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

Planars & Exotics ESL's, planars, and alternative technologies

MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)
MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)
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 16th October 2019, 05:22 PM   #21
claudiogan is online now claudiogan  Italy
diyAudio Member
 
claudiogan's Avatar
 
Join Date: Apr 2011
Location: Sassari
Quote:
Originally Posted by turk 182 View Post
when foam starts being used as a correction in a loudspeaker design it's time to move on....
If (you don't like foam)
  • increases the number of aluminum waveguides,
  • increases the cost of the material,
  • increases assembly time,
  • reduce the impedance peaks as in the 54m42 project.
elseelse
  • add a few pieces of foam,
  • reduce the impedance peaks in five minutes,
  • the budget remains below 100 euros of material.
The purpose of MDD technology is not to regularize the frequency response but to emit delayed and consistent secondary sound waves to improve the listening experience.
The use of foam rubber cubes is only one option, it can be used by those who want to try to make prototypes, saving on the purchase of materials and reducing construction times.
Attached Images
File Type: jpg 54m42 33 L09 FRZ.jpg (87.5 KB, 49 views)
  Reply With Quote
Old 16th October 2019, 06:43 PM   #22
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)
Quote:
Originally Posted by turk 182 View Post
when foam starts being used as a correction in a loudspeaker design it's time to move on....
Then it is time to abandon most speakers… they almost all use some kind of damping. Foam is not particularily effective, as pictured it would be more like a slight push towards aperiodic… i use this same technique if the bass in one of my miniOnkens needs damping down.

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 16th October 2019, 07:05 PM   #23
turk 182 is offline turk 182  Canada
diyAudio Member
 
Join Date: Oct 2012
damping yes.... but in the direct path....sorry not for me...it's just like the "grill on" vs "grill off" debate.
  Reply With Quote
Old 16th October 2019, 07:16 PM   #24
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Isn't this more of an instrument than a speaker?
  Reply With Quote
Old 16th October 2019, 07:37 PM   #25
claudiogan is online now claudiogan  Italy
diyAudio Member
 
claudiogan's Avatar
 
Join Date: Apr 2011
Location: Sassari
Quote:
Originally Posted by scottjoplin View Post
Isn't this more of an instrument than a speaker?
Yes. An instrument that can reproduce all the others (almost).
  Reply With Quote
Old 16th October 2019, 07:38 PM   #26
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)
Quote:
Originally Posted by turk 182 View Post
damping yes.... but in the direct path....sorry not for me...it's just like the "grill on" vs "grill off" debate.
No TLs for you then.

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 16th October 2019, 07:51 PM   #27
turk 182 is offline turk 182  Canada
diyAudio Member
 
Join Date: Oct 2012
don't transmission lines come in two flavors, open and closed?

and yeah heard a few and can't say i like them,sorry...
  Reply With Quote
Old 16th October 2019, 10:53 PM   #28
pelanj is online now pelanj  Czech Republic
diyAudio Member
 
Join Date: Jul 2008
I tried a little open cell foam - and it can definitely improve things - but I put in too much on one side. It is definitely worth trying, I will do some measurements later to confirm.
  Reply With Quote
Old 16th October 2019, 11:37 PM   #29
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)
Quote:
Originally Posted by turk 182 View Post
don't transmission lines come in two flavors, open and closed?
They can be open at one end (1/4 wave line) or closed (1/2 wave) or both (1/2 wave). Most are quarter-wave but there is a quite large design space.

This design is a bunch of undamped TLs with lots of ripples, lots of pipes spreads those out, we see the same concepts in DMLs and in speakers like the Hegeman wher ethe pipes are inside the box.

Quote:
...and yeah heard a few and can't say i like them,sorry...
How old were they? What were they? How well designed? There was a HUGE change in TLs after 2000 as proper modelers started to appear. Instead of a guess at the right size, you could see what the pipe did by modeling it.

I am certainly well satisfied with the TLs i am listening to, the ones downstairs, and some in the field (one set i loaned out and he declined to return them :^) — used as bass support for an OB Lowther.

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 17th October 2019, 12:23 AM   #30
turk 182 is offline turk 182  Canada
diyAudio Member
 
Join Date: Oct 2012
Quote:
Originally Posted by planet10 View Post
How old were they? What were they? How well designed?
can't say on all three counts as they didn't make any impression on me to want to inquire about them.
  Reply With Quote

Reply


MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
MDD Multi Delays Difraction claudiogan Full Range 0 15th May 2019 11:12 PM
Multi channel volume controller, active filtering and multi amp gug42 Analog Line Level 4 16th July 2018 12:19 PM
Real multi room, multi input-multi output audio system for smart home gryzli133 PC Based 3 26th January 2018 05:15 PM
Multi purpose multi channel gainclone PCB: Team project - group buy rick57 Chip Amps 14 29th March 2003 06:54 PM


New To Site? Need Help?

All times are GMT. The time now is 08:58 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki