Me too, I was more meaning why camplo would have picked super cardioid as the better option over plain cardioid or sub cardioid.
Pushing it but the satori wo24p-4 and Bohzen horn ribbon tweet cd just about manage 1200hz X/O. 26hz f3 or thereabouts
I have no idea...its the word used to describe the Dutch everyone seems to like so much...
I look at the diagram you posted and I see the super cardioid also has a more narrow front polar...that is desirable...I am wondering how does one create a shotgun cardioid polar or is that just a microphone thing...
On the same note for active cardioid and diy....
The thought crossed by mind... I see people take advantage of cheap n small drivers to build powerful line arrays...
My idea was to use an multi array of "smaller" drivers covering the sides of the monitors...to achieve active cardioid....might make for a nice SQ boost at my nearfield listening position..
DR. Geddes, I looked on your website, where exactly is this information you wrote about setting up active cardioid systems?
^ in microphone there is two ways to have super/hyper cardioids:
_either you have a dual membrane condenser capsule and you play with polarity and biasing of one membrane vs the other,
_ either you use an 'acoustic' labirynth to delay the backwave which will hit the membrane( the openings are entry of the labirynth which can be multitaps to 'shape' the response. Most dynamic unidirectional are done this way).
Shotgun can be a mix of both for what i've seen.
So either you switch to some back to back ESL and play with polarity and biasing, either... 😉 😀
_either you have a dual membrane condenser capsule and you play with polarity and biasing of one membrane vs the other,
_ either you use an 'acoustic' labirynth to delay the backwave which will hit the membrane( the openings are entry of the labirynth which can be multitaps to 'shape' the response. Most dynamic unidirectional are done this way).
Shotgun can be a mix of both for what i've seen.
So either you switch to some back to back ESL and play with polarity and biasing, either... 😉 😀
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That would be Audio Transducers, Chapter 9, pg. 216. http://www.gedlee.com/downloads/AT/Chapter_9.pdf
OK thank you....before I dig into the literature, humor this....
Lets say I'm dealing with a side driver purposed for directivity control....play main driver(s)....measure at certain distance in front of the side driver...take that measurement and invert it...inverse phase....time align it to get max cancellation? Done?
Lets say I'm dealing with a side driver purposed for directivity control....play main driver(s)....measure at certain distance in front of the side driver...take that measurement and invert it...inverse phase....time align it to get max cancellation? Done?
I have taken into my notes your idea of filling up the inside of a sealed cab, (while making sure not to compress any fibers)...
From studying TL I know the trait of spitting a chamber in half, helps to tame resonance...
What if one where to layer the inside of a cabinet with say 1inch layer of damping material on top of one thin separating sheet, and repeat? Would this help further to kill resonance?
From studying TL I know the trait of spitting a chamber in half, helps to tame resonance...
What if one where to layer the inside of a cabinet with say 1inch layer of damping material on top of one thin separating sheet, and repeat? Would this help further to kill resonance?
Best is just to fill the cabinet with loose damping material. Excessive technique won't be of much advantage, if at all.
I bought a cheap multimeter so I could take some 1watt (2.86v?) measurements? Cause I couldn't figure out any other way to do it lol...
Hmm, can't imagine how I posted it here as it's where it belongs: https://www.diyaudio.com/forums/sub...offset-tapered-tl-sub-design.html#post6557940
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Watts = Voltage squared / resistance. One watt is conveniently the square root of the resistance.
Might as well start with the correct nominal voltage, 2.83v (2.828v) into 8 ohms = 1watt, 2v@4, 4v@16. That said, you will be lucky to find two cheap multimeters to agree within .01 volts, but you have to start somewhere ;^).
Best to calibrate using 50-60 Hz sine waves, as the multimeter voltage circuit is made for correct readings with alternating current as used in typical power distribution, higher frequencies, or music or noise signals will not read as accurately.
Art
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Thanks Art!
GM I reposted your links here hoping to spread the info
Spreading info is not that easy....I tried to share some of my new found knowledge of speaker design to a mastering engineer group and it did not go well lol! I went down through the story of surface area, excursion and sound quality and I got shunned....I'll get back to them when I have everything assembled and have some measurements...and my ban is up...
GM I reposted your links here hoping to spread the info
Spreading info is not that easy....I tried to share some of my new found knowledge of speaker design to a mastering engineer group and it did not go well lol! I went down through the story of surface area, excursion and sound quality and I got shunned....I'll get back to them when I have everything assembled and have some measurements...and my ban is up...
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The cheap (<$40) DVM I have owned have produced random numbers on music. they are designed for 50-60 hz.
Cheap analog VOM are quite useful on music. I started measuring voltage on speaker with a $10 Radio Shack jewel. The bad news started my practice of replacing e-caps, and later tube & selenium rectifiers. At 5000 ohms/volt like a simpson 260, you can use them for tracing music through broken amplifiers. Takes a 2 vac scale to do much good near the front end, but 20 v or 50 v scales are fine for speaker wattage.
I calibrate meter with a zener diode bought from an authorized distributor. Resistance set to produce nominal zener current, the voltage is within 5% for A suffix parts.
Cheap analog VOM are quite useful on music. I started measuring voltage on speaker with a $10 Radio Shack jewel. The bad news started my practice of replacing e-caps, and later tube & selenium rectifiers. At 5000 ohms/volt like a simpson 260, you can use them for tracing music through broken amplifiers. Takes a 2 vac scale to do much good near the front end, but 20 v or 50 v scales are fine for speaker wattage.
I calibrate meter with a zener diode bought from an authorized distributor. Resistance set to produce nominal zener current, the voltage is within 5% for A suffix parts.
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Lets say I want to create a polar map of my horns performance so I can workon the crossover in Vituix...what software are you guys using to input measurements and create the polar map?
It looks like a FR text file from REW for each angle is enough to get me going in Vituix.
It looks like a FR text file from REW for each angle is enough to get me going in Vituix.
Vituix will create you a polar map as part of a design. This document will tell you how to use REW to get measurements to work with Vituix.
https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_Measurement_Preparations_REW.pdf
https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_Measurement_Preparations_REW.pdf
Fluid to the rescue as usual, thank you kindly sir.
I sorta passed on the 2.83v measurements, My meter doesn't read past whole numbers for voltage....I guess it was just for research anyway....I wanted to see how sensitivity the CD + horn was....maybe if I set the output to 3volts at 50-60hz sinewave....the results can be extrapolated
I sorta passed on the 2.83v measurements, My meter doesn't read past whole numbers for voltage....I guess it was just for research anyway....I wanted to see how sensitivity the CD + horn was....maybe if I set the output to 3volts at 50-60hz sinewave....the results can be extrapolated
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Camplo,
You could turn the level up by 20dB and measure 28 (28.3) volts, then turn it back down for the actual test for a bit more accuracy.
That said, do you know the impedance of the horn/driver?
You could turn the level up by 20dB and measure 28 (28.3) volts, then turn it back down for the actual test for a bit more accuracy.
That said, do you know the impedance of the horn/driver?
Consider getting something like this, cheaper from Aliexpress but the link was too long and you may prefer to buy more locally
Server Busy
Perhaps not as cheap as what you have, but very cheap for the performance they offer. These are also accurate at 400Hz.
Server Busy
Perhaps not as cheap as what you have, but very cheap for the performance they offer. These are also accurate at 400Hz.