AudioAficionado.org  

Go Back   AudioAficionado.org > Manufacturers Forums > PMC Speakers

PMC Speakers UK's Finest

Reply
 
Thread Tools Display Modes
  #11  
Old 01-04-2012, 03:26 PM
metaphacts's Avatar
metaphacts metaphacts is offline
Lower Provo River, UT
 
Join Date: Jan 2010
Location: Springville, Utah
Posts: 4,470
Default

Quote:
Originally Posted by jdandy View Post
Screws in wood or composite speaker cabinets will not hold a constant torque value as will machined threads into a threaded metal hole or a threaded nut. You have to be extremely careful when tightening screws into wood or composite materials. Snug is usually where you want to be, but not wrenched down to a higher torqued value like you would a threaded bolt. In addition, tightening screws should be done back and forth across the speaker frame from one side to the other rather than one screw to the next around the speaker frame. I this manner an even pressure is applied to the speaker frame as it is pressed to the cabinet mounting hole.


This applies to any dynamic driver mounted on a baffle.

Most often, mis-tightening that causes buzzing is atttributable to one of 2 causes: 1) uneven tightening of the driver frame or faceplate can cause the voice coil to rub typically at frequency/excursion extremes - on some drivers the amount of difference in torque is tiny and the order in which you apply pressure (see Dan's post above) can exacerbate the issue, and 2) an air leak caused by uneven tightening.
Reply With Quote
  #12  
Old 01-04-2012, 03:50 PM
jdebonth jdebonth is offline
Senior Member
 
Join Date: May 2011
Posts: 446
Default

Good bits of information here...

The 1/2 turn past initial impact with the spring lock washer is exactly what I ended up using as a guideline and setting all screws at, great to hear this is PMC's official reco.

Metaphacts, interesting information however could you elaborate on your point 1? Would the voice coil rub occur due to the driver not being situated in a perfectly horizontal fashion?

Reply With Quote
  #13  
Old 01-04-2012, 04:03 PM
metaphacts's Avatar
metaphacts metaphacts is offline
Lower Provo River, UT
 
Join Date: Jan 2010
Location: Springville, Utah
Posts: 4,470
Default

Quote:
Originally Posted by jdebonth View Post
Good bits of information here...

The 1/2 turn past initial impact with the spring lock washer is exactly what I ended up using as a guideline and setting all screws at, great to hear this is PMC's official reco.

Metaphacts, interesting information however could you elaborate on your point 1? Would the voice coil rub occur due to the driver not being situated in a perfectly horizontal fashion?

The frame edge torques/is no longer flat relative to the pole piece. That's why you only hear it at highest excursions. This can also be affected by the way the manufacturer chooses to couple the driver to the baffle, milling of the mounting hole, and stiffness of the gasket (if there is one).

The best solution is to follow precisely the manufacturer's recommendation.
Reply With Quote
  #14  
Old 01-04-2012, 04:10 PM
jdebonth jdebonth is offline
Senior Member
 
Join Date: May 2011
Posts: 446
Default

Thanks for the clarification, makes sense.
Reply With Quote
  #15  
Old 01-07-2012, 10:20 AM
jaxwired's Avatar
jaxwired jaxwired is offline
Senior Member
 
Join Date: Aug 2011
Location: Fort Worth Texas
Posts: 281
Default

But, but, but...screws work loose over time! I mean we are talking about screws holding in something that is constantly vibrating when in use. It's just plain gonna happen.

The good news for me is, apparently I didn't do any harm. I hear zero ill effects from my tampering. And as I stated, they do sound better to me (but that could be my imagination). : )
__________________
C.A.P.S Music Server -> Wyred4Sound DAC2dsd SE -> Wyred4Sound ST1000 mkii -> PMC IB2s
Reply With Quote
  #16  
Old 04-17-2012, 09:04 PM
larevoj larevoj is offline
Guest
 
Join Date: Mar 2011
Posts: 218
Default

Quote:
Originally Posted by jaxwired View Post
But, but, but...screws work loose over time! I mean we are talking about screws holding in something that is constantly vibrating when in use. It's just plain gonna happen.

The good news for me is, apparently I didn't do any harm. I hear zero ill effects from my tampering. And as I stated, they do sound better to me (but that could be my imagination). : )
Mate, I don't think its your imagination...otherwise we both are!

Just for your info I have done the same on Dynaudio and Sonus Faber speakers too and hear the same effects where bass gets tighter and mids clearer too. However, do it at your own risk and I will suggest to tighten it evenly across screws.

Cheers!

Last edited by larevoj; 04-17-2012 at 09:08 PM.
Reply With Quote
  #17  
Old 04-17-2012, 09:08 PM
GaryProtein's Avatar
GaryProtein GaryProtein is offline
Member
 
Join Date: Jan 2012
Location: NY
Posts: 5,393
Default

Proper screw torque in any material is 1/4 turn before it strips.
Reply With Quote
Reply

Thread Tools
Display Modes

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

Audioaficionado.org tested by Norton Internet Security

All times are GMT -4. The time now is 03:11 AM.



Powered by vBulletin® Version 3.8.10
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
©Copyright 2009-2023 AudioAficionado.org.Privately owned, All Rights Reserved.
Audio Aficionado Sponsors
AudioAficionado Subscriber
AudioAficionado Subscriber
Inspire By Dennis Had
Inspire By Dennis Had
Harmonic Resolution Systems
Harmonic Resolution Systems
Wyred4Sound
Wyred4Sound
Dragonfire Acoustics
Dragonfire Acoustics
GIK Acoustics
GIK Acoustics
Esoteric
Esoteric
AC Infinity
AC Infinity
JL Audio
JL Audio
Add Powr
Add Powr
Accuphase - Soulution
Accuphase - Soulution
Audio by E
Audio by E
Canton
Canton
Bryston
Bryston
WireWorld Cables
WireWorld Cables
Stillpoints
Stillpoints
Bricasti Design
Bricasti Design
Furutech
Furutech
Shunyata Research
Shunyata Research
Legend Audio & Video
Legend Audio & Video