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

Amount of hornloading in a Synergy horn
Amount of hornloading in a Synergy horn
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 11th June 2019, 09:52 PM   #51
Cask05 is offline Cask05  United States
diyAudio Member
 
Cask05's Avatar
 
Join Date: Nov 2007
Location: Arlington, TX
Quote:
Originally Posted by Droco View Post
1. You don't need a chamber between the woofer and the off axis port?
No, you don't.

Quote:
Originally Posted by Droco View Post
Does it matter when distance the off axis port will have?
Which distance?

Quote:
Originally Posted by Droco View Post
Also, to ensure that the horn doesn't vibrate due to the woofers I would like to use 1" or even thicker MDF for woofer pad. Just model it like this, or should I keep the port shorter?
Thinner at the port entrance to the horn would be better.

Quote:
Originally Posted by Droco View Post
2. Does Danley also use a 10:1 ratio? Doesn't look like it?
Close--about 7:1 on the SH-50.

Quote:
Originally Posted by Droco View Post
3. How much space of a horn would you dare to take in with ports? You used 1" wide ports, and elongated them, but my horn is a bit bigger.
My off-axis ports use a diameter of 2.6 inches each.

Quote:
Originally Posted by Droco View Post
4. When using woofer pads, do I still need to strengthen the walls of the horn?...Or would it still be smarter to reinforce the walls of the horn (where it is not covered by a wooferpad) with some epoxy/other material to make sure it doesnt vibrate with the generated backchamber vibrations and pressure?
The areas not supported by the woofer's mounting surface need to be reinforced. That means it would be advantageous to use a horn with reinforced horn walls that the woofers are not mounted on.

Quote:
Originally Posted by Droco View Post
5. It looks like Danley doesn't place it ports in the center of the woofer. Does this matter?
Yes, I think it does. I've talked about this in the full-range MEH kit thread.

Chris
  Reply With Quote
Old 11th June 2019, 10:06 PM   #52
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Quote:
Originally Posted by Cask05 View Post
My off-axis ports
These are the multiple entry ports, who's purpose is to put sound on-axis? and if they cause interference it will show on-axis?
  Reply With Quote
Old 11th June 2019, 10:43 PM   #53
Cask05 is offline Cask05  United States
diyAudio Member
 
Cask05's Avatar
 
Join Date: Nov 2007
Location: Arlington, TX
I recommend some light reading, Allen: http://www.danleysoundlabs.com/wp-co...apped-Horn.pdf
  Reply With Quote
Old 11th June 2019, 10:46 PM   #54
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
All the more reason to stand by them then?
  Reply With Quote
Old 11th June 2019, 11:21 PM   #55
Droco is offline Droco
diyAudio Member
 
Join Date: Oct 2017
Quote:
Originally Posted by Cask05 View Post
No, you don't.

Which distance?

Thinner at the port entrance to the horn would be better.

Close--about 7:1 on the SH-50.

Ok, so if I'm planning on using 4 woofers, using a smaller ratio might be benificiary to not take in too much place with the port openings into the horn.

My off-axis ports use a diameter of 2.6 inches each.

2,6" wide then? Because otherwise you wouldnt get the 10:1 compression ratio right?

The areas not supported by the woofer's mounting surface need to be reinforced. That means it would be advantageous to use a horn with reinforced horn walls that the woofers are not mounted on.

Will do.

Yes, I think it does. I've talked about this in the full-range MEH kit thread.

Chris
Sorry I was incorrect about the length thing between woofer and horn, so nevermind that. But if you say, keep it as short as possible, how short? Because the horn curves too early there will be a gap of about 1-2cm (although maybe less, got to remeasure tomorrow) between the mounting pad and the horn. I can fill this gap up on the sides, but it will still be an added "thickness" of the off-axis port. In any case, I'll stay with 0,75" MDF then, as to not increase this even further.
  Reply With Quote
Old 11th June 2019, 11:33 PM   #56
Cask05 is offline Cask05  United States
diyAudio Member
 
Cask05's Avatar
 
Join Date: Nov 2007
Location: Arlington, TX
Everything inside the MEH is within 1/4 wavelength:
Attached Images
File Type: png side lobe level vs separation distance.png (58.7 KB, 230 views)
  Reply With Quote
Old 11th June 2019, 11:34 PM   #57
Droco is offline Droco
diyAudio Member
 
Join Date: Oct 2017
Quote:
Originally Posted by Cask05 View Post
No, you don't.

Yes, I think it does. I've talked about this in the full-range MEH kit thread.

Chris
Reading through it now, and will read through it tomorrow some more. Already some interesting things, also pertaining to my other questions.

"2. The off-axis ports in my prototype are actually 2.5 cm deep (1"), but I'd recommend they be much shallower. You can taper the woofer mounting pads in the off-axis port areas to thin them down to the horn's ABS material thickness, starting about 2.5 cm or more away from the through hole."

=> using this I can ensure that I keep a shallow port, even with the little gap I might have. I was already planning in rounding them, but not to this extent.

Sadly I dont readily find the discussion about the port position. Will have to look for it tomorrow.
  Reply With Quote
Old 12th June 2019, 06:02 AM   #58
Droco is offline Droco
diyAudio Member
 
Join Date: Oct 2017
Also, how far should I take the wooer modelling? I know the response you finally got wasnt what you modeled, but why then do it? What do I look at? Is it a good way to compare woofers? Or? And if I cant go by modellling, then how do I know it is a good fit? What T/S parameters would you recommend I focus on for the best low-end performance (down to 60-100hz).
  Reply With Quote
Old 12th June 2019, 11:35 AM   #59
Cask05 is offline Cask05  United States
diyAudio Member
 
Cask05's Avatar
 
Join Date: Nov 2007
Location: Arlington, TX
Modeling in Hornresp will tell you the first notch frequency of your off-axis port locations (which is a vital piece of information) but not the performance of size of the ports. It won't tell you the on-axis SPL of your woofers but it will tell you the relative performance of woofers in a qualitative way. You'll need to build and test them to see the real frequency and phase responses. That's where a DSP crossover comes in handy: to EQ the output flat below the first notch frequency and to attenuate the response above the first notch frequency.

In the K-402-MEH, that means setting two to three attenuating PEQ filters above the first notch frequency of ~650 Hz: one peak at 1320 Hz and another at ~2600 Hz, and perhaps a third notch centered at 3400 Hz. The woofers and 2" compression driver will couple and act as one driver in their crossover interference band. The other frequency bands will behave like a regular horn-loaded loudspeaker. You can use a first order crossover filter between the woofers and compression driver, or you can simply set the woofer channel delay to around 0.5 ms (corresponding to 90 degrees of phase lag to approximate a first order crossover) and use no crossover filters. The results will perform almost identically in terms of phase and on-axis SPL response in my experience (surprisingly). This is most likely true due to the coupling of the compression driver output to the woofer output. This is a phenomenon that is largely absent from other horn-loaded loudspeakers, i.e., the coupling that takes place between drivers in an MEH.

I would not use any higher order crossover filters than first order, only attenuating PEQs to bring down SPL response peaks. The resulting SPL and phase response of the MEH will get your attention when you play good music recordings having a high degree of phase fidelity (i.e., acoustic music performances recorded with all musicians playing at the same time in the same open venue).

Chris

Last edited by Cask05; 12th June 2019 at 11:52 AM.
  Reply With Quote
Old 12th June 2019, 11:10 PM   #60
Droco is offline Droco
diyAudio Member
 
Join Date: Oct 2017
Quote:
Originally Posted by Cask05 View Post
Modeling in Hornresp will tell you the first notch frequency of your off-axis port locations (which is a vital piece of information) but not the performance of size of the ports. It won't tell you the on-axis SPL of your woofers but it will tell you the relative performance of woofers in a qualitative way.
Chris
" that means setting two to three attenuating PEQ filters above the first notch frequency of ~650 Hz: one peak at 1320 Hz and another at ~2600 Hz, and perhaps a third notch centered at 3400 Hz."

Can you show me the graph showing you those 3 notches? So I can figure out myself what the notches will be in mine. And where do you apply the 3 PEQs? On the input? Or only on the HF driver?


but it will tell you the relative performance of woofers in a qualitative way.

As in that it is a way to compare woofers? So if a woofers performs better in the modelling, it should also work better in the MEH? You wont know how it wil perform if you dont measure it, but it can help me pick the one that is gonna be the best one?

Or what do you mean by qualitative?
  Reply With Quote

Reply


Amount of hornloading in a Synergy hornHide 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
Synergy horn for 135 dB+ Thijs666 Multi-Way 107 24th November 2018 04:07 PM
horn, bandpass, horn, synergy? fotsinijts Multi-Way 32 31st August 2018 09:30 AM
M2 Synergy Horn Patrick Bateman Multi-Way 43 23rd December 2017 02:08 PM
DIY Synergy horn paulspencer Multi-Way 53 5th December 2015 09:29 AM
synergy like horn, using CD rvrazvan Multi-Way 5 4th November 2011 08:28 AM


New To Site? Need Help?

All times are GMT. The time now is 09:09 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