Beyond the Ariel - Page 721 - 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 16th August 2010, 08:09 PM   #7201
Sheldon is offline Sheldon  United States
diyAudio Member
 
Join Date: Dec 2003
Location: San Diego
Quote:
Originally Posted by Elias View Post
Hi,

I plotted some wavelets from the RAdian/Azurahorn IR file.

Here's a 'CSD' equivalent wavelet:

Can I see consecutive reflections/diffractions? Either the driver, or the throat-mouth ping-pong?
- Elias
A little open cell foam, ala Geddes, might be worth a try.

Sheldon
  Reply With Quote
Old 16th August 2010, 08:31 PM   #7202
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
Reflection off the lower bass cabinet is a possibility too.

It doesn't look like the system is going to need much equalization, except for a possible 1.5~1.8 kHz moderate notch filter for the woofer to smooth out the lowpass curve.
  Reply With Quote
Old 16th August 2010, 09:14 PM   #7203
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Here's what REW shows:
Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.

A horn polar response and we're ready to build a crossover. I don't know that I'd worry too much about that top octave. I'm sure that's just me however. If you want a deeper look into the noise floor, just let me know.

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 16th August 2010, 10:06 PM   #7204
g3dahl is offline g3dahl  United States
diyAudio Member
 
g3dahl's Avatar
 
Join Date: Jun 2004
Location: Silverdale, WA
Quote:
Originally Posted by Lynn Olson View Post
Reflection off the lower bass cabinet is a possibility too.
I expect there would be some. Measurement was done with the horn in position on top of the bass cabinets. I buried the bass cabinets in a mountain of Bonded Logic to attenuate the reflection, but that would have only .

During the test, I set the window at about 4.4 ms, which would shut out reflections from other objects in the room, such as the amp on the floor. But eventually they all get there!

BTW, the picture is a quick re-creation of the arrangement so you can see how things were placed. During the test, the mic was on axis with the driver.

Gary Dahl

Click the image to open in full size.
__________________
"So many tubes, so little time..."

Last edited by g3dahl; 16th August 2010 at 10:09 PM.
  Reply With Quote
Old 16th August 2010, 10:44 PM   #7205
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Yeah, lot's do a crossover.
How fancy do you want to get?
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 16th August 2010, 11:29 PM   #7206
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Quote:
Originally Posted by g3dahl View Post
... I have attached the corresponding files in .pir and .wav formats. Vertical scale is arbitrary; the gain of my power amp hasn't been accounted for. The mic preamp doesn't invert phase, so it's probably the power amp, a Parasound HCA-1500A.

...

Gary Dahl
If you are using a wm61 type electret condenser capsule, its normal connection method results in inverted signal.
__________________
Hear the real thing!
  Reply With Quote
Old 17th August 2010, 04:12 AM   #7207
g3dahl is offline g3dahl  United States
diyAudio Member
 
g3dahl's Avatar
 
Join Date: Jun 2004
Location: Silverdale, WA
Started on the Zobel network for the TD15M this afternoon.

The calculator at mh-audio.nl - Calculations provided values of 8.25 ohms and 2.94 uF, so I began with 8 ohms and 3 uF:

Click the image to open in full size.

Next, I tried it with a 2 uF cap. The green trace shows 3 uF; the yellow trace shows 2 uF:

Click the image to open in full size.

Finally, I tried a 4 uF cap (yellow trace). The green trace is 2 uF.

Click the image to open in full size.

I wish I could overlay all three traces, but I couldn't get more than one overlay.

Comments? I think 2 uF looks best, but I'm new at this.

Gary Dahl
__________________
"So many tubes, so little time..."

Last edited by g3dahl; 17th August 2010 at 04:15 AM.
  Reply With Quote
Old 17th August 2010, 04:14 AM   #7208
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
With an impedance plot like that, why do you need a Zobel?
  Reply With Quote
Old 17th August 2010, 06:38 AM   #7209
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
I would recommend flatening the system impedance rather than doing it for each driver. The thing is that components will all interact with each other. Of course you can still flatten the final impedance of the system and still have zobels for each driver, but it seems component count would be more, and there may not be audible benefits to be gained.
__________________
Hear the real thing!
  Reply With Quote
Old 17th August 2010, 07:58 AM   #7210
Elias is online now Elias  Finland
diyAudio Member
 
Elias's Avatar
 
Join Date: May 2003
Location: Where you live
Hi,

In the wavelet reassignment I draw red arrows to point the consecutive reflections/diffractions, and mapped them back to the wavelet shown in white lines.

These consecutive reflections/diffractions are typical for horns and waveguides and they can be repeatedly seen in the horn honk thread with all the horns and waveguides. Some have more of them than others.

Click the image to open in full size.


- Elias

Quote:
Originally Posted by Lynn Olson View Post
Reflection off the lower bass cabinet is a possibility too.

Quote:
Originally Posted by g3dahl View Post
I expect there would be some. Measurement was done with the horn in position on top of the bass cabinets. I buried the bass cabinets in a mountain of Bonded Logic to attenuate the reflection, but that would have only .
Click the image to open in full size.
  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



New To Site? Need Help?

All times are GMT. The time now is 03:28 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