Looking for some advice on either a diy or pre-made dust cap. The hole is 1 inch, the outer "flared" part seen is 1-1/4 inch diameter.
Thanks in advance!
Thanks in advance!
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Sort of sideways: One of these might work:
http://www.planet10-hifi.com/downloads/B200-phase-plug.pdf
http://www.planet10-hifi.com/downloads/FE16x-PhasePlugs.pdf
dave
http://www.planet10-hifi.com/downloads/B200-phase-plug.pdf
http://www.planet10-hifi.com/downloads/FE16x-PhasePlugs.pdf
dave
Awesome, thank you guys! So basically, what I'm getting is that anything that fits, it's ok to use?
These look pretty sharp but, I'm not getting how these are installed and then, the bottom part of the plug has screws for magnetic mounting to what? I'm a bit confused as I thought any cap would be glued to the cone or coil and would move along with the cone. I appreciate your input, thank you!
Screws get sucked to the pole piece which is a magnet. You have done the hard part, losing the dustcap.
dave
dave
I figured that but then, you still have a gap since the cone and coil need to move. I thought the point was to eliminate any gaps to prevent dust from getting in?
Basically, yes. In many applications the dust cup doesn't make much difference, especially if it's small. If you want it to be closer to the way it was, you can try to match the dust cap material (paper, plastic, etc.).
In some cases you'll run across a vented cap (one that has or is made of a mesh material), but I don't think they are as common in smaller drivers. That could affect cooling.
For some drivers that cover a very wide frequency range the dust cap material and shape can make a difference, but it's not likely to be an issue in your case since you have a tweeter covering the high frequencies. And the effect is typically going to be small even when there is a difference.
Most people just replace the cap and go on their merry way without a second thought about it.
You do take the chance of dust. But how often is that ever an issue? Not often at all IME.
dave
Phase plug looks cool but i really do not know what they are doing? Some dust caps are very flimsy and some are very stiff, and some are small and some are large, some are air tight and some are not, if not sure what you want or what is best then stick to something that is most close to the original
Maybe contact JM lab and ask for the original dust cap.
However I would take a dust cap of similar size like the old one and if it was plastic I would try to find if same material
However I would take a dust cap of similar size like the old one and if it was plastic I would try to find if same material
As far as I know the original dustvap of the Focal/JMl is coated cloth of some 35 mm dia. The dustcaps displayed on the on the sales sites are most either (hard )paper or way too large cloth.
Do not use any of these: you may ruin the smooth performance of this midwoofer with its well damped plastic cone because if the serious break up of these large dustcaps. What you need is either doped cloth or soft supronyl of the same 35 mm dia. Hard dustcaps are a no go.
Do not use any of these: you may ruin the smooth performance of this midwoofer with its well damped plastic cone because if the serious break up of these large dustcaps. What you need is either doped cloth or soft supronyl of the same 35 mm dia. Hard dustcaps are a no go.
http://www.troelsgravesen.dk/JA8008.htm
"Quite some work went into the dust cap. Should it be paper, fabric or a phase plug? Should the dust caps be coated or non-coated, etc.? All these possibilities were tried for measuring performance and evaluated sonically by setting up the drivers in the TQWT cabinet and listening to a wide range of music. Last but not least a thick felt ring was added to the pole piece and this required SEAS to have special tools made for punching out these felt pads.
The phase plug did not measure better or sound better than the domes and eventually a non-coated paper dome was chosen for having a more vivid upper mid. The coated fabric dome sounded a bit dull in comparison. All in all hard choices as the sonic differences were surprisingly small."
"Quite some work went into the dust cap. Should it be paper, fabric or a phase plug? Should the dust caps be coated or non-coated, etc.? All these possibilities were tried for measuring performance and evaluated sonically by setting up the drivers in the TQWT cabinet and listening to a wide range of music. Last but not least a thick felt ring was added to the pole piece and this required SEAS to have special tools made for punching out these felt pads.
The phase plug did not measure better or sound better than the domes and eventually a non-coated paper dome was chosen for having a more vivid upper mid. The coated fabric dome sounded a bit dull in comparison. All in all hard choices as the sonic differences were surprisingly small."
