Any drawbacks to using ferrofluid in a low-excursion woofer? - diyAudio
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Old 9th December 2006, 03:55 AM   #1
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Default Any drawbacks to using ferrofluid in a low-excursion woofer?

Or retrofitting a pro woofer (of course the excursion would be kept in check)...

Power compression should be reduced, at least.
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Old 9th December 2006, 05:07 AM   #2
infinia is offline infinia  United States
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Hi
Unless it's used in a low power midrange the fluid would get blown out of the gap reducing the heat flow benefits of the oil itself. Unless you could ensure this from happing ... I'm really not sure what you are asking/ getting at. Seems most VC power is dissipated by the air flow across the coil and former itself, so wouldn't it be a net loss if using oil for this application as it would block air movement. But like anything else it depends upon all the other factors/details as well?
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Old 9th December 2006, 07:28 AM   #3
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Unless there is inherent forced-air cooling (such as the dust cap forcing air through notches/vents in the pole piece of JBL's VGC woofers), ferrofluid should conduct heat away from the voice coil much more efficiently, since the thermal conductivity of air is less than almost anything except other gases.
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Old 9th December 2006, 12:23 PM   #4
infinia is offline infinia  United States
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A wise man once said "Identify and characterize a problem before you attempt to solve it".

I think this is more complicated than I know how to handle with out empirical data. As you pointed out movement might be a problem here. Possibly adding shearing forces to the oil and it's solid content perhaps reducing it's effectiveness. It's benefits to tweeter design is well known allowing the VC and former to be lighter at higher power levels.

Thermal compression is the problem then devise a test to see how bad it is and if the oil can be a solution indeed.
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Old 9th December 2006, 12:48 PM   #5
sreten is offline sreten  United Kingdom
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Hi,

My observation is that if something works people do it.

Ferrofluid damped woofers don't exist, tells me it doesn't work.

/sreten.
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Old 9th December 2006, 01:14 PM   #6
infinia is offline infinia  United States
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Quote:
Originally posted by sreten
Hi,

My observation is that if something works people do it.

/sreten.
Good thing the innovators don't think like this, else we all would be living like the Amish.
Maybe not a bad thing (Amish) on the other hand.
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Old 9th December 2006, 01:37 PM   #7
AKN is offline AKN  Sweden
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Hi,

I know at least one pro audio manufacturer who uses ferrofluid in their woofers namely Community.

Se for example this Pro sub:
http://www.community.chester.pa.us/f...34e616cc06391f

Would be interesting to see their solution in more detail.
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Old 9th December 2006, 03:40 PM   #8
sreten is offline sreten  United Kingdom
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Quote:
Originally posted by infinia

Good thing the innovators don't think like this, else we all would be living like the Amish.
Maybe not a bad thing (Amish) on the other hand.
You misunderstand, there were plenty of attempts to make FF woofers, /sreten.
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