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Old 22nd August 2011, 04:33 PM   #2011
gedlee is offline gedlee  United States
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Originally Posted by Esperado View Post
I am sorry, but Zobel and motional impedance compensation makes a noticeable difference you can measure and listen with evidence.
We will have to differ on this.

There is no published evidence to support your claims and they contradict my knowledge and experince. Amps with output impedances as low as .1 ohm are quite readily available and this level of impedance could only make less than a .1dB change in response. And as to the load affecting the amp, this to is nonsense in any good amplifier.

If you believe all this audio "snake oil" dogma then there is no wonder why you think that my approach is the falicious one.
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Old 22nd August 2011, 05:43 PM   #2012
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Originally Posted by gedlee View Post
No one would agree with you that smoothing to 1/24th octave is a problem. ...SO don't kid yourself that there is some "magic" measurement box or technique that is error and averaging free, because it does not exist.
If you are talking about tonal balance, i agree. But slow sweeping frequencies measurements in free air or big anechoic chamber give a better feeling aboutl the HQ cone"s material resonances due to fractioning. Helps to chose the best (far from perfect) hight cutoff frequency of a given loudspeaker, or to chose between several loudspeakers.. Nothing more.
About motors and horns, we all live in a poor real world. No one can knows what exactly happens in a specific motor and his phase piece. And it will differ from a model to an other. Of course it will be far from a spheroidal wave. In fact, far from any simple geometric figure at all the frequencies. Agree ?
Well, we all try to get some mathematical model in order to design horns. Some approaches gives quite good and close listening results. One can be better with a specific horn or room, worse with an other. No one, including you can pretend he own the perfect formula.
A specific attention to the first centimeters of the curve figure, witch is the one of the driver, slightly conical, and differ of any theoretical calculed curve. Did you manage this point and modify your drivers ?
About diffractions in horns and what you call HOM, i had too this kind of thinking, several years ago, and tried absorbent material too, thinking that it will damp the multi reflected lateral waves more than the direct ones, because they will have to across the damping material several times. But i had forgotten this idea as listening the result produced a feeling of some kind of "Dead" sound and medicine worse than the disease.

I would be very interested to listen to your solution, will try some dau to find someboly in Paris ,or better, Toulouse.

I wonder if some kind of long fibers oriented very light material ? Will try again with some very light fiberglass wool, fibers oriented in the depth direction of the horn. or, like for damping enclosures, some cross of thin absorbent material all along the center axe of the horn ?
Best regards.
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Old 22nd August 2011, 05:55 PM   #2013
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Originally Posted by gedlee View Post
If you believe all this audio "snake oil" dogma then there is no wonder why you think that my approach is the falicious one.
Where did i said your approach was "falicious"in any way ? Some paranoiac reaction ? Impossible to explore different technical approach things in a open minded way ?

Please, be gentle, i'm not that kind of audiophile you think, and i have a little experience in loudspeakers and enclosures, (i was head of the electro acoustic department of the first French hifi manufacturer during the seventeens). And sound engineer during more than 30 years, not very sensible to snake oils because my scientific formation. Jut to gives-you an idea about what i'm able to hear, compare, or not.
You knows 30years of contact with real musical instruments and musicians 10 hours a day, and more or less bad 'state of the art' professional equipments.
See what i mean ?
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Old 22nd August 2011, 06:38 PM   #2014
gedlee is offline gedlee  United States
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You need to understand at the very begining that I give no credence to subjectiuve listening tests that have not been done using rigorous scientific methods. Your personal experiences on any of this subject matter will make no points with me. I learned a long time ago that converations that have a "well it sounds good to me!" always become pointless. This is a claim that can neither be proven or disproven so the rest of the conversation can only be meaningless.

You did claim that my work sounded like "snake oil" - lots of people here noted that. So by falicious I meant this reference. I suspect that maybe you are seeing things a little differently now.

Compression drivers are, to me, a given, I can't make them so I can only use what is available. But you will find that I hold several patents on the proper way to make a phase plug for a compression driver, so this is not something for which I am unaware. There is still an optimum waveguide for any given driver. It just may not be the best possible design of the combination of the two. That drivers and horns are designed independently of one another is certainly a big problem. That needs to change and my patents show how that can be done.

There are none of my speakers in France - as yet - I have an order for some smaller baffles to France, but thats all. Shipping to the EU is prohibitive so there has not been much interest. One smart guy, years ago when they didn't charge for luggage, flew in from Germany and took back some speakers as baggage. It cost him less that way!!

I am very open minded, but with 45+ years in audio, I have heard it all. I am not going to argue about subjective things. My speakers are designed using science and science alone and I'll stand behind every inch of them from that standpoint, but I won't argue about "this speaker sounds better than that one" etc. Its all gets rather pointless.

You probably believe that to each person there is a "best" speaker and that this is different for everyone. Well, you see, I don't believe that, and I don't think that any of my customers believe that anymore either. There is a "best" speaker and it actually is the one that measures "best". Coincidence? I think not.

Last edited by gedlee; 22nd August 2011 at 06:45 PM.
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Old 22nd August 2011, 07:23 PM   #2015
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Originally Posted by gedlee View Post
You did claim that my work sounded like "snake oil" -
I had said that the way you present-it on your web site... etc...
Not your work itself. it is not at all the same thing.

And a lot because it seems you consider all the other people, searching with the same passion than you, scientific methodologies too, and different approach as wrong or even stupid.
On my side, what can i say about the quality of your results or the validity of your theories without any hearing and measurements ? Did you provide somewhere formulas on witch i can experiment your horns designs ?

By example, you tell me that impedance compensation is "snake oil" ?
I believe then you have never even tried-it.

Ok: just one testing methodology.
Take you beloved amplifier.

Compensate the loudspeakers of one of your enclosure (i believe you know how to calculate those parallels circuits.)

Build a comparator with an Op amp gain 1 or more, feed the + with the input signal of your amplifier. The loudspeaker output have to be connected in // to your loudspeaker and a potentiometer followed by a serial resistance in the - of the operational amplifier.
Tune the potentiometer to reduce at the minimum the output signal of the Amp op in order to see only the difference between the input and the output of your amplifier.

Now, record on some multi-track a dynamic musical source, with drums and so...
Play the musical track at a normal listening level and, in the same time, record the out of the comparator on a new track.
Remove the impedances compensations, and make the same recording on an other track.

Compare the two tracks from the comparator. (and you can listen to).
Come back and argue against the utility of such a impedance compensation, now.
I will eat my hat.

And this test is just on the amplifier side.

On my side i do not believe in measurements, as i do not believe to my ears . I believe in what i hear that i can correlate to measurements, and the contrary.
and for a very good reason, we do not know how to measure everything, and the way we listen is a complex mix of mechanic-acoustical material( our ears) and complex neuronal treatment by our mind,including our desires and memory.

Last edited by Esperado; 22nd August 2011 at 07:41 PM.
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Old 22nd August 2011, 09:58 PM   #2016
gedlee is offline gedlee  United States
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Originally Posted by Esperado View Post
you consider all the other people, ... different approach as wrong or even stupid.
I do consider most of what is out there wrong, that much is correct, but not stupid, just behind the times. I used to believe that distortion was critically important in audio, I wasn't stupid, but I was wrong. I learned by doing just what you suggest - attempting to correlate what we hear to what we measure.

I have heard all your arguments before and checked them out. I'm not going to do it all again.
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Old 22nd August 2011, 10:33 PM   #2017
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Originally Posted by gedlee View Post
I have heard all your arguments before and checked them out. I'm not going to do it all again.
Well, i see any objective (scientific or technical) discussion is impossible with you. And seems to afraid you. You do not consider any evidence opposed to your "certainty", do not share any so calling "knowledge", and anything is wrong if it does not come from YOU.
Just think about the image you give of yourself, your intellectual honesty and your credibility when you says here :
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Trust satisfied customers
and here:
Quote:
I give no credence to subjectiuve listening tests
EOT, for me, i am sure i have nothing interesting to learn here, and that my fist feeling about reptilian lubricant was right.

Best regards and good sells.

Last edited by Esperado; 22nd August 2011 at 11:01 PM.
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Old 23rd August 2011, 12:30 AM   #2018
soongsc is offline soongsc  Taiwan
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Originally Posted by gedlee View Post
I do consider most of what is out there wrong, that much is correct, but not stupid, just behind the times. I used to believe that distortion was critically important in audio, I wasn't stupid, but I was wrong. I learned by doing just what you suggest - attempting to correlate what we hear to what we measure.

...
It's not whether distortion is critically important or not, but at what level they become more critical than other factors. Due to the method of distortion measurement, it covers a very limited aspect of distortion that can be revealed.
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Old 23rd August 2011, 01:08 AM   #2019
tinitus is offline tinitus  Europe
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well, there's no doubt in my mind that the worst distortion comes from crossover malfunction
it is very easy to hear when the right adjustment makes it less
and it can be so very small adjustment that you hardly believe it would make much difference
whether its phase related, or whatever, I don't know
but very audible, and makes a huge difference
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Old 23rd August 2011, 04:15 AM   #2020
soongsc is offline soongsc  Taiwan
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It seems to me if the phase changes rapidly at some point within the listening angle, no matter at what distance it occurs, then it is audible.
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