My Morel MTM Project - Page 15 - 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 10th November 2011, 10:22 AM   #141
diyAudio Member
 
pheonix358's Avatar
 
Join Date: Jul 2008
Location: Stockport South Australia
Nicely done!
__________________
What we don't understand is called magic.
  Reply With Quote
Old 10th November 2011, 10:27 AM   #142
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Quote:
Originally Posted by wintermute View Post
I think there is something suspect with the phase,
It looks like group delay, maybe 1 to 2cm in the measuring distance.

On Love Over Gold I can't go past Telegraph Road, myself.
  Reply With Quote
Old 10th November 2011, 10:37 AM   #143
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
Thanks Terry!

Allen yes it would only be about a cm I would guess, I should have marked where the feet were, to get an exact match but wasn't thinking

edit: I love telegraph road as well, but I just can't go past the strings and drums in private investigations. Piano is great too.

Tony.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos

Last edited by wintermute; 10th November 2011 at 10:40 AM. Reason: add telegraph road comment
  Reply With Quote
Old 11th September 2013, 08:16 AM   #144
tcpip is offline tcpip  India
diyAudio Member
 
Join Date: Jan 2003
Location: Mumbai, India
Hey, what's the current picture? Are you still planning to add the woofer at 300Hz?
  Reply With Quote
Old 11th September 2013, 11:38 AM   #145
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
Hi tcpip, yes, but it may be 200Hz. I have to get my active crossover project back on the boil. I took some in room measurements of the MTM's and the 10" current cabinets last week with the idea that I would tailer the active crossover to give me the best response in room. I've put the circuit diagram into tinycad and need to do the board layout (verro board). I might need to revise to third order electrical on the bass though I suspect (only addition of one resistor to my circuit though I think).

It's a very slow process with me unfortunately

Tony.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote
Old 11th September 2013, 12:02 PM   #146
tcpip is offline tcpip  India
diyAudio Member
 
Join Date: Jan 2003
Location: Mumbai, India
Quote:
Originally Posted by wintermute View Post
Hi tcpip, yes, but it may be 200Hz.
I have some thoughts on my own 3-way project which may have some bearing on this. Hope you get around to reading this page which has all my thoughts and rationale.

I have been thinking of this 3-way for a long time. There is this strange belief among many speaker builders that the human voice is between 300-3000Hz. The reality is that male voices can go much lower than 300Hz, maybe down to 150. And the 300-3000Hz range is the range of maximum sensitivity of our ears, but not the range of the human voices. Since we all want to get fantastic realism with the human voices, I don't want to entrust a woofer with the job. The driver which reproduces the thump-thump of bass percussion with large Xmax should not be asked to reproduce any part of the human voice range, I felt.

Therefore, I was thinking of crossing over my woofer at 100Hz. This is also the reason why I want a conventional midbass driver (at least 6", with an Fs below 80Hz) for my midrange. I can't use a typical ultra-low-Xmax ultra-sensitive 4" midrange driver.

There is another reason (very attractive to a lazy designer like me) to do this. If you push down the Fc lower and lower, it becomes less and less critical getting phase alignment between woofer and midrange at Fc. Think about it. At 100Hz, the wavelength is about about 11-12 feet. This means that woofer and midrange will need to be displaced by 3 feet to be out of phase by even 90-degrees. This gives the designer a much larger margin for error than, say, at 200Hz or 300Hz.

Therefore, for my 3-way, I was thinking of simply building an electrical LR4 LP for the woofer at 100Hz (which would also pretty much give me acoustic LR4), and an acoustic LR4 for the midrange in its sealed enclosure. I could do this by using LT to get 2nd order at 100Hz, and then adding another electrical LR2 to make it fourth order. I have a suspicion that textbook filters will do the job, and no careful phase matching will be needed.

These were the two reasons why I suggest that you consider moving your Fc down. You'll get the active filters built on breadboard in no time, and no measurements (other than impedance measurement of the midrange in its enclosure for the LT) will be needed.

Does this make sense?

Last edited by tcpip; 11th September 2013 at 12:14 PM.
  Reply With Quote
Old 11th September 2013, 05:34 PM   #147
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Quote:
Originally Posted by tcpip View Post
an acoustic LR4 for the midrange in its sealed enclosure. I could do this by using LT to get 2nd order at 100Hz, and then adding another electrical LR2 to make it fourth order.
Would you need the Linkwitz transform if you built the box for the 100Hz response?
  Reply With Quote
Old 11th September 2013, 06:20 PM   #148
tcpip is offline tcpip  India
diyAudio Member
 
Join Date: Jan 2003
Location: Mumbai, India
Quote:
Originally Posted by AllenB View Post
Would you need the Linkwitz transform if you built the box for the 100Hz response?
I guess you are referring to the midrange box, right?

In that case, if you have accurate T/S parameters of the driver and can size your enclosure to get 0.7 Qts in the box, then you can skip the LT. I was intending to size and shape the box as per my convenience, and then use LT to get the rolloff to fit. Gives me more flexibility in box dimensions.
  Reply With Quote
Old 12th September 2013, 03:45 AM   #149
diyAudio Member
 
pheonix358's Avatar
 
Join Date: Jul 2008
Location: Stockport South Australia
Quote:
Originally Posted by tcpip View Post
I have some thoughts on my own 3-way project which may have some bearing on this. Hope you get around to reading this page which has all my thoughts and rationale.


snip

These were the two reasons why I suggest that you consider moving your Fc down. You'll get the active filters built on breadboard in no time, and no measurements (other than impedance measurement of the midrange in its enclosure for the LT) will be needed.

Does this make sense?
Please consider the following.

Most 6" drivers will happily go down to 120Hz in a sealed box. You get a better midbass performance.

I would never cross to a sub any lower than 150Hz and any sub should handle this easily. There is no stereo info at or below 150 Hz, ther can be at higher Fs.

Just my two cents worth.

P
__________________
What we don't understand is called magic.
  Reply With Quote
Old 12th September 2013, 06:58 AM   #150
tcpip is offline tcpip  India
diyAudio Member
 
Join Date: Jan 2003
Location: Mumbai, India
Quote:
Originally Posted by pheonix358 View Post
I would never cross to a sub any lower than 150Hz and any sub should handle this easily. There is no stereo info at or below 150 Hz, ther can be at higher Fs.
We are not talking about a sub here. We are talking about a woofer in a 3-way design. The fact of whether there is or isn't any stereo separation is not very relevant here, right, once we have already decided to put one woofer driver per channel?

Therefore can you please explain your thoughts a bit here? Why not cross over below 150Hz?
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dusted off an old project. Morel Pure_Brew Multi-Way 7 3rd June 2010 03:14 PM
My MTM Project Twisted85 Multi-Way 34 10th March 2008 03:10 PM
Morel 3-way tri-amped project Joe-Al Multi-Way 0 12th December 2005 04:20 PM
new morel MTM project: rantings wintermute Multi-Way 22 30th January 2005 11:13 AM
Help with Morel sub project andrew Multi-Way 5 11th May 2002 02:29 AM


New To Site? Need Help?

All times are GMT. The time now is 04:02 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