IB grill material

[ayreonaut]

I was considering using perforated metal to cover my ceiling IB opening, since it won't flutter like cloth would. Do you have any recommendations for a minimum percent open area?

For example, I was considering an ornamental cloverleaf pattern that has a 51% open area. Is that too consrtictive? What would the sonic consequence be if any?

[ThomasW]

Without researching this my suggestion is go for whatever is available that has the highest percentage of open area.

[penngray]

I will be using 18" metal grills on my 4 IB drivers.

[moro]

Ideally you would want at least as much open area as speaker area.

If the grill has twice as much total area as your speakers and the percent open is 51% thats right at the same open area as speaker area.

If you go less your getting a high pass filter on your subs. I don't have a general rule of thumb to tell you what percent becomes audible and it will also depend on the shape(s) of those openings and how much the grill moves. Even metal grates will vibrate. You can fix some with EQ but you have to watch boosting the very low end, for amp clipping and hitting Xmax on the speakers.