Sub Enclosure Port Help...

[InfiniteGSX]

About to make another one of my sub enclosures except this time I'm making my own box. Usually I just use a pre made box. But this time I'm making a box, perfect size for the sub. However my issue is port direction. The sub will be flat facing up toward the rear window. Port can point toward the front of the car, the left of the car, the right of the car or the rear of the car. Hell I can even make it shoot down toward the tire. Yes the box is going to be right above the spare tire, I've already made sure with the spare tire in, that I'll have enough room without killing any real trunk space vs a 2g awd stock trunk (with all the plastics that level out the trunk floor) using the specific sub I'm going to use.

And besides port direction, general side of the box, Driverside, Passenger side, Front, Rear... I'd prefer not to port up, the same direction the sub is facing. Just because I don't want dirt or tools or anything to fall in it. Which would be a royal PITA to salvage. If its best, maybe I can make some sort of port cover with a light cloth (like what you see on house speakers) to block dirt and debris from entering.

Anyway here's the box. Its a thin but square box.

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Give me your thoughts. This will be my first real enclosure. Also any hints on a port. I was just going to do a wall, like a hallway that will be 6x3x19.5" in size.. Maybe less if thats too much. LMK. MDF costs a lot so I prob only have one or two shots at this.

 

[AGSX2NV]

I would go with the port facing the front. It gives off added depth to the lows. Make sure your matching the sub with your sub enclosure specs. Any box will sound but being precise makes all the difference.

 

[InfiniteGSX]

I would go with the port facing the front. It gives off added depth to the lows. Make sure your matching the sub with your sub enclosure specs. Any box will sound but being precise makes all the difference.

Well yeah. I just posted the image of the sub specs and requirements. The image is the exact specs of the box with the sub and port volume. Just needed opinions on the port shape, direction. If the port is facing the front it will be facing the.... the center .... its called. Right behind the rear seat, that hump. I'm actually changing around the box size a little to make things more flush.

but mainly just need help with the port.

 

[krackit]

port shape doesn't matter too much....it's the cross-sectional area of the port that matters and should be in your sub manual but i stick with circular ones. it should also tell you how deep your port should be. i believe mine are something like 4". but the purpose of the port is for air to move...so face your port in which ever direction the air can move more freely.

 

[SD_TSI]

Seems like the box should be a bit bigger. Do you have any idea what your box will be tuned to? If you do all the work and build it and then throw it in the car and its tuned WAY too high you're not going to be happy and with a box that small it might almost happen, somewhere online there is a calculator that you can plug in all the dimensions and figure it out.. The Eclipse likes to peak anywhere from 39-43hz I think.

I swear by aero (circle) ports. Much easier to tune frequencies using an aero port versus a slot port like you're describing because if you don't like how the box sounds with an aero port, you can pull it out and trim it to your preference, unlike a slot port. Just an idea, if you put some thought into it you'll be very happy.

 

[krackit]

sorry, i didn't notice the drawing said to do a rectangular port...it' gives you a volume for the port.. so use a circular one and just adjust to the same volume.

also. MDF isn't that big of a cost. make sure you do it right otherwise it will feel like a waste of money when it sounds like crap. I like to use a subfloor glue on my inside joints also just to help hold everything tight.

 

[jakelandry]

What sub/subs are you building for? How many subs? Are you going for spl or sq? What amp?

 

[BIGBLAZE79]

For my ports I go to home depot and buy PVC tubing. You can get up to a pretty big diameter, not sure how big mine is but its about 4'' in diameter. You get a PVC cap for the end and glue it on. Then cut off the cap leaving a little left on the end and it makes a nice lip to hold the pipe in place. you can trim to whatever port length you want. The bigger the port volume the better the lower bass frequencies sound in my experience.

 

[InfiniteGSX]

Seems like the box should be a bit bigger. Do you have any idea what your box will be tuned to? If you do all the work and build it and then throw it in the car and its tuned WAY too high you're not going to be happy and with a box that small it might almost happen, somewhere online there is a calculator that you can plug in all the dimensions and figure it out.. The Eclipse likes to peak anywhere from 39-43hz I think.

I swear by aero (circle) ports. Much easier to tune frequencies using an aero port versus a slot port like you're describing because if you don't like how the box sounds with an aero port, you can pull it out and trim it to your preference, unlike a slot port. Just an idea, if you put some thought into it you'll be very happy.

Are you serious? Did you read my first post at all? How is the box small when the box is within "Mid" Spec of the subs requirements for a ported box.... I'm not understanding any word you just said. Large box doesn't mean better sound, no matter who told you that. I've been in the car audio industry for years, but the only thing I haven't done is make my own. I use boxes. The last enclosure I did this same shit to in the back of an eclipse was smaller! It was a ported Truck Box, angled with smaller top than the bottom. And it not only cracked the rear window, it pissed off some of my customers that had huge subs and their shit didn't sound half as good as mine. The only reason I'm making my box this time, is to save space because the angled box design just wastes a bunch of space under the enclosure..

Sub Requires 1.25-1.75cubic ft. Ported. I'm giving the entire box before sub and port volume 1.758cubic ft. After sub and Port that leaves it at 1.505 cubic ft! So thats in the middle of the required spec of the sub. And yes I did use a calculator. Which is why I chose the specific size. The Thickness of the box is the thickness of the sub so I can save space, but its made up for the 22"x22" size. Which for the sub, is pretty big.

sorry, i didn't notice the drawing said to do a rectangular port...it' gives you a volume for the port.. so use a circular one and just adjust to the same volume.

also. MDF isn't that big of a cost. make sure you do it right otherwise it will feel like a waste of money when it sounds like crap. I like to use a subfloor glue on my inside joints also just to help hold everything tight.

Ugh, MDF Used to be 20 bucks for 4'x8'x3/4". Now its 38 bucks! As for port, I don't care. It wont be visible. It will be under the floor face. I was thinking a round port with and internal and external velocity stack. To eliminate air movement noise. But its easier to make a rectangular port, bose style. Plus all my pre made boxes are that way. I haven't seen any box with a circular port since like 2005. All Boxes now days have large flat ports.

What sub/subs are you building for? How many subs? Are you going for spl or sq? What amp?

Kicker CVR 10". Amp I dont' know yet, whatever comes my way at the time. Last one I used in this same setup was a JBL 600w Amp, which is the same setup I pissed off my customers with. But I'm not sure yet. It will come to me. Using a Kicker because Its free. If I could get a 10" P2 then I'd be better off, because then I can run a smaller non ported box for extreme bass. I know P2's LOVE small Sealed enclosures. Friend has a couple in 11x11"x5" boxes each with no port and holy crap they hit hard. But I don't really think Kickers like sealed enclosures much. Even tho they give the specs for them which requires less volume than a Ported Enclosure. I'm just not wanting to risk it. Unless I have that much extra MDF I could try.

For my ports I go to home depot and buy PVC tubing. You can get up to a pretty big diameter, not sure how big mine is but its about 4'' in diameter. You get a PVC cap for the end and glue it on. Then cut off the cap leaving a little left on the end and it makes a nice lip to hold the pipe in place. you can trim to whatever port length you want. The bigger the port volume the better the lower bass frequencies sound in my experience.

Yeah I might do this.



To everyone that isn't understanding me, I've done this before (not the box making, But the sub in small box shit.) What I'm doing is, Installing a sub in a ported box, facing upward right above the spare tire in a 2g AWD. Then a Large Sheet of MDF Cut to the Trunks Carpet specs is placed above it so the box is flush and clean. Then I'm going to use JL Audio 10" Speaker grill because its wire mesh and will keep debris off the woofer. I've done it before with a Kicker CVT and it hit hard! But the box was pre made by a company out in texas that was our supplier. However the box was like 8" on the bottom, and like 3" on the top, say 22x23" and the port was on the top, about 3" port along the roof of the top of the box. AKA a truck Box.

So the reason I'm building it, is to make a fully square box because the truck box wasted a lot of space under the box and I couldn't use the spare tire compartment. I'm making this one so that I can utilize everything down there with an easy to remove flush box. And this isn't for competitions. Its for my personal Pleasure.

 

[TunaTalon]

So far no one has mentioned that the interior of the enclosure should be asymmetrical to prevent standing wave distortation.

 

[marineeagle28]

asfrom learning from db drags and such.. look at folded horn designs, used in hatches likes ours, or more similarly shaped to a CRX. and honestly, having fabricated EVERYTHING when it comes to custom stereo, you havent really done ANYTHING or really know diddly until you really get into the inner workings.
There were a few key questions raised such as are you going for SQ, SQL, or SPL. Also, what kind of music do you like. I am WAY overly familiar with CVR10's and 600 true RMS watts suits a pair of 10's well. in our vehivle i recommend an interior airspace of 1.55 cubes per woofer, port tuned to about 34hz, subs up port back in order to make full use of vehicles resonant frequency of 38-43 hz.

As to the choice of what kind of port, Slot ports can be made just as accurate and smooth as any aero port. the idea is to really seal up any corners, and make the path as smooth as possible, such as instead of 90degree turns, make it a 45. and dont forget to route them corners.

Last system of my own was 2 12"CVR on JL 500/1 in 4.5cubes tuned to 32.5hz slot ported in the back of my xterra.. bassrace 149 everyday

 

[krackit]

i don't know about anyone else...but i consider 40$ for a full sheet cheap considering how much custom sound setups cost....when my speakers, subs, and equipment cost me $2400, and the fiberglass sub enclosure is gonna cost me like 400$....i consider 40$ cheap...your system is only as good as your cheapest component....

and your original question was about port direction. it doesn't matter the shape. its the volume of it matters, and it needs to be able to move air freely...if it is stuffed against the back of the seats, then might as well just build a sealed enclosure.

 

[InfiniteGSX]

Well, Not going for a huge setup. Just something personal. And the port if facing forward wont be hitting the seats, Just telling the direction. I just want something basic that is good for saving space. I didn't read the last two because it started giving me a headache and is too much for this system. Not going to competitions or anything. Just like my music. I jam out too much.

My last system was amped components in doors and rear. with a small Pioneer Sub in a small ported enclosure and it was awesome for me to jam out. I'm a music buff, thats all I care for. I don't have a single Bass CD or anything like that.

My main concern is bass in small box in order to save my trunk. Stock 2g AWD's have these plastics that are like 5" deep, under them is the spare tire. On top is the cardboard. well I'm replacing that with a box and MDF... that way I can keep all of my trunk and have bass. So I just asked about the port size, shape, direction for that box which has been calculated to fit my needs and the needs of the sub I have.