microTower bipolar ML-TL for CHR-70 or EL70 - Page 48 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 17th May 2012, 07:16 PM   #471
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Robert,

How many plys in the plywood?

Except for issues with driver rebates, 12mm, with maximum bracing, would be fine, if the ply is of sufficient quality -- we have a pair of subwoofers (push-push SDX10) here that we did in 15mm BB just to see how far the concept can be taken (waiting for the 4 channel amp)

The act of adding an addiitonal layer will push you towards a higher quality material if done right (and with a press sounds like you are).

One ofmy gurus did extensive research into materials. He found that he wasn't happy with MDF, but very happy with a board he made from 7 layers of 1/8" MDF (he used a 10 ton press).

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 May 2012, 07:43 PM   #472
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Quote:
Originally Posted by planet10 View Post
One ofmy gurus did extensive research into materials. He found that he wasn't happy with MDF, but very happy with a board he made from 7 layers of 1/8" MDF (he used a 10 ton press).

dave
Very interesting. So layers count!
  Reply With Quote
Old 18th May 2012, 05:29 AM   #473
leeoh is offline leeoh  Australia
diyAudio Member
 
Join Date: Jun 2008
Quote:
Originally Posted by planet10 View Post
Robert,

How many plys in the plywood?

Except for issues with driver rebates, 12mm, with maximum bracing, would be fine, if the ply is of sufficient quality -- we have a pair of subwoofers (push-push SDX10) here that we did in 15mm BB just to see how far the concept can be taken (waiting for the 4 channel amp)

The act of adding an addiitonal layer will push you towards a higher quality material if done right (and with a press sounds like you are).

One ofmy gurus did extensive research into materials. He found that he wasn't happy with MDF, but very happy with a board he made from 7 layers of 1/8" MDF (he used a 10 ton press).

dave
There are 5 plys in the 12mm board and 3 in each of the 3mm. If I decide to go with the ply I will put the 3mm on both sides of the 12mm, to balance it. That will also give me a little more depth to play with when rebating for the speakers. I will also work to interior dimensions that you show for the enclosures, so the additional thickness of the sides won't make for a smaller enclosure. Robert.
__________________
Robert
  Reply With Quote
Old 18th May 2012, 06:24 AM   #474
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
If you have the press, i'd be tempted to just lay up 5 thicknesses of the 3mm...

The local Home Despot sells some 3/4" with 5 plies...

BB has 9 in 12mm, the new Murphy ply we are using likley more -- the 15 (13 plies) & 18 (15? plies) both do.

the triple laminate should be good, the dissimilar material in the middle will go a long way to increasing the damping.

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 21st May 2012, 05:02 AM   #475
leeoh is offline leeoh  Australia
diyAudio Member
 
Join Date: Jun 2008
Dave I have more confidence in getting a decent job with the 12 ply centre and 3mm ply on either side than glueing five of the 3mm plies into one. I've tried doing that on another job and found the resulting piece was somewhat warped. Possibly something to do with the fact that the ply is not top quality (hence its price). Plantation grown pine can do strange things when wet! I've used 12mm particle board with 3mm ply on either side without any problems, so would hope that the 12mm ply centre would be the same.
__________________
Robert
  Reply With Quote
Old 5th June 2012, 12:23 AM   #476
leeoh is offline leeoh  Australia
diyAudio Member
 
Join Date: Jun 2008
Dave. I'm part way thro' the build but am undecided about speaker placement. I rather like my Windermere placement of two EL70s facing outwards. If I do that with the Castles, how far apart should the speakers be on the forward facing baffle and how should the damping be fastened? Is a curtain from top to bottom, suspended diagonally OK? Should the bare inside faces also be covered? Thanks.
__________________
Robert
  Reply With Quote
Old 5th June 2012, 05:25 PM   #477
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Robert,

I don't get your question. The Castle is the arrangement of 1 driver on the front, the other on the top.

I like to line the panels in the vicinity of the driver, the diagonal curtain of ~3" insulation is a good starting point for damping.

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 5th June 2012, 06:11 PM   #478
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by leeoh View Post
Dave. I'm part way thro' the build but am undecided about speaker placement. I rather like my Windermere placement of two EL70s facing outwards. If I do that with the Castles, how far apart should the speakers be on the forward facing baffle and how should the damping be fastened? Is a curtain from top to bottom, suspended diagonally OK? Should the bare inside faces also be covered? Thanks.
Quote:
Originally Posted by planet10 View Post
Robert,

I don't get your question. The Castle is the arrangement of 1 driver on the front, the other on the top.

I like to line the panels in the vicinity of the driver, the diagonal curtain of ~3" insulation is a good starting point for damping.

dave

Robert - the other variation of the dual driver MT enclosures that we've built to date is the "true" bipole - 2 drivers in push/push configuration opposite sides. Each format has its advantages, but for ease of placement and spacious soundstage, I quite prefer the "castle" version. Of course we used CHR70s in the bipole, and dual EL70s in an MLTL certainly punch further above their weight class in the low frequency department than the CHRs. .
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote
Old 5th June 2012, 06:19 PM   #479
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by chrisb View Post
Robert - the other variation of the dual driver MT enclosures that we've built to date is the "true" bipole - 2 drivers in push/push configuration opposite sides. Each format has its advantages, but for ease of placement and spacious soundstage, I quite prefer the "castle" version. Of course we used CHR70s in the bipole, and dual EL70s in an MLTL certainly punch further above their weight class in the low frequency department than the CHRs. .
Soon to be reborn with CHP7-.2 + ERT26 tweeters, a MicroTower II as it were.

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 6th June 2012, 06:56 AM   #480
leeoh is offline leeoh  Australia
diyAudio Member
 
Join Date: Jun 2008
Quote:
Originally Posted by planet10 View Post
Robert,

I don't get your question. The Castle is the arrangement of 1 driver on the front, the other on the top.

I like to line the panels in the vicinity of the driver, the diagonal curtain of ~3" insulation is a good starting point for damping.

dave
Sorry Dave, I thought that all the same sized enclosures, regardless of the speaker placement position were called Castle. I had thought of placing one speaker facing up and the other on the baffle, but liking the sound of the Windermere with both speakers facing forward, thought I could do the same with this enclosure. Not so? The holey brace placement would be more straight forward with both facing forward, but I can at this stage still put one on top.
__________________
Robert
  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
Offset Bipolar MLTL with CSS EL70 Drivers--Part 1 Jim Griffin Full Range 48 18th October 2012 04:24 AM
Introducing The new CSS EL70 CSS/XBL CSS 41 19th April 2010 09:23 PM
Bipolar electrolytics dsavitsk Parts 3 8th January 2006 10:48 PM
How does this bipolar look? punchpeanut Solid State 11 2nd October 2003 07:48 AM


New To Site? Need Help?

All times are GMT. The time now is 12:40 AM.


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