Acuton diamond tweeter

[edorr]

Question out of left field. Does anyone know why the mm2, mm3, mm7 does not use the Acuton diamond tweeter?

 

[jtinn]

Question out of left field. Does anyone know why the mm2, mm3, mm7 does not use the Acuton diamond tweeter?

We did not like them as much as the tweeters we use. We found them very low in distortion, but too beamyand not enough "air".

 

[edorr]

We did not like them as much as the tweeters we use. We found them very low in distortion, but too beamyand not enough "air".

Thanks for clarifying. I was wondering If economics played a role, since using these tweeters would add materially to the cost of the mm2 and mm3 (rounding error on the mm7).

 

[jtinn]

Thanks for clarifying. I was wondering If economics played a role, since using these tweeters would add materially to the cost of the mm2 and mm3 (rounding error on the mm7).

Cost had nothing to do it. We were looking for the best sound period. Its a good tweeter as was the beryllium, just not to our tastes.

 

[Lyubo]

Edorr, you can find the answer to your question here:

Exclusive Interview with Evolution Acoustics – December 11, 2009 By Frank Berryman of Ultra High-End Forum:

"Question 8:

You also use aluminum ribbon tweeters in all of your speakers. What are the advantages of ribbon tweeters over cone and dome tweeters?

Response:

We touched on one aspect already, being that the particular ribbon tweeter we use is perfectly mated to our midrange driver. It was the combination of these two drive units which had us sold on this design. However, there are other reasons which led us down this eventual path. Obviously there is no shortage of tweeter design available. Air motion, cones, domes, dual concentric ring radiators, flat ribbons, folded ribbons, plasma, horn, magnetic planar, leaf, and so on all have very strong points and low points. Having evaluated just about everything available, it became very clear that a pure folded aluminum ribbon tweeter is our best solution. There is a purity and extension in the upper frequencies that this type of tweeter possesses, that no other tweeter design does.

The other aspect which had us sold on this type of tweeter was the extremely wide and linear dispersion. Our goal was to create good off-axis response and this strength will certainly aid in that effort. Of course ribbon tweeters have horrible vertical dispersion, but the majority of our speaker designs are concentric line arrays. Concentric line arrays, sometimes mislabeled as D’Appolito designs, inherently have poor vertical dispersion because of the woofer and midrange drivers being above and below the central tweeter axis. Filters can be created to minimize this effect. However, doing so would not result in a true MTM concentric array.

In a true MTM concentric array and based on the laws of physics, driver path lengths change as you move your head up and down causing cancellations, so we knew that having good vertical dispersion from the tweeter is really non-essential for this type of loudspeaker. In addition, time coincident design requires a precise seated listening position, so horizontal and vertical dispersion is not as critical as the on-axis directed response

When it came to selecting a particular make of ribbon tweeter there were several options at all price points. We settled on a customized OEM unit which is not necessarily the most expensive, with the highest sensitivity, or the widest frequency response. However, this particular ribbon has the fastest decay response of any ribbon tweeter available and is perfectly mated to our ceramic drive units. Once again, we use this tweeter on every model we make at every price point, so we stand behind it 100%."

 

[andromedaaudio]

The negative thing i found on the accuton diamond is , that it can sound glazy when driven pretty hard.
there are also good things off course

 

[edorr]

Edorr, you can find the answer to your question here:

Exclusive Interview with Evolution Acoustics – December 11, 2009 By Frank Berryman of Ultra High-End Forum:

"Question 8:

You also use aluminum ribbon tweeters in all of your speakers. What are the advantages of ribbon tweeters over cone and dome tweeters?

Response:

We touched on one aspect already, being that the particular ribbon tweeter we use is perfectly mated to our midrange driver. It was the combination of these two drive units which had us sold on this design. However, there are other reasons which led us down this eventual path. Obviously there is no shortage of tweeter design available. Air motion, cones, domes, dual concentric ring radiators, flat ribbons, folded ribbons, plasma, horn, magnetic planar, leaf, and so on all have very strong points and low points. Having evaluated just about everything available, it became very clear that a pure folded aluminum ribbon tweeter is our best solution. There is a purity and extension in the upper frequencies that this type of tweeter possesses, that no other tweeter design does.

The other aspect which had us sold on this type of tweeter was the extremely wide and linear dispersion. Our goal was to create good off-axis response and this strength will certainly aid in that effort. Of course ribbon tweeters have horrible vertical dispersion, but the majority of our speaker designs are concentric line arrays. Concentric line arrays, sometimes mislabeled as D’Appolito designs, inherently have poor vertical dispersion because of the woofer and midrange drivers being above and below the central tweeter axis. Filters can be created to minimize this effect. However, doing so would not result in a true MTM concentric array.

In a true MTM concentric array and based on the laws of physics, driver path lengths change as you move your head up and down causing cancellations, so we knew that having good vertical dispersion from the tweeter is really non-essential for this type of loudspeaker. In addition, time coincident design requires a precise seated listening position, so horizontal and vertical dispersion is not as critical as the on-axis directed response

When it came to selecting a particular make of ribbon tweeter there were several options at all price points. We settled on a customized OEM unit which is not necessarily the most expensive, with the highest sensitivity, or the widest frequency response. However, this particular ribbon has the fastest decay response of any ribbon tweeter available and is perfectly mated to our ceramic drive units. Once again, we use this tweeter on every model we make at every price point, so we stand behind it 100%."

I am completely ignorant about speaker design, but I always felt that an advantage of having one woofer on top and one at the bottom is you can place the tweeter at listening position height. Designs like the ISIS and Big Wilsons with two woofers at the bottom have a tweeter beaming down at you. To make this work you are probably resticted in choice of tweeter, and it is probably a lot harder to get phase/time alignment of the drivers. I find the aesthetix of the MM3 "hourglass" look questionnable, but it is probably well worth stacking the drivers this way.