A lot of people ask me about those drivers and I’ll try to compile my vision about them. I did try most of the possible tweeters: dome tweeters with cloth cones, varies type of hard metal domes, compression drivers with aluminum, titanium, phenolic and beryllium diaphragms, ribbon tweeters, electrostats, Hales tweeters, piezo tweeters, early version of plasma tweeters…
First, to understand what I mean it would necessary to “get” my requirements to the tweeters. I do not really care about the foolishness that many audio Morons spread about the SACD-compatible tweeters that reportedly go to 60K or 100Khz. Those tweeters are something that completely out of my interest me. What I concerns me is only HOW the tweeter dose 10K-14K. Certainly the sensitively, directivity and the rest are important but this would a different subject that I would not touch not. Second, it is important to acknowledge I use tweeters over 10KHz and I religiously despise any tweeters operating from 3-5K (most of the 2-3 ways box loudspeakers). So, all my future “analyses” is applicable to the tweeters crossed above 10K.
My experience indicates that the best result I was able to get from silk-dome tweeters and compression drivers with phenolic diaphragms. To me all searches for better tweeter concentrated around a proper reproduction of string group. When the entire string group of a full orchestra kicks-in then practically all tweeters do gown despite that those violin not do not even reach the frequencies where tweeters operate. What I mean “tweeters go gown” is following: a half-hundred sting instilments produce a fat lover frequency tone and the tweeters add to this pitch a specific amalgam of glitzy “schmultz”. As the result a violin section sound too sharp and too hi-fi-ish. This artificially-effective pseudo-sound converts the violin tone of Vienna Philharmonic into Leningrad Philharmonic and produces an impressiveness of reproduction instead of the impressiveness of original musicality
Pretty much 3 second of listening of one weepy violin tone of 34 instruments playing together instantaneously allow to discard or accept a tweeter. A violin groups in real live (if they are not Boston Pops) never sound metallic or bright but rather soft and syntactic. The never sound impressive of the do not play imprecise. This “not impressive sound” I was able to get only from the better silk dome (the best) or phenolic tweeters. Unfortunately the silk dome have no sensitively and therefore I stick to the EV 350T with plastic cones.
EV T350 in a way reminds a SET amp that “clips softly”. It does not sound glitzy, aggressive and for many out there who are addicted to the brutal force of JBL-like compression driver the EV T350 might appear “not impressive”. The “audio impressiveness” usually comes from positioning a microphone 3 inches from a violin. This positioning is very nice for recording the Patricia Barber Trios but it is absolutely not appropriate way to listen a serious music. A symphonic orchestra’s sound form a normal listening position, when the orchestra is property integrated and balanced should not sound striking of extraordinary. The impressiveness of orchestra comes from the performing quality not form the sonic grandeur.
The Furtwangler’s Orchestra with Bruno Kittel Chorus in 1942 sounded impressive, probably the more impressive then any other orchestra in 20 century. That impressiveness is true impressiveness based upon a performing mastership not upon the reproductive means. Reproducing a good transfer of this for instance performance of Beethoven IX and adding 1/2dB to properly balance tweeter will severely destroy the impressiveness of Furtwangler’s Orchestra. It will make it slightly faster and slightly sharper and slightly hysteric. Do not forget that we are taking about the recording the hardly when over 10kHz.
I can testify that the majority of audio installations that I heard sounded more “instantaneously impressive” then sound of live orchestra. The poor quality of tweeter is one of the major contributors the HF misery of those installations.
It is hard to explain how a tweeter should be tuned, as there are very-very many variables involved in the tuning. ¼ db matters and if a tweeter ¼ louder then it should be then it will add “audio impressiveness”. Forget about the “air” and “space”, this is not the job for the tweeters. My inexperience indicted that it is very good to hold tweeter on a “frustration diet”. It means that better result you can get if you underused the tweeter then overuse it. Run your system without any tweeter and get good sound. Get familiar and comfortable with this sound: it should not frustrate you and it should be musical and self-contained. If the sound is not good enough then change the MF driver. Then, in a couple weeks add a tweeter. Peace your head horizontally at ~ .5M from the tweeter at the same distance from MF driver and begin to add the tweeter output (or raise the value of the cap moving the tweeter dope on the transition slop). Play some slow weepy violin section (Tchaikovsky, Smetana, and etc…) and turning you tweeter up. As soon you hear that Sound become slightly “whiter”, “softer”, “bright”, more or less “busy”, “neurotic”, of more “messy” (you tweeter might not to time aliened) then stop. Form the discovered setting remove approximately 2/3dB and let yourself to listen your playback system like this for a t list 2-3 weeks. Then add or most likely to remove 1/4-1/2 db and you would be all set.
The rule with the tweeters is very similar like with LF module – if you hear it then it set up too loud. Be advised the practically all capacities the you will be using in your tweeter will change in 3-5 days quilt dramatically. BTW, the T350 would also care a LOT of abuse and the excessive 1db form T350 would be equally musically-damaging as 1/3 dB of JBL-077 or Fostex T90.
Romy the Cat
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche