So I had a look and was able to pull off the rubber boot. And put it back on. So playing here doesn’t cause any irreversible damage. I tried measuring the boot thickness and it’s difficult due to the presence of a lip and I lent out my calipers so they are not around. It looks to be about 2 mm thick. So it’s not going to save much space but it’s easy to take off and put back on should there be a need.
Agreed.
Yes, I noticed that, too. Fix one problem, create another. I guess more measurements will tell us which way is the best to go.
Right. The ER15 has a much more open rear side. Although the ER15 speaker is more of a cheap option for other people. I’ll put more time into optimizing the W16 version.
I understand how the stuffing influences the location/frequency and the height of the big impedance peak. But does the blob of increased resistance at the lower frequencies (e.g., 30-60 Hz) bother you or signal anything too bad?
At this point, I think that I have a straightforward plan:
-Remove the rubber boot from a W16 woofer
-Add felt around the top side of the magnet, at least as much as I can fit on there.
-Keep the Whispermat in the cabinet
-Retake frequency and impedance measurements for the “revised” speaker in which the boot is removed and the Whispermat is present.
-Compare these new measurements with the old measurements for which the rubber boot is present and the Whispermat is absent.
-Pick whichever set of measurements look better and go to the crossover design from there.
-I will also retake measurements of the ER15 speaker with added felt on the magnet and Whispermat at the back of the cabinet.
For perspective, here are those photos. You can see how little space there is between the driver hole and the inside cabinet edge. Almost no clearance, just a few mm’s.
This photo is dark but you can see how wide the W16 driver is relative to the flange and such. A piece of Whispermat is also placed there showing that you can’t get the driver into the cabinet with anything added to the magnet.
I tried squeezing this arrangement in but no go.
Here you can see the Whispermat thickness relative to the cabinet and an ER15.
Here is a photo showing the Whispermat at the back of the cabinet.
Agreed.
Yes, I noticed that, too. Fix one problem, create another. I guess more measurements will tell us which way is the best to go.
Right. The ER15 has a much more open rear side. Although the ER15 speaker is more of a cheap option for other people. I’ll put more time into optimizing the W16 version.
I understand how the stuffing influences the location/frequency and the height of the big impedance peak. But does the blob of increased resistance at the lower frequencies (e.g., 30-60 Hz) bother you or signal anything too bad?
At this point, I think that I have a straightforward plan:
-Remove the rubber boot from a W16 woofer
-Add felt around the top side of the magnet, at least as much as I can fit on there.
-Keep the Whispermat in the cabinet
-Retake frequency and impedance measurements for the “revised” speaker in which the boot is removed and the Whispermat is present.
-Compare these new measurements with the old measurements for which the rubber boot is present and the Whispermat is absent.
-Pick whichever set of measurements look better and go to the crossover design from there.
-I will also retake measurements of the ER15 speaker with added felt on the magnet and Whispermat at the back of the cabinet.
For perspective, here are those photos. You can see how little space there is between the driver hole and the inside cabinet edge. Almost no clearance, just a few mm’s.
This photo is dark but you can see how wide the W16 driver is relative to the flange and such. A piece of Whispermat is also placed there showing that you can’t get the driver into the cabinet with anything added to the magnet.
I tried squeezing this arrangement in but no go.
Here you can see the Whispermat thickness relative to the cabinet and an ER15.
Here is a photo showing the Whispermat at the back of the cabinet.
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