It went very well, I didn´t bother to powder the table.
Should have had assistance though, got some folds in the middle so the membrane is effectively 158 mm high, it´ll do
.
Resistance is 6,7 ohms!
Weight is 4,7 grams but the membrane is 10 % too long now.
Maybe it´ll be just above 4 grams when cut to right size.
Again, the area is 960 square centimeters so there´s no need to worry about the hf response.
On the contrary, it might be good to have that weight when it comes to the lf response.
I will still apply the cotton threads for the suspension and then a second layer of film on the aluminium side as well. So maybe the membrane will weigh some 6 grams.
I´ll know in a short while...
Should have had assistance though, got some folds in the middle so the membrane is effectively 158 mm high, it´ll do
.Resistance is 6,7 ohms
!Weight is 4,7 grams but the membrane is 10 % too long now.
Maybe it´ll be just above 4 grams when cut to right size.
Again, the area is 960 square centimeters so there´s no need to worry about the hf response.
On the contrary, it might be good to have that weight when it comes to the lf response.
I will still apply the cotton threads for the suspension and then a second layer of film on the aluminium side as well. So maybe the membrane will weigh some 6 grams.
I´ll know in a short while...
AMT playing
The suspension was a little tricky to apply, but I managed in the end.
I think I have some work to do on that:
Anyway, AMT is playing. Some resonanses in the low but from 300 Hz there´s usable output.
A couple of dBs rise per octave up to 13 kHz where acoustic lense of 3 mm makes the directional output drop.
It´s a totally different soundstage compared to my focused line arrays
Next step is to come up with a better solution for the suspension, hopefully the resonances in the low will be fewer, and build a complete pair.
The suspension was a little tricky to apply, but I managed in the end.
I think I have some work to do on that:
Anyway, AMT is playing. Some resonanses in the low but from 300 Hz there´s usable output.
A couple of dBs rise per octave up to 13 kHz where acoustic lense of 3 mm makes the directional output drop.
It´s a totally different soundstage compared to my focused line arrays
Next step is to come up with a better solution for the suspension, hopefully the resonances in the low will be fewer, and build a complete pair.
The bad lf response is probably due to that the membrane is too stiff in the folds.
So I´ll make the next membrane with only one film layer.
The suspension will be from the middle of each pleat, so there will be a second layer on that pleat.
Also I will try to remove the glue in the folds, I noticed that it accidently came off in some folds when I did the first membrane.
I don´t know if the hf response is desirable or not.
I guess I´ll know better when I have a stereo pair.
So I´ll make the next membrane with only one film layer.
The suspension will be from the middle of each pleat, so there will be a second layer on that pleat.
Also I will try to remove the glue in the folds, I noticed that it accidently came off in some folds when I did the first membrane.
I don´t know if the hf response is desirable or not.
I guess I´ll know better when I have a stereo pair.
"The suspension will be from the middle of each pleat, so there will be a second layer on that pleat."
I´ll change the suspension to having pieces of yarn on both sides of the membrane at the top and bottom. That ought to keep the membrane centered but still allow the membrane some sideways movement, especially a bit in the membrane.
The yarn has to be supported at the bottom of course, perhaps with some tape.
I´ll change the suspension to having pieces of yarn on both sides of the membrane at the top and bottom. That ought to keep the membrane centered but still allow the membrane some sideways movement, especially a bit in the membrane.
The yarn has to be supported at the bottom of course, perhaps with some tape.
So I did a new membrane with another alu/paper combo (see båndsei´n thread for picture). Film only on one side.
It´s 10 um aluminium and the finished membrane´s resistance is below 4 ohms.
The new membrane weighs 8,12 grams.
The alu weighs 56 % of the total alu/paper weight.
So I guess it´ll be under 5 grams if I can peel the paper off.
It´s 10 um aluminium and the finished membrane´s resistance is below 4 ohms.
The new membrane weighs 8,12 grams.
The alu weighs 56 % of the total alu/paper weight.
So I guess it´ll be under 5 grams if I can peel the paper off.
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