Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Help needed with TL calculation
Help needed with TL calculation
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 22nd November 2017, 08:18 PM   #21
Ingborgbo is offline Ingborgbo  Sweden
diyAudio Member
 
Join Date: Aug 2017
Thanks a lot for taking your time to design that cab, Pkitt!

I have a question though. Would it affect the performance if I was to fold the line 90 degrees near the open end, to make the "port" face forward above the woofer?
  Reply With Quote
Old 22nd November 2017, 10:43 PM   #22
pkitt is offline pkitt  United States
diyAudio Member
 
Join Date: Feb 2009
My model of the tapered line was for its simplest form, a continuous line without folds, because that was the quickest modeling I could do. When a line is folded, one needs to model how the line's area actually changes as it goes around corners, turning right or left or through U-turns. So, to be absolutely accurate, it would have to be modeled exactly how you'd want to build it, with presumably one U-turn and one right angle turn, and might need some tweaking in line length and/or tapering in order to end up with the results as my modeling predicted.
Paul

Quote:
Originally Posted by Ingborgbo View Post
Thanks a lot for taking your time to design that cab, Pkitt!

I have a question though. Would it affect the performance if I was to fold the line 90 degrees near the open end, to make the "port" face forward above the woofer?
  Reply With Quote
Old 22nd November 2017, 10:46 PM   #23
Bill poster is offline Bill poster  Thailand
diyAudio Member
 
Bill poster's Avatar
 
Join Date: Jun 2008
Location: Bangkok/London
Quote:
Originally Posted by pkitt View Post
Assuming the woofer's specs posted by the OP are reasonably representative, I used them and the predicted performance of the TL I modeled looks quite good to me.
Paul
Oops ok, *takes it back* hadnt read the whole thread. I'd assumed it wd need a crazy size box, plus the qts looked a little low
  Reply With Quote
Old 1st December 2017, 08:23 PM   #24
Oneminde is offline Oneminde
diyAudio Member
 
Join Date: Jun 2014
I am lurking in the background, reading and thinking. I am about to adventure into designing and building TL loudspeakers myself, but as someone stated earlier, the art of listening is somewhat lost with all the calculations. Calculations are useful yes, but I am advocating more listening and measurements after the cabinet is built. The TL is only part of a whole build. The shape of the cabinet is equally as important. Take baffle diffraction as an example and the material used on the front, both will dictate the overall sound emanating from the drivers / cabinet.

Anyway, here is another older debate that might be interesting for the OP to check out. An Improved Transmission Line Alignment.

Last edited by Oneminde; 1st December 2017 at 08:25 PM.
  Reply With Quote
Old 1st December 2017, 09:36 PM   #25
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Help needed with TL calculation
That was Patrick, discovering that offset drivers can be used to almost kill the 1st unwanted harmonic — something that has been known long before he made that post. So improved yes, new not.

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 1st December 2017, 09:42 PM   #26
Oneminde is offline Oneminde
diyAudio Member
 
Join Date: Jun 2014
Quote:
Originally Posted by planet10 View Post
That was Patrick, discovering that offset drivers can be used to almost kill the 1st unwanted harmonic — something that has been known long before he made that post. So improved yes, new not.

dave
Indeed. not new but very useful information.
  Reply With Quote
Old 2nd December 2017, 09:56 AM   #27
Scottmoose is offline Scottmoose  United Kingdom
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Short version: for a given pipe, end loading (as in sealed end or throat if you prefer) provides maximum excitation to the fundamental and all its harmonic modes. As you shift the driver along the pipe (change its tap location) you will reduce excitation of different harmonics, which & how much depending on the specific placement. See MKJ's alignment tables for some basic guidelines for driver placement on pipes of various geometries.
__________________
"'That'll do", comes the cry of the perfectionist down the ages.' James May -The Reassembler
www.wodendesign.com Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 6th December 2017, 01:05 PM   #28
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Hi Ingborg,All

Here is an attempt to Design a ML-TL Tower (f-3dB=~27Hz) using a Minimum Volume Box that if the Port is closed resembles a Sealed Box with Qtc= ~0.707( f-3dB=~37.5 Hz).
You may object(anyone) to the suggested placement of M and T Driver but if put them above the B Driver, your TV would IMO be elevated to high up if a Central Phantom is expected at dead center of the Screen.

There is more to say of your Room lay-out if using only two Main Speakers.

I will Post later some Simulations showing plausible Room interaction and Spatial Standard Deviation from the B Driver when placed High and low with the respect of the Floor.

b
Attached Images
File Type: jpg Monacor_SPH-300KE_ML-TL.JPG (725.5 KB, 111 views)
File Type: jpg Monacor_SPH-300KE_SPH-165KEP_ML-TL.JPG (258.7 KB, 107 views)
  Reply With Quote
Old 11th December 2017, 07:11 PM   #29
Ingborgbo is offline Ingborgbo  Sweden
diyAudio Member
 
Join Date: Aug 2017
I'm doing my best to decipher all the stuff you posted!
Right now I'm most confused about the stuffing and XO points. 147Hz XO for woofer/mid, right? The 47Hz confuses me. Care to explain the numbers a little, please?

I would love to place the mid and tweet ontop (becouse I love that look) since the TV has its own sound system, and the TLs will only be used for music.

Thank you so much for taking your time to help me out, bjorno!
  Reply With Quote
Old 17th January 2018, 11:32 PM   #30
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
Quote:
Originally Posted by Ron E View Post
Transient response is also not likely any better than vented.
I disagree with the above statement.
__________________
"The response of the inner ear extends to at least 200khz" Dr W. Tempest
  Reply With Quote

Reply


Help needed with TL calculationHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Vas calculation didelcas Multi-Way 7 12th November 2017 01:53 AM
Help needed in Crosstalk calculation popilin Tubes / Valves 15 31st January 2017 02:36 AM
Zobel calculation, help needed! martinbls Multi-Way 5 23rd February 2011 08:42 PM
Calculation aguantesoda Solid State 5 31st December 2006 09:02 PM
Sime filter calculation help needed. Nordic Parts 20 15th November 2006 02:42 PM


New To Site? Need Help?

All times are GMT. The time now is 11:11 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki