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

Rebuilding the Enigma...
Rebuilding the Enigma...
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 5th August 2019, 04:44 PM   #101
Brian Steele is offline Brian Steele  Grenada
diyAudio Member
 
Join Date: Nov 2007
Quote:
Originally Posted by Brian Steele View Post
The only thing that sticks out at me is perhaps the sweep length (unfortunately I didn't record it, but I believe that I used 512K long test signals - REW suggests using 1M long test signals as shorter ones apparently result in less accurate harmonic information in the resulting distortion graph).
I don't have the Enigma on-hand to repeat the distortion tests on it. However, I do have on-hand a 4th order BP subwoofer that I built many years ago (see The Subwoofer DIY Page v1.1 - El Uglito for more details. Note however that it now uses different drivers, so FR and distortion measurements done back then don't apply), so I did some distortion testing on that subwoofer to see if the signal length made a difference. The results suggests that the signal length makes little difference at bass frequencies, at least when set to 512K or 1M. If anything, distortion measurements using a 512K signal seem to be a little higher than distortion measurements using a 1M signal.

Note: cursor set to 34.9 Hz, mic about 3" from the subwoofer's vent (to minimize impact of the room on the measured response).

Test signals:
1. 10-20K, 512K
2. 10-20K, 1M
3. 10-2K, 512K
4. 10-2K, 1M

Attached:
1. Measured FR using test signals indicated above. Basically identical at bass frequencies.
2. Distortion measurement using 1st test signal
3. Distortion measurement using 2nd test signal
4. Distortion measurement using 3rd test signal
5. Distortion measurement using 4th test signal
Attached Images
File Type: png 20190805-el uglito.png (50.7 KB, 34 views)
File Type: png 20190805-el uglito (10-20K 512K).png (54.9 KB, 33 views)
File Type: png 20190805-el uglito (10-20K 1M).png (55.3 KB, 34 views)
File Type: png 20190805-el uglito (10-2K 512K).png (50.9 KB, 33 views)
File Type: png 20190805-el uglito (10-2K 1M).png (50.6 KB, 32 views)
__________________
www.diysubwoofers.org
  Reply With Quote

Reply


Rebuilding the Enigma...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
Another enigma with my "Enigma" Brian Steele Subwoofers 9 4th November 2018 07:27 AM
Audio Analogue Enigma service manual hamradioman Solid State 0 21st August 2015 02:24 AM
Help With DEQ2496 For Subwoofer (Enigma) Gwho Subwoofers 7 15th October 2013 01:11 AM
Someone with Enigma 3 and a scanner: Can you help me? Hybrid fourdoor Music 0 21st September 2003 10:22 AM
I'm rebuilding my amp Lisandro_P Everything Else 2 4th July 2002 08:53 AM


New To Site? Need Help?

All times are GMT. The time now is 06:11 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki