Suitable midrange cone, for bandpass mid in Unity horn.

I use the Goal Seek function in Excel to find it for me. I have a cell that has the formula something like =A*B. Then I have a cell with formula =A*0.618. The third cell does not have a formula, just an arbitrary number. I then go to the DATA tab in Excel. I highlight the cell with the formula of =A*B. I then click the WHAT IF ANALYSIS. I have Excel solve for the area I want by altering the other two cells.

I get it. It's called "Målsøgning" in danish:cheers:

/Thomas
 
actually, I have been looking at that one a few times :rolleyes:
and thought it looked interesting ... but unknown quality

do you know it ?
is it good ?
I do not know tinitus.

They are not expense my concern is they are typical classic loudspeaker design. No short ring to reduce distorsion. Very limited xmax.

But they still can be used in a line array so all the points I named above will not play a large roll.

The 12" woofers had my interest for a long time to make a closed cabinet they look cool to.
Now you can buy a 10" alucone scanspeak for same money with all the new design upgrades, so tvm do not have any sale points for me. Oke one to make a real new classic style speaker a 70-80 ties speaker for a nice price.
 
The design challenges you run into with larger cone mids is it requires much larger port holes to reduce the air velocities. This in turn pushes the crossover point lower, which then forces you to use a larger compression driver, which results in a larger throat area and cross sectional mid tap in point.....etc. And it goes on and on.

The practical cutoff for mid size is about 5.25". You might be about to get away with a 6" if you use a 1.4" or 2" compression driver that can work down to about 600Hz - 700Hz. I had a design for using a pair of Eminence Beta-6A mids with Faital HF146 compression drivers. I never took it anywhere because dropping $500 just on the compression drivers is too much for my blood.

John - do you still have that Faital/Beta-6A script, maybe I'll pursue it! I just might be stupid enough to spend $500 on a pair of tweeters:drink:

/Thomas
 
The rubber and foam surrounds are too compliant. You will never have a suspension "blowout", but under pressure they do deform. This will allow the cone to tilt and lead to voice coil rubbing. As difficult it is to design and build a Synergy horn, I want something that will last a lifetime. Rubber and foam surrounds don't fit this criteria. Why build something that will deteriorate in 10 - 15 years and be discontinued so you won't even be able to repair it? Buying extras and letting them sit in the box doesn't work either. Ozone will still deteriorate the surrounds over time. Treated cloth surrounds avoid all these issues. Tom Danley uses cloth surround mids and woofers in his own designs.

Thank you. A good explanation. I'll keep this in mind.
 
I have a question, and I could figure it out with Hornresp, but maybe someone knows off the top of their head.

In a Unity or Synergy horn, the midranges are in front of the tweeter. One of the reasons that the design works is that the coupling chamber in front of the midranges creates a delay at the Fb of the coupling chamber.

Well, it occurred to me today:

Wouldn't that delay be dependent on the Q of the resonance?

I'm not 100% sure if this is the case. But if it IS, then it means that the location of the ports would have to be closer to the throat if the Q of the resonance is low.

I imagine that the net effect is relatively small, perhaps only a fraction of an inch.

But I've noticed that the Pyles sound a bit 'slower' than the Miscos, and maybe that's why. Perhaps the higher Q of the Pyle is screwing up the phase.

(I've never been able to measure phase well, so that's part of my problem. It's something that I need to learn how to do, but I'm not even 100% sure if Arta can record phase accurately. I understand Danley uses TEF?)
 
I have a question, and I could figure it out with Hornresp, but maybe someone knows off the top of their head.

In a Unity or Synergy horn, the midranges are in front of the tweeter. One of the reasons that the design works is that the coupling chamber in front of the midranges creates a delay at the Fb of the coupling chamber.

Well, it occurred to me today:

Wouldn't that delay be dependent on the Q of the resonance?

I'm not 100% sure if this is the case. But if it IS, then it means that the location of the ports would have to be closer to the throat if the Q of the resonance is low.

I imagine that the net effect is relatively small, perhaps only a fraction of an inch.

But I've noticed that the Pyles sound a bit 'slower' than the Miscos, and maybe that's why. Perhaps the higher Q of the Pyle is screwing up the phase.

(I've never been able to measure phase well, so that's part of my problem. It's something that I need to learn how to do, but I'm not even 100% sure if Arta can record phase accurately. I understand Danley uses TEF?)

The biggest delay is from the crossover.
 
I have a question, and I could figure it out with Hornresp, but maybe someone knows off the top of their head.

In a Unity or Synergy horn, the midranges are in front of the tweeter. One of the reasons that the design works is that the coupling chamber in front of the midranges creates a delay at the Fb of the coupling chamber.

Well, it occurred to me today:

Wouldn't that delay be dependent on the Q of the resonance?

I'm not 100% sure if this is the case. But if it IS, then it means that the location of the ports would have to be closer to the throat if the Q of the resonance is low.

I imagine that the net effect is relatively small, perhaps only a fraction of an inch.

But I've noticed that the Pyles sound a bit 'slower' than the Miscos, and maybe that's why. Perhaps the higher Q of the Pyle is screwing up the phase.

(I've never been able to measure phase well, so that's part of my problem. It's something that I need to learn how to do, but I'm not even 100% sure if Arta can record phase accurately. I understand Danley uses TEF?)

Hi Patrick

Is that Pyle not a speaker with weak motor? a horn needs a strong motor and a very stiff and strong conus who is light, this is not easy for speaker makers.

A slow sounding speaker has prperly a weak small magnet and a high qts, a very small speaker with a big magnet and thus drive can sound quite faster. The fase
when not properly corrected make a speaker slow and thin sounding.

It is just a thought.

kees
 
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Ex-Moderator R.I.P.
Joined 2005
Hi Patrick

Is that Pyle not a speaker with weak motor?

cheap drivers often have too big pole gap
easier to produce and assemble

but also means you can have poorly alligned voice coil
and still no risk of voice coil rubbing

on these drivers you are likely to notice the combination of a quite big magnet and high Qts

leads to poor control, low dynamics, and distortion
 
This you can see on the QTS, if it is higher then expected for such big magnet then the gap is wide.

als you see on fostex, these have a qts of 0,27 means good control, low distortion and nice for horns.

But fostex is more expensive, low qts drivers sometimes needs frequency correction for the peaks, the more
newer fostex are better these days and need no correction sometimes..
 
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You guys need to quit focusing so much on Qts and Qes. Once you seal the rear of any driver, the Q will go up anyway. Tom Danley uses the figure of (Bl^2)/Re as a figure of motor strength merit. A good expample that is apples to apples would be comparing the Eminence Alpha-6A and the LA6-CBMR.

Alpha-6A | Eminence Speaker

LA6-CBMR | Eminence Speaker

The Qts for the Alpha-6A is 0.54
The Qts for the LA6-CBMR is 0.89

However, the LA-CBMR has more than twice the motor strength of the Alpha-6A. In addition, anyone that has heard or used these two drivers will tell you the LA-CBMR is a beast and the Alpha-6A is more of a kitten. Lastly, if you model it and it works, who really cares what is written on the spec sheet?
 
You guys need to quit focusing so much on Qts and Qes. Once you seal the rear of any driver, the Q will go up anyway. Tom Danley uses the figure of (Bl^2)/Re as a figure of motor strength merit. A good expample that is apples to apples would be comparing the Eminence Alpha-6A and the LA6-CBMR.

Alpha-6A | Eminence Speaker

LA6-CBMR | Eminence Speaker

The Qts for the Alpha-6A is 0.54
The Qts for the LA6-CBMR is 0.89

However, the LA-CBMR has more than twice the motor strength of the Alpha-6A. In addition, anyone that has heard or used these two drivers will tell you the LA-CBMR is a beast and the Alpha-6A is more of a kitten. Lastly, if you model it and it works, who really cares what is written on the spec sheet?

In my situation, I had a couple drivers which were very similar. Basically the same Fb, same size. But the qts on one was much higher. I believe this is because of the foam surround and treated cone of the Pyle.

Here's the specs:

Pyle PDMR5:

Re: 6.736 ohms
Fs: 465 Hz
Qts: 2.43
Qes: 3.277
Qms: 9.395
Le: 0.8465 mH

Misco JC5RTF-B
Resonant Frequency (fo) 491 Hz
D.C. Resistance (Re) 6.7 ohms
Mechanical Q (Qms) 7.6
Electrical Q (Qes) 2.41
Total Q (Qts) 1.83
Compliance Equivalent Volume (Vas) 0.2 ltr
BL Product (BL) 5.4 T-M
Maximum Linear Excursion (Xmax) 0.9 mm
Surface Area of Cone (Sd) 64.0 cm2

It's interesting that the Misco actually uses a magnet that's 2/3rds the size.

I think this is also one of the reason that those cheap cone tweeters perform so well. They're a ridiculously crude design, but they're very horn friendly.