It's mostly sad how poor datasheets are.
ALL data is available and 90% of all known professional driver manufactures have a Klippel system anyway.
So they even have all data. (sometimes you can get it, when you beg really really really sweet and hard)
Yet, we are left with a piece of papyrus with some cobbled numbers together with less information than tube datasheets from the freaking '30s .
Actually, it used to be better, if you look at old Seas and Dynaudio datasheets, they have a lot more information, incl distortion plots!
Yes, I know I have ranted about this many times before, and I won't stop.
It absolutely annoys the sh*t out of me, as professional and hobbyist.
What's also amazing is that with all these cheap and easy tools there are still brands, able to deliver absolute garbage systems to the market.
I am not talking about taste here, but systems full of issues and problems.
Okay, I will get of my soap box again 😀 😀 😀
Soapbox he, many years ago i did design tubecelectronics, and the document i used was called Tubes and was printed in 1948.
It descibes all possible circuits one could make with tubes. Although i do not have it anymore, i have since not seen a tube circuit that - as far as memory serves me- that was not in that book.
Wrt to speakers the industry has indeed come a long way since, but its documentation is not up to current sota, given the standard being the tooling available to design, measure, simulate and evaluate.
Not only small signal T/S nor large signal , which btw i prefer.
Having said i find that the info Purifi publishes is quite good. So it can be done.
Big difference with accutone or scanspeak or way past with siare, audax, volt, seas.
It descibes all possible circuits one could make with tubes. Although i do not have it anymore, i have since not seen a tube circuit that - as far as memory serves me- that was not in that book.
Wrt to speakers the industry has indeed come a long way since, but its documentation is not up to current sota, given the standard being the tooling available to design, measure, simulate and evaluate.
Not only small signal T/S nor large signal , which btw i prefer.
Having said i find that the info Purifi publishes is quite good. So it can be done.
Big difference with accutone or scanspeak or way past with siare, audax, volt, seas.
@Kravchenko_Audio , in a previews post ypu mentioned "Speaking of embarrassed, who taught me about the REW method?" . I probably missed it but what is this REW method?
I am looking for was to reduce room impact on measurements(given my limitations), but sofar found it requiring math, and that i am no longer good in.
I am looking for was to reduce room impact on measurements(given my limitations), but sofar found it requiring math, and that i am no longer good in.
I am no longer good in Math either!
The method has been posted, And I am posting it as I learned it!
You need not worry about some of the information. But the basics are there. I have proved this out. You can compare it in posts that I have made. It is not perfect, but so close to ground plane or anechoic that it is plenty good enough.
Mark
Thank you for the kind words Mark! 🙂 It really is a wonderful time to be a technically minded, curious but poor DIY audiophile, not only the extremely reasonable cost of hardware and software, but the availability of information and knowledge (like, say, a Polish Professor's measurement method making it all the way to Wisconsin and beyond). Plus, being able to come to understand something is a reward indeed!
I have seen here or references in this thread a measurement technique that uses two cardioid mics closely spaced, but I cannot find it anymore. I would like to read more about it.
Generally two mics close together measure sound velocity rather than sound pressure. Cardioid does not matter much. It is a simple thing to revise the equations to use velocity instead of pressure in the modal expansion. There are advantages to this technique as it is less influenced by extraneous noise.
Taking these measurements on two concentric spheres allows for cancellation of all incoming room reflections as Klippel does (ala Weinreich.) This is basically the same idea.
Taking these measurements on two concentric spheres allows for cancellation of all incoming room reflections as Klippel does (ala Weinreich.) This is basically the same idea.
As this is the Klippel on a shoestring thread I assume we are discussing automation of measurements.
The method of using REW vector averaged measurements with incrementally increasing distance is quite time consuming if one uses 25 samples as @Kravchenko_Audio refers to in this thread. Do not know much about the subject but it looks like one could use the shareware Arta_Tic http://nicholasmart.in/measurement_platform/ as is and combine this with a standard guide rail with a stepper motor like this: https://www.ebay.com/itm/124901880488?hash=item1d14bb72a8:g:BpEAAOSwUFVhQbMk
For a really long axis a solution with the motor on the slide can give you several meters of action: https://openbuildspartstore.com/nema-17-belt-and-pinion-bundle/
The method of using REW vector averaged measurements with incrementally increasing distance is quite time consuming if one uses 25 samples as @Kravchenko_Audio refers to in this thread. Do not know much about the subject but it looks like one could use the shareware Arta_Tic http://nicholasmart.in/measurement_platform/ as is and combine this with a standard guide rail with a stepper motor like this: https://www.ebay.com/itm/124901880488?hash=item1d14bb72a8:g:BpEAAOSwUFVhQbMk
For a really long axis a solution with the motor on the slide can give you several meters of action: https://openbuildspartstore.com/nema-17-belt-and-pinion-bundle/
If one wants to use REW for the measurements I think it would be quite easy to use a standard step motor controller to move the mic assembly in the desired increments both fast and reliable. Then one only needs to set the appropriate delay between measurements in REW. With a mechanically robust setup less than 2 sec between measurements is doable I guess. (These things are FAST).
Combining this with a turntable.... Klippel on a shoestring?
On my old laptop REW crashes when I enable the function to make several measurements in a row. I use RME ASIO drivers that normally is as stable as it gets. Any suggestions?
Combining this with a turntable.... Klippel on a shoestring?
On my old laptop REW crashes when I enable the function to make several measurements in a row. I use RME ASIO drivers that normally is as stable as it gets. Any suggestions?
Use something else than REW. ARTA may have some built-in features for automation of external devices, and MATAA will help you to do pretty much anything you want (as long as it it's about audio measurements).
I think that Arta_Tic is not available anymore. Fortunately an alternative is available, written by yours truly 🙂
Most info can be found here: https://www.diyaudio.com/community/...arta-stepper-motor-and-tic-controller.387325/
Very nice!
So what to do with the files? And which ones do I need? Oh! Sorry I should follow that thread.
So what to do with the files? And which ones do I need? Oh! Sorry I should follow that thread.
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What would the software have to do? Automate some measurements? Do all the complicated math?
What do you mean with automated data system?
In a perfect world, it would automate the measurements and do the math. But we don't live in a perfect world. My personal preference would be for software that can do the math, but realistically, at this stage, automating some measurements is a step toward the goal, so I'd be mighty happy with that.
We can cobble together a few different pieces of software to get done what we are currently doing in a rather tedious manner. There are more creative ways to remove room effects that have been worked out by a gent on the ASR forum and we can measure with automation via ARTA. It's not free, but it's also not expensive. I'm in!
Yes, basically.
Just automate the entire procedure etc.
Importing things in Excel works, but it's not user friendly and very fiddly