Even though what you state is apparent to the casual observer I would be careful where I said that out loud-hahah The TS followers will come take you away! This is a joke by the way and thanks for that.
As a T/S "follower" I have a lot more to learn now.....I must reread your body of work... A hearty meal to digest.
When I first heard the disclaimer "Values of Vas can be as much as 50% off stated specifications".....I knew a host of equipment was needed to properly engineer a well made loudspeaker system. Now you have expanded our thinking with a host of other parameters to deal with.
Sumaudioguy..Publish....in any way possible, thru any "forum" you can find.
Reading your "thoughts" here has affected all who have read it......be not dismayed. Your time will come.
"Those who tend to ignore a shout will strain to hear a whisper"
________________________________________________________Rick.......
When I first heard the disclaimer "Values of Vas can be as much as 50% off stated specifications".....I knew a host of equipment was needed to properly engineer a well made loudspeaker system. Now you have expanded our thinking with a host of other parameters to deal with.
Sumaudioguy..Publish....in any way possible, thru any "forum" you can find.
Reading your "thoughts" here has affected all who have read it......be not dismayed. Your time will come.
"Those who tend to ignore a shout will strain to hear a whisper"
________________________________________________________Rick.......
Cheapest way to measure a woofer
In the past I did this all with a DVM rated for 400Hz AC (very common) with a built in frequency counter and a sine oscillator that I bought new for $45. For a DC current source used a 6 volt lantern battery and a couple of pots- one for course and one for fine to adjust the current precisely for measuring BLi. To gauge the return to zero point measuring BLi was just a line struck on a plastic cup with a very fine marker set on the dust cap held in place with more clay so it did not wiggle. The line was "sighted" against an aluminum bar that was simply set across the speaker. There was a receiver that provided power amplification for the voltage needed in Z and delta m test. My 100 gram "test clay" used for both delta m and BLi was weighed at the local school on their scale and I checked that from time to time. It never really changed...less than .2% and was wrapped in a plastic sandwich bag when not used.
One does not have to get to fancy if not in a hurry and can just be patient and careful. Statistical averaging of BLi taking 20 measurements I found I never tricked myself. Obvious clustering of data occurs when careful. Everything else was just slow- checking for the peak with a DVM- yes very slow and very accurate.
The $100,000 dollars in gear I have now only makes it faster, not more accurate really.
In some locations I am known as "the slowly man." HAHAHAH
You know what is truly really funny? I still use the same chunk of clay!
In the past I did this all with a DVM rated for 400Hz AC (very common) with a built in frequency counter and a sine oscillator that I bought new for $45. For a DC current source used a 6 volt lantern battery and a couple of pots- one for course and one for fine to adjust the current precisely for measuring BLi. To gauge the return to zero point measuring BLi was just a line struck on a plastic cup with a very fine marker set on the dust cap held in place with more clay so it did not wiggle. The line was "sighted" against an aluminum bar that was simply set across the speaker. There was a receiver that provided power amplification for the voltage needed in Z and delta m test. My 100 gram "test clay" used for both delta m and BLi was weighed at the local school on their scale and I checked that from time to time. It never really changed...less than .2% and was wrapped in a plastic sandwich bag when not used.
One does not have to get to fancy if not in a hurry and can just be patient and careful. Statistical averaging of BLi taking 20 measurements I found I never tricked myself. Obvious clustering of data occurs when careful. Everything else was just slow- checking for the peak with a DVM- yes very slow and very accurate.
The $100,000 dollars in gear I have now only makes it faster, not more accurate really.
In some locations I am known as "the slowly man." HAHAHAH
You know what is truly really funny? I still use the same chunk of clay!
As a noobie (in relative terms) I find this as exciting as watching a nearby thunderstorm (awesome).
I will explain, I have long held the opinion, that, there are so many differing opinions out there, on sooo many levels, that there seems to be a 'missing link', I don't know this for a fact, but intuition keeps pointing me there. I'm pleny sure I'm not the only one.
You see, plenty of people just like me, have never had the chance to study any of this stuff. As such we can only go by 'What IS known'. Thats a hard path to follow when there are differing opinions on so many subjects.
DIYaudio is the closest thing most of us have to the Answer.
This can be a mine field for a noob! especially if you suspect a missing link, I have always put this down to, different 'schools'. (no offence to anybody, at all, ever!)
I will butt out on discussions here, due to lack of any real knowledge (at least for the now), but I will keep a good eye on whats going on.
Anyhow I always figured, if there is a missing link, some audio guy, would probably know the answer, but is being paid to keep it that way!
(glad I was wrong). WOULD be a sadder place without the likes of you (and all from noobs to experts) inside these dangerous walls!
Kind regards, and thanx heaps, Mick.
I will explain, I have long held the opinion, that, there are so many differing opinions out there, on sooo many levels, that there seems to be a 'missing link', I don't know this for a fact, but intuition keeps pointing me there. I'm pleny sure I'm not the only one.
You see, plenty of people just like me, have never had the chance to study any of this stuff. As such we can only go by 'What IS known'. Thats a hard path to follow when there are differing opinions on so many subjects.
DIYaudio is the closest thing most of us have to the Answer.
This can be a mine field for a noob! especially if you suspect a missing link, I have always put this down to, different 'schools'. (no offence to anybody, at all, ever!)
I will butt out on discussions here, due to lack of any real knowledge (at least for the now), but I will keep a good eye on whats going on.
Anyhow I always figured, if there is a missing link, some audio guy, would probably know the answer, but is being paid to keep it that way!
(glad I was wrong). WOULD be a sadder place without the likes of you (and all from noobs to experts) inside these dangerous walls!
Kind regards, and thanx heaps, Mick.
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It's important to note, though, that other parameters vary in the same way such that the calculated resonance frequency and Q don't have nearly that variation with driver variability.
Whenever drivers come in we spot test them using this same method. Batch to batch and driver to driver, as long as nothing is changed in manufacture, the variations are little unless there is some problem. Because all drivers here are made into matched pairs we know them well. These fall into 4 groups- 3 groups of acceptable drivers and then a small group of strange variations. The strange ones are sold or traded away. We have not been able to identify the specific source of strange variations. All we know is no match is available.
In that past have also used the Small technique to measure the same drivers and variations appeared much larger than variations really were. The Small technique does not give reliable or repeatable results across many drivers that are very nearly the same.
Thanks-
Delay is the essence of recorded music. The time from the recording to the time of playback is "group delay" of uniform value. This is funny and also true with no insult intended. For analysis it is much easier to for me to consider phase and excess time. Excess time is the uniform value all signals are delayed by through any circuit or transducer and the recording process. Subtract that value off and what remains is phase, the difference (remainder) in time at a specific frequency divided by period of that frequency multiplied by 360.
To have a better understanding of this D. Pries (maybe Preis) wrote several papers published in the Journal of the AES. The first was "Linear Distortion" which I consider a landmark work. Of course that means it is almost entirely ignored. That paper says more about delay than anyone. The second is another landmark work, the original Linkwitz paper on "phase of multiple driver transducer systems" which is completely ignored by every person who says "first order crossover used guarantees phase coherence" which is an outright lie.
Doug was a neighbor and taught at Tufts. I have a copy.
I have been finding a lot of people using DSP frequency shaping and ignoring phase, like "zero" phase FFT filtering.
Doug was a neighbor and taught at Tufts. I have a copy.
This is very cool. Doug is one of the few I wish to have met. I know about everyone personally except Pass.
Have not seen that many using FIR filters but a few do as a friend of mine does. There are many advantages in multi-way speakers with FIR active crossovers if out of band is kept below at least -40dB.
Do you know of any particular FIR filter systems? MediaMatrix Nion had a full complement in early software but it was missing from later versions. Have not checked the recent version. I love DSP and believe DSP is the greatest invention since audio itself. Use it all the time from MediaMatrix as they are far ahead of everyone else in the products field.
No, I have been playing with IIR filters, trying to follow some stuff Robert Orban wrote up. Unfortunately I never took a course in DSP.
Check this out - it runs without the hardware and all the tools work also. It will not do the logical functions without hardware though. Modeling filters works without hardware and is very easy to use. Object oriented GUI. Must have an input and an output connected to do anything. Use a BOB for that in the software program.
I think this is it_
http://mm.peavey.com/assets/software/Miniframe_208_v2-3_Software_599.zip
Is there a place I could upload a 22 meg exe file here? I would just post it to my web page but that would let the cat out of the bag.
Here is the correct link :
http://mm.peavey.com/assets/software/MWare_3-3-5_493.exe
Sorry, I run software and not OS. OS is secondary to the software and there is no software I have ever used that required Apple. Got 4 OSs running already and sure am not looking to add another.
Here is the correct link
:http://mm.peavey.com/assets/software/MWare_3-3-5_493.exe
Sorry, I run software and not OS. OS is secondary to the software and there is no software I have ever used that required Apple. Got 4 OSs running already and sure am not looking to add another.
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