Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

A dip at around 10KHz. Reason and correction.
A dip at around 10KHz. Reason and correction.
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 22nd February 2019, 08:02 PM   #11
Juhazi is offline Juhazi  Finland
diyAudio Member
 
Juhazi's Avatar
 
Join Date: Mar 2007
Location: Jyväskylä, Finland
^most often it gets smoother - at 30¤ plus. And this applies to deep waveguides too!

SEAS MR18 with aluminium tweeter and SEAS T18
Attached Images
File Type: jpg mr183w 0-90¤ stand 7ms 112.jpg (149.4 KB, 184 views)
File Type: jpg aw7 0-90¤ 9ms 112.jpg (125.0 KB, 185 views)
__________________
Radikal aktivist AINOgradient speaker project

Last edited by Juhazi; 22nd February 2019 at 08:08 PM.
  Reply With Quote
Old 22nd February 2019, 08:28 PM   #12
silverprout is offline silverprout  France
diyAudio Member
 
silverprout's Avatar
 
Join Date: Apr 2008
Quote:
Originally Posted by Juhazi View Post
^most often it gets smoother - at 30¤ plus. And this applies to deep waveguides too!
SEAS MR18 with aluminium tweeter and SEAS T18
Sorry i've take a deep for a peak, i remember a terrible issue with a ribbon tweeter, on your measurements the cancelation is tamed by still there.
IMHO, people are minimizing the problem in order to reconfort Aucosticraft.
__________________
Things I Should Have Learned In School (But Probably Didn't)
  Reply With Quote
Old 24th February 2019, 12:45 PM   #13
Aucosticraft is offline Aucosticraft  India
diyAudio Member
 
Join Date: Nov 2009
Location: Pune
I am back to my home location, Here is the frequency response measured from a distance of 1 meter @ 0 Axis. The dip looks shifted and looks useable.
Attached Images
File Type: png Holmimpulse.png (23.6 KB, 164 views)
__________________
There is always a first time....
  Reply With Quote
Old 1st March 2019, 02:42 PM   #14
Aucosticraft is offline Aucosticraft  India
diyAudio Member
 
Join Date: Nov 2009
Location: Pune
While thinking on , your all suggestions and theory, A thing stuck to me is , why don't we see those dip in the manufacturer's FR measurement. ie what they do to avoid the dip in there measurement.

Reference: CX120-8 4" Coaxial Driver with 3/4" Silk Dome Tweeter 8 Ohm Specification Sheet
Attached Images
File Type: png Untitled.png (117.8 KB, 123 views)
__________________
There is always a first time....
  Reply With Quote
Old 1st March 2019, 04:07 PM   #15
silverprout is offline silverprout  France
diyAudio Member
 
silverprout's Avatar
 
Join Date: Apr 2008
Quote:
Originally Posted by Aucosticraft View Post
While thinking on , your all suggestions and theory, A thing stuck to me is , why don't we see those dip in the manufacturer's FR measurement. ie what they do to avoid the dip in there measurement.
Because the manufacturer measurements are performed in a anechoic room, and your measurements are performed in a reverberant environement, the reverberant field is smoothing the dips in the far field.
__________________
Things I Should Have Learned In School (But Probably Didn't)
  Reply With Quote
Old 1st March 2019, 04:28 PM   #16
Juhazi is offline Juhazi  Finland
diyAudio Member
 
Juhazi's Avatar
 
Join Date: Mar 2007
Location: Jyväskylä, Finland
That specific driver's cone diameter is only 85mm and it has a textile dome 3/4". Looks like it has off-axis dip at 15deg instead! At those frequencies very small details matter.
__________________
Radikal aktivist AINOgradient speaker project
  Reply With Quote
Old 2nd March 2019, 10:21 AM   #17
silverprout is offline silverprout  France
diyAudio Member
 
silverprout's Avatar
 
Join Date: Apr 2008
Quote:
Originally Posted by Juhazi View Post
That specific driver's cone diameter is only 85mm and it has a textile dome 3/4". Looks like it has off-axis dip at 15deg instead! At those frequencies very small details matter.
At the beginning of the formation of the sound wave every small error can become a big mistake
Here you can see a good design :
Click the image to open in full size.

Here you can see a bad design :
Click the image to open in full size.

Do you see the difference ?
__________________
Things I Should Have Learned In School (But Probably Didn't)

Last edited by silverprout; 2nd March 2019 at 10:29 AM. Reason: Do you see the difference ?
  Reply With Quote
Old 4th March 2019, 01:05 AM   #18
Aucosticraft is offline Aucosticraft  India
diyAudio Member
 
Join Date: Nov 2009
Location: Pune
Somehow I feel this driver selection was a wrong choice. I have never used coaxial driver before. And I bought 8 of those thinking they would do good job for Home theater 7.1.
__________________
There is always a first time....
  Reply With Quote
Old 4th March 2019, 03:36 PM   #19
silverprout is offline silverprout  France
diyAudio Member
 
silverprout's Avatar
 
Join Date: Apr 2008
Quote:
Originally Posted by Aucosticraft View Post
Somehow I feel this driver selection was a wrong choice. I have never used coaxial driver before. And I bought 8 of those thinking they would do good job for Home theater 7.1.
You can glue a hollowed wizzler on the exterior periphery of the tweeter suspension, at first you can try some prototypes made with some sheets of paper and a pair of scissors.

Click the image to open in full size.
__________________
Things I Should Have Learned In School (But Probably Didn't)
  Reply With Quote

Reply


A dip at around 10KHz. Reason and correction.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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Do some tweeters intentionally have a peak at around 10KHz? andy2 Multi-Way 5 1st July 2017 02:55 PM
Quartz Tuner Reads 10khz Out? redrooster Digital Source 15 22nd August 2015 02:35 PM
Which measurement microphone for 20~10KHZ? wyan Equipment & Tools 3 4th December 2014 01:04 AM
Damping factor of 100 at 10KHz? rhythmsandy Solid State 38 5th October 2014 08:17 PM
Class D BandWith DC to 10KHz mederic Class D 3 25th November 2010 07:35 AM


New To Site? Need Help?

All times are GMT. The time now is 02:23 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki