Audax HD3P - 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 6th July 2007, 02:09 PM   #1
diyAudio Member
 
Join Date: Jun 2007
Default Audax HD3P

Hi everybody. I've got a big problem that I'm hoping someone here will be able to help with...I'm the proud owner of a pair of Audax HD3P tweeters which have been slowly deflating over the last couple of years.
Last week I dismantled one to see how it goes together and hopefully fix the leak. While I was cleaning off some adhesive from the gold dome, I knicked the membrane. Now I have one HD3P.
Going by a thread posted last year, there appears to be a few members with deflated HD3P's in their bottom drawer and if anyone wants to free up some storage space, I'd love to purchase one of those little beauties from you.
  Reply With Quote
Old 6th July 2007, 02:53 PM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
if you had not damaged the piezo would you have been able to re-pressurise the dome?

Have you any idea of the voltage (ac or dc) the piezo can take?

I was enquiring about high voltage direct drive rather than through the air cored transformer.
But, I got no info on what operating voltage they can take.
__________________
regards Andrew T.
  Reply With Quote
Old 7th July 2007, 03:46 AM   #3
diyAudio Member
 
Join Date: Jun 2007
Hi Andrew.

I reckon I can re-pressurise the piezo sac and I'll be having a go at my remaining tweeter this week.
As far as the voltage tolerance of the piezo material...I've no idea.
  Reply With Quote
Old 8th February 2010, 08:17 PM   #4
diyAudio Member
 
Join Date: Dec 2004
Location: Roma
Hello,
can you please come back with the way you inflate the gas in the HD3P again? I have a pair of these but very low sounding due to the gas leakage (how I also read in other forums).

Anyone can help with advices, please?

I would really like to restore them....

Thank you,
gianmaria
  Reply With Quote
Old 8th February 2010, 10:00 PM   #5
Dr_EM is offline Dr_EM  United Kingdom
diyAudio Member
 
Dr_EM's Avatar
 
Join Date: Oct 2006
Location: Swindon
A very curious tweeter, can anyone explain how it works? What is the function of the inflated sack, it somehow helps couple the piezo element to the surrounding air more effectively? Does it just rest/press against the element?
  Reply With Quote
Old 16th February 2010, 10:37 PM   #6
diyAudio Member
 
Join Date: Jun 2007
Hi Gianmaria. If you pm me with your e-mail address, i'll send all the details on how to re-inflate these beautiful tweeters.
Cheers.
Hammerworks
  Reply With Quote
Old 17th February 2010, 06:24 PM   #7
diyAudio Member
 
jerome69's Avatar
 
Join Date: Feb 2008
Location: Lyon
In France, this tweeter HD3P seems difficult to find. I have always heard, this tweeter is very fragile.
Great if you have a solution to inflate this fragile tweeter

I see here, the designer Gilles Millot gave this company address MOCA-AUDIO. This company proposes to inflate the HD3P or as a replacement this tweeter. A magnesium dome like the SEAS T29MF001. It seems to have the same diameter than the HD3P. You should redesign the crossover. I also understand they can sell and install a system to inflate the HD3P periodically.

My opinion is to change the tweeter if you cannot find a solution. Excellent tweeter exists at good price, cheaper than repair.
  Reply With Quote
Old 18th February 2010, 12:07 AM   #8
diyAudio Member
 
Join Date: Jun 2007
To the best of my knowledge, the piezo crystals are ground to a dust and bonded to one side a mylar film. They react when an electrical charge is passed through/over them by physically contracting, the mylar being inert doesn't move, so the laminate bends. When the charge is stopped, the laminate resumes it's original size and shape. When a varying charge from an audio amplifier is used, the piezo film flexes at different rates and generates sound waves.
There is plenty of info on the web at places like Wikipedia, etc.
  Reply With Quote
Old 18th February 2010, 12:30 AM   #9
diyAudio Member
 
Join Date: Jun 2007
Hi Jerome, I have managed to re-inflate my HD3P's and they sound better than when they were new, probably because they were a couple of years from the factory by the time I bought them. They've been running for a couple of years since I repaired them and no sign of sagging.
Before I did this though, I tried repacing them with a pair of Bohlender Graebener Neo 3's; nice but nowhere near the clean sound of the HD3P.
BTW, is there any way of reading the MOCA-AUDIO web site in English. My French stopped at year 8 high school.
Cheers.
  Reply With Quote
Old 18th February 2010, 06:28 AM   #10
diyAudio Member
 
jerome69's Avatar
 
Join Date: Feb 2008
Location: Lyon
Hi

This is a very good news if you can re-inflate them.

You can use google translator

Translation on the fly

Cheers.
  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
HD3P - wanted Alfaa Swap Meet 4 5th April 2009 02:27 PM
Hd3p hammerworks Vendor's Bazaar 2 5th December 2008 10:44 AM
Audax HD3p tweeter - design ideas? AndrewT Multi-Way 18 2nd December 2008 07:26 AM
Audax HD3P tweeters phibes Multi-Way 0 9th July 2007 05:41 AM
Audax HD3P/Meadowlark help needed! Laney Multi-Way 6 13th October 2006 04:33 PM


New To Site? Need Help?

All times are GMT. The time now is 06:03 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