[cstory]

I received my latest Stereophile in the mail at the end of last week, and I read with interest the review they had of a Sonist Concerto 3 which uses the Fountek NeoCd3 tweeter. The subjective opinion was that it sounded pretty good, but that there was (paraphrasing here) a slight grain in the treble that added a bit of splashiness to small cymbals. The measured response in the treble region was quite ragged (to my eyes) and quite a contrast to a speaker that was reviewed the previous month (the Aurum Cantus V2M). The V2M response looked quite smooth and was generally given high marks for treble purity by the reviewer. (This review is on the Stereophile web page)

Now I'm not ragging on the Sonist since the reviewer was happy with it overall, especially for the price, but it did seem that, based on the wording of the reports, that the Aurum Cantus speaker was liked a bit better. (more neutral, more detailed, lacking only extreme low bass)

Given that Rick has stated that he felt the Fountek tweeter was a little bit better than the Aurum Cantus Ribbon I was surprised by the measured difference in the two speakers.

I guess this is an illustration of how important it is to properly implement the driver that you are using. The Sonist was rated at 95dB efficiency and the Aurum Cantus at 84dB efficiency. Obviously, the quest of higher efficiency comes at a price, and until you design crossovers, you may not understand how much of a part they play in determining the overall frequency response of the speaker. Also the Sonist has a shallow "horn" surrounding the tweeter which may also affect things.

I just thought it makes an interesting comparison of two designs using similar tweeters. It also highlights how all speaker designs involve compromise, and you want to match your own views of what is important or not to the design (or designer) of your choice. In the end there is no substitute for solid design followed by in depth listening. From what I have read (and heard on a limited basis) I think Rick's choices match my own ideas on what is important for a speaker.

Cheers,

Chuck

[Rick Craig]

I received my latest Stereophile in the mail at the end of last week, and I read with interest the review they had of a Sonist Concerto 3 which uses the Fountek NeoCd3 tweeter. The subjective opinion was that it sounded pretty good, but that there was (paraphrasing here) a slight grain in the treble that added a bit of splashiness to small cymbals. The measured response in the treble region was quite ragged (to my eyes) and quite a contrast to a speaker that was reviewed the previous month (the Aurum Cantus V2M). The V2M response looked quite smooth and was generally given high marks for treble purity by the reviewer. (This review is on the Stereophile web page)

Now I'm not ragging on the Sonist since the reviewer was happy with it overall, especially for the price, but it did seem that, based on the wording of the reports, that the Aurum Cantus speaker was liked a bit better. (more neutral, more detailed, lacking only extreme low bass)

Given that Rick has stated that he felt the Fountek tweeter was a little bit better than the Aurum Cantus Ribbon I was surprised by the measured difference in the two speakers.

I guess this is an illustration of how important it is to properly implement the driver that you are using. The Sonist was rated at 95dB efficiency and the Aurum Cantus at 84dB efficiency. Obviously, the quest of higher efficiency comes at a price, and until you design crossovers, you may not understand how much of a part they play in determining the overall frequency response of the speaker. Also the Sonist has a shallow "horn" surrounding the tweeter which may also affect things.

I just thought it makes an interesting comparison of two designs using similar tweeters. It also highlights how all speaker designs involve compromise, and you want to match your own views of what is important or not to the design (or designer) of your choice. In the end there is no substitute for solid design followed by in depth listening. From what I have read (and heard on a limited basis) I think Rick's choices match my own ideas on what is important for a speaker.

Cheers,

Chuck

The main culprit here is the attempt by Sonist to create a horn or waveguide with the sculptured baffle. It could also be a result of the woofer's upper end response and / or crossover problems.

[Kris]

The Sonist concerto 3 uses the older JP3.0 Fountek wich is not the same as the NE0 CD3.0. I think it is discontinued.

[FredT300B]

The Sonist uses first order crossovers, with a single auricap in the tweeter signal path. Most speaker designers use at least second-order, and more frequently third-order crossovers with ribbons. I wonder if the "slight grain" in the treble isn't at least partially a result of the crossover design. Many other speakers use Fountek and Aurum Cantus tweeters and are often praised by reviewers for their silky smooth grain-free treble. For example: http://www.positive-feedback.com/Issue15/selahaudio.htm

[RandyB]

During development of the Sonist Concerto 2 standmount and Concerto 3 floorstander I used 2nd order on the Fountek JP3.0 ribbon tweeter for several years, changed to 1st order last year since I thought it had better transient detail and coherence with the woofer. 

I'm running 1st order on the tweeter around 8KHz, the waveguide adds about 3-4dB of gain between 2KHz and 8KHz, which provides a nice transition to the woofer rolloff.  The JP3.0 is rated at 95dB by the factory, I'm using the waveguide to reduce diaphragm travel for a given SPL, which reduces distortion, I'm not using the horn to achieve more than 95dB from the tweeter, just lift the 6dB per octave slope to fill in down to 2KHz. 

Not sure about the texture issue, I have tried to be very careful to not make the tweeter too hot, ribbons are typically very silky and it is easy to make them too hot without irritating artifacts, definitely a balancing act. 

Final voicing is done by listening to a wide variety of music genres, my goal is to get a nice blend of natural tonality and harmonic overtones without the treble being artifically etched and crispy. 

Madisound stopped importing the Fountek JP3.0 last year, they are now importing the NeoCD, which is the same tweeter with a multi-layer mylar diaphragm which is almost twice the mass of the single-layer aluminum diaphragm of the JP3.0.  Although both tweeters measure very close to each other, I find that the JP3.0 is considerably faster and has more air and ambience than the NeoCD.  I'm getting my JP3.0's direct from the factory, since there is currently no U.S. distributor. 

Best regards, Randy - Sonist Loudspeakers