Acoustat Answer Man is here - Page 92 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

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

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 11th March 2014, 06:56 PM   #911
diyAudio Member
 
Join Date: Jul 2011
Location: Arlington, Texas
Quote:
Originally Posted by bolserst View Post
Target temp for heat shrinking Mylar is 150 C - 170 C
Capaciti mentioned that he set his heat gun to 250 C and used a thermal probe to determine that keeping the heat gun 5cm above the surface of the mylar provided 150 C at the Mylar surface. I'm sure this distance would vary depending on specfic heat gun nozzle shape and blower speed, but would give you a starting point to experiment.
Mechanical Sectioning .vs. Silicon dots for resonance control

As AcoustatAnswerMan mentioned, heating shrink Mylar with a heat gun is a bit of an art.
It may be worth your time/money to obtain some surplus mylar to practice with before working on your Acoustat panel to avoid accidently melting a hole in the diaphragm.

The key think is to keep the heat gun moving steadily across the surface, never pause with the heat gun over the diaphragm.
Complete a series of passes at a given distance and heat setting. If the diaphragm tightened up as you desired, your done. If not, try a slightly higher temperature setting or closer distance until you notice the tension increasing.
Thanks for the info, bolser. Wow...based on that I didn't get it nearly hot enough as I should've been at least twice the temperature I was at. Sounds like I'll need to take my heat gun I have here at the shop home.....no way a blow dryer is gonna' heat to 300+ F.
  Reply With Quote
Old 11th March 2014, 07:05 PM   #912
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by tinnitusintx View Post
...no way a blow dryer is gonna' heat to 300+ F.
No sir
A heat gun is definitely needed to properly heat shrink Mylar.
I use it for retensioning diaphragms as well.

That being said, I have heard many people say that they have improved tension on Acoustat and Sound Lab diaphragms with only a hair dyer. Perhaps once Mylar has been shrunk to a given tension it requires less heat to return to that tension once stretched out. Maybe I will give it a try next time the need arises, to compare with results I get from a heat gun.

@AcoustatAnswerMan,
When retentioning diaphragms at the factory, did Acoustat stick with the heat gun used for original tensioning?
Or did they switch to using a hair dryer.
  Reply With Quote
Old 11th March 2014, 07:11 PM   #913
diyAudio Member
 
Join Date: Jul 2011
Location: Arlington, Texas
Quote:
Originally Posted by bolserst View Post
No sir
A heat gun is definitely needed to properly heat shrink Mylar.
I use it for retensioning diaphragms as well.

That being said, I have heard many people say that they have improved tension on Acoustat and Sound Lab diaphragms with only a hair dyer. Perhaps once Mylar has been shrunk to a given tension it requires less heat to return to that tension once stretched out. Maybe I will give it a try next time the need arises, to compare with results I get from a heat gun.

@AcoustatAnswerMan,
When retentioning diaphragms at the factory, did Acoustat stick with the heat gun used for original tensioning?
Or did they switch to using a hair dryer.
Well, at least now I have some idea how much heat Mylar can handle....I had no idea before so I was pretty cautious with the temps I exposed it to. Sounds like I have a good way to go before I risk damage. However, I am inclined to wonder if exposing the plastic grids to 300 F would be such a good idea.
  Reply With Quote
Old 11th March 2014, 07:24 PM   #914
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by tinnitusintx View Post
, I am inclined to wonder if exposing the plastic grids to 300 F would be such a good idea.
One more reason to keep that heat gun moving.
The melting point for Mylar is 250 C, melting point for polystyrene is similar.
However, the glass transition temp for polystyrene is only 100 C, so some deformation could certainly take place if you left a heat gun pointed at the grids long enough to heat them up.
  Reply With Quote
Old 11th March 2014, 07:32 PM   #915
diyAudio Member
 
Join Date: Jul 2011
Location: Arlington, Texas
Quote:
Originally Posted by bolserst View Post
One more reason to keep that heat gun moving.
The melting point for Mylar is 250 C, melting point for polystyrene is similar.
However, the glass transition temp for polystyrene is only 100 C, so some deformation could certainly take place if you left a heat gun pointed at the grids long enough to heat them up.
Ah...good to know. Thanks again for the info........BTW, I'd like to introduce myself since we're in the same area. You know, now that I put two and two together I know who you are....I saw some of your prototype ESL's at the Toby facility when they were still on Montgomery and really, really liked the Bolser dipoles (those left quite an impression on me when I heard them some three or so years ago). Nice to see you on DIY audio!

Take care,
Michael
spcoating.com
  Reply With Quote
Old 11th March 2014, 09:22 PM   #916
tyu is offline tyu  United States
diyAudio Member
 
Join Date: Jul 2009
Heres the one an only......Mr Stricklin working on his panels.....an the lady an her heat gun......EZey with that Gun....you can pull the Mylar an open up the coating....i would stay away from the coating bias feed at the bottem right side where the wire feeds these panels
you can kill these panels......
Attached Images
File Type: jpg 941-ACO-Factory_Tour-P-B04[1].jpg (40.2 KB, 234 views)
File Type: jpg 941-ACO-Factory_Tour-P-B08[1].jpg (81.0 KB, 234 views)
  Reply With Quote
Old 17th March 2014, 01:05 PM   #917
diyAudio Member
 
Join Date: Dec 2010
Regarding information on mylar shrinking, on the SLOG site in the articles section there is a piece written by Roger West describing how they heat shrink the membranes a Soundlab.
He makes mention of the Sears heat gun they use at the factory, expensive but works great as you can set the desired temperature with top mounted temp. control dial. Have used this on my own SL's in the past.

Link to SLOG:
SLOG

John
  Reply With Quote
Old 17th March 2014, 02:16 PM   #918
tyu is offline tyu  United States
diyAudio Member
 
Join Date: Jul 2009
The ACOUSTATis diff................the coating is put on after the panel Mylars is heated!....see the lady in the pic you see no coating.............an well pull an get thiner......as you heat.....an can crack.....an lose output in spots......the coating has No give!!........an CAN lose contack............not miney ways to kill Acpustat panel....this is one.........just be Ezzy
good luck
  Reply With Quote
Old 11th April 2014, 04:44 AM   #919
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Extra - Extra - Extra - Mr. Roy A. Esposito of ( Sounds Like New ) as a new E-mail address - - - acoustat.service.usa@gmail.com - - - sometimes your in good hands with Allstate and sometimes it's with Roy.
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.

Last edited by MrAcoustat; 11th April 2014 at 04:49 AM.
  Reply With Quote
Old 13th April 2014, 07:02 PM   #920
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Quote:
Originally Posted by AcoustatAnswerMan View Post
I agree. I watched that movie on my system and recall that it had very prominent LF content. Even my Spectra 4400's complained a little bit, despite being crossed-over to a subwoofer below 80 Hz. I like movies with lots of LF content, but I think some of them overdo it, leaving only a few very fine systems capable of properly reproducing it. Of course, the average sound system probably doesn't even try, so lots of folks never realize what they're missing.
Hi Andy another one with great LF content is this old classic - - - Le Grand Bleu - - - by Eric Serra Virgin France 1988 double album.

Click the image to open in full size.
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.
  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
No answer Antoni D The Lounge 2 13th February 2011 06:19 AM
need a tech to answer this one pks71 Car Audio 1 19th November 2004 11:50 AM


New To Site? Need Help?

All times are GMT. The time now is 01:08 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