Suitable midrange cone, for bandpass mid in Unity horn.

[JLH]

Sorry, been too busy holding down my real job. Just not enough time for audio lately.

Rgs, JLH

[bubblersound]

I have one driver in my test horn awaiting my PE order. Does unity horns exhibit the double cone area = +3db theory?
On another note, I find it difficult to couple larger (6"+) drivers to the horn properly. I've had good results (6-15db gain) with a $2, 2" x 3.5" driver.

[bubblersound]

Made a 24x24x20d horn and tried a few cheap drivers. So far, the Jamo 20470 4.5" works the best but only good down to about 700-800hz. It has a very steep rolloff below 400. I'm going to try a vertical array of 10/side on a two sided conical horn.

[jeno]

Have you guys seen Danleys latest creation?

http://danleysoundlabs.com/pdf/SM%20...ec%20sheet.pdf

It has a 5" coax with unity style entry holes for the midrange. See the patent for details. I guess it is this BMS driver:

Overview

[panjilaras]

forget about celestion TF0410MR. they are made to order only. minimum quantity 300 pcs per batch. that's what i got from Kevin Shove - Celestion Sales Manager (Europe & Asia).

[panjilaras]

i was initially excited finding this 5" sealed back midrange.
available locally for $4 apiece.


took some measurements,
smaart impedance curve:


sinegen as sweep tone generator, soundcard scope to measure freq and Vrms:


t/s results:


crap! qts is way too high.

[SunRa]

Since this is one of the latest theoretical discussions on Unity, I thought is a proper place to discuss this:

CoEntrant Topology and Patent.

Also, where you aware of the 3" midranges from FaitalPro ? Would these be a good choice once sealed?

[Patrick Bateman]

Originally Posted by jeno

Have you guys seen Danleys latest creation?

http://danleysoundlabs.com/pdf/SM%20...ec%20sheet.pdf

It has a 5" coax with unity style entry holes for the midrange. See the patent for details. I guess it is this BMS driver:

Overview

Wow, I haven't seen anything so infuriating in months

Why didn't I think of that?

In my Unity horn projects I've traded the big 5" mids of the 'real' Unity horn for 2" models from Tangband, since it shrinks the footprint dramatically. And then I use the dash of my car to extend the horn mouth. (All of my Unities have gone in my car.)

I never even considered using a coaxial at the apex! That's a much easier solution to shrinking the footprint. Looks better too

[Patrick Bateman]

Originally Posted by GM

Greets!

To get 'in the ballpark', find one that either is a closed back unit that resonates at ~SQRT(200*1400) = ~529 Hz, or if open back, then ~529 = 2*Fs/Qes. How you get there doesn't matter if you're not trying to get max efficiency out of it with 'X' diameter x 'Y' long vents. IIRC, TD's prototype driver's published specs were ~2*250 Hz/0.99 = 505 Hz, so I wouldn't get too hung up on the apparent need for a low Qt just because it's a horn app.

GM

Here's a quick rundown of a couple of coaxes.

First off, the BMS 5CN140 which appears to be used in that new synergy horn. Our goal is to pop the values of FS and QES into the equation "2*fs/qes" and find one with a value of 500hz or higher. The higher it is, the higher we can cross the compression driver over. If the value is too low, we get a gap between the midrange and the tweeter. The BMS weighs in at 317. So that's pretty darn low. In my experiments I've found that it's possible to extend the upper frequency limit by carefully manipulating the volume of air under the cone, and the shape of the ports. I'd guess that Danley did the same thing, and extended the response via trial and error.

Assistance Audio doesn't list the BMS on their site right now - if someone wants it, they should give him a call. Jack has been known to do special orders, and has offered drivers that aren't on the site.

I checked out the options from B&C, but the smallest option is 8". At that size, geometry starts to limit your options. The closer you can get them together, the better.

This is a neat one. You can buy this from US Speakers today. It's a Beyma 6XC200ND. It weighs in at 382hz. Still a bit low.

I'm surprised the Beyma works as well as it does. Most of the ones that work well have a paper cone, an accordian surround, and a massive motor. Basically an ultra-light cone and surround married to a powerful motor.

[GM]

??? The point of using a coax is to get rid of the mid drivers. If they designed it correctly, B&C has already optimized the XO point/time/phase between the two drivers, so all you need do is design the WG (and TH loading if cloning DSL's SM-60F).

GM