bit of problem during the gluing process.
All the speakers were reworked with new crossover caps and socks. They're now residing somewhere in the SF Bay Area with happy owners. Agreed, add lots of power and they will stand up and sing. I used 250 wpc Hafler amps to get that job done.
Enjoy! Its a fun, somewhat messy but satisfying project and the factory is just excellent for support for 40 year old speakers.
Cheers,
David
