Dual Mid-Ranges in a 3-way Design - 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 24th September 2004, 02:22 AM   #1
diyAudio Member
 
wigginjs's Avatar
 
Join Date: Dec 2003
Location: Columbia, SC
Default Dual Mid-Ranges in a 3-way Design

I'm currently designing a 3-way speaker that will use a 1" dome tweeter, 5 1/2" midrange, and 10" woofer actively crossed. The mid-range in question is rated for 35W continous power (nominal impedance of 8ohm). The power ratings of the tweeter and woofer are significantly higher and the amp I plan to use to power the midrange has a max output of about 60W@8ohm. I'm considering wiring two of these woofers in parallel to increase the power handling capability of the midrange section of this speaker. A few questions:

1) In my cabinet design I've made sure to keep the midrange and tweeter very close, but the addition of a second midrange driver obviously creates a much larger area from which midrange frequencies will be produced (from about 200Hz - 3000Hz). The two midrange drivers will be arranged so that one is right above the other on the front baffle. I'm not sure if this larger radiating area will have a positive or negative effect on the overall sound and imaging of the speaker. Any comments on this?

2) Does wiring the midranges in this way create any problems with respect to interference between drivers? This is to say, if I use two as opposed to one will the create a problem when crossing over from one set of drivers to another.

3) Is this the correct way to go about increasing the power handling capabilities of the mid-range section? I listen to music at relatively low volume levels (never any louder than about 100dB), the midrange driver in question has an SPL of about 87, should I even be worrying about the added power handling?

Thanks very much for your time.
__________________
The Four Chairs
DIY Home Theater
  Reply With Quote
Old 24th September 2004, 03:31 AM   #2
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
Use 2 mids in parallel, one above and one below the tweeter. At 87db each, they should match nicely to a 91 or 92db tweeter.
  Reply With Quote
Old 24th September 2004, 11:37 AM   #3
diyAudio Member
 
wigginjs's Avatar
 
Join Date: Dec 2003
Location: Columbia, SC
Justify your answer =)
__________________
The Four Chairs
DIY Home Theater
  Reply With Quote
Old 24th September 2004, 05:24 PM   #4
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
I don't really need to as scores of very good MTM designs will attest.

On the other hand, as you pointed out, you may have concerns where none need be. Your mid, with the need for reproducing low frequencies removed, is likely up to the task at hand.
  Reply With Quote
Old 24th September 2004, 06:15 PM   #5
Kittle is offline Kittle  United States
diyAudio Member
 
Join Date: Jun 2004
Location: KC
And is it safe to assume one can get the same SPL and wattage adjustments by using 2 woofers in the same configuration?

Where woofer SPL = 88 and midrange/tweeter SPL = 91-93.
  Reply With Quote
Old 24th September 2004, 09:48 PM   #6
diyAudio Member
 
wigginjs's Avatar
 
Join Date: Dec 2003
Location: Columbia, SC
Quote:
I don't really need to as scores of very good MTM designs will attest.
I didn't mean it that way. I just wanted a more elaborate explaination of your reasoning for a MTM arrangement instead of a TMM or TM arrangement.
__________________
The Four Chairs
DIY Home Theater
  Reply With Quote
Old 25th September 2004, 12:00 AM   #7
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
An MTM needs lowering the cross frequency bcs lobing occurs with 2 mid sources separated by the tweeter as the L/2 frequency they reproduce exceeds their centre to centre distance.
Also if the phase difference is anything other than 90 deg where the mids cross to the tweeter you get no symmetry and tilts on the vertical polar response.
One common deviation of neutriality that such an arrangement has is that it exagerates the horizontal dispersion around cross to T. Resulting in a hump of room power response and perceived forwardness. A neat trick to keep the benefits of sensitivity and power handling (see lower distortion) is to keep down the forward response around cross about a dB or so. It takes careful voicing and a calibrated mic.
  Reply With Quote
Old 25th September 2004, 07:20 AM   #8
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by m0tion
I didn't mean it that way. I just wanted a more elaborate explaination of your reasoning for a MTM arrangement instead of a TMM or TM arrangement.
1st off, power handling for home hifi speakers is given alot more attention than it deserves -- there is no reason to consider a 2nd mid just because of the power handling ratings.

As for TM vrs TMM vrs MTM, i like TM better, but if you are going to add a 2nd mid to the front the MTM gets the tweeter closer to both mids so should be able to support a higher XO.

This is a fairly common arrangement (especially when you consider all the MTMs used with subs)

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  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
dual atc mid xover design mclsound Multi-Way 12 29th July 2009 12:56 AM
TB 2" Full Ranges MiniVanMan Full Range 6 22nd June 2008 03:29 PM
dual sub one box design v1d9uy Subwoofers 13 11th January 2006 07:41 AM
Looking for suggestions on a 1300W Dual 18 sub design. mjcohen Subwoofers 5 21st December 2004 07:38 AM


New To Site? Need Help?

All times are GMT. The time now is 03:08 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