Plexi glass in a ported box

I'm going to guess it's because of the plexi flexing.

 

Where did you read that info?

I could see plexiglass flexing if you used something thin, but I dont think 1" thick plexiglass will flex.

 

I was thinking of the stuff you can buy at home depot.Like the pre-made bandpass boxes.I didn't read that,I guessed.

 

I have a 9"x9"x.75" plexi window in my box and it dont flex at all.

 

I had a cheap pre-made bandpass box that had 1/4" plexi and it flexed like heck.I'm thinking that's the stuff people are saying not to use.

 

The use of plexi in any box is fine so long as it is thick enough so as not to resonate. For a .75 inch stock, i wouldnt do bigger than about 18x18 square.