what are the thoughts of stand alone super tweeter

Tgb said: "what you say is true only for those supertweeters that extend down into the music range."

Earlier you've stated that a supertweeter shouldn't have any output below 15 KHz. Let's grant that for a moment just for the sake of argument: it is stipulated that we have a tweeter that cuts off very sharply right at 15 KHz.

If one can step back and think about the implications for a transition from the speaker's tweeter to the supertweeter, what you get is a completely unpredictable response.

Take a speaker with strong response from 15 KHz to 20 or above. Adding a supertweeter in this situation would give you a response that would have a significant peak in this range.

Take a speaker with more limited output in the highs (say a single full range driver design that falls rapidly above 10 KHz) and now you have a major dip in response before the supertweeter kicks in.

High frequency curves vary widely among the thousands of speakers on the market, so the above are hardly the only two examples.

So the argument essentially becomes, no matter what the characteristics of the main speaker, more is always better when it comes to high frequencies.

I find that a suspect proposition. In virtually every other aspect of audio reproduction, effort put into having well-integrated, carefully crafted matches between individual components yields better results than simply throwing a mishmash of parts together, even if each part is excellent in its own fashion.

I guess the red flag just goes up for me anytime I encounter a situation that says one product or solution is always the answer no matter what the circumstances.

Mlsstl, I was suggesting that many people's difficulties with supertweeters derive from those that have music in what they reproduce. That is certainly my personal experience.

I have used the Murata with Beauhorns which meet you rapid roll off speaker and with the Acapella LaCampanellas which "supposedly" extent to 40k Hz. The benefits on the Acapella are not as great as on the Beauhorns but still are something that I will not do without.

I grant the logic of what you say but not the reality. As I say all too often, I act on what I hear not based on logic or out limited understand of sound reproduction. Do listen to such a supertweeter if you find it illogical, I won't mind in the least. If you do, however, and like it, please explain why you do.

10-09-08: Tbg
Kal, all audio is anecdotal. Again this is not a science, it is a taste choice.

I would not say all but I would not dispute your position about audio and matters of taste.

OTOH, I was pointing out that the scientific studies have not been corroborated. Offering audio anecdotes as supporting evidence is simply inappropriate, especially in view of your statement.

Kal

Kr4, I haven't a clue what "inappropriate" means in any scientific sense. I suspect that by corroborated you mean replicated, but again I don't understand what this has to do with anything except to say that better experiments are needed and perhaps better instrumentation is urgent.

The only value I personally derive from various internet sites is the personal experiences of others. I do draw clues as to whether I care what someone reports from what they say and what their equipment looks like. This is, of course, anecdotal, the least value defense of a hypothesis and an early level of science. IMHO this is where we are in the science of audio reproduction, but I do need my music so I do as well as I can.

It might be helpful to look at the paper by Martin Colloms on his web site. He is the author of HIGH PERFORMANCE LOUDSPEAKERS as well as being a speaker designer and audio critic. It is too long to reproduce but in part it states:

2.5 Anecdotal Consumer Press Reporting
I have considered that informal, anecdotal reports from reviewers concerning the advantage of addon
super tweeters to be rather suspect since I feel that generally the basis of their evaluations has
generally been so flawed that the results may be discounted. The difficulties encountered are
manifold and only a few need be considered to confirm my negative view. Firstly the test for
response extension benefit will only be valid if the extended response is achieved without affecting
the performance in the existing ‘audible’ range.
Testing for a subtle effect, which may well be barely audible, is a manifest nonsense if it changes
the uniformity and loudness in the already operative treble range. Yet this is what is happening in
these tests. So far, no commercially available add-on tweeter and matching crossover can avoid
this fundamental error. Note that when such a driver and crossover is patched on to an existing
audio chain, as it often is, it will inevitably change the loading on both the cable and the amplifier,
and thus very likely impart another audible difference.
These ‘super tweeter’s typically operate in parallel with the existing tweeter over about an octave
bandwidth, and may destructively interfere with the primary tweeter output. Thus there is a potential
to impair as well as alter the results. Sadly, some critics are so pleased to have heard a difference
they are tempted simply to judge it as an improvement. Often the crossover is a simple capacitor
feeding a metal dome tweeter, perhaps with a beryllium composite diaphragm. Such a crossover is
something of a disaster since a calculated 20kHz ‘crossover’, comprising a single capacitor for a
nominal 5ohm rated tweeter, provides the response shown in Figure 1. The intrinsic output is
compared with the crossover objective, which is seen to be markedly different from the practical
result generally obtained with such a single element filter. The cause is the complex impedance
presented by the high frequency driver compared with a plain resistor load. Even with more
complex, higher order filters, the practical crossover points for super-tweeters are often placed well
into the audio band. It is not surprising that audio professionals dismiss such published subjective
results, which often seem to be produced in support of media and equipment marketing.