All systems go !
All systems go !
DRIVE UNITS BY MANUFACTURER:
FFAPG O87
APG O87, an ester based fluid with a saturation of 250 Gauss and a viscosity of 750 centipoise. Made by Ferrotec USA.
Other available formulations, contact us for details:
CDF 2250 (Ester based): 220 Gauss, 500 cP
APG 1134 (Hydrocarbon): 220 Gauss, 1000 cP
There is over 100 grades of ferrofluid; the above are the most common specific fluids used by major drive unit manufacturers
Beware: some unscrupulous sellers are offering the cheap, commonly available science project type ferrofluid as an audio product. This results in an unpredictable / overdamped output and can soften drive unit adhesive - always double check the origin and the specification.
Ferrofluid is a cooling / damping compound used in the magnetic gap of many tweeters to increase power handling and smooth out the frequency response; it has a tendency to thicken with age, gradually reducing tweeter output to zero. Many old tweeters from the 1980s/90s can be restored to perfect working order by carefully dismantling and cleaning out the old coagulated fluid then replacing with fresh.
This refill kit comprises a high accuracy syringe pre-filled with Ferrofluid specifically formulated for high fidelity tweeter application. There is sufficient in the syringe for 2 tweeters & a micro applicator nozzle is supplied.
Willys-Hifi Ltd, the UK speaker specialist.
Helpline 01702 523999
Excellent product, what a difference in sound. Took me about 2h to clean the old ferrofluid, very carefully thought... refilled with Willys and it sounds like new!
Thank you for bringing my old girls back to life !
Thanks for the review Matt !
Will & Caroline
Very easy to do on this model speaker as no soldering is required. Made a noticeable improvement. Well worth the effort and cost.
Has fixed the slight grainy sound on my old Mission 771s. The tweeter had a stain on the back suggesting the fluid had escaped. Make sure you release(unsolder) the coil wires before splitting the tweeter. Audax have replacement tweeters TM025C1 albeit 8 ohm which is another way to go.
Thanks for the review John!
Will & Caroline
Delivered quickly. 0.5ml is more than enough for two tweeters and the syringe is essential in order not to over-fill the gap. Well worth it - this has brought a pair of Mission 752 Freedoms back to life.
Thanks for the review Pete !
Will & Caroline
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
Quick dispatch
Product as described, easy to cut & fit.
On reflection having now fitted the foam, I wish it was 15mm to 18mm or even 20mm thick. This is not a complaint. For a small speaker under 30cm high it’s perfect. For a larger speaker I feel a thicker sponge would hold its structure more pleasingly, its aesthetics, but important for the finished look.
I’ve been building my own home cinema as a complete DIY project and reached the stage where I needed some decent acoustic foam for my speaker panels (also DIY!) so I picked up 3 large sheets from here. They were sent quickly, packed well and moreover, are of excellent quality. With them being folded into the shipping box they were slightly creased but after leaving them out overnight on a flat surface, the creases fell out completely. They’re now in place and doing their job brilliantly. Cheers Willys Hifi!
The crossover was constructed well, I just need to figure out the best way to attach it to my Kef Concertos as they are bigger than the ones supplied by Kef that are mounted on the front of the baffle board.
Very nice deep bass look amazing with my custom made speaker
Great speedy delivery and very easy to fit. The plastic in my drivers had perished and they had suffered one too many parties! No need to make any adjustments (someone above did suggest that). I just screwed them in and the foam compressed into place. Before and after below (before I changed speaker number 2). Thank you!
