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

Dual Opposing Driver as Full(er) Range?
Dual Opposing Driver as Full(er) Range?
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 13th June 2017, 10:29 AM   #1
ShaunR is offline ShaunR  Australia
diyAudio Member
 
Join Date: Jun 2017
Location: Perth
Default Dual Opposing Driver as Full(er) Range?

Hi Everyone,

First time poster and long time lurker...

I have always had an interest in audio and now have a keen interest in making my own speaker cabinet.

Now I have looked at posts like:

http://www.diyaudio.com/forums/multi...configure.html

and:

Dual opposing drivers cancellation issues?

But they are not answering my question directly and my poor overloaded (with new found knowledge) mind is struggling a little with the idea.

I would like to create a full range cabinet which is not isobarik, and I guess the correct term is bipole? This is with drivers opposing each other (wired in the same polarity) so that they get the vibration cancellation effect and still retain the increased SPL of the dual drivers. The issue comes in with the following questions:

1. Can I use these in a full range setup?

2. If not, at what frequency will they start to phase cancel, that is if they do cancel at all and is this related to the effective driver spacing between them? i.e. quarter wavelength or half/full etc?

3.With regards to enclosure as well, what would be the difference between having each driver with its own enclosure space (i.e. essentially two cabinets back to back but joined as such) vs a shared space?

4. With regards to using a mids driver if the phase cancellation issue is present, what is a good rule of thumb for power rating of mid/high drivers to woofer drivers as they require more power to obtain that low end thump than the mid to high drivers?

I apologise if this is a strange post and if I have oversimplified it, but I have read so much and I am starting to go round in circles with the sheer amount of information out there.
  Reply With Quote
Old 13th June 2017, 02:44 PM   #2
ewollowe is offline ewollowe  Australia
diyAudio Member
 
Join Date: May 2014
Location: Perth, Western Australia
Hi Shaun,

Yeah looks like you're overloaded a bit mate

If you're just talking about making a full range bipole like this

http://diyaudioprojects.com/Speakers.../FE127E_SB.htm

Then you'll be fine.

Bipole need room to breath though, wouldn't be placing them close to the wall.

I'd put them in a shared enclosure, couple the magnets together as best you can.
__________________
Irishman downunder
  Reply With Quote
Old 13th June 2017, 03:03 PM   #3
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Correct.

1. Yes.

2. This gets a bit complex, but if you don't like the added ambiance of all the extra delayed reflections from the rear driver, then roll if off with a hi-pass filter. This is called a 1.5 system.

3. Basically nothing, but the divider braces the cab, which is a good thing, so the technically preferred construction.

4. This too gets a bit complex, but ideally you use the same amp model when multi-amping except for separate sub systems typically limited to <100 Hz.

Understood and made much worse by all the [not so] well meaning 'misunderstandings' to outright 'floobydust' littering the net.

Maybe some links you missed: https://www.google.com/search?q=Jim+...hrome&ie=UTF-8

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 14th June 2017, 10:43 AM   #4
ShaunR is offline ShaunR  Australia
diyAudio Member
 
Join Date: Jun 2017
Location: Perth
Quote:
Originally Posted by ewollowe View Post
Hi Shaun,

Yeah looks like you're overloaded a bit mate

If you're just talking about making a full range bipole like this

DIY Sealed Bipole Speaker Project with Fostex FE127E Driver

Then you'll be fine.

Bipole need room to breath though, wouldn't be placing them close to the wall.

I'd put them in a shared enclosure, couple the magnets together as best you can.
Quote:
Originally Posted by GM View Post
Correct.

1. Yes.

2. This gets a bit complex, but if you don't like the added ambiance of all the extra delayed reflections from the rear driver, then roll if off with a hi-pass filter. This is called a 1.5 system.

3. Basically nothing, but the divider braces the cab, which is a good thing, so the technically preferred construction.

4. This too gets a bit complex, but ideally you use the same amp model when multi-amping except for separate sub systems typically limited to <100 Hz.

Understood and made much worse by all the [not so] well meaning 'misunderstandings' to outright 'floobydust' littering the net.

Maybe some links you missed: https://www.google.com/search?q=Jim+...hrome&ie=UTF-8

GM
Thanks, both these posts have restored my hope in the build again!

I found this document though which talks about the cancellation issue, would a 4dB dip be a problem? The author does not seem to think so.

http://www.creativesound.ca/pdf/OffsetBipolarMLTL.pdf

He said this:

"While I
did notice that there was a dip of 4 dB in the on-axis response in the 400 to 500 Hz range because of the wraparound of energy from the rear driver to the front driver when the front to rear spacing between the drivers was a half wavelength, I could not hear an appreciable degradation to the overall performance of these speakers. "
  Reply With Quote
Old 14th June 2017, 03:34 PM   #5
ewollowe is offline ewollowe  Australia
diyAudio Member
 
Join Date: May 2014
Location: Perth, Western Australia
That's a really good paper to read. Here's another connected one.

The Controlled-Pattern Offset Bipole Loudspeaker

These are well respected guys and solid builds. If you're smart about room placement they should work well.

Don't expect to get everything perfect first time, if that's what you're mainly concerned with either buy a kit or follow a well documented design (or buy 2nd hand).
__________________
Irishman downunder
  Reply With Quote
Old 14th June 2017, 06:06 PM   #6
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
Dual Opposing Driver as Full(er) Range?
Quote:
Originally Posted by ShaunR View Post
Hi Everyone,

First time poster and long time lurker...

I have always had an interest in audio and now have a keen interest in making my own speaker cabinet.
Welcome to DIYAudio Anonymous as an active poster

We're all adicts here

I started my DIY activities with a full range speaker. I enjoyed it hugely and learned a lot. The results weren't very good, I discovered full range drivers are too bright, too sharp and make my ears hurt. I started with the Fostex FE127 and it was awful (to my ears). Anyhow, it's a great hobby. My advice is 1)to invest in some good tools - I didn't do that and struggled more than I should have. And be anal about safety in using them. 2) start building something very soon or you'll end up going mad as your brain tries to absorb decades of collective knowledge through that information fire hose, the internet.

I believe I would have been happier if I had started out by copying Dave's Tysen speaker design (named after his son I believe). It has two things that I believe you will like. It has opposing drivers in a push-push and it uses that for the lower frequencies where vibrations are more of an issue. The higher frequencies are handled separately by a full range driver that is small enough to push most annoying cone resonances above the 'presence' region where my ears are more sensitive.

Thread here: http://www.diyaudio.com/forums/full-...ions-fast.html

Edit: found a sketch of the design (copyright Dave)
Attached Images
File Type: gif Tysen-V2-extents.gif (25.3 KB, 196 views)
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.

Last edited by Bigun; 14th June 2017 at 06:18 PM.
  Reply With Quote
Old 14th June 2017, 06:24 PM   #7
chrisb is offline chrisb
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Speaking of the TysenII - Dave has had those with the passive XOs installed in his system for a couple of days now - perhaps he has some observations to share?

(godson, actually)
__________________
Technology honors no Hippocratic oath
  Reply With Quote
Old 14th June 2017, 10:22 PM   #8
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
Dual Opposing Driver as Full(er) Range?
I'm eager to hear more about it. I have had an interest in this approach for a long time. I'd like to start a FAST project of my own but haven't got around to it. I was leaning towards sealed-box for the woofers though but the overall approach is consistent.
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 15th June 2017, 02:53 AM   #9
ewollowe is offline ewollowe  Australia
diyAudio Member
 
Join Date: May 2014
Location: Perth, Western Australia
Bigun is right, build something quick before you get bogged down in details like me

I like that Tysen build a lot.
__________________
Irishman downunder
  Reply With Quote
Old 15th June 2017, 03:58 AM   #10
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
+1, my first was an oval mobile audio driver stuck in a cardboard Kleenex box just because it had a 'close enough' size oval punch out. Got two [Cub] Scout badges for it. Used it hooked up to a tube mono AM car radio/6 V battery in my shop till '75.

+1 on some 'flavor' of FAST bipole, best of both 'worlds', 'FR' with real bass without a huge BLH.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote

Reply


Dual Opposing Driver as Full(er) Range?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
full range driver for cheap(er) =] kan3 Full Range 8 22nd May 2017 04:42 AM
Full range driver as a wide range tweeter. midrange Multi-Way 49 23rd April 2015 07:32 AM
full range driver opposing magnet in dipole configure sagamotto Multi-Way 11 18th April 2012 01:35 PM
Dual opposing drivers cancellation issues? hornloaded Subwoofers 23 12th April 2010 03:48 AM
Full range driver recomendation for dual mono LM3875 gainclone? zebra100 Full Range 5 4th August 2009 08:23 AM


New To Site? Need Help?

All times are GMT. The time now is 06:26 AM.


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