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Posted by Romy the Cat on
11-29-2014
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fiogf49gjkf0d In one if the Brits forums rowuk wrote
about Linaeum diapole tweeters:
“Give them their own amplifier, then the efficiency does not
matter. Great amps are not that expensive and with the standard distribution of
acoustical energy, the tweeter does not need to get 115dB loud.”
http://www.audio-talk.co.uk/phpBB2/viewtopic.php?t=5322
My subject is not about Linaeum, wish I do not like but writher
the generalization that rowuk made. Does a tweeter has a need to be able to
push 115dB if the MF can? I know the answer but I would hold it for initial
post and let other to express own views on the subject.
Rgd, the Cat
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Posted by rowuk on
11-30-2014
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fiogf49gjkf0d Yes, it was a very "bad" generalization.
In the context of GoodSoundClub, I will say that amplification removes the absolute necessity for matching of efficiency within a couple of dB. Whether or not the tweeter needs 115dB output depends on what range that we are talking about. For someone crossing over at 1.5 - 2K, yes a great deal of "headroom" is needed (I will question 115dB however). If they cross over at 10-13K I believe the world looks much different. The question at UHF is more about integration than efficiency. The transient nature of UHF may need incredible peaks which is far different that the more sustained nature of sound as we go down the frequency scale.
I can envision a higher powered amplifier to preserve that peak nature......... 115dB UHF is not the question for me however.
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Posted by Paul S on
12-02-2014
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fiogf49gjkf0d Hmmm...
I like my tweeters +/- "matched" in terms of efficiency, but I am not starting out at 115 dB efficiency. Sure, headroom, practically speaking, is more than a mere luxury. However, is it really that hard to wring out a tweeter, and how much power can a worthwhile tweeter take, anyway? The question for me has been rather, when (or, at what frequency) is it OK to transition from one "type" of driver to another, say, from paper to ribbon. The question of dedicated HF amplification is also interesting; I have to say, I've never given it that much thought. I have thought about "efficiency" with respect to tweeters, however, and I never found one "rated" at 115 dB. It seems like HE people may have to give some here; at least I would if to use any tweeter I know of that I would want in my system.
Best regards,
Paul S
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Posted by Jorge on
12-03-2014
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fiogf49gjkf0d Tweeters are a real mistery. Some should sound great and they dont, and some never will.
I think you do need a lot of dynamics even at 10khz in order to get those sparkling highs that really jump out like the real cymbals and other crashing metals!
Of course it is not only the tweeters, cable and xover have a lot of detrimental effects on highs...
Highs is one of the first things that go bad when power is not good. It is one of the first things that let me know I am geting close to the time alingment sweet point...
They should be sparkling but not over bearing: When you dont have enough dynamics on the tweeters, then they become ever present if you want sparkle... and that is one of the worst things you can have in audio: A tiring hisss always coming out of the speakers.
On the contrary low volume and plain bad tweeters and you get those "spray can" highs, the other end of one note bass.
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Posted by Paul S on
12-04-2014
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fiogf49gjkf0d Jorge, I like your idea of "spray can" faulty HF. The best HF I get is when it is not "in the air" but it immediately "comes from the source" appropriately and then it's gone immediately, with no trace or "artifacts". HF should not "energize the room" like lower mids, not even in "bursts", like upper mids can.
Best regards,
Paul S
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