How big of 45

[Got_Bass89]

So my port is 10x18.5... How big of a 45 you guys think i should do? 7? 8 mabie?

[Miskin]

Assuming your port is 10 wide, I'd do your 45 piece sqrt(200) inches long, or a hair over 14" long at the widest part.

[Got_Bass89]

Huh? Ya 10" tall and 18.5" wide... 185 sqin port

[dappa5]

ho w long is the port LV???

[Got_Bass89]

20 down and is gonna be 1" over... 35.88 hz

[Lakota]

I say just don't do one.

[dappa5]

no need 4 the 45

[Got_Bass89]

Really no 45? Subs up port up on this one... Port is in the middle of 2 18's firing off back glass

[Lakota]

Don't worry about it unless you're competing.

One thing that you got to keep in the back of your mind, which a lot of the newer guys on this site don't understand, is that corners are not always a good thing. Corners can often times cause you to lose output. If you look at the inside of a serious competitors spl box, you will not see a 45 degree corner in every corner of the box. This is stuff that you have to test with a Termlab, so unless you're competing then it's really a waste of time. You will not hear a difference.

[Immacomputer]

Don't worry about it unless you're competing.

One thing that you got to keep in the back of your mind, which a lot of the newer guys on this site don't understand, is that corners are not always a good thing. Corners can often times cause you to lose output. If you look at the inside of a serious competitors spl box, you will not see a 45 degree corner in every corner of the box. This is stuff that you have to test with a Termlab, so unless you're competing then it's really a waste of time. You will not hear a difference.

45s offer more than just tenths of a dB to your peak. They help even out pressure transfer and prevent corner loading in the enclosure (which can help or hurt peak output just like you said) which can help smooth out your total frequency response. They aren't just for trying to increase some meaningless single frequency. Corner loading can be great in an enclosure if you use it to drive the port for competitions but that will almost always make the response peaky which may not be desirable for daily setups.

If you want to put a 45 in your port corner, 8.25" is what will work to keep the port width at 10" through the majority of the corner.