WinISD model
Printed From: Speakerplans.com
Category: Plans
Forum Name: Ported Enclosures
Forum Description: Post all your reflex and bandpass and 'other' boxes with holes in stuff here...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=93735
Printed Date: 27 March 2026 at 6:53am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: WinISD model
Posted By: sn95
Subject: WinISD model
Date Posted: 01 November 2015 at 9:16pm
| when modeling drivers in WinISD is transfer more important then SPL driver 1 has a better trans and driver 2 more spl. |
Replies:
Posted By: ceharden
Date Posted: 01 November 2015 at 9:46pm
| If you are comparing drivers then you must look at the SPL plot. The transfer function only shows the shape of the response and is relative only to the average sensitivity of the driver. |
Posted By: bob4
Date Posted: 02 November 2015 at 10:12am
|
you need to consider driver excursion as well! IMO you need to balance AT LEAST max SPL, magnitude response and excursion (port air velocity would be good too to prevent "farting") I haven't designed anything of my own, just simulated known designs with different drivers and some of my own ideas (only CB and reflex so far!) my method (corrections and improvements warmly welcome! :) ): 1. adjust box volume (and tuning freq for reflex) if unhappy with Winisd's suggestion 2. check freq response 3. set signal to half rated RMS power 4. examine excursion plot -> if it's at half xmax, you can mess with box size or eq (linkwitz transform) to get the LF response the way you want it; if excursion is close to or exceeding the limit there is something wrong! at the very low end between 20 - 40 you will usually run out of excursion anyway, so you can set a HPF to limit excursion there. Above 40 Hz, you can actually decrease excursion by tuning the cabinet higher (port resonance decreases driver excursion!!!). 5. recheck magnitude response and SPL; if the curve looks good, check if there is excursion to spare -> if yes increase signal power until you reach excursion limit; That gives you max input power and SPL max for your current design 6. if not happy with freq response, you can readjust box volume, tuning freq and EQ/filters all these are interdependent. Bigger box also decreases cone control -> increasing excursion What happens depends on the individual driver. Try simulating many drivers with a certain set box volume. You will see the difference between the different drivers, some will be impossible to get acceptable results with......    IMO one way to recognize a potentially suitable driver for your design goal is if WINISD automatically comes up with a box volume close to your design goal - you shouldn't have to fiddle around too much to get a good result. |
Posted By: sn95
Date Posted: 02 November 2015 at 12:48pm
| thank you very much for all your inputs I have mess around with box size port tuning.and also adjusted input voltage to indicate driver xmax.looking at trans driver a is about +3dB and looking spl driver b is + 3 to 4 dBs in the 30/40 hz.My go is good spl to about 25 hz. |