3way CD Mid CD hi or cone mid CD hi?

cpc748

Member
2015-03-27 4:01 pm
I'm looking for some inputs and advice.

I'm planning on building a pair of 3way towers with dual 10" low, 2" compression driver mid and 2" compression driver high or dual 6.5" cone drivers mid and 2" compression driver high.

Drivers that I have in mind.
Aurum Cantus 10" low, 6.5" mid
Selenium D408Ti mid and D3300Ti high.

The reason I want to use 2" CD mid and high with the same horn I want the drivers to line up in the box. if I go with 1" high due to the horn configuration the drivers will not line up.

What would be the best layout as for as driver placement/configuration?

If I decide to go with CD drivers which diaphragm material to go with titanium or aluminium or phenolic? What's good for mid and what's good for high?
 

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What speaker-drivers do you already own and desire to use on this project?
What well reviewed horn speakers are similar to your design/build vision?


In diyAudio it is "accepted" and even "recommended" to lust after the best expert-reviewed speakers, and to clone the one which sounds best and best fits the listening room.

Probably the most successful two*10" + horn columns use a 10" woofer on the bottom with a crossover between 150-200Hz, TO a 10" midbass above with a crossover between 1200-1300Hz, TO a 1" compression driver attached to a tweeter horn/waveguide which has the desired directivity(polar pattern) for the listening room. The 10" midbass has different T/S parameters than the 10" woofer. One of many Econowave type speaker designs. SEOS-10 and SEOS-12 waveguides with a 90H x 40V polar pattern are very popular, but there are respected alternatives with different polar patterns from different shape/size.
Fusion-10 Series DIY Sound Group

If above the two 10" woofers column you want to add a horn midrange for greater dynamics and polar pattern control over a wider frequency range, then most expert designs use either: (1) 1.4" compression driver from 800Hz to over 16Khz in the proper horn/waveguide(crossover may boost 15Khz - 20Khz); (2) 2" midrange compression driver in a "large-enough" midrange horn/waveguide for 500Hz to ~9Khz-10Khz, plus a 0.5" - 1"tweeter compression driver above in a second "small-enough" tweeter horn/waveguide for 10Khz-20Khz. The 500Hz midrange horn must be wider than the woofer tower to maintain polar control.


For home use, either an aluminum diaphragm bonded to a Mylar suspension, or a PET platic diaphragm with integrated suspension are currently favored for sound quality and cost. Titanium is used in pro-sound because it better withstands deformation from high air pressures.
 

cpc748

Member
2015-03-27 4:01 pm
What speaker-drivers do you already own and desire to use on this project?
What well reviewed horn speakers are similar to your design/build vision?


In diyAudio it is "accepted" and even "recommended" to lust after the best expert-reviewed speakers, and to clone the one which sounds best and best fits the listening room.

Probably the most successful two*10" + horn columns use a 10" woofer on the bottom with a crossover between 150-200Hz, TO a 10" midbass above with a crossover between 1200-1300Hz, TO a 1" compression driver attached to a tweeter horn/waveguide which has the desired directivity(polar pattern) for the listening room. The 10" midbass has different T/S parameters than the 10" woofer. One of many Econowave type speaker designs. SEOS-10 and SEOS-12 waveguides with a 90H x 40V polar pattern are very popular, but there are respected alternatives with different polar patterns from different shape/size.
Fusion-10 Series DIY Sound Group

If above the two 10" woofers column you want to add a horn midrange for greater dynamics and polar pattern control over a wider frequency range, then most expert designs use either: (1) 1.4" compression driver from 800Hz to over 16Khz in the proper horn/waveguide(crossover may boost 15Khz - 20Khz); (2) 2" midrange compression driver in a "large-enough" midrange horn/waveguide for 500Hz to ~9Khz-10Khz, plus a 0.5" - 1"tweeter compression driver above in a second "small-enough" tweeter horn/waveguide for 10Khz-20Khz. The 500Hz midrange horn must be wider than the woofer tower to maintain polar control.


For home use, either an aluminum diaphragm bonded to a Mylar suspension, or a PET platic diaphragm with integrated suspension are currently favored for sound quality and cost. Titanium is used in pro-sound because it better withstands deformation from high air pressures.

All the speakers I have are all home built 3 way towers and some book shelf type.

I've never experience with compression drivers but have listen to a few and love the dynamic.

I'm considering dual 10" woofer at the bottom in parallel crossover at 750Hz and a 2" compression driver for mid-range crossover at 3.5K to a 1" compression driver for tweeter.

I've heard that Phenolic diaphragm has smoother mid-range vs. Titanium. Is that for pro-sound only?

You recommend Aluminum diaphragm?
 
Last edited:
For a 2" compression driver, a good sounding 750Hz horn will be at least 20" wide... not small .and. not cheap!
The SEOS24 is one possible option. BIG HORN, little 10" woofers. What's wrong with this picture?

-- 1.4" CD can be used down to 800Hz in the proper horn. The high frequency extension satisfies many owners.
-- 2" CD is usually used up to 8000-10,000Hz. (3500Hz in your post seems wastefully low) 2" CDs are usually found in BIG SPEAKERS
-- Titanium diaphragms in 2" CDs produce severe breakup around 18Khz, and the Xover must attenuate it or many listeners report "sizzle".

Have you found a well-reviewed speaker which is close to your design?
 

cpc748

Member
2015-03-27 4:01 pm
For a 2" compression driver, a good sounding 750Hz horn will be at least 20" wide... not small .and. not cheap!
The SEOS24 is one possible option. BIG HORN, little 10" woofers. What's wrong with this picture?

-- 1.4" CD can be used down to 800Hz in the proper horn. The high frequency extension satisfies many owners.
-- 2" CD is usually used up to 8000-10,000Hz. (3500Hz in your post seems wastefully low) 2" CDs are usually found in BIG SPEAKERS
-- Titanium diaphragms in 2" CDs produce severe breakup around 18Khz, and the Xover must attenuate it or many listeners report "sizzle".

Have you found a well-reviewed speaker which is close to your design?

I understand what you're saying. I've attach 2 photos for JBL and Klipch both are larger mid CD and 1" CD high. As you can see in the photos the JBL is a 14" low driver, Klipsch is 3, 9" low drivers.

The JBL is a 2" aluminum mid, 1" titanium high. It has a very large horn but it's vertical. x-over 750hz, 8Khz

The klipsch 4.5 mid, .75 high, x-over frequency 500hz and 3.2Khz

I'm thinking of a 90x40 mid horn 11" wide. tweeter horn similar but a tad smaller in size.
 

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The lower frequency of transmission for a horn of square section must AT LEAST meet:
--Mouth Area Exceeds: (cut-off wavelength ^2) / 4*Pi

500Hz MINIMUM horn area = 60sqin

Study the polar plot for each horn.
========
A 90x40 mid horn mouth that is 11" wide could not be used down to 500Hz for acceptable pattern control

Expert designers use the 12" SEOS waveguide above ~1200Hz with a 1" CD.
=====
Have you sketched your listening room and seating position to estimate the best horn polar pattern? 1-seat Man Cave? Home Theater Family Couch?
 

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