Ferrofluid or not? (1 Viewer)

[JonahWicky]

I'm researching tweeters for a pair of main speakers I want to build for a 100 watt/channel system. I'd say it's primarily for home theater, but I also want good music quality. It seems that most of the high-end tweeters are using ferrofluid, but one that I'm seriously considering (Vifa XT25TG30-04)touts "the absence of ferrofluid" as a plus. Now I'm confused!

What are the advantages or disadvantages of ferrofluid? How does it affect the sound quality? Does it present any special design considerations?

Any comments, opinions or experience are welcome. Thanks.

 

[Chu Gai]

Ferrofluid is a generic term for a fluid that is magnetic and is most often found in tweeters where it aids in thermal dissipation and can mitigate various mechanical resonances occurring at the fundamental frequency of the assembly.

In order for ferrofluid to be used, certain guidelines need to be adhered to. These include, but are not limited to, things like chemical compatability between the fluid and whatever it's in contact with, avoidance of putting materials that can cause the fluid to wick into it, adequate venting so that during large driver excursions the pressure doesn't cause the fluid to shoot out like the blow-hole of a whale, etc.

I haven't looked up the specs on the driver you mentioned but it may be that the material of construction precludes the use of ferrofluid. If so, then the manufacturer would say something like "contains no ferrofluid!". It's just a way to draw some attention, creative marketing if you will.

I'm sure you'll find a number of tweeters suitable for whatever project you're considering and I'd not get too hung up on whether the tweeter has it or doesn't. Certainly designing a good crossover will prove to be more challenging.

 

[Kenneth Harden]

Chu Gai said what I have heard.

All I can say is DON'T WORRY ABOUT IT!!!

However, personally, I seek 'bullit proof' gear, and ferrofluid certainly helps.

 

[Chuck Kent]

If memory serves, until we had ferrofluid, tweeters weren't nearly as rough and tough as they are today. I myself lost a few tweeters many years ago. For me, I consider it a plus (but as Chu Gai notes, there are other things that also matter too.)

 

[John Garcia]

What are you using for a x-over, as this is EXTREMELY important to consider when selecting a tweeter. The crossover and relationship between the drivers play a huge role in the sound of a speaker.

Have you built your own speakers before?

Price range?

 

[JonahWicky]

To answer your 2nd question, no, this is my first adventure into speaker building. From my research so far I know that the crossover is the key to making a speaker system work. My plan is to start by replacing the tweeters in a vintage 1970s pair of Genesis IIs and experiment with a crossover for them. Eventually, I'd like to build system from scratch.

I'd appreciate any suggestions.

 

[Steve Lumbert]

Vifa drivers are excellent. I wouldn't let their lack of ferrofluid be an issue.

 

[John Garcia]

Loudspeaker Design Cookbook by Vance Dickason is a good place to start.

Next suggestion might be the DIY section here on HTF and possibly starting with a kit speaker, possibly one like those available here. Take a look at the A/V-1, A/V-2 and A/V-3.

Vifa drivers are definitely good stuff.