Input need on single 8" sub box with external aeroport

[eddie_93 10+ year member]

Hi all,

Seeking input on box design. I'm trying to design an external aeroport ported box for my little Rockford P1 8" (200 rms), will be powered off ~150rms. Goal is sound good for daily music.

My current plan is 3" PVC aeroport (flared). Want to tune to around 35-37 hz. My question is as follows:

Should I make the aeroport completely external? Or say 7" of it internal and only 10" external as in my second design? I realize Torres Tuning Calculator which I'm using doesn't account for the displacement of the port if I was to place some of the aero inside the box.

This is completely for fun so don't rip me if my ideas are way off //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Thanks!

Design 1



Design 2

Click to read more...

 

[The_Dealer]

On the aero box I did for my 2 xd8's I went fully external. I wrapped the port tubes with electrical tape so I could change the ports out to change tuning. I suggest doing the same so you can play around with tuning to find what you like, then you can glue the port tube to the coupler for something more permanent. On the aero box I did for my Skar zvx-8 I kept around 10" inside the box because I needed to take up some of the box volume without changing the outside dimensions. By doing some of the port inside the box you'll raise the port area slightly. So IMO your 2nd design would be the one to go with. BTW you don't have to enter 3 in the width box, that's for slot ports. I did my box for the xd8's the exact same volume and tuning as my slot port and metered it. The aero was almost 3db louder than the slot port.

I'm running a lot more power so I screwed & used liquid nails to attach the port, then used filler to smooth things out and fill the screw holes. Picture was taken before sanding BTW.



I like to use piece of mdf on the outside to serve as a brace and helps clean up the look. I usually hit the cutout with a roundover for looks. I also used one on the inside of the box for my Skar. Gives you more surface area for the glue/adhesive to hold. I have kids so my port has been climbed on, stepped on, and had **** dropped on it and it's still holding strong.





Hope this helps you out man.

Sent from my G870a on 38's

 

[eddie_93 10+ year member]

On the aero box I did for my 2 xd8's I went fully external. I wrapped the port tubes with electrical tape so I could change the ports out to change tuning. I suggest doing the same so you can play around with tuning to find what you like, then you can glue the port tube to the coupler for something more permanent. On the aero box I did for my Skar zvx-8 I kept around 10" inside the box because I needed to take up some of the box volume without changing the outside dimensions. By doing some of the port inside the box you'll raise the port area slightly. So IMO your 2nd design would be the one to go with. BTW you don't have to enter 3 in the width box, that's for slot ports. I did my box for the xd8's the exact same volume and tuning as my slot port and metered it. The aero was almost 3db louder than the slot port.
I'm running a lot more power so I screwed & used liquid nails to attach the port, then used filler to smooth things out and fill the screw holes. Picture was taken before sanding BTW.



I like to use piece of mdf on the outside to serve as a brace and helps clean up the look. I usually hit the cutout with a roundover for looks. I also used one on the inside of the box for my Skar. Gives you more surface area for the glue/adhesive to hold. I have kids so my port has been climbed on, stepped on, and had **** dropped on it and it's still holding strong.





Hope this helps you out man.

Sent from my G870a on 38's

Hey thanks alot. Extremely helpful response. I was also wanting to go with my second design so I didn't have my aero sticking out so far. I like your idea about not making the length permanent right away. Did you notice any ill effects from placing your port so close to the back wall of your box? I've read you should keep it at least the port diameter distance from any adjacent wall.

 

[Umbra]

Sorry, I didn't read through the whole thread, but I just wanted to say Torres should calculate how much of your port is external and not remove it from your net volume. That's why there's a field for external port length. Try changing that value to zero and see if your net volume goes down

Sent from my SCH-I545 using Tapatalk

 

[The_Dealer]

Sorry, I didn't read through the whole thread, but I just wanted to say Torres should calculate how much of your port is external and not remove it from your net volume. That's why there's a field for external port length. Try changing that value to zero and see if your net volume goes down
Sent from my SCH-I545 using Tapatalk

Huh? His first design was fully external, and his 2nd showed some of the port internal and some external.

Sent from my G870a on 38's

 

[Umbra]

Huh? His first design was fully external, and his 2nd showed some of the port internal and some external.
Sent from my G870a on 38's

I get that. My response was regarding his statement:

"I realize Torres Tuning Calculator which I'm using doesn't account for the displacement of the port if I was to place some of the aero inside the box."

I just want to clarify that it does do that so he doesn't try to figure out the volume separately and subtract it a second time.

OP, you also don't need to have anything in the width field in Torres, that's for slot ports; just use the lower two fields - # of ports and diameter for aeros (although in testing it doesn't look like adding that extra value screws anything up unless you put height as well)

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[The_Dealer]

Hey thanks alot. Extremely helpful response. I was also wanting to go with my second design so I didn't have my aero sticking out so far. I like your idea about not making the length permanent right away. Did you notice any ill effects from placing your port so close to the back wall of your box? I've read you should keep it at least the port diameter distance from any adjacent wall.

Nope, but I added a piece of wood to separate the closest sub from the port. I didn't take a picture of it when building the box, I decided to add that in right before putting the last panel on. Here's a quick sketchup of what I mean. Obviously my sub isn't that close to the divider



I think what your talking about is having a port's distance between the inner opening and a wall. I could be mistaken, but with both boxes I haven't had any issue.

Sent from my G870a on 38's

 

[eddie_93 10+ year member]

I think what your talking about is having a port's distance between the inner opening and a wall. I could be mistaken, but with both boxes I haven't had any issue.

Sent from my G870a on 38's

That is what I was referring to. Thanks for the help! I built the box tonight and mocked up the ports. The external aero will likely be trimmed down because as it sits tuning is about 33hz. The back of the sub also ended up really close to the internal aero flare, hopefully no issues from that. Will try it out tomorrow.

 

[The_Dealer]

It shouldn't be an issue as long as there's a least an inch between the sub and the inner flare. With 150rms I don't see you having port noise or port compression, I'd think it would be fine. Did your pvc start to wrinkle? I kept having that problem until I started using cooking grease. Put about an inch of cooking oil in a pot and heat it on the stove. Set your bowl on top of a couple towels, stick the pvc in the oil for a couple of seconds, then hold it on the bowl until it cools. Alot easier than the heat gun, and it's alot less time consuming.







Sent from my G870a on 38's

 

[eddie_93 10+ year member]

It shouldn't be an issue as long as there's a least an inch between the sub and the inner flare. With 150rms I don't see you having port noise or port compression, I'd think it would be fine. Did your pvc start to wrinkle? I kept having that problem until I started using cooking grease. Put about an inch of cooking oil in a pot and heat it on the stove. Set your bowl on top of a couple towels, stick the pvc in the oil for a couple of seconds, then hold it on the bowl until it cools. Alot easier than the heat gun, and it's alot less time consuming.






Sent from my G870a on 38's

I think there is probably only 1/4"-1/2" clearance right now. If there are any problems I'll just add another baffle on the front. I did see the cooking oil trick around online, I'll try that. Yours look awesome!

Sent from my XT1254 using Tapatalk

 

[The_Dealer]

I'd add one anyways if you have the room for it. You could just do a shaped spacer piece like I did for my port trim. That'll get it out from the port and would only take a few minutes.

Sent from my G870a on 38's

 

[eddie_93 10+ year member]

Hey all. Thanks much for everyone's input! Everything is installed. Still need to fix up the flare on the port for cosmetics but it works for now.

Box is currently tuned at ~35 hz with 19" of port, about 10" of that external. I placed the closest walls of the port 3" from the rear and bottom walls of my box. Sounds great, no port noise and good output for only 150W. Hopefully this thread can help someone else in designing a small Aeroport box someday.