Understanding round port calculator
Administrator
Joined: Feb 2006
Posts: 16,860
In theory? You mean hypothetically? Well let's take a look here..
What does this mean? A vent design will have a diameter and a length. The vent should be as close to this as possible. Diameter is hard to change but if you blow the length it will change the tuning. By how much is determined by the rest of the design.
Define "needed" and clarify how much more. Once you are below 0.5mach it makes little sense to have more port area from an SQ point of view but having too much vent can be bad as well.
I never recommend this, but more from an aesthetics and fluid dynamics standpoint than anything else.
People have tried this. It will definitely change the tuning of the box. What are you trying to achieve though? A few extra DB by tuning a box higher? Not worth the effort IMO.
Is an apple too much compared to hammer? How about shoe to magenta?
Attempting to correlate vent area to enclosure volume with no consideration given to displacement and tuning is poor design practice. You would be wise to forget this.
IMO let's say it is less than ideal.
How forgiving are round/flared ports for port area? Can you use more ports than needed, ports outside the box, and stuff one or two ports with something so it can be tuned on the fly from 28-35-40 Hz, like this... ?
4 8" aeros
22.4" length
Vb 11.995 cf^3
4 ports - 39.99 Hz / 16.746 per cube
3 ports - 34.63 Hz / 12.56 per cube
2 ports - 28.275 Hz / 8.373 per cube
1 port - 19.995 Hz / 4.186 per cube
Is 4.186 & 8.373 too little port area or 16.746 too much? Is 22.4" too long?
4 8" aeros
22.4" length
Vb 11.995 cf^3
4 ports - 39.99 Hz / 16.746 per cube
3 ports - 34.63 Hz / 12.56 per cube
2 ports - 28.275 Hz / 8.373 per cube
1 port - 19.995 Hz / 4.186 per cube
Is 4.186 & 8.373 too little port area or 16.746 too much? Is 22.4" too long?
How forgiving are round/flared ports for port area?
Can you use more ports than needed
ports outside the box
stuff one or two ports with something so it can be tuned on the fly from 28-35-40 Hz
Is 4.186 & 8.373 too little port area or 16.746 too much?
Attempting to correlate vent area to enclosure volume with no consideration given to displacement and tuning is poor design practice. You would be wise to forget this.
Is 22.4" too long
Last edited by Dukk; Dec 2, 2010 at 03:30 PM.
Thread
Thread Starter
Forum
Replies
Last Post
420guy
Enclosure Design & Construction Help
15
Feb 16, 2009 12:22 AM
phat_71
Enclosure Design & Construction Help
28
Jan 5, 2009 06:46 AM
