Reckhorn D-165

Got myself a Reckhorn D-165 and 2 x P-6.5 passive units, intended for a mini subwoofer for my home office.

On paper the 6.5 inch D-165 looks really promesing.
Link to shop: Reckhorn

Amazing build quality for 30 € only?!
Fast delivery and nicely packed … good job Reckhorn 😊

The passives are not as impressive and quite flimsy. Seem the suspension is somewhat more soft than the D-165 .. giving a lowe Fs. Comes with 3 small discs to add weight to the 20g alu cone.

Plan is to build a small active sub in a box of 11 – 15 liter.
I’m thinking AceBass, a small inexpensive but good class-d and a SMPS.

Just ran the bass on my Dayton DATS v2, and the parameters given by Reckhorn seem to be ok. Need to burn in the unit before they reach the right parameters of course.

But how to measure the passive??
Any good ideas??

Reckhorn can not provide the relevant data effective Sd, Vas, Qm and Fs.
Sd can be estimated, measuring the diameter including half of the surround.

Cms can probably be found by adding weight and measuring how far the cone moves ……