Which 15" sub for a sealed enclosure?

[Inertia]

TLS Guy I meant to say i wanted to do the Epic in a ported enclosure tuned to roughly 20hz.

So you're saying roughly 4ft3 after bracing, sub and port displacement tuned to 20hz? Would it be better to make the port a little bigger since the vent velocity is 18 m/sec?

 

[Inertia]

Now that i ran it the vent velocity looks like .08 not .18.... Did I do it wrong? Also... size of the box does not matter.... would 5ft3 be better than 4ft3 tuned at 20hz?

 

[TLS Guy]

TLS Guy I meant to say i wanted to do the Epic in a ported enclosure tuned to roughly 20hz.

So you're saying roughly 4ft3 after bracing, sub and port displacement tuned to 20hz? Would it be better to make the port a little bigger since the vent velocity is 18 m/sec?

You can not tune that driver to 20 Hz, 24 Hz is the maximal extension for F3 point.

The vent velocity of the designed port is 18 m/s and anything in the neighbor hood of 17 Hz is fine. I think the port is already plenty long.

The air in the box must be 4 cu.ft, however you have to add bracing, driver volume, port volume and amp volume to get the final total volume Vt. So I suspect that the total volume is going to be at least 5 cu.ft, or a bit more depending on your design.

 

[Inertia]

But on your box properties for the vented design the Fb you have is 20.3hz.... doesn't that mean the box is tuned to 20.3hz with 4ft3?

 

[TLS Guy]

But on your box properties for the vented design the Fb you have is 20.3hz.... doesn't that mean the box is tuned to 20.3hz with 4ft3?

Yes, but I was making sure you did not think Fb was the same thing as a response to that frequency point.

The 4 cuft. is Vb, but that is the air in the box. So the port, bracing, etc (anything that displaces air in the box) must be added to Vb to get Vt which is the box you build. That way the air in the box will be 4 cu. ft which is Vb. Note the volume of damping material in the box is already allowed for so does not need to be added.

 

[Inertia]

Would it perform better with a Vb of 5ft3?

 

[TLS Guy]

Would it perform better with a Vb of 5ft3?

No! I optimized Vb for you. It needs 4 cu.ft of air in the box, port not included. So you add everything I told you about to Vb to get Vt. Vt is the box size you build not Vb.

 

[Inertia]

I understand that the box will have to be bigger than roughly 4ft3 because of the port, bracing, and sub displacement.... but a guy on home theatre shack said it would perform better in a box that is 5ft3 after all displacement. Thats why i am asking.

 

[TLS Guy]

I understand that the box will have to be bigger than roughly 4ft3 because of the port, bracing, and sub displacement.... but a guy on home theatre shack said it would perform better in a box that is 5ft3 after all displacement. Thats why i am asking.

He is wrong.

 

[Inertia]

I hope i didn't upset you by asking you what another person suggested... Hes a well known guy on the board is why I asked you.

 

[Guiria]

shameless plug kappa for sale

To the op I know you've mentioned building a second vq. I am selling mine right now so I can build a smaller sub to fit in a recently redesigned bonus room. Pm me if interested.

I am interested to see what you end up with to match your current kappa build.