Speaker Design Basics: 2 steps to know before you build.
Good design is vital for successes in a speaker or subwoofer enclosure performance. This first video about SpeakerEnclosureDesign goes into basics of air volume and vented box tuning. There is two tips that help to measure box volume and measure vented box tuning and then using that tuning to design different size port for your project.
There is 2 Key things to know in your subwoofer or speaker cabin design, especially if this is your first build. These are:
- Speaker enclosure air volume
Too small air volume for your project mostly hearts low bass output. If you can, measure first, how much space you have and choose speaker drivers that works for that space. It is better to have more than less air volume of the recommended. Also note that port and braces take up space.
So what should be my box volume, go with the speaker element manufactures recommended size or check my next video for how to do custom design. If you have old speakers that you are going to do makeover and you don’t know parameters for, measure old volume and use that.
Easy trick to measure volume in litres is to use decimetres. Example if sub box is 82.5 centimetres wide, that is 8.25 decimetres, that times 3.1 for the depth times 3.4 decimetres for the height and you get straight to the litres, in this case about 87 litres.
Or if we need 200 litre box divide that by our width 10dm minus thickness of the wood 0.4dm times height without wood sheet thickness 4.4dm And that gives out how far that box needs to come from that back wall. And it is with wood about 5.1dm so that is 51cm.
Also one important thing is that cabin is tight with no holes and all the seems are good, so that air volume can function proper.
2. Vented box tuning.
Getting the vented box right is harder and more complex than sealed but rewards can be amazing. Vented utilises also a back side of the bass driver for the sound that is coming to the listening area. That gives opportunity for much more bass for given speaker size and prize. Before you just drill holes for all your speaker boxes, plan if that driver is going to work for vented box and with size of enclosure and port it needs. Speaker driver manufacturer probably has recommendations. If you are changing already existing design note that both and cabin air volume and port size terminates system tuning. And for the reflex port if area of the vent increases so has to length to keep the tuning a same.
Example you got factory made vented box but you want to change the shape of it and also port is little stuffy sounding so you want to make it larger. First we measure the old designs inside air volume. Then we measure the port area and length. We can use calculator at the mh-audio to plug our numbers in and see the supposed tuning of our system and then use that tuning to measure our new port length with this calculator, we just put our new wanted diameter and we get the length, notice that this length doubled for the same tuning because our actual area here doubled. Now we have our new port size just measure how much that will take up space and what the dimensions of the outside box will be.