Go Back   Home > Forums > >

Slotted port length and aero port length.
Slotted port length and aero port length.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 26th March 2013, 02:07 AM   #1
deebeez92 is offline deebeez92  Canada
diyAudio Member
 
Join Date: Mar 2013
Location: Ontario Canada
Default Slotted port length and aero port length.

In WinISD, the ABC enclosure (basically 6th order bandpass) I have designed has insanely high air velocities in the port. Well above 20 m/s , while I believe the recomended is <17?

Anyways, to get it right and under control, I have my rear chamber using a slot port, my front chamber using an aero port, and the intrachamber using an aero port. Switching any of those increases the air velocities way too high, not sure why slot reduces in one chamber, while raising in other.

I can't come up with any reason why I couldn't use both styles of ports, as they each offer benefits.

My question is:

Is port length and port area calculated the same? In ABC's, all three ports have to be exactly the same size (or tuned the same, i'm not sure if there is a difference), so is one square inch of slot port worth one square inch of aero port?
  Reply With Quote
Old 26th March 2013, 03:43 AM   #2
just a guy is offline just a guy  Canada
diyAudio Member
 
Join Date: May 2006
What is aero port? I did a quick search and it seems that it might be a brand name for a regular heavily flared port. If so you should use those whenever possible, but they are very expensive and you can make your own heavily flared ports from heated abs.

I'm not sure why all three ports would have to be the same size, you simulate until you get a good result and then you use whatever length and diameter you end up with in the sim.

Some people recommend 17 m/s as a good balance between port size and velocity issues, some people are happy with much higher velocity than that, but a lot of people are much more conservative and recommend under 10 m/s. Ports introduce losses into the system unless they are very large, even at 10 m/s there are losses, and as velocity gets higher the losses increase as velocity turns into turbulence, distortion and noise, and when it gets really bad you get severe compression and the port ceases to function at all.

Flared ports need to be a bit longer than straight ports to achieve the same tuning. There are rules of thumb for this but it's best if you can measure impedance and adjust as required.

Last edited by just a guy; 26th March 2013 at 03:45 AM.
  Reply With Quote
Old 26th March 2013, 04:07 AM   #3
deebeez92 is offline deebeez92  Canada
diyAudio Member
 
Join Date: Mar 2013
Location: Ontario Canada
An aero is just a name for a pvc port. slot port vs aero port. if you google that you'll get a better idea. Why they say all three ports have to be the same size idk.

thanks for the info.

say even in a dual reflex, could you see any reason why I could not use a wooden slot port and then a pvc (aero) port?
  Reply With Quote
Old 26th March 2013, 04:18 AM   #4
just a guy is offline just a guy  Canada
diyAudio Member
 
Join Date: May 2006
I did google image search and it looks like regular heavily flared abs ports. But I think you are just talking about round ports vs slot ports.

You can use whatever you want, including passive radiators. There might be very specific situations where one type won't work but in general flared ports are always preferred to non flared and passives are used where ports won't fit or when the extra price is worth the size reduction. Slot ports are fine too but if the aspect ratio gets too high air won't flow as well as it would in a circular port.

Last edited by just a guy; 26th March 2013 at 04:28 AM.
  Reply to this post

Reply


Slotted port length and aero port length.Hide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
port length tald Multi-Way 7 14th January 2010 01:26 PM
port length jwhit67 Multi-Way 1 6th March 2008 12:29 PM
Help with port length please Bobhof Multi-Way 3 2nd May 2006 06:32 PM
port length dave k Multi-Way 13 13th July 2003 02:32 PM


New To Site? Need Help?

All times are GMT. The time now is 03:08 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki