FrankC

Hi Kent,

I have not done a refoam yet, but ordered the kit. I am more comfortable with electronic components - vac amps and vintage solid state equipment.

Will give it a try.

Thanks for the encouragement and will post the results.

Frank

soundminded

Thank you for the in depth response. That helps greatly.

Frank

The surround is one of the factors that could potentially limit the maximum excursion of the cone.  If the diameter of curvature, that is the crosssectional diameter through the material is the same, then the 5/8 inch roll will allow for a slightly greater maximum excursion if it and not some other factor is the limiting element.  Otherwise it won't matter.

Far more important besides making an airtight seal and not deteriorating over time is the compliance of the material.  Not compliant enough and it will impose too tight a mechanical restraint on the cone's movement.  This will increase the driver's inherent resonant frequency fc.  Too low and the driver will have no restoring force at all except the trapped air to return the cone to its nominally neutral position.  Somewhere on one of these threads, I think someone who worked at AR  said that  about 90% of the restoring force is due to air pressure, about 10% due to mechanical force of the suspension.  The fc should be in the range of around 16 to 19 hz in free air.  The f3 in the enclosure should be 42 hz with critical damping of 0.707.  This results in the smoothest lowest extended bass response for this driver in this enclosure without any peak in its response (I assume it's the same as AR3a, AR3, etc.) and is what it was designed for.  The other critical element is the stuffing being the right amount, the right consistency, and evenly distributed.  Hope that helps.