Will there be chuffing with a 4" port?

[Inertia]

I have a 12W7 that will be in a 2ft3 box powered with 750 watts. Will a single 4" port be chuffing or not?

 

[j_garcia]

4" is a pretty good size port, but that has more to do with the sub design than just the port diameter. My Tempest had a 4.5" flared port and I never had any chuffing. Are you using a subsonic filter on it, since I saw that you had it at 29Hz?

 

[Inertia]

yup using a subsonic filter... what should I set the subsonic at?

 

[j_garcia]

What are your options for the filter? My Tempest was tuned to 17.5hz and I set the subsonic to 14Hz, but my only choices were 28, 20 and 14.

 

[Inertia]

20hz or 30hz... Honestly though is it necessary to get down to 20hz for movies or would 30 be fine?

 

[j_garcia]

I'd do 20Hz. It will let you get full use out of the sub without letting it go low enough to cause damage, which is really the intent of that filter and is actually what I was going to suggest as a starting point without knowing that You can try it both ways though.

 

[Inertia]

Ill try out both options! Thank you!

 

[annunaki]

A single 4" vent is WAY too small on a 12W7. You would ideally want 3 of them at a minimum to keep vent velocity in check much less keep it in audible.

A 12W7 ideally needs in the neighborhood of 40-45+ in^2 of vent surface area. A single 4" vent is 12.57in^2

 

[j_garcia]

That much vent?

 

[annunaki]

That much vent?

On a W7 with rated power, you bet!!

 

[pureiso]

Just a side note, but make sure the port is flared to reduce the chance of chuffing as well. You probably already got that, but always good to throw that out there.

 

[Inertia]

I turned it up pretty loud and no chuffing and yes its a flared port... They sound great in the house but need to hear them in the car now!

 

[Dan76]

i dunnoooo