Eminence Magnum 15LF suitable for sealed box?

[edfallon]

Modeling and T/S parameters indicate this driver should be suitable for a sealed box, but Eminence only mentions vented alignments. Does anyone know if there is anything about this driver that would make it less than optimum for a sealed box? Since it doesn't use a sealed dust cap because of the goofy looking phase plug, I suppose air loss is greater around the voice coil than most drivers meant for sealed boxes. Qtc is .45 and EBP is around 77 btw.

Thanks,

-Ed

[wg_ski]

> Modeling and T/S parameters indicate this
> driver should be suitable for a sealed box,
> but Eminence only mentions vented
> alignments. Does anyone know if there is
> anything about this driver that would make
> it less than optimum for a sealed box? Since
> it doesn't use a sealed dust cap because of
> the goofy looking phase plug, I suppose air
> loss is greater around the voice coil than
> most drivers meant for sealed boxes. Qtc is
> .45 and EBP is around 77 btw.

> Thanks,

> -Ed

Nothing is preventing you from using a sealed box. Not the EBP or the funky phase plug. Most users in sound reinforcement applications would use it vented to get the extension, but it's not carved in stone.

The air loss around the phase plug has a similar effect to reducing the driver Qms or using an aperiodic vent. Reduce the box Q from 7 to about 3 in your simulator to get an idea what happens. If you want an accurate answer, measure the driver in a known sealed box, and back-fit a new Qms value based on the reduction in the height of the impedance peak compared to free air. But with sealed boxes, you don't need to get that technical anyway.

[troystg]

So what is the recommended sealed box size? Also vented if you worked that one up too.

Troy