Transmission Line Questions - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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
Reply
 
Thread Tools Search this Thread
Old 7th July 2003, 10:56 PM   #1
diyAudio Member
 
Matttcattt's Avatar
 
Join Date: Feb 2003
Location: Bristol
Default Transmission Line Questions

I do not know anything about transmission line speakers (is that how they are described? ). i first got the idea from planet10 here. i have seen, and read the page about, El-Pipe-O. i would like to see, and read about, any other exapmples (maybe on a smaller scale ) of transmission line speakers.

i would like to know how i work out the box size, tube diameter and tube length for a set driver. can i use normal speaker software and input the tube as a port?

thank you very much for any info.
__________________
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote
Old 8th July 2003, 12:21 AM   #2
MJK is offline MJK  United States
Account disabled at member's request
 
Join Date: Feb 2002
Location: Clifton Park, NY
Hi Matttcattt,

I have recently added some classic transmission line alignment tables to my www.quarter-wave.com site. You can use these tables to quickly scope out a design for any applicable driver.

If you want more TL theory, there is a series of documents that derive the basic equations I use to model TL's in my MathCad worksheets. I have included a link to a free downloadable MathCad Explorer program which will run any of my MathCad Version 8 worksheets.

Also, there are four "quarter wavelength" loudspeaker projects that I have designed and built along with a gallery showing a number of other speakers DIYer's have built based on one of my designs or their own original design based on the MathCad worksheets.

Hope that helps,
  Reply With Quote
Old 8th July 2003, 01:59 AM   #3
kneadle is offline kneadle  United States
diyAudio Member
 
kneadle's Avatar
 
Join Date: Dec 2002
Location: Buffalo, NY
Send a message via AIM to kneadle
Default Shameless Plug

This Spiral Shaped Transmission Line Enclosure Project Complete is what I did with MJK's mathcad worksheets. A synopsis will be posted on the www.t-linespeakers.org website as soon as Planet10 has time to post it.

Good Luck!

Dave
  Reply With Quote
Old 8th July 2003, 07:20 AM   #4
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Default Re: Shameless Plug

Quote:
Originally posted by kneadle
synopsis will be posted on the www.t-linespeakers.org website as soon as Planet10 has time to post it.
Hey Dave,

You wanted to go thru the text and tweak it and i need to embed the pictures.

Preview (ie work in progress) is here:

http://www.t-linespeakers.org/projects/davidduke/
The Seraphim -- Spiral TLS

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 8th July 2003, 07:23 AM   #5
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Besides my site, and Martin's mentioned above, one needs to go thru Bob Brines.

My site has ideas, classic designs, & some few based on Martin's ground breaking work. Martin's & Bob's cover modern TL design.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 8th July 2003, 08:26 AM   #6
diyAudio Member
 
Matttcattt's Avatar
 
Join Date: Feb 2003
Location: Bristol
thanks, ill look through those.
__________________
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote
Old 8th July 2003, 11:48 PM   #7
diyAudio Member
 
Matttcattt's Avatar
 
Join Date: Feb 2003
Location: Bristol
i looked at all the links posted, but i could not find any explination of how i work out the box volume, and tube length and diameter. i could not understand any of the graphs as they were not explained. can i use winisd or any other speaker calculator program to work out the box size, classing the tube as a port? i am interested in a box, with a tube, like el pipe-o.
__________________
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote
Old 9th July 2003, 12:04 AM   #8
kneadle is offline kneadle  United States
diyAudio Member
 
kneadle's Avatar
 
Join Date: Dec 2002
Location: Buffalo, NY
Send a message via AIM to kneadle
Right, that's just it. Transmission line design frees you from volume and such. It has to do with surface area and line length. Again, it's all about the quarter wavelength of the Fs of the driver. You want to design an enclosure that best supports that frequency while damping all the resonant frequencies. That's it! No more boxes! It's miraculous and so liberating.

Download the mathcad worksheets and start fiddling. Pick a driver, enter its attributes, then mess with the two Sd parameters, the stuffing density and the line length. And keep posting back here.

The graphs are hard to explain. I'll let someone else contribute.

Dave
  Reply With Quote
Old 9th July 2003, 10:57 PM   #9
diyAudio Member
 
Matttcattt's Avatar
 
Join Date: Feb 2003
Location: Bristol
ok, ill have a look.
__________________
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote
Old 9th July 2003, 11:05 PM   #10
diyAudio Member
 
Matttcattt's Avatar
 
Join Date: Feb 2003
Location: Bristol
can someone help me put the driver parameters into the mathcad worksheet?

the parameters are:

Eminence Model No. Beta 15
Nominal Chassis Diameter: 15", 318mm
Impedance: 8Ohms.
Power Rating: 350Wrms
Resonance: 35Hz
Usable Frequency Range: 35Hz to 4kHz
Average Sensitivity 1W @ 1m: 98dB
Magnet Weight: 34oz.
Magnet Gap Depth: 0.312", 7.94mm
Voice Coil Diameter: 2", 50.8mm
Mounting Information
Overall Diameter: 15.15", 384.8mm
Baffle Hole Diameter: 13.77", 349.6mm
Front Sealing Gasket: fitted as standard
Rear Sealing Gasket: fitted as standard
Fixing Holes Diameter (8 off): 0.25", 6.4mm
Fixing Hole P.C.D.: 14.56", 369.9mm
Depth: 6.05", 153.6mm
Weight: 9lbs, 4.08kg
Shipping Weight: 11lbs, 5kg
Thiele-Small Parameters
Resonant Frequency (fs): 35Hz
Impedance (Re): 6.32Ohms.
Coil Inductance (Le): 1.10H
Electromagnetic Q (Qes): 0.63
Mechanical Q (Qms): 8.10
Total Q (Qts): 0.58
Compliance Equivalent Volume (Vas): 334.6 litres
11.82 cu.ft
Peak Diaphragm
Displacement Volume (Vd): 327cc
Mechanical Compliance
of Suspension (Cms): 0.35mm/N
BL Product (BL): 11.5 T-M
Diaphragm Mass inc. Airload (Mms): 60 grams
Equiv. Resistance of Mechanical
Suspension Loss (Rms): 1.61N*sec/M
Efficiency Bandwidth Product (EBP): 55
Voice Coil Overhang (Xmax): 4.0mm
Surface Area of Cone (Sd): 823.7cm=
Impedance at Resonance (Zmax): 88Ohms.

here is the mathcad worksheet:
Attached Images
File Type: jpg mathcad.jpg (32.7 KB, 414 views)
__________________
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote

Reply


Hide this!Advertise here!
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ZD5 damping and transmission line questions. gl Multi-Way 4 27th July 2007 04:26 PM
technical transmission line questions BAM Multi-Way 13 20th June 2005 07:30 AM
Transmission Line Questions Solid Snake Multi-Way 16 24th June 2003 02:28 PM
Just a few Transmission Line Questions kneadle Multi-Way 10 16th January 2003 03:03 AM


New To Site? Need Help?

All times are GMT. The time now is 12:05 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