Don't us it. Giving up a little symmetry for more compliance is ok but with 0.3mm
we are begging for high distortion.
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I have recently moved from the inner city to the adelaide hills (15km from the CBD) where I have a few acres of land, never been happier with big sheds and a free standing music room with horns hanging out the back
copper will form a shorting ring?
horns down to 100Hz that actually *reach* 100Hz will have a rather large mouth?
Afaik for low frequencies the expansion rate of the throat area, +/- say 15-20% probably will have very little effect.
What might be very cool is a manifold with 3-4 of these 370 type drivers output combined at the input of a nifty LF horn... that ought to have some decent "jump factor"....
Fwiw, as a side note, personally I have reservations about xover points in the upper midrange, lower HF...
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horns down to 100Hz that actually *reach* 100Hz will have a rather large mouth?
Afaik for low frequencies the expansion rate of the throat area, +/- say 15-20% probably will have very little effect.
What might be very cool is a manifold with 3-4 of these 370 type drivers output combined at the input of a nifty LF horn... that ought to have some decent "jump factor"....
Fwiw, as a side note, personally I have reservations about xover points in the upper midrange, lower HF...
_-_-
I was on the phone with Dietmar on Wednesday and I ask him our questions
in the Analog Forum. He has used 0.15mm paper as a spacer.
Did you notice a sonic improvement with Aquaplase?
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I don't know Bear, I think it would be a little to far away from the
air gap to have a significant effect.
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Why not invite Dietmar to come here in person? Assuming his english is passable, or else he can use one of the translate programs, etc... it would be nice to have him in person!
But I am unclear on what the great benefit of the spacer is WRT to the improved flatness and extension in the LF response? I understand it will improve the max SPL at low frequencies, but it ought not substantially effect the frequency response?
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But I am unclear on what the great benefit of the spacer is WRT to the improved flatness and extension in the LF response? I understand it will improve the max SPL at low frequencies, but it ought not substantially effect the frequency response?
_-_-
Why not invite Dietmar to come here in person? Assuming his english is passable, or else he can use one of the translate programs, etc... it would be nice to have him in person!
_-_-
I put this line before him. Let's see.
I don't think the primary reason is to achieve more excursion. This benefit would
not come to play until an already to high spl would make our ears bleed in our
listening room. Max achievable excursion would by itself not exhibit an
extended low frequency.
What does benefit from the spacer though is that FS is lowered simply because
the spacer claps the surround more on the outside and thus is equivalent to a softer surround.
Just for illustration I will post the corresponding picture again.
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I highly doubt that the spacer is changing the fs because of the difference in clamping changing the properties of the surround. More likely is that you have changed the acoustical loading of the diaphragm by increasing the air volume between the diaphragm and the phase plug. I can see how you would increase the excursion limit as at those frequencies below a couple hundred cycles any increase in distance will help before you hit the phase plug with the diaphragm. I can't imagine that the upper limit is very high before you run out of excursion but I guess in your homes that is enough for you to do what you are trying to do.
Two drivers working in parallel seems to be a better choice than trying to use the spacer but then you have to design a throat that will combine the two sources together without other problems.
Two drivers working in parallel seems to be a better choice than trying to use the spacer but then you have to design a throat that will combine the two sources together without other problems.
Did you get the ones for $33. The guy selling them said he just cleaned the
one showing on the first picture. The others look really horrible.
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hi Kindhornman,
actually if he wouldn't have put another spacer on top of the diaphragm, it
would have decreased the air volume between the dia and the phase plug
as the dia moves up while the phase plug stays in place.
But since he used the same spacer on top of the diaphragm, the housing
of which the phase plug is a part of moves upwards accordingly and thus
the distance of the dia to the phase plug stays the same. Just as the stock driver.
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To be able to go all the way down to 100hz I wanted to know how much a steep high pass filter was reducing the 2nd an 3rd harmonics.
Dietmar said he had not done any direct comparsion with steep fliters, but
he had two measurements done with his Vitavox GP1. Fist with no crossover.
second with 12db oct high pass at 200hz.
Dietmar said he had not done any direct comparsion with steep fliters, but
he had two measurements done with his Vitavox GP1. Fist with no crossover.
second with 12db oct high pass at 200hz.
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Okay Radian,
I took another look at the picture and see what you are saying. That is not something you can normally do as the surround is usually a part of the holder that mounts the diaphragm assembly. I see also that the picture shows the shim as having a larger inside diameter which explains the notion that you are changing the suspension. How is that diaphragm made that it is a loose part like that, it doesn't have a permanent annular plastic mounting section?
I took another look at the picture and see what you are saying. That is not something you can normally do as the surround is usually a part of the holder that mounts the diaphragm assembly. I see also that the picture shows the shim as having a larger inside diameter which explains the notion that you are changing the suspension. How is that diaphragm made that it is a loose part like that, it doesn't have a permanent annular plastic mounting section?