How do i calculate triangular ports?
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 Thread Tools Search this Thread
 15th June 2012, 09:45 PM #1 CCU   diyAudio Member   Join Date: Apr 2007 Location: Kgs. Lyngby How do i calculate triangular ports? Hi I'm building some PA speakers and i wanted to make the refleks ports triangular so i can place the on the front around the speaker unit. But i can't find any calculator or formulas to calculate the size of the ports (that provide the same answer...) Can you guys help me? Thanks a bunch!
 15th June 2012, 10:15 PM #2 DBMandrake   diyAudio Member     Join Date: Nov 2010 Location: Glasgow, UK As a first approximation I would probably calculate based on a square/rectangular port of the same area, as a triangle would have turbulence closer to a square than a round port, as they both have sharp corners. A triangle has half the area of a square port of the same width and height, so I would just enter the width of the triangle base as the rectangle width and half the height of the triangle as the rectangle height. Bear in mind that calculation of ports is only a rough approximation anyway - even if you use a smooth round tube or a rectangle it will never be exactly what is calculated because there are other variables at play that are only estimated in the calculation, such as proximity of the internal end of the port to other cabinet walls, the size of the baffle the port is located on and how close it is to the edge of the baffle etc. (Most programs assume the port is flush mounted in an infinite baffle) Always allow room for an extra 30% length beyond that calculated and expect to trim the length down based on measurement... __________________ - Simon Last edited by DBMandrake; 15th June 2012 at 10:19 PM.
 15th June 2012, 10:19 PM #3 Moondog55   diyAudio Member     Join Date: Jun 2007 Location: Norlane; Geelong: Victoria: Australia Just a wild guess here but the true value of a triangular port would probably be closer to the diameter of the circular tube that would fit inside the triangle __________________ QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"
 16th June 2012, 12:31 AM #4 sreten   R.I.P.   Join Date: Nov 2003 Location: Brighton UK Hi, Most sims include the necessary end corrections and rectangular ports. So simply halving the shortest dimension should work, i.e triangle area is half base time height, make the base the longest dimension and plug in a port base x half height into a simulator, should be near. rgds, sreten.
 16th June 2012, 12:33 AM #5 tvrgeek   diyAudio Member   Join Date: Dec 2009 Location: Md I too would guess closer to the round. You'll have to prototype and measure, then report back. I can see the attraction of putting ports in the corners.
 16th June 2012, 12:44 AM #6 sreten   R.I.P.   Join Date: Nov 2003 Location: Brighton UK Hi, It depends on the end corrections built into simulators. You can guarantee the end corrections are wrong for slot ports formed with a cabinet edge or triangular ports across corners. rgds, sreten.
sreten
R.I.P.

Join Date: Nov 2003
Location: Brighton UK
Quote:
 Originally Posted by Moondog55 Just a wild guess here but the true value of a triangular port would probably be closer to the diameter of the circular tube that would fit inside the triangle.
Hi,

Clearly totally wrong for a say 2" high 5" wide triangle.

rgds, sreten.

Moondog55
diyAudio Member

Join Date: Jun 2007
Location: Norlane; Geelong: Victoria: Australia
Quote:
 Originally Posted by sreten Hi, Clearly totally wrong for a say 2" high 5" wide triangle. rgds, sreten.
OK point taken, although most of the designs I have seen are of equilateral triangles, as these fit the corners of most boxes more easily
__________________
QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"

sreten
R.I.P.

Join Date: Nov 2003
Location: Brighton UK
Quote:
 Originally Posted by Moondog55 OK point taken, although most of the designs I have seen are of equilateral triangles, as these fit the corners of most boxes more easily
Hi,

They are not equilateral (60 degrees each vertex), they are half squares.
Equilateral does have the least difference between its area and a circle
that fits inside, but the same for half a square is clearly much worse.

rgds, sreten.

Moondog55
diyAudio Member

Join Date: Jun 2007
Location: Norlane; Geelong: Victoria: Australia
Quote:
 Originally Posted by sreten Hi, They are not equilateral (60 degrees each vertex), they are half squares. Equilateral does have the least difference between its area and a circle that fits inside, but the same for half a square is clearly much worse. rgds, sreten.
This is why I failed geometry LOL
__________________
QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"

 Thread Tools Search this Thread Search this Thread: Advanced Search

 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 Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post dannyjmf Subwoofers 17 14th August 2011 07:40 AM dead rat Class D 27 11th November 2008 05:54 PM Craig Multi-Way 1 22nd September 2002 07:30 AM Bose(o) Multi-Way 4 12th June 2002 12:55 AM

 New To Site? Need Help?

All times are GMT. The time now is 05:26 AM.

 Home - Contact Us - Advertise - Rules - diyAudio Store - Sponsors - Privacy Statement - Terms of Service - Top - Opt-out policy

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki