Sealed or Ported ??? WHAT?

[johnviera]

The woofer says "good for small sealed enclosure" right under the specs.

http://www.madisoundspeakerstore.com/approx-6-7-woofers/madisound-6102-4-6-polypropylene-cone-woofer/

I plugged the specs into WINisd and it says EBP=105 !

That's vented baby !

What's going on here ????

http://imageshack.us/photo/my-images/52/madisound61024.png/

>

[billfitzmaurice]

What's going on here ????

>Low Fs low Qts can work OK, but not with F3 being anywhere near Fs.

[johnviera]

So is it better sealed or vented ?

[Wolf]

These are what I measured on a pair I had for a door-prize at this past InDIYana event.

The suspensions are VERY loose and easy to move, feels more like an acoustic-suspension woofer.
I get an EBP of 76/74 respectively. EBP is a value indicator that actually gets less useful the smaller the driver gets.

Hope this helps!
Wolf

[Whitneyville1]

A normal sealed box will have a Fs of .707, you're showing a much larger box of.66. Ported, you gain about an octave of F0, and considerably more F3, at the expense of a 60-100% larger enclosure. We don't get anything for free. I didn't sim these myself, so take these as "guesstimates". Bandwidth product isn't the only factor in whether a woofer performs better vented or sealed, either. I'm just learning how much I DON'T know from some books I got.

[Wolf]

You've got your parameters all mixed up, bud.

The optimal sealed box for lowest F3 is 0.707 Qtc. F3 increases to either side of that Qtc figure.

If you want a design kit that was used for these 6.5" woofers, Madisound used to have the 'Sledgling' as an affordable option. The wayback machine may help you out, since the tweeter from that kit is now NLA.

Later,
Wolf

[isaeagle4031]

I'm the one that was fortunate enough to win the pair of these at InDIYana this year, the 8ohm version. As Ben said, the suspension is very loose. Even though the EBP is so high, these really would be better in a sealed enclosure. I'm actually considering running my pair sealed and using them more as a midwoofer. By the graph I got with them from Ben, they are looking like they won't be much good above the 2-2.5k mark