Elipticor Midrange

Seems like there are at least 3-4 versions of HiVi DMN-A/DM 7500 in the www...
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I think the main attraction of a 3" dome mid compared to a 4" cone is that the cone driver will typically have a sensitivity of 85 - 89 db/2.83V, whereas the dome will have a sensitivity of 92 - 96 dB/2.83V.

From what I can tell, sensitivity is the only technical advantage to a dome mid, while the small cone mids have many other technical advantages.

Subjectively there may be important differences.

j.
 
Certainly the best midrange I've heard came from ESL57s - and ATC domes (in SCM40a speakers).

I can see why domes are preferred for tweeters (decent size voice-coil, yet small piston). But there seems to be less of a case for (larger) domes in a midrange driver. In fact, the dome will always be subject to uncontrolled ripples initiated at the voice-coil and unterminated at the dome centre (I think ATC gets round this by making the dome heavily doped). At least a cone allows the surround to act as a resistive termination, if executed correctly.

Sensitivity seems to be one positive attribute, as hifijim says. The other would be power handling, owing to superior heat dissipation.
 
I think the main attraction of a 3" dome mid compared to a 4" cone is that the cone driver will typically have a sensitivity of 85 - 89 db/2.83V, whereas the dome will have a sensitivity of 92 - 96 dB/2.83V.

From what I can tell, sensitivity is the only technical advantage to a dome mid, while the small cone mids have many other technical advantages.

Subjectively there may be important differences.

j.
The main attraction is clean performance in usable range due to the lack of problems with cone edge resonance that are usually main problem with cone drivers without increasing Mms to much (Purifi).

Hard domes from Bliesma really had a chance for stellar performance in the midrange, but obviously there is a bit of work to do with soft parts. On measurements from hificompass everyone can se that distortions are rising below 1kHz which can be blamed on either nonlinear suspension or motor. Also some blips on impedance suggests resonances in suspension. For me Bliesma mids look like a bit half finished/rushed product. I'm not even talking about single suspension and rocking modes.
Se how far Dali went with extending distance bettwen suspensions in new woofers to further stabilize cone movement. It has triple suspension and distance between must be like 8".

@noamgeller I stole your Munich pic
 

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The main attraction is clean performance in usable range due to the lack of problems with cone edge resonance that are usually main problem with cone drivers without increasing Mms to much (Purifi).

Hard domes from Bliesma really had a chance for stellar performance in the midrange, but obviously there is a bit of work to do with soft parts. On measurements from hificompass everyone can se that distortions are rising below 1kHz which can be blamed on either nonlinear suspension or motor. Also some blips on impedance suggests resonances in suspension. For me Bliesma mids look like a bit half finished/rushed product. I'm not even talking about single suspension and rocking modes.
Se how far Dali went with extending distance bettwen suspensions in new woofers to further stabilize cone movement. It has triple suspension and distance between must be like 8".

@noamgeller I stole your Munich pic

It won't be suspension non-linearity, because, as you get above resonance, the dome is mostly mass-controlled (meaning that its motion behaves as an object with mass alone, exposed to the force applied by the motor system).

Those resonances will be due to the fact that the dome is a transmission medium, excited at its periphery by the attached voice-coil, but unterminated (at its apex). Cleverest design would be lossy attachment to the voice-coil and addition of damping material applied to the dome itself.

Let's face it, smaller domes used in tweeters can't really satisfy the simple model of pure pistonic motion, so a large mid-range is always going to be compromised by resonances - which, even out of band, will respond to any non-linear distortion...
 
It won't be suspension non-linearity, because, as you get above resonance, the dome is mostly mass-controlled (meaning that its motion behaves as an object with mass alone, exposed to the force applied by the motor system).

Those resonances will be due to the fact that the dome is a transmission medium, excited at its periphery by the attached voice-coil, but unterminated (at its apex). Cleverest design would be lossy attachment to the voice-coil and addition of damping material applied to the dome itself.

Let's face it, smaller domes used in tweeters can't really satisfy the simple model of pure pistonic motion, so a large mid-range is always going to be compromised by resonances - which, even out of band, will respond to any non-linear distortion...
I can only guess what's the problem, but already T34B got me puzzled. With 10cm2 and 1,5mm Xmax one way this dome should be capable down to almost it's Fs at 790Hz... but it's not.
 
Somewhat lagging thread but for me, the D7608-9200 is still one of the great large mid domes. These large domes have a significantly different sound than a cone driver, regardless of price. Tricky to tame, but rewarding if done properly.
 
Possibly carefully designed to limit edge diffraction when matched to the 8" mid-bass for a modern slim baffle?

View attachment 1056568

https://www.scan-speak.dk/datasheet/pdf/d8404-552000.pdf
New for me - discover by change. Looks like the answer from Scan-Speak to ATC's dome midrange SCM75-150S:
https://studio-hifi.com/images/ATC75-150S_JeffBagby.pdf

Who have heard both ?
Scan Speak released a real game changer here ?

According the price called of approximately 6000€/pair it could actually be.
 
That inflation of prices all over the world is becomming somewhat ridiculous... vendors do not construct things anymore but marketing where the prices are not collerated with the production costs... it will brings to nothing as at the same time all the monney they grab will cost less due to general prices increases ! The increase of prices of the passives parts as if copper was at the gold price as capacitors also start the beginning of a sticking hobby... in relation of what we had 15/20 years ago !

All that products are very basics to make and cost more than high techology ones ! The banks and founds should land imho ! As everyone that profit of the situation to take his little too big margin in all the level of the supplychain... disgusting ! Do they pay their employee with the same income increase ? For sure, no !
 
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The high pricing started way before inflation hit. Raising prices is a double barreled gun: margins of profits increase and at the same time the snob appeal of the product is immensely increased, often leading to even higher sales.

Rumour has it when Dynaudio was pulling out of the diy market, prices were substantially increased by Dynaudio to deter the buyers.
But instead, with the typical audio -lack of- logic, sales only increased untill supply simply and finally stopped.