hey so i want to build an aeroport enclosure for a fi ssd 12 @ 33 hz and i have no idea if this graph is good or not. this box is 2.5 cubft and also i want to use a pvc port but i only have a 6inch pvc pipe at 15 inches in length and for what i need i will need a 21 inch long port for 6 inch port but i have also have a 4 inch pipe that i only need around 9 inches in length so im thinking about using the 4 inch but not sure if that will give me enough port area and not choke the sub. so can anyone tell me if this graph is good or is it too peaky at the 33hz point and if this is too much of a peak how can i make the tuning of the box more flat?

test1 graph.bmp

I can't see the graph.  Did you model it with the amplifier power added and then check port velocity?  That will tell you more about port size than anything.

How are you sure you don't want some peak?  A little gain (peak) is desired by many.  Can lengthen the port if you want it to change or of course change the box size.

The biggest problem with doing what I described above is that now you will know you get to choose your port velocity.  No matter your choice you get to live with it since you built it.  If you don't like it later, you'll blame knowing...but of course you will know exactly how to fix it.  I'd rather know and re-do than guess and re-do

file:///C:/Users/jjcag_000/Downloads/test1%20graph%20(1).bmp

test1 graph (1) (1).bmp

i dont have the pro version and cant see were the velocity is

Every version I have ever seen does and the Pro is also free...

Still can't see your pics.  Host them on imageshack, photobucket or the like

took a pic with my phone kinda dark

Edited August 25, 20169 yr by FiAudioSubwoofersjj

can i get a link to a download for winisd pro cuz for som reason everytime i try to enter linearteams websitemy computer says that it cannot connect to the page but everyother website i am able to enter. thanks

http://www.linearteam.dk/?pageid=winisdpro

 

This one is a tutorial, if you need it.

http://www.hometheatershack.com/forums/diy-subwoofers-general-discussion/6330-winisd-pro-tutorial-download-detailed-guide-how-use-winisd-pro.html

Cool thanks

... So what do u guys think if the graph too peaky??

I think it looks good, I personally prefer a peak in the low 30's. Check port velocity though. As you will get audible port "chafing" (undesired port noise) if it's to small. 

What's the most velocity I can get away with without any port noise?? Oh and for more info I want this for an "SQL" Build and is going into a 2001 Mazda Tribute and the miss and highs are going to be played by NVX NSP68 coaxials for now until I can get some active components

Edited August 25, 20169 yr by FiAudioSubwoofersjj

Without ANY?  Not much...

Not the right question.  The question is how much are you willing to deal with and at what listening levels does it become acceptable.  Exactly why I hinted above sometimes knowing sucks since everything is a compromise and now you get to pick it.

Some people will tell you 10m/s others deal with 100m/s.  In a car 10 is absurd, but 100 is always absurd.  Go model both extremes at full power and you will see the variance it creates.  You will also find out that it becomes prohibitive in a car to get anything super low (either tuning or port velocity)....but being in a car it is easy to chase a law of diminishing returns as well.  ie, remember the easiest way to make your car sound better is to lower the noise floor of your car, not improve your stereo further.

Without modeling, I would suggest getting a longer piece of the 6".

 General rule is 16 to 20 in.² of port area per square foot.  The last ported I built sounds steller with about double that.

What do u mean exactly when u say no modeling ??... Meaning no winisd?

When I model this on TermPro, my results seem to be similar on the Relative graph. It's kinda peakish. But that's due to the t/s parameters of the sub. The graph doesn't look too hateful but, to get a more flat of a response the tuning would have to be stupid low. The roll off on the graph basically you're gonna have to deal with. As for the port velocity, a single 4" round models out way too high on velocity. I get a mach percentage of 17.54%. Using 2-4" ports cuts it down almost in half to 9.11% but also doubles the length of each to 20.54". Using a single 6" port at a length of a little over 23" which yields the lowest of 8.13%. All of this was done using your 2.5 cu.ft. net tuned to 33 hz at 1000rms. Based on the whole design of what you are actually trying to build and the space need to do so being vague, this is not really info that I would take off to the table saw with.

2 hours ago, Jay-C76 said:

 

i have no idea why but in when i setup everything of a 2.5 cuft with 1 6 inch port at 23 inches length is says vent mach is .02 .. and with 2 4 inch ports at 21 inches in length it says vent mach is .01

2 hours ago, Jay-C76 said:

When I model this on TermPro, my results seem to be similar on the Relative graph. It's kinda peakish. But that's due to the t/s parameters of the sub. The graph doesn't look too hateful but, to get a more flat of a response the tuning would have to be stupid low. The roll off on the graph basically you're gonna have to deal with. As for the port velocity, a single 4" round models out way too high on velocity. I get a mach percentage of 17.54%. Using 2-4" ports cuts it down almost in half to 9.11% but also doubles the length of each to 20.54". Using a single 6" port at a length of a little over 23" which yields the lowest of 8.13%. All of this was done using your 2.5 cu.ft. net tuned to 33 hz at 1000rms. Based on the whole design of what you are actually trying to build and the space need to do so being vague, this is not really info that I would take off to the table saw with.

 

Edited August 26, 20169 yr by FiAudioSubwoofersjj

16 hours ago, FiAudioSubwoofersjj said:

What do u mean exactly when u say no modeling ??... Meaning no winisd?

I meant I did not model your particular sub.

Personally I don't like winisd I have had too many variances when I try to design using the program. Maybe it's just me. That being said, I have never had an issue with accuracy using TermPro. Most people don't usually need to design a lot of enclosures so spending money on a program isn't logical. I'm not sure why the two programs are so far off from each other on round port velocity. Here are pics of what I came up with, maybe you might see something I'm missing.

On 8/26/2016 at 1:59 PM, Jay-C76 said:

Personally I don't like winisd I have had too many variances when I try to design using the program. Maybe it's just me. That being said, I have never had an issue with accuracy using TermPro. Most people don't usually need to design a lot of enclosures so spending money on a program isn't logical. I'm not sure why the two programs are so far off from each other on round port velocity. Here are pics of what I came up with, maybe you might see something I'm missing.

why are there two lines in your graph?

17 hours ago, FiAudioSubwoofersjj said:

why are there two lines in your graph?

I can actually have 4.

Green is relative response which shows deviation from flat -vs- frequency. This is used to basically show any frequency roll off. The more flat of a line at zero the more the design is capable of playing a wider range of notes equally loud. Flat is very good for sound quality. 

Blue is spl (not in reality). This is used to trace applied power in & out.

Yellow would be power trace. It's used to show power applied before possible mechanical or thermal failure.

Pink would be cone displacement. Used for excursion -vs- frequency.

so is there an aeroport design that is tuned correctly that i should build? or will the 2.5 cuft box with 2 4 inch aeroports tuned at 33 hertz with the high peak at 33 be good enough? i dont know what i am doing wrong , im inserting all the t/s parameters with the proper size box and tuning and always ends up being peaky at 33 herts