Driver Hole Chamfer and Alpair 7 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Markaudio

Markaudio Designers and builders of audiophile grade drivers

Reply
 
Thread Tools Search this Thread
Old 24th August 2011, 10:21 PM   #1
diyAudio Member
 
Join Date: Aug 2011
Default Driver Hole Chamfer and Alpair 7

Any unique recommendations for the Alpair 7 driver hole chamfer. Typically I cut the back of the hole at a 45 degree angle using a router.
  Reply With Quote
Old 25th August 2011, 01:04 AM   #2
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Quote:
Originally Posted by pizzachef View Post
Any unique recommendations for the Alpair 7 driver hole chamfer. Typically I cut the back of the hole at a 45 degree angle using a router.
Hi Pizzachef,
Yes to 45 degrees. This is a good way to minimise any reflections coming from the side of the baffle back on to the rear of the cone.

The 45 angle is usually easy to do on thicker baffles (over 18-mm). For those guys on thinner baffles (less than 18-mm) who want to use the 7's front cover and recess the driver, the mount behind the driver will be shallow. In these cases, it may be better to round off the back of the baffle opening. A radius of 2mm to 3mm will help minimise any disturbance around the rear of the driver.

Thanks
Mark.
  Reply With Quote
Old 25th August 2011, 01:06 AM   #3
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
I believe Troels Graverson did a test of this theory and showed that it did not make a significant difference. I could be remembering wrong.
  Reply With Quote
Old 25th August 2011, 01:27 AM   #4
diyAudio Member
 
Join Date: Aug 2011
Thanks. Sorry to ask such small questions, but I have found Markaudio to be as helpful as any manufacturer I have met to the DIY community. Not to mention having some pretty awesome product. Been running in my bare Alpair 7's at low volume for about 100 hours now, can't wait to get them in a box
  Reply With Quote
Old 25th August 2011, 02:18 AM   #5
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Quote:
Originally Posted by buzzforb View Post
I believe Troels Graverson did a test of this theory and showed that it did not make a significant difference. I could be remembering wrong.
Hi Buzz, Guys
For Markaudio drivers, it is wise the chamfer the inside of the baffle opening. The rear of the Markaudio driver frames are near wide open to help minimise back wave losses so large side wall with a sharp edge could expose the rear of the cone to reflection.

When I first kicked off making my Gen. 1 Alpair 10's, we kept getting some weird peaks during the anechoic sweep tests. It took me and Evan ages to find the problem. We'd been using a 19-mm thick suspended baffle with a straight cut mounting insert. When we changed to another baffle that used a 3-mm aluminium central mounting plate, ran the sweep test again, the problem was resolved. I'll look at our archive data and see if I've kept an LMS data copy of these tests.

I can't speak for other driver designers since their designs will likely have differing criteria. It could be that for some drivers, chamfering baffle edges isn't needed. But as a handy good practice tip, its usually worth trying to smooth off sharp edges inside baffles, similarly on ports and vents.

Hope this helps.

Thanks

Mark.

Last edited by markaudio; 25th August 2011 at 02:29 AM.
  Reply With Quote
Old 25th August 2011, 02:29 AM   #6
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Quote:
Originally Posted by pizzachef View Post
Thanks. Sorry to ask such small questions, but I have found Markaudio to be as helpful as any manufacturer I have met to the DIY community. Not to mention having some pretty awesome product. Been running in my bare Alpair 7's at low volume for about 100 hours now, can't wait to get them in a box
Hi Pizzachef,
No need for apologies, helping guys with their ideas and projects is the major part of Markaudio section's purpose. Please accept my apologies for sometimes not being readily available to answer all posts.

I'm hoping that more members will share the knowledge and project build experiences so this section of the Diyaudio forum gets close to being self-supporting, me helping with technical supports on the drivers.

Cheers
Mark.

(PS. keep it nice and gently on the run-in. Soft, easy music and cone's shouldn't move - thanks)

Last edited by markaudio; 25th August 2011 at 03:03 AM.
  Reply With Quote
Old 25th August 2011, 02:45 AM   #7
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Very interesting info Mark. Thanks for the advice. I will be getting my 7.3 soon and will start a post about the 7.3 vs 10.2.
  Reply With Quote
Old 25th August 2011, 03:05 AM   #8
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Quote:
Originally Posted by buzzforb View Post
Very interesting info Mark. Thanks for the advice. I will be getting my 7.3 soon and will start a post about the 7.3 vs 10.2.
Hi Buzz,
Sounds cool, will be interesting to read about your experiences. Hoping you'll show your builds (pics) and offer some tips about your projects.

Cheers
Mark.
  Reply With Quote
Old 25th August 2011, 06:14 AM   #9
diyAudio Member
 
Join Date: Aug 2011
I have treated the drivers like eggs. Began with 50 straight hours of very low volume Vivaldi from the Four Seasons. Have steadily added music types and a bit of volume. Never saw the cone even budge in the first 100 hours.
  Reply With Quote
Old 25th August 2011, 07:15 AM   #10
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Quote:
Originally Posted by pizzachef View Post
I have treated the drivers like eggs. Began with 50 straight hours of very low volume Vivaldi from the Four Seasons. Have steadily added music types and a bit of volume. Never saw the cone even budge in the first 100 hours.
Hi Pizza,
Good work. They're about ready for mounting into boxes.
Cheers
Mark
  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
First attemt to cut driver hole with router.... FAIL!!! The Paulinator Multi-Way 34 20th October 2011 12:07 AM
Avaclone driver hole chamfering? superapplekid Multi-Way 7 9th April 2011 07:08 AM
Alpair 10 wide bass driver and Alpair 10 Fullrange _henry_ Full Range 71 15th March 2009 12:37 PM
Hole in driver dome 3-LockBox Full Range 10 30th August 2007 11:27 PM
Roundover or chamfer behind the driver? mazeroth Multi-Way 4 28th January 2005 08:32 PM


New To Site? Need Help?

All times are GMT. The time now is 02:37 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