Specifically drilling out the pole piece.
I've never drilled out a pole piece before, although I have once tried to do this on a Realistic dome midrange.
I've had these tweeters on the shelf almost forever [ Dick Smith sell-out almost 25 years ago] and while they are OK as-is; I'd like to see if I can drop the Fs down a bit from 1100hz.
I've got a 6mm Cobalt drill bit waiting but I'm wondering if I should try and go bigger?
I'm also wondering how best to do the rear damping and the easiest way to fix a cup to the back; I've got some screw-top plastic lids that could be made to fit but LDPE isn't easy for me to glue. Next in line would be scrap of MDF with a hole gouged out. I did think about a small cat food tin epoxied on but I thought that adding a steel cap to the rear was probably not the best idea.
EDIT
Just wondering now if drilling all the way through is needed or if just drilling down enough to stuff some long fibre wool inside would be sufficient?
I've never drilled out a pole piece before, although I have once tried to do this on a Realistic dome midrange.
I've had these tweeters on the shelf almost forever [ Dick Smith sell-out almost 25 years ago] and while they are OK as-is; I'd like to see if I can drop the Fs down a bit from 1100hz.
I've got a 6mm Cobalt drill bit waiting but I'm wondering if I should try and go bigger?
I'm also wondering how best to do the rear damping and the easiest way to fix a cup to the back; I've got some screw-top plastic lids that could be made to fit but LDPE isn't easy for me to glue. Next in line would be scrap of MDF with a hole gouged out. I did think about a small cat food tin epoxied on but I thought that adding a steel cap to the rear was probably not the best idea.
EDIT
Just wondering now if drilling all the way through is needed or if just drilling down enough to stuff some long fibre wool inside would be sufficient?
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I'm guessing the area within the tape is the gap and the rear volume? Note that if the rear enclosure is small, you won't so much need stuffing as modes won't develop, so if you enlarge it, you will. Efficiency may go down.
It's to mate to the small Peerless 830656 so if a little less efficient I won't need so much padding down.
Still debating with myself on using these crossed at 3k [ although I've had success in the past] or just buying something better from SBA
Still debating with myself on using these crossed at 3k [ although I've had success in the past] or just buying something better from SBA
I did it, see here:
https://www.diyaudio.com/community/threads/seas-tweeter-pole-piece-drilling.372405/
I don't recommend installing a "cup", because you create a helmholtz resonator. But I found adding a long, dampened "aperiodic" chamber was improving things, see post #45.
https://www.diyaudio.com/community/threads/seas-tweeter-pole-piece-drilling.372405/
I don't recommend installing a "cup", because you create a helmholtz resonator. But I found adding a long, dampened "aperiodic" chamber was improving things, see post #45.
