[andygaof]

Hi all,

I come from China and Just joined, maybe the english is not good enough. I need some help to understand EDGE simulator better.

1. What does the 'edge sources' and 'Speaker source density' mean?

2. Does MIC distance means how far the MIC is infront of the OB?

Also can somebody show me some other tool can simulate the U type OB?

Many thanks

[JohnR]

1. I understand it's to do with the simulation. More sources = more accuracy but slower results.

2. yes

You could try Martin J. King's software. There's a very modest donation/payment required. http://www.quarter-wave.com/ ... or not, since it now says "Out of Business, Restricted Access 2/1/14"... not sure what that means.

The other option is to just build a prototype and measure it.

[MJK]

You could try Martin J. King's software. There's a very modest donation/payment required. http://www.quarter-wave.com/ ... or not, since it now says "Out of Business, Restricted Access 2/1/14"... not sure what that means.

At the beginning of January I notified my Yahoo mailing list that I was discontinuing access to the MathCad worksheets. There was no one big reason, just a lot of little reasons. The MathCad Explorer program was issued in 1998 and is no longer straight forward to get running under Windows 7 and 8 like it was under XP, I could no longer easily maintain the worksheets in a version compatible with the free Explorer program once I reformatted my main desktop computer last summer (my old laptop crashed this week eliminating my last potential link to the version 8 worksheets), I still had a huge issue with DIY license users funneling designs to commercial speaker builders (I keep a list of both), and finally the biggest reason was a lack of interest in the DIY community which saw the number of new users drop dramatically over the last six months of 2013. It was just not worth my time any more.

Will I provide new more powerful worksheets in the future? Definitely not in the near future. I have started upgrading all of the worksheets for my own use, the biggest improvements are the extension of the TL models to 10 kHz, the inclusion of a midrange driver or tweeter, and general passive/active crossover design capabilities (in other words include the whole system in the model). I have a bunch of other improvements I also intend to add. If these models ever become available they will not run under the free MathCad Explorer program which is a huge limitation for DIY users. If I eventually decide to make new worksheets available the distribution will be limited (those current bad actors will not be given access). As a result I do not believe the average DIYer will be able to run new worksheets without a significant investment in a real MathCad license, probably not very likely to happen. After a great 10+ year run I think it is safe to conclude that MathCad worksheets will not return for general DIY use.

Martin

[JohnR]

At the beginning of January I notified my Yahoo mailing list that I was discontinuing access to the MathCad worksheets.

You didn't notify the people that had paid for access to them... anyway, it's no big deal, I think I downloaded most of them and will try to use them when and as I can. Best of luck with the new sims and dev.

[MJK]

You didn't notify the people that had paid for access to them... anyway, it's no big deal, I think I downloaded most of them and will try to use them when and as I can. Best of luck with the new sims and dev.

John,

Existing users should not be impacted, I have only stopped access for new users. New users, which were not that many, started to have problems running the worksheets on the latest versions of Windows. The free MathCad Explorer program was first made available in 1998, like many other programs from this era it is aging poorly. Many new users were struggling to get the software running and I started to take a lot of crap including fraud complaints. It was no longer a fun hobby.

An existing user with a correct User ID and password should be able to log in and download anything that is currently available. If you are having problems let me know and I will double check to make sure everything is working correct and update your information if necessary.

If somebody is interested in what I am doing, they should join my Yahoo Group. This is my main avenue for discussion and distributing information, I rarely post on DIY audio forums any more.

Martin

[DanH]

Martin I am sorry to hear that your mathcad spreadsheets came to cause you grief. I have enjoyed my copies. They were well worth your licensing fee. I have designed more speakers than I will ever have the time and resources to build though. I really appreciate the fact that you developed these and made them available for hobbyist like myself. As they say "no good deed goes unpunished".

I am running mathcad explorer under windows 7, occasionally something called "resdll" crashes but it is not a deal breaker.

[MJK]

Hi Dan,

Thanks for the positive feedback, it is greatly appreciated.

Martin

[andygaof]

all,

thanks for your feedback. can somebody share me some reference to use edge? as well as, some documentations I  can use to understand OB well?

many thanks again.

[guest42212]

http://www.hi-fiworld.co.uk/loudspeakers/68-technology/144-designing-loudspeakers-open-baffles-and-bass-part-15.html

[MJK]

thanks for your feedback. can somebody share me some reference to use edge? as well as, some documentations I  can use to understand OB well?

The Edge program will only tell you the behavior of the baffle's influence, it does not model the actual driver in the baffle so the results are somewhat incomplete. Be careful how you interpret the results and don't read too much into the plotted curves.

A couple of links.

http://www.quarter-wave.com/OBs/OB_Theory.html
http://www.quarter-wave.com/Project08/Project08.html
http://www.quarter-wave.com/Project09/Project09.html
http://www.quarter-wave.com/Project10/Project10.html

http://www.musicanddesign.com/index.html

http://www.linkwitzlab.com/

http://www.dipolplus.de/thema11.php

These are just a few of the many sites on dipole speakers. The physics and math are the same but each makes slightly different trade-offs. Wide or narrow baffle, passive or active crossover, number of drivers, and so on.