Sonitus Audio Ferro Fluid 0.5ml

Ferro fluid for compression driver voice coil gaps, ideal for replacing contaminated or dried ferro fluid. Supplied in a capped syringe with an applicator nozzle.

Ferrotec's APG S11N Ferrofluid is a member of Ferrotec's family of APG S Series ferrofluids for tweeter and compression driver applications. The APG S11N is a black-brown viscous fluid and uses a synthetic ester oil carrier liquid. We purchase this in 1000ml bottles, and then make up individual 0.5ml syringes in the UK.

Specifications:

• Saturation Magnetization (Ms) 220 Gauss - this sits in the middle of suitablity for tweeter and mid-range - making this broadly compatible with most common tweeters. Very small tweeters, intended as supertweeters may need a lower level of 110-200
• Viscosity @27°C 85 cP - this is towards the bottom end of viscosity available in ferrofluids - and provides minimal damping - most woofers require higher viscosity of 500 cP or more. This fluid is NOT suitable for woofers that require damping.
• Density @25°C 1.15 g/cc
• Pour Point -34 °C
• Flash Point >200 °C
• Thermal Conductivity @38°C 150 mW/(m.K)
• Surface Tension @25°C 32 dynes/cm
• Coefficient of Thermal Expansion 7.5 x 10-4 ml/ml°C

0.5ml of ferro fluid supplied, typically sufficient for approximately 1-2 small tweeters, or 1 larger compression driver when replacing a diaphragm to top up any fluid lost. If you are cleaning out the voice coil gap completely, and replacing old dried up ferrofluid you may need to use slightly more. Unfortunately we don't have any way of knowing exactly how much fluid you need, as voice coil gaps vary in size/shape quite significantly.