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Discussion Starter · #1 ·
After trying many different designs, I have found that my ears prefer a Transmission Line enclosure.
I have done TL's the easy way taking only into account the VAS, FS and sd of the driver but I have left out the QTS when calculating my TL's.

sd of driver to figure out line diameter:
1/4 wave of FS to figure out line length
Vas to figure out .5 q in a sealed alignment

Can anyone on here help me figure out the correct way to put a Mal-X into a transmission line? :innocent:

There might be other members on here that would be interested in a TL Mal-x....

When building a box this large and heavy and using expensive wood I really don't want to miss calculate. :bigsmile:
 

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Discussion Starter · #3 ·
Thanks dyohn, I am familiar with his work and used his formula to bid some experiments with smaller drivers, but can't figure out how the QTS plays into the formula. I really did not want to go experimenting with 120.00 dollars worth of wood and a 60 pound woofer. :rolleyesno:

I figured if I could figure out a TL for the mal-x it would be another DIY enclosure to add to the database.:)

Matt
 

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The Qts of the woofer (or what Mr. King refers to as the Qtd in some of his documents) determines the resistance factor (Dr) in his math spreadsheets, which he uses to determine the "driver offset ratio." Download this document: http://www.quarter-wave.com/TLs/Alignment_Tables.pdf to see how he uses it. Read especially the notes on pages 20-21 concerning how Qts affects the resonance in a TL.

The 18" Maelstrom woofer has a Qts listed as 0.37 and the 21" as 0.42. Normally a woofer is best suited for TL loading if its Qts is between 0.25 and 0.7 so either one is right in the middle and should work well.
 

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Isn't Martin selling his software again? Thought I read something about it on diyaudio recently.

Hornresp can apparently model TLs from some of the posts I've seen on diyaudio. One guy there (who's moniker eludes memory right now) has used it to show examples.
 

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Discussion Starter · #6 ·
Has anyone used his software? His work sheets are really math intensive and a lot his theory's are to complicated, to say the least. :bigsmile: To much time spent reading his work and it will make a man :dumbcrazy:

The software sounds like the way to go if it is usable.


Matt
 

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Discussion Starter · #7 ·
After frying my poor brain reading Martin Kings tables. I am still stuck on how to select the "area ratios SL/S0". :scratch: Is there a way to do it or do you have to actully calculate that crazy formula? :dumbcrazy:

Quote from the document:
Tables 1 and 2 contain the effective
lengths and the peak shape function magnitudes for classic transmission lines tuned
between 20 Hz and 70 Hz and having area ratios SL/S0 between 0.1 and 10.
 

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did you ever get further on this?
 

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Discussion Starter · #9 ·
Thanks to planet 10 I have found out there is a spread sheet that can be downloaded but I have not tried it yet. Do you want me to dig up the link?

Matt
 

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yeah!!!
 

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From what I've been told if you actually buy Martin King's worksheets and run them in Mathcad they're as straight forward and easy to use as WinISD. Or so I have been told by people who have done this. Food for thought.
 

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Discussion Starter · #13 ·
Here is the link to the excel file, it is down near the bottom. You have to look for it, as I missed it the first time.
http://www.quarter-wave.com/TLs/TL_Theory.html

Mmmm maybe I should buy the worksheets just to take a peek. :scratch:

Matt
 

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Not if I buy it first Muwahahahahahh...aha!
 
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