Video - https://youtu.be/S39hhux7l8s
WinISD - http://www.linearteam.org/
Volume Calculator - https://www.the12volt.com/caraudio/boxcalcs.asp
This is a very important step, but not a difficult one (save the fear for crossover design… jkjk). We will use free and easy to use software to help us get the enclosure volume and port diameter and length needed to hit the tuning frequency we are looking for.
Enclosure design is one of my favorite steps. How your enclosure is designed is a great place to express your creativity in speaker design.
Step 1 - Load Your Driver
If the driver you’re using isn’t preloaded into WinISD, watching 123Toid’s tutorial and get that info in there.
Tutorial - https://youtu.be/Ol7K5wQrFAg
Step 2 - Choose Enclosure Design
You’ll now have the choice of the type of enclosure you’ll be using: sealed, vented, passive radiator, or others. Look back into step one and select the type you want to test.
I would recommend starting out with selecting a Chebyshev alignment or branching out to others if you’re feeling adventurous.
Step 3 - Vent Dimensions
Once you have the numbers the software spit out, it’s time to play. Head over to the “vents” section and make sure the length of the vent will:
- Fits inside a reasonable enclosure size.
- Matches a port available for purchase (if you won’t be building your own).
Remember: The smaller the port diameter, the shorter the length needs to be.
Step 4 - Port Chuff
Too much air going through a small port will make a noise called “chuffing”. To get ahead of this problem:
- Set your wattage under “signal” to the driver RMS.
- Switch the graph to “rear port - air velocity”.
- Make sure the spike on the graph is under 20.
If the graph spikes over 20, increase the diameter of the port.
Step 5 - Enclosure Volume
Find enclosure volume under “box” and take note of the number. Head over to the volume calculator and start inputting enclosure dimensions until you come up with an enclosure volume that is slightly above what is recommended by WinISD.
Remember: Driver magnet, port tube, and any cabinet bracing all take up volume inside the enclosure. If you want to be exact, add up that volume and subtract it from your calculated enclosure volume.
Also, remember to keep your goals and constraints close by during this step.
Step 6 - Sketch It Out
Now that you have a rough size of what the enclosure needs to be, you can start sketching out how you want it to look. Be creative! This is your chance to let it all out. Do something fun!
Remember: This is an iterative process. If you want a wider or taller design, go back to the calculator and find out what can be done. Keep circling back to step 5 until you have exactly what you want.