I would like to know how many or even if anyone uses a 4 inch aeroport for a 12 inch sub without any problems. Reason i ask is because i built a 2 cu. ft. box for my audiopulse axis with a 4 inch aeroport tuned to ~34 hz and it sounds fine, only up to a certain point though. I don't like the noise it makes, i guess that's what chuffing sounds like and i can't stand it so i turn the volume down. I was also only using a saz 1000d on it with absolutely horrible electrical so there's no way i was reaching its limits with it's insane power requirement.

Now i know for a fact that that's not enough port area but i would still like to know if anyone uses a 4" and gets away with it. I'm building a new box for it: 1.85 cu ft. with 32 inches of port area to make sure that i don't hear that sound again.

that noise u are hearing is called port noise...it comes from not having enough port area. try adding 1 or 2 more and tuning to the same frequency and u will probably not have that noise.

also, if u dont have ur gains set right u can still clip the heck out of ur sub and blow it up. so set ur gains right to make sure ur not clipping the sub to death. upgrade ur electrical by doing the big three and possibly an extra battery or h/o alternator or both if u want to add more power later on.

It's called Port noise, Try a Kerfed enclosure it'll reduce or eliminate port noise

I'm building a new one. I'm just curious if anyone uses a 4 inch for a 12 inch without port noise.

you would have 2 use more than 1. there isnt enough port area with just 1.

I'd have to add them externally as they would take up too much room in the current box but that's a no go anyway since it's scrapped.

i meant when u build ur new box...check out this site. it mite help you out a bit...just make sure to stay within the recommended 12-16 sq inches of port area per cubic foot of space in ur box. scroll down a bit

to find the part with porting and then just punch in the numbers to get the desired specs.

Speaker Enclosure Volume Calculator

This is my new box.

I can never stay on topic.

A single 4" port would probably only be sufficient for subs with relatively minimal xmax capabilities. If you want to know what xmax that would be, look at the sub and see how far it's moving right when the port noise starts.