gedlee said:
I could try to answer this by searching an extensive material database.
I have a question before I'll try this... Maybe Steve would like to elaborate this.
Basically every resonance is determined by stiffness of material/construction and its mass (besides damping). When determining a "figure of merit" like Steve calls it, would we have to use sqrt(E / density) (which equals speed of sound and already contains mass and stiffness), or would we have to multiply this by density like Steve does in his paper, getting sqrt( E / density^3)?
I'm also wondering if damping should be included in such an expression, since it does not really influence break-up frequency.
All this is very interesting theoretically; however, if certain material advertised to have good properties do not publish any data? Rather, so called bogus material are have more measured data?
Guys,
Just because I don't reply to questions and/or comments right away doesn't mean that I will not do so as time permits. I have made requests for more documentation.
Usher has replied to http://www.s-m-audio.com/truth.zip but subjectively with absolutely no documentation whatsoever. They do however use inuendo and the format is "very nice". http://www.usheraudiousa.com/docs/Be-Response.pdf
So in response to their subjective response, I have obtained more information and I have analyzed their 28mm gray dome tweeter. The results are facinating. Here they are, http://www.s-m-audio.com/usher.pdf .
Just because I don't reply to questions and/or comments right away doesn't mean that I will not do so as time permits. I have made requests for more documentation.
Usher has replied to http://www.s-m-audio.com/truth.zip but subjectively with absolutely no documentation whatsoever. They do however use inuendo and the format is "very nice". http://www.usheraudiousa.com/docs/Be-Response.pdf
So in response to their subjective response, I have obtained more information and I have analyzed their 28mm gray dome tweeter. The results are facinating. Here they are, http://www.s-m-audio.com/usher.pdf .
mowry said:
Of course, but this would not be a problem if the resonance is well outside the frequency range for which the driver is used, correct? I am aware that there are different (subjective?) views on this...
Again, this is some very interesting reading. If we summarize the situation up to now, we can understand some trends:
1. Not all the Be drivers have been analyzed to the same standards for composition.
2. Lower priced devices are being bashed.
3. There is no performance data comparing various driver claiming to use Be.
4. Some people are trying to make generic claims about superiority of exotic material, but do not have real measurement data to back up such claims.
5. Some people seem to take advantage of such unbacked claims with a lower priced solution, and present performance data openly.
6. There is a war to get customer support of the two camps, and some mud throwing is going on.
How worse will things get in an econimy like this as a result? Loss in consumer confidence in the whole audio idustry?
Come on guys, let's get some really good suff developed, and get to the real guts of audio.
1. Not all the Be drivers have been analyzed to the same standards for composition.
2. Lower priced devices are being bashed.
3. There is no performance data comparing various driver claiming to use Be.
4. Some people are trying to make generic claims about superiority of exotic material, but do not have real measurement data to back up such claims.
5. Some people seem to take advantage of such unbacked claims with a lower priced solution, and present performance data openly.
6. There is a war to get customer support of the two camps, and some mud throwing is going on.
How worse will things get in an econimy like this as a result? Loss in consumer confidence in the whole audio idustry?
Come on guys, let's get some really good suff developed, and get to the real guts of audio.
a_tewinkel said:
No, its still a problem, but less
May be outside audible frequency range, but still there
If theres a ressonance at say 8khz, it can be dealt with, but still present
If theres severe ressonance at say 25khz, you will say "no problem"
Im sure that if it werent there at all, all other frequencies would improve as well
soongsc said:
True, but theoretically materials like diamond and beryllium have very good characteristics (stiffness/density ratio) if you want to push break-up as high up in frequency as possible. However, this is a minor problem since more ordinary materials like aluminum, kevlar etc. are good enough for almost any driver design. Since non-linear distortion is also non-problematic for most drivers available today, I guess it would be wiser to simply look for a driver that's good enough for the intended application at a reasonable price. Even Linkwitz with his expensively equipped Orion concluded with his Pluto that even cheap drivers can perform well, if other more important issues like polar response are correctly handled.
I have actually tried diamond material, and the situation is not so simple. Until I get my setup to sample at up to 192KHz, I really won't be able to comment too much. What I can say is that most manufcturers will probably do some analysis based on available material properties data, plug the data into canned software, look at the breakup mode go up, and then start making predictions, and the sales people build a story around the predictions to start marketing before any real product emerges. The real difficulty is in the manufacturing process to produce a product that can come close to predictions. I have never seen any analysis/simulations that come close to the real product concenring the high frequency region when a broad spectrum needs to be considered like in audio.a_tewinkel said:
It is best to start out with reasonably priced drivers for the intended application, but it would be nice to be able to expect more. It's the motivation behind development. Too bad that investors may not be enthusiatic enought about audio to trickle in long term investment.
Re: lies and damned lies
-The truth is boring.
-The truth will never make companies distinct enough for people to want to buy their products.
Marketing departments role is to sell the products hence the truth is only a possible by-product to them there is a HUGE grey area to be used before they actually tell a lie 😉
AndrewT said:
-The truth is boring.
-The truth will never make companies distinct enough for people to want to buy their products.
Marketing departments role is to sell the products hence the truth is only a possible by-product to them there is a HUGE grey area to be used before they actually tell a lie 😉
a_tewinkel said:
While they may be different views on absolute criteria, no one can doubt that above about 8 kHz the "importance" of diaphragm breakup is becomeing less and less are a part of the total picture. I give above 10 kHz almost no value at all, others some and still others a lot, but its has to be getting smaller and smaller such that this whole thing become moot when talking about a tweeter.
a_tewinkel said:
I have been saying for a long time, and getting criticized for it all the way, that the drivers are pretty much a commodity. Once you have "decent" drivers (there are some minimum standards), the rest is system implimentation and room acoustics.
Re: Re: lies and damned lies
I would say that the "truth" is only a minor inconvenince to marketing which can be easiliy circumvented as we have seen.
doug20 said:
I would say that the "truth" is only a minor inconvenince to marketing which can be easiliy circumvented as we have seen.
It was a little humor (obviously is was a failed attempt).
You talked about design and in room placement,etc. I thought I would add Audyssey as something that improves SQ for so many people because I know your opinion of it.
You talked about design and in room placement,etc. I thought I would add Audyssey as something that improves SQ for so many people because I know your opinion of it.
doug20 said:
You know, its a funny thing (pun intended) how tricky humor on the web can be. There is often no context, which requires assumptions and those assumptions can often be wrong. It's so easy for a "joke" to go astray. Thats why I tend to stay serious because my humor often gets lost.
Ya know kiddies... people keep saying "SQ" here. I keep thinking "Quad LP" which, iirc is/was "SQ"??!!
_-_-bear
_-_-bear
tinitus said:I wonder why GOTO have chosen to use titan diaphragm, as it seems they could still get the BE, if they wanted it
Still guessing
I was told last year that they do, for domestic drivers, but by law are not allowed to export them; so use ti for export diaphragms.
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