Thoughts on adding a Super tweeter .

I have posted something like this before,but thought I may ask for follow up input.
I already have a superb tweeter,ruler flat to 25khz(titanium),yet wonder if something like the Townshend(it starts to come in above 20 khz,and goes out to a zillion khz,almost)or Murata(comes in at 15 khz,Too low?, goes to a trillion,just kidding btw,)would add "real world"enhancements to my existing set-up.I have NO problems,with high freq performance,as of now,yet in this hobby,one can always be surprised.
Any thoughts would be most appreciated!

You will be overrun with bats.
Music for insects... Yes I suppose it is fair to play the hash generated by digital equipment and blast it out at the small insects who can hear it.
Sort of like a poor bugs "Muzak".
You could tell if your system sounded good if the bugs stay instead of leave?
You would have to try it, but I suspect the better, more extended and energetic your regular tweeter, the less you would benefit. I would opt for a trial basis only.
A lot of women think all men are insects, so you might benefit there as well.
the problem with most stereo systems is that they are unbalanced with too much energy in the upper mid/lower treble region.

i suspect that with an over emphasis on the upper treble, you might enjoy your stereo system.
>>the problem with most stereo systems is that they are unbalanced with too much energy in the upper mid/lower treble region.<<

That's an incredible generalization. On what study or data is that based? Thanks in advance.
I agree with Cjfrbw
I auditioned a super tweeter...non ribbon variety...that went out to 50khz, I believe. It added a subtle bit of air and openess to the presentation. Super tweeters reproduce frequencies that are beyond what humans recognize as treble energy.

The effect of the super tweeter was subtle. I decided it wasn't worth the $1000, but we all put different price tags on these things.
I agree with the Tennis man on the overabundance of upper mid / lower treble energy. I base this assertion on my experience at CES / THE this year. Room after room had this characteristic. Even my own system has it to a degree, which annoyed me until I came home from CES. Then I turned on my system and it was a relief, because many (most?) of the rooms at the show had it far worse than my system does.

Also, keep in mind that a CD can not reproduce sounds above 20KHz. While it may theoretically be capable of producing "perfect sound" below this frequency, it has never been billed as having any capability above that point. So what you will be reproducing from a CD is not the musical content,but the residual digital noise that doesn't get filtered out by the player's filters. The better your player, the less of this there should be. Maybe if you're playing analog, there would be some content from the original event buried in the grooves.
Also, keep in mind that a CD can not reproduce sounds above 20KHz. While it may theoretically be capable of producing "perfect sound" below this frequency, it has never been billed as having any capability above that point.
Honest1 (Threads | Answers)
That's true for redbook CD, but SACD and DVD-A reproduce sound up to 100khz.
I heard a super tweeter on a neighbor's SET system. Although there was
noticeable HF extension over his single driver speakers, the superimposed
lower HF brought on a heightened upward tilt that I didn't care for.
My experience is a bit different than most of what has been reported here.

I am definitely not an insect: my hearing dies well short of 15kHz, however the addition of the Townsend supertweeters to my Quads was a revelation: the entire sound stage became better developed (source is vinyl). I did not hear increased upper frequency 'hash': in fact the upper midrange is where I heard the most dramatic improvements (perceived improved clarity, lucidity). The overall effect: 'it sounds more real'.

I don't really 'hear' the supertweeters when listening, but it is quite noticable if you take them away. My non-audiophile wife was listening with me and clearly heard the difference when the tweets where taken out and put back into my system. I have also heard from other quad owners that the Townsend's enhanced their systems in a similar manner. The Quads do not have 'dc to light' frequency response so YMMV.

The addition of the supertweets is somewhat akin to the addition of a good, well integrated subwoofer; with a 'woof it's not merely the lower frequencies that are audibly improved, the upper frequency ranges also benefit.

I think this is one of those 'listen for yourself in your own system' situations. Supertweets cannot be dismissed as 'crackpot audiophile psuedoscience'. They can make an audible improvment in a high resolution audio system.
Cjsmithmd,et al...The reason for my post was for a couple of reasons(thanks to all,for responding).I have heard the Townshends(I like the Muratas,but they come in too low,to consider)in a fellow music lover's wonderful set-up.He was sporting the "shockingly good" Sonus Faber Extremas,a design long since gone(what a mistake,to discontinue these),and since I believe those had a tweeter roll off of 17khz,he gave the Townshends their day in court.BOY,the difference was NOT subtle.Better air/texture!For sure!Much more palpable.
So,with the non- stop talk of Berrylium/Diamond tweets,I simply felt,maybe,I could get that extra something,I read so much about.Bear in mind I felt my own speakers,which are flat to 25khz,had more air/extension,than the stock Extremas,but the Townshend demo was amazing.
Now,some time ago I added a Rel Stentor sub,to integrate with my system.I have my speakers almost 9 feet out from the rear wall,and have a very deep "stage presentation".However,as my speaker is a sealed box design,I suspected I could gain a touch(that's all I was looking for)of added heft/depth,in the lowest frequencies.
My friends were all dead set against this,as my speakers are amazingly fast,and articulate in the midbass.They did not think I could get a good blend.They were wrong,thankfully.Though it took me a long time to get past the "WOW I have loads of bass,and isn't it fun" factor.The blend is now,absolutely seamless,and hence my having a sneaky suspicion that I could pull a "touch" more off,in high freq air,or whatever.
Believe me,I could be making a mistake here,and am aware of it,as the Townshend comes in,and will overlap my own tweets by about 5khz.This can be trouble,and if my bass experience is an example(any overlap in low frequencies came off as "tubbyness") I can easily screw up something I have no actual criticisms of.YET,AND YET...I am always trying to push the envelope,and believe in my system.This could spell trouble,but as I see it,I may have to scratch the issue,or take a trial run.
I hope to get some meaningful feedback by those(few?)who have possibly tried or heard a supertweeter on a speaker with an,already extended high freq response.
Thanks,so much.
Tvad - You are right of course, I forgot about the high-res media.

Cj - Your experience is what I think is supposed to happen w/supertweeters. The ultrasonic frequencies they reproduce aren't supposed to be heard by themselves, but by their interaction with other frequencies. The best analogy is if you play the same note on 2 guitar strings that are slightly out of tune, you will hear a low frequency wavering. This is called a beat frequency by acoustic engineers (and has nothing to do with the beat of the music). The supertweeters are supposed to produce audible results by modulating the rest of the frequency spectrum. In order to do this, though, they must be fed a signal that represents the ultrasonic content of the original musical event. This is not possible with Redbook, but is with hi-res and probably vinyl
I agree with Muralman1. I have recentlty tried Super tweeters and I think they overlap the other Speakers tweeter's too much.
I also think it threw off the balance of the mid and low range of the main speakers.
But, I was experiminting with vintage Rat Shack Super tweeters. (5K to 45K hz 96db). I knew the original crossover network 5k was too low, so I took all that out.

I tried changing crossover points all the way up to 18,000 hz, and I also tried first order and 2nd order slopes and it still added too much overlap.

So unless someone will let me try a Murata, I am done with that idea for now.
The super tweeters I tried were custom built, and they had an adjustment knob on the back of the module which either changed the volume or crossover point, I'm not sure which. I definitely had to adjust the super tweeter to find a point at which it blended nicely, but I was able to find a point at which the blend worked very well.

So, I would highly recommend a super tweeter with an adjustment.
Tom Port uses Townsend Supertweeters on Legacy Focus speakers. He brought over just one and attached it using duct tape at the inside on my right channel Focus speaker at the level of the existing ribbon tweeter. We listened to vinyl and immediately heard the increased airyness of the recordings. The speakers disappeared with the supertweeter (and I have Hallographs behind the speakers in a 25' X 21' X 12' high room with the speakers 6' from walls). If one worked wonders, two should be fantastic. However, the setting was at the low end at 2 (out of 10) because the Focuses are rather efficient at 96 to 98 db/watt. So, this is the first time I've heard a supertweeter blend so well with rolled off speakers (Focuses have a very pleasant rolled off highs, at least the first model from the 1990s did, maybe the new ones have better ribbon tweeters).
No one super tweeter for all loudspeakers, each super tweeter needs to be carefuly matched in level and crossover so no over lap,phase,time problems or boosted frequincys. The one tweeter that matchs all is just asking for grief maybe you will get lucky and it will match but your taking a chance. So if your thinking of adding one realy look into it and maybe DIY or have a pair custom built than you can also match finish as well as transducer crossover.
Most likely the benefits of adding inaudible content are inaudible.

It is known that sharp filters to remove out of band noise can effect the "in band" sound, however, that seems to be the only convincing argument for greater bandwidth (well beyond what you can hear) in audio reproduction.
I love my Fostex F200a Mid matched perfectly (to my ears) with the wonderful Fostex T90A-EX super tweeter, thank you JohnK!

A friend of mine uses the 'Townsend' super duper super tweeter with his horns and swears by it.
If you have a supertweeter crossed too low (like 15kHz) it will interfere with your main tweeter with unpredictable results. Remember that at 15kHz, the wavelength of sound is in the order of a few millimeters, so if you place your supertweeter off by a fraction of an mm, the interference pattern will be different. The high frequencies may be either enhanced or destroyed ... depending on the summation of waves by the time it reaches your ear.

You may or may not like the sound this interference, but of course that is up to you :)
Is it easier to add a super tweeter to horn speakers with better results than to add super tweeters to non horn speakers?
Depends on the horn speaker!

Horns are designed to work over a fairly narrow frequency band. If the wavelength is too long to fit the horn, the horn won't effectively couple the motion of the cone to air. End result is - sound is attenuated at that freq. and below. The same situation happens with high frequencies - short wavelengths bounce around chaotically in the horn - again it fails to couple cone motion to air - and again you get rolloff.

Some horns are designed for high frequency extension, but most horns I have heard do not do very well above 10-15kHz. If this is the case - supertweeters, or even normal tweeters with a HP filter, will work quite well.
The only loudspeakers that are hard to add super tweeters to are ones with cabinets that dont allow super tweeters to be close to main drivers plus you need to beable to move the tweeter to ajust time arrival. A full range driver and horns are fairly easy to match too because of hi-frequincy roll off.If you have good extention above 25khz I wouldnt add one but most loudspeakers dont and many dome tweeters roll off far below this even if manufacter states 20khz is probly at -3db or greater. And off axis drop is is even lower for many domes.
Johnk...The wavelength of 20 KHz is about 2/3 inch so a supertweeter movement of 1/3 inch represents a 180 degree phase shift. Since the supertweeter and the tweeter are not exactly colocated even a small change of listener position will alter the phase relationship.

We really can't hear the frequencies that the supertweeter produces, yet I agree that it changes what we do hear. I think that the ultrasonic energy sensitizes the ear to the fact that something is going on up there. Then the sense of hearing creates what ought to be there in terms of harmonics of lower frequencies. If this is true phasing is unimportant. Some speaker systems that have supertweeters have them mounted on the back. Clearly phasing is completely random for such a speaker. Small movement of a forward firing supertweeter may affect the sound because of beaming, rather than phase change. This is why rear firing supertweeters are used.
Most loudspeaker are not flat on axis to 20khz, off axis even less so, so many super tweeters are running in the range we can hear, we custom set crossovers but many are arround -6db at 15khz.Then phase maters but crossover 25khz higher not as much.