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kabosh
07-02-2013, 10:51 AM
I am having a buddy chop up and put n L port into my box for an OA18. The guy who made the box made it well except for the ports, seems like he just three two aeroports in there without tuning. I need to know the dimensions I need to make the port tuned to 28 Hz. Let me know what information I need to supply to get the info to make the port.

I took some pics of the box, can't figure out how to upload pics I already have to this post.

hispls
07-02-2013, 10:57 AM
INb4 box is 4 cube.

kabosh
07-02-2013, 11:16 AM
I think it's more like 7

pro-rabbit
07-02-2013, 11:20 AM
We need more info to help you out.

Enclosure specs would be ideal to start with.

H x W x D

Thickness of the wood (any double baffles)

What bracing?

What are the current port sizes and lengths?

kabosh
07-02-2013, 11:23 AM
I'll try to get the dimensions after work. It is all double baffle 3/4 mdf, bracing dowel in the center and bracing on all the corners inside as well. Right now there r two aero ports and it doesnt hit lows hardly at all

kabosh
07-02-2013, 11:34 AM
I'm wanting to just cut out the aeroports put n L slot in and close it back up

kabosh
07-02-2013, 11:53 AM
I thought I might just need like this much port length, this much port width at this height. Something like that lol

Spooney
07-02-2013, 12:08 PM
I thought I might just need like this much port length, this much port width at this height. Something like that lol

We need to know the exact size of the enclosure to give you an accurate port spec. Without that all we can do is guess like your other builder did and you would be no better off in the end. There is no magic/generic port size for an 18 that you can just slap in there and be guranteed that it sounds good. Once we find out the size of the enclosure you might find its easier to just lengthen your aero ports to get the sound you want. When you get around to measuring the enclosure go ahead and measure the length on the aero ports as well as giving us the diameter of the ports so we have all the info we need. Are you sure your subsonic filter isn't set too high and killing your lows?

NoLoud4U
07-02-2013, 12:11 PM
Can you just extend the ports that are already there? Longer port means lower tuning. Considering everything else is right it will help

kabosh
07-02-2013, 12:12 PM
Well the deep bass hits just not with authority like at all

kabosh
07-02-2013, 12:13 PM
How do I extend these plastic aeriports

Random1010
07-02-2013, 01:04 PM
Tell us the **** box dimensions man. Been asked for multiple times. Without that we cannot offer any assistance.

pro-rabbit
07-02-2013, 01:08 PM
How do I extend these plastic aeriports

By replacing them or rebuilding them.


As for the enclosure currently, if you can play low but not with much or any "authority" then it is likely the enclosure design and/or port area limitations.

The best solid answer you will get, is build a new enclosure.

Silverado SS
07-02-2013, 01:24 PM
By replacing them or rebuilding them.


As for the enclosure currently, if you can play low but not with much or any "authority" then it is likely the enclosure design and/or port area limitations.

The best solid answer you will get, is build a new enclosure.

Best advice so far

T.I.K.
07-02-2013, 01:30 PM
adding a slot port to a box designed for aeroports is destined for disaster. Aeroports take up much less space than slot ports, so adding a slot port in there is going to make the actual chamber your sub is in much smaller. You're better off figuring out what your current box's airspace and tuning, seeing if you can make your ports longer, or building a new box.

kabosh
07-02-2013, 02:13 PM
Ok the dimensions are H=15 3/4 W=41 1/2 D= 27 3/4 in. That's sub facing up. The box is a lil too big I think so the port displacement will be good.

T.I.K.
07-02-2013, 02:16 PM
Ok the dimensions are H=15 3/4 W=41 1/2 D= 27 3/4 in. That's sub facing up. The box is a lil too big I think so the port displacement will be good.

You wouldn't happen to drive an explorer would you? 41.5 is the exact dimension between the wheel wells in a 2nd gen explorer.

That box is 6.6ft^3 total(you said the whole box was double layered 3/4" MDF). What kind of sub(s) do you have? and what size and length are your aero ports?

bassman_soundki
07-02-2013, 02:28 PM
You wouldn't happen to drive an explorer would you? 41.5 is the exact dimension between the wheel wells in a 2nd gen explorer.

That box is 6.6ft^3 total(you said the whole box was double layered 3/4" MDF). What kind of sub(s) do you have? and what size and length are your aero ports?

I came up with 7.03FT3 before ports sub(s) and bracing. I might have done something wrong?
**edited because I cant read lol

T.I.K.
07-02-2013, 02:30 PM
I came up with 8.65 before ports sub(s) and bracing. I might have done something wrong?

OP said the whole box is double layer 3/4" MDF, so the wall thickness is 1.5" instead of .75"

bassman_soundki
07-02-2013, 02:32 PM
OP said the whole box is double layer 3/4" MDF, so the wall thickness is 1.5" instead of .75"
Yeah just caught that.
I have 7.03 now gross

T.I.K.
07-02-2013, 02:39 PM
Yeah just caught that.
I have 7.03 now gross

me too, I must have left a decimal out somewhere.

Oraclem19
07-02-2013, 02:48 PM
Yeah just caught that.
I have 7.03 now gross

me too, I must have left a decimal out somewhere.
More sleep (or coffee/Red Bull) , less box calculations.

kabosh
07-02-2013, 03:02 PM
So I want to just chop it up put a L port in and have it facing rear with sub facing up. Tuned to 28 hz to murder those lows. I have one OA18. Now tell me wjat iI need to do to get it tuned right.
Oh and yes it's a mountaineer. Weird thing is the box wasn't made for my sub lol.

I measured the port w, just measured across it... 6 1/4. Length is 7 3/4

kabosh
07-02-2013, 03:26 PM
Now that I have the information u need plz dont forget about me I still need the port info lol

kabosh
07-02-2013, 04:08 PM
OP said the whole box is double layer 3/4" MDF, so the wall thickness is 1.5" instead of .75"

So can u help me with the port dimensions

bassman_soundki
07-02-2013, 06:20 PM
So can u help me with the port dimensions

Do you have any internal bracing?
If so please describe dimensions then bracing and driver disp can be deducted and get proper tuning.

bassman_soundki
07-02-2013, 06:48 PM
port 12.75highx5.5wide
L1 20.75
L2 6
FB 28
this isnt taking into account for sub or port displacement, and is based on RE's box calculator....some say not the best.

kabosh
07-03-2013, 01:26 AM
Which of these specs on the port should I be changing to get the tuning how I want? On re caclulator do I adjust port width or length to get the tuning I want? Its confusing

bassman_soundki
07-03-2013, 02:27 PM
Which of these specs on the port should I be changing to get the tuning how I want? On re caclulator do I adjust port width or length to get the tuning I want? Its confusing

The longer the port the lower the tuning, also if you make the port narrower for a given length it will effectively lower tuning as well.
I hope someone that has bassbox will chime in and give you some help as well. My disc is lost after moving.

kabosh
07-04-2013, 02:00 AM
The longer the port the lower the tuning, also if you make the port narrower for a given length it will effectively lower tuning as well.
I hope someone that has bassbox will chime in and give you some help as well. My disc is lost after moving.

So when I put in the dimensions on RE calc, it says 6.6 cubic feet with a 1.5 in wide port. When i alter the port to get 32hz (7 inch wide, 8 in port L2, tell me if i should do that differently?) the cubic feet goes down to 4.9. Is that normal and ok? Doesnt seem to be counting any space inside the port so idk. This sub asks for about 6 cubic feet tuned 28-32

kabosh
07-04-2013, 02:09 AM
Just tinkered around with this Products Menu (http://www.psp-inc.com/tools.html) aero port calculator and it looks like this box is currently tuned to close to 50 hz at the moment lol...

bassman_soundki
07-04-2013, 02:12 AM
Just tinkered around with this Products Menu (http://www.psp-inc.com/tools.html) aero port calculator and it looks like this box is currently tuned to close to 50 hz at the moment lol...

Well if you can lengthen them, it would be a lot easier that making an L-Port.
How long are they now, inner diameter (tube not flare)?

kabosh
07-04-2013, 02:18 AM
I posted that earlier, inner diameter is 6.75. length is around 7.75

kabosh
07-04-2013, 02:42 AM
26543407
This is the only pic i could get to work for some reason. Does this box look too big? lol

bassman_soundki
07-04-2013, 03:34 AM
I cant find any info on 6/75" inner dia aeros, but I will give you a suggested port length for (2) 6" dia aeros to tunes to 28 hz and that is 26.5" long each, and you can use tubes from Home Depot and 90* elbows if needed. This length is not including the flares
Looks like you are tuned around 46 hz right now, not safe for that sub.

If you were to just seal one of the ports and leave other as is it would tune you to around 31 hz

kabosh
07-04-2013, 12:12 PM
I cant find any info on 6/75" inner dia aeros, but I will give you a suggested port length for (2) 6" dia aeros to tunes to 28 hz and that is 26.5" long each, and you can use tubes from Home Depot and 90* elbows if needed. This length is not including the flares
Looks like you are tuned around 46 hz right now, not safe for that sub.

If you were to just seal one of the ports and leave other as is it would tune you to around 31 hz
Well what would be the best way to seal it
Also does it matter that the ports arent coming out of the box at all? like in the picutre there just screwed into the port hole

kabosh
07-04-2013, 12:25 PM
So this box is only double baffled on the top where the sub is coming out, I cant figure out how to account for just one slab being 1.5 thickness and the rest being .75
On torress doing the box at .75 thickness its more like 8.6 cubic ft. So if I seal one port, and it still doesnt hit the lows, could it be because my box is TOO big?

bassman_soundki
07-04-2013, 03:50 PM
So this box is only double baffled on the top where the sub is coming out, I cant figure out how to account for just one slab being 1.5 thickness and the rest being .75
On torress doing the box at .75 thickness its more like 8.6 cubic ft. So if I seal one port, and it still doesnt hit the lows, could it be because my box is TOO big?

Bigger box=lower bass.

If you removed port and sealed with a board with liquid nails and screws you will be fine.

With the new info on box thickness it makes this more guesswork, but that 31hz I stated to you will be lower with more airspace internally.

Oh, and the port inside or outside makes no difference except that inside you deduct its displacement from calculations

kabosh
07-05-2013, 11:44 AM
Bigger box=lower bass.

If you removed port and sealed with a board with liquid nails and screws you will be fine.

With the new info on box thickness it makes this more guesswork, but that 31hz I stated to you will be lower with more airspace internally.

Oh, and the port inside or outside makes no difference except that inside you deduct its displacement from calculations

Ok man you have been a huge help I apreciate it
I've decided to close both ports up and re aero port it with just one facing the rear instead of up. So sub up port back. I might chop off the width to get close to 6 cubes as well, that or put more **** in it for displacement lol

kabosh
07-05-2013, 12:02 PM
Bigger box=lower bass.

If you removed port and sealed with a board with liquid nails and screws you will be fine.

With the new info on box thickness it makes this more guesswork, but that 31hz I stated to you will be lower with more airspace internally.

Oh, and the port inside or outside makes no difference except that inside you deduct its displacement from calculations

One more question for ya. If i finnaly get this box tuned low is it gonna make a big difference like I'm expecting? Right now it looks to be tuned high 40s and it's an 18 OA. it hits but my 12 hdc3 blew it out of the water hard even on lows.

bassman_soundki
07-05-2013, 02:56 PM
Yeah it is basically unloading the driver below 40 or thereabouts instead of re-enforcing those frequencies.
You might see around 6db boost in the lower notes after the repair. 3db around port frequency is normal, but also you are losing at below tuning now so 6db+from 30-40 hz sounds reasonable.
3db is what is considered an audible increase, and 6db will sound a lot louder.

To use up internal space you can add lots of bracing as well. The less flex a box has the better sounding and louder the bass

kabosh
07-06-2013, 12:30 AM
Yeah it is basically unloading the driver below 40 or thereabouts instead of re-enforcing those frequencies.
You might see around 6db boost in the lower notes after the repair. 3db around port frequency is normal, but also you are losing at below tuning now so 6db+from 30-40 hz sounds reasonable.
3db is what is considered an audible increase, and 6db will sound a lot louder.

To use up internal space you can add lots of bracing as well. The less flex a box has the better sounding and louder the bass

Ok I finished remaking a port on it its tuned to 28 hz. It is officially a monster its a day and night difference. So happy. I might mess with putting stuff in it for displacement later but for now im solid. Thanks so much for your advice man much appreciated you helped a ton.
Before and after shots.

bassman_soundki
07-06-2013, 02:53 AM
Nice man glad it worked out!

SounDrive
07-06-2013, 03:05 AM
Nowhere near enough port area..... You're choking your sub

kabosh
07-06-2013, 12:46 PM
Nowhere near enough port area..... You're choking your sub

Well I wish I would have known that before.

bassman_soundki
07-06-2013, 04:12 PM
Nowhere near enough port area..... You're choking your sub

He is way better off than he was.
He isnt a box builder, and making both ports would have resulted in really long ports with elbows.
At least he wont be playing below tuning now so driver damage potential is wayyy reduced.
I have a single 6" port in my HT 18 6.7ft3 net, and I dont hear any port noise with 2Kw going to it.

He also plans to make the box smaller as well, so this is just temporary.

Silverado SS
07-06-2013, 04:24 PM
Nowhere near enough port area..... You're choking your sub

Agreed

SounDrive
07-07-2013, 06:12 AM
He is way better off than he was.
He isnt a box builder, and making both ports would have resulted in really long ports with elbows.
At least he wont be playing below tuning now so driver damage potential is wayyy reduced.
I have a single 6" port in my HT 18 6.7ft3 net, and I dont hear any port noise with 2Kw going to it.

He also plans to make the box smaller as well, so this is just temporary.

Uhh... Okay... I'll just bite my tongue on that one. Have fun with your 4 in port per ft

bassman_soundki
07-08-2013, 12:52 AM
Uhh... Okay... I'll just bite my tongue on that one. Have fun with your 4 in port per ft

Maybe I would think you were interested in helping, but your derogatory undertone tells the real story.

Several ppl saying what not to do, but where were you when he asked for help, or where is the "SAGE" advice now?

SounDrive
07-08-2013, 01:03 AM
Maybe I would think you were interested in helping, but your derogatory undertone tells the real story.

Several ppl saying what not to do, but where were you when he asked for help, or where is the "SAGE" advice now?

He has half the port area he should so it's going to still sound like trash. Add another 6" aero and adjust port length accordingly. There's the advice.

bassman_soundki
07-08-2013, 02:48 AM
He has half the port area he should so it's going to still sound like trash. Add another 6" aero and adjust port length accordingly. There's the advice.

Bad day here, didnt mean to come off like a ****.

Anyway I agree 2 ports is better, but he is going to reduce box size.
When he rebuilds box would be a better time to buy tubing and port it correctly, based on remaining volume, or just do a slot port.

SounDrive
07-08-2013, 04:19 AM
Bad day here, didnt mean to come off like a ****.

Anyway I agree 2 ports is better, but he is going to reduce box size.
When he rebuilds box would be a better time to buy tubing and port it correctly, based on remaining volume, or just do a slot port.

I'd just recommend him to go ahead and redo the box ASAP. Maybe even get a design from Buck or get someone to build it so there's little to no room for error