Why Cubo subs work so well ?

I would like to have them run as low as they can go......17hz would be nice and lower would be better.

That driver got, imo, reflex cabinet driver written all over it. That's because it has a very low Fs and large Xmax. That 285 liter nett, tuned to 17 Hz is the kind of cabinet that immediately comes to mind. If it was ment for either Cubo Sub or Cubo 18, it could do with double the Fs and half the Xmax.

Best regards

Cubo

The Beyma 21L45 is an oldie but it's a nice one.

Re is about half the Re of the 8 ohm version but it's best to use either the 8 ohm parameters or the complete set of 4 ohm parameters

With a 30 Hz high pass it's save. It will be more of a 33 Hz and up cabinet due to it's specific parameters. On the good side it will take a lots of power. I would love to hear one with a big amp.

Best regards

Cubo

Thanks, definitely an old driver but well worth a try!
33Hz would be good, especially given their power rating as you say.
Mik

audiomik wrote: Thanks, definitely an old driver but well worth a try!
33Hz would be good, especially given their power rating as you say.
Mik

A couple of relevant test results for one of these Drivers, Fs measured at 28Hz with Impedance at 44.44 Ohms. It is quoted as 30Hz in the spec sheet so as this driver has had some use then the suspension will have loosened to some extent.
Also the Minimum impedance at 125Hz, very close to the point where the VI phase angle reverses from lead to lag, is 3.35 Ohms.

Also measured it's impedance at 50Hz as 5.75 Ohms with a VI Phase angle of 54.7º; which will certainly 'stress' a few Amplifiers!

Mik