diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Multi-Way (http://www.diyaudio.com/forums/multi-way/)
-   -   TL - cross section (http://www.diyaudio.com/forums/multi-way/84754-tl-cross-section.html)

00940 15th August 2006 11:59 AM

TL - cross section
 
I'm attempting to build a pair of colums based on the vifa D25TG-05-06 and P17WJ-00-08. I found a few designs using this woofer in transmission lines :

- Timc's here : http://www.diyaudio.com/forums/showt...threadid=11333
- These : http://www.geocities.com/bunkie21/index.html
- The PMC FB1.

Looking around the web I found a lot of info. I've been playing a bit with Martin King alignement tables and now I'm a bit puzzled.

The size of the boxes above are all around 200/300mm for the external width/length. But, from the results from the alignement tables (for a tapered TL, SL/SO=0.5), I need a cross section of 4*136mm˛ for SO. This is way more than the cross section found on the designs above. A tapered line with a ratio of 0.5 for Sl/So won't fit in such columns.

Question one thus is : should I build a bigger box to follow the alignement tables or go with known speakers ?

Question two (unrelated) : a single fold line with the vent on top (such as this one : http://www.humblehomemadehifi.com/Optimo.html ) seems the easiest way to design and build a TL. Any reasons not to use it ?


Thanks :)

00940 15th August 2006 05:03 PM

2 Attachment(s)
here's the rough idea of what I've in mind :

Notax 15th August 2006 08:39 PM

Quote:

Originally posted by 00940
here's the rough idea of what I've in mind :
Something like that, but its to big cross section. I recommend 80 mm instead 130 mm, 120 mm instead 200 mm and 180 mm instead 270 mm. Width 180 mm.

So=8x18=144 cm2 (little more than cone - Sd)
Sl=17x18=306 cm2

00940 16th August 2006 06:13 AM

Thanks Notax. :) If I may ask (I'm trying to learn), what are you basing yourself on for deciding on the cross-section ? Experience, other equations ?

Notax 16th August 2006 12:10 PM

Quote:

Originally posted by 00940
Thanks Notax. :) If I may ask (I'm trying to learn), what are you basing yourself on for deciding on the cross-section ? Experience, other equations ?
Other projects. Mostly open area is something between 0,65-1,15*Sd.
And Sl/So is from 1:1 till 10:1 (but more till 3:1). Smaller Sl is mostly for 2-way. Its more complicated. Look at


www.quarter-wave.com

and

t-line


All times are GMT. The time now is 03:18 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2