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

Small Speakers using Infinity CMMD Drivers
Small Speakers using Infinity CMMD Drivers
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 25th March 2020, 04:12 AM   #1
BradH is offline BradH
diyAudio Member
 
Join Date: Jul 2019
Default Small Speakers using Infinity CMMD Drivers

Looking to build some small speakers that will be used in a 7 channel system. I have 12 Infinity 336545-002 CMMD 4" woofers and 10 Infinity 336417-001 CMMD 3/4" tweeters. Infinity used them in a few different designs but of interest to me is the Modulus ms-1 center channel.

There are numerous options. They'll all involve building cabinets, so there's flexibility. But these drivers are all I'd be using to get down to subs.

-----------------------------------------------------------------------------

Left Wide, Left, Right, Right Wide - MTM or TMW

Center - MTM or WMTMW

Surrounds - TM, TMW, or two separate TM's for each side

------------------------------------------------------------------------------

It's important for this build to stay affordable. I paid a little under $200 CAD for all the drivers, it would be nice to not spend more than $100 on crossover parts, is that a pipe dream? I don't know much about passive crossovers so I'd really be relying on help. Are the Infinity crossovers worth replicating? Improving? Completely changing?

How should I replicate the little waveguide on the tweeters? I'd be CNC or 3D printing them. The throat is 3/4" and the mouth is about 2.5"

Here is what little info I could get on them

Tweeter

I realize the PDF is basically unreadable, but it has a bit of an image of the TM crossover. For whatever that's worth.
Attached Images
File Type: png ms1 center crossover.png (534.8 KB, 194 views)
File Type: png ms1 center specs.png (86.8 KB, 199 views)
File Type: png ms1 center exploded.png (791.4 KB, 189 views)
Attached Files
File Type: pdf ms1 crossover.pdf (33.2 KB, 4 views)

Last edited by BradH; 25th March 2020 at 01:39 PM.
  Reply With Quote
Old 25th March 2020, 04:07 PM   #2
sgrossklass is offline sgrossklass  Germany
diyAudio Member
 
Join Date: Nov 2004
Location: Germany
You've really got your work cut out for you here.

I assume that there are no TSPs available for these OEM drivers, so those should really be measured.

While the original crossover may provide a good starting point, in the details each crossover is unique to a given combination of cabinet and drivers, and is optimized by means of first simulation and later measurements.

This waveguide business could become fun, too... there isn't that much available to hobbyists in this regard.

The Modulus Center is a better than average design IMHO, as it at least attempts to address the inevitable lobing issues that plague MTMs in the horizontal. I might have placed the mid-woofers even closer together, but at some point is becomes a tradeoff betwen horizontal and vertical dispersion, and vertical may be somewhat more important for centers as they often find themselves in shelves and the like. A design like this actually may not be bad if placed vertically, with symmetrical left and speakers.

With 4" mid-woofers, using two per speaker seems kind of inevitable if you want to get anywhere near sub terrain at a decent level either way. You could certainly try a CB design of a decent size and have boundary gain help you out when wall mounted.
  Reply With Quote
Old 25th March 2020, 04:42 PM   #3
BradH is offline BradH
diyAudio Member
 
Join Date: Jul 2019
Yes, you hit on all the points there.

I think the base case is that I build replicas of the center channel, albeit with a more conventional looking box. Same internal volume. I'll need someone to chime in about the waveguide. Can one follow an OS shape with such a small waveguide?

And yes, I too was wondering about the placement of the tweeter with regard to the woofers. If it should be changed or left the same.

These speakers were one of the first CMMD implementations after the Prelude MTS, with Toole at the helm of engineering. They went for a pretty penny too, so I trust the design was well thought out within it's constraints. The sub that came with them was nearly the same as the one that came with each channel of the Prelude MTS as well.

Unfortunately no T/S to be found.
  Reply With Quote
Old 25th March 2020, 04:54 PM   #4
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Small Speakers using Infinity CMMD Drivers
Sidewise MTMs are not a good idea. The idea comes form the marketing dept.

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
Old 25th March 2020, 05:02 PM   #5
tuantran is offline tuantran  Canada
diyAudio Member
 
tuantran's Avatar
 
Join Date: Jun 2011
Location: Ottawa
Here is speaker crossover for Infinity 3/4" tweeter and 4" woofer
Attached Images
File Type: jpg DSCN6371.jpg (212.8 KB, 137 views)
__________________
Flat on-axis frequency response with wide bandwidth; wide, constant dispersion; low distortion and resonance.
  Reply With Quote
Old 25th March 2020, 06:20 PM   #6
BradH is offline BradH
diyAudio Member
 
Join Date: Jul 2019
Dave - You're talking horizontal MTM for center is not good? What do you think about the vertical MTM with that offset little tweeter for sides? I think it's crossed at 2.5k from factory.

tuantran - Thank you! Does that cross at 2.5k like the other one? My last one to figure out is what a TMM would like look with the top driver highpassed and the lower one doing midbass duties.

Last edited by BradH; 25th March 2020 at 06:30 PM.
  Reply With Quote
Old 25th March 2020, 08:24 PM   #7
tuantran is offline tuantran  Canada
diyAudio Member
 
tuantran's Avatar
 
Join Date: Jun 2011
Location: Ottawa
BradH, this is the original design for two way Infinity bookshelf speaker crossover at 3000 Hz.
__________________
Flat on-axis frequency response with wide bandwidth; wide, constant dispersion; low distortion and resonance.
  Reply With Quote
Old 25th March 2020, 10:21 PM   #8
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Small Speakers using Infinity CMMD Drivers
Quote:
Originally Posted by BradH View Post
Dave - You're talking horizontal MTM for center is not good?
Not me, i donít have a centre and if i did it would be one-way. It was Toole who really showed how bad horizontal MTMs.

Quote:
What do you think about the vertical MTM with that offset little tweeter for sides? I think it's crossed at 2.5k from factory.
If i am doing a 2-way XO is rarely above 400 Hz. The tweeter to the side is usually reseved for left right pairs and there will be, in theory at least will have differing dispersion left or right, but probably insignificant. An MT makes more sense with vertical alignment, AFAC an MTM needs a maximum c-c of a 1/4 wavelength at the XO frequency (if you got the spacing that close, a sideways MTM becomes OK).

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
Old 25th March 2020, 11:21 PM   #9
BradH is offline BradH
diyAudio Member
 
Join Date: Jul 2019
Crossover of 2.5k is 5.4". CTC spacing between woofers for the infinity design is 6". So no bueno...

Other option is to see how low one can cross the tweeter? I have extra, I guess I could sacrifice. How can I test to see?

But then one asks... Why didn't the original designers just do that? Was it to play it safe for power handling?

Or I just do TMW for everything and WTMW for the center with the tweeter and mid aligned vertically. Woofers of course being the same 4"ers but low passed. I would just need help designing a crossover for that.

Last edited by BradH; 25th March 2020 at 11:27 PM.
  Reply With Quote
Old 26th March 2020, 12:24 AM   #10
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Small Speakers using Infinity CMMD Drivers
Quote:
...WTMW for the center with the tweeter and mid aligned vertically...
That works because you can get the W to M XO within that 1/4 wavelength metric.

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


Small Speakers using Infinity CMMD DriversHide 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
Infinity midrange drivers, two marknoir Swap Meet 0 1st September 2019 01:59 PM
Infinity SM122 drivers for OB with CHP70? wendelltate Multi-Way 2 1st May 2014 10:10 AM
Thiele Small Parameters - Infinity Kappa Perfect gwolfman Multi-Way 8 28th April 2011 10:35 PM
FS: Infinity 6x9, 2 way car speakers Stuart Easson Swap Meet 0 8th August 2006 01:06 AM
Drivers - Infinity, MB Quart or what? MikeFarad Car Audio 3 23rd March 2004 09:39 PM


New To Site? Need Help?

All times are GMT. The time now is 10:49 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki