need help verifying Winisd(added pics)

[poolman966554]

so i figured out i want to run a single SA-12 (4ohm wired to 2 ohm) and want a custom slot ported 2cu ft box at 34hz. Ive done all the math to calculate port area/lenght, and box airspace to fit my car.

i installed winisd and input the parameters to create the sa-12 sub in the program. upon loading the new sub, it says the sa-12 peaks at 138hz in a 2ft box tuned to 34hz. even when i input my port dimensions, it barely changes

how can this be? i triple checked all data i entered, and even let it auto calculate everything as it was more precise.

I wanna say fk it and just build the dam box, but ive read over and over that people love this program. i just wanted to see what the port air speed was going to be

edit:

http://i.imgur.com/F4roqYT.jpg - sub parameters winisd is using

http://i.imgur.com/GCzcHUM.jpg - what winisd is showing

Click to read more...

 

[wew lad 5,000+ posts]

Use WinISD alpha, not beta. Beta has an easier GUI, and alpha has more in depth options such as port velocity.

Changing the port size will change the tuning of the box, so what I'd recommend is choose your volume, then choose your tuning frequency that gives you the most gain where you want it (or flat if you want that). Then go to the port tab to see what it recommends, if you need a square or circle click on that. Modify it to your needs and try to keep it as close to your original tuning frequency while keeping port velocity low. Ideally you want less than I think 10% the speed of sound (this is where air compression starts, and you'll get noise, complicated subject I'll leave it at that). Ends up requiring a port velocity under 30m/s or so.

 

[poolman966554]

i have winisd pro Alpha

 

[wew lad 5,000+ posts]

i have no idea what you did, that never happened to me..

 

[poolman966554]

interesting.. could you possibly run the sa-12 for me? maybe you could tell me what the port velocity is?

 

[wew lad 5,000+ posts]

I did the port velocity with 1000w RMS, right click - view image if it's too small to read. it's 25m/s if you wanted it converted, looks reasonable to me

 

[poolman966554]

thanks alot ! i appreciate you taking the time to help. looks like i need to sit down and figure out my results are off the charts! thanks again!

 

[wew lad 5,000+ posts]

you have to be deliberate about entering the numbers. there's a method online somewhere, but if you do it incorrectly you'll end up with bad results, I can see you definitely did this because of the 98 db sensitivity in your first pic.

you're welcome, glad i could help

 

[Pav26 10+ year member]

You messed up on inputting parameters. Vas is not 24 cubic feet, lol - more like liters //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif