Wonderful lectures. Doug reminds me of my old very much admired lecture. Old but very knowledgeable. Step by step and enthused into the topic. wonderful! Valve old analogue still rules. Thanks Dave.
Dave, thanks for doing these videos, I'm sure they don't get as many views as say mailbag Monday but they have a value in their own right. Just as your videos on Op-map theory.
Curious as to if there were other materials used for the diaphragm before the age of plastics, or did this design arise only after? If so, were the only designs preceding it of the ribbon and carbon-impregnated capsule variety that Doug mentioned in the introductory video #602? EEVblog
What kind of microphone would you need to record elephants who are known to communicate with infra-sound (sub 10 Hz )? Every microphone I've ever heard of dies a horrible death at low frequencies. Would you be in pressure transducer range and would you need multiple microphones to get a high fidelity wide range recording?
Jammit Timmaj I'd just use a bass speaker as a dynamic mic and apply an apropreate bandpass. But using a 1DOF accelerometer is an interesting idea assuming it can pass
metaforest Any large mass diaphragm would have a low frequency cutoff, so a bass speaker would be good. Just get the amplifier impedance right. A 600 ohm impedance matching transformer might not have the low frequency you're looking for. I was thinking of an accelerometer that would be used for earthquakes.
E-Quakes can have frequency content well into to low KHz, and obviously it has a lot of energy... so the accelerometer needs to have excellent response at very low energies, (e-quake from far side of planet) and not clip at Mag 10+ right on the sensor. COTS devices are no where near good enough for that yet. However for a simple hobbyist bit of kit, take your 3DOF 3Gs accelerator and put it in a 5 Gallon bucket of cement, and bury that about 3 feet underground. That should get you good isolation from surface noise. (except for big trucks, etc)
How about Noise, I just got a mic in and it humms like hell. Its a Electret SE1000A, had the same problem with the older version SE1000. I thought I could bias it with a 10k Trim Pott? Any one have a cure for this?
hey really trying hard to study sound technology very passionate about it but some of the anagrams e.g puffs and a couple others I didnt understand maths I get circuitry I get powersource etc but puffs etc I don't is there a video to explain them or could u reply please to explain some thanks very much great video very funny love when education is made with humour and is intresting
Thanks for getting Doug in Dave, Might be a 101, but I'm gonna feel like I have a degree on mics by the end of this series. Great stuff.
This is what I needed. Many thanks!
Wonderful lectures. Doug reminds me of my old very much admired lecture. Old but very knowledgeable. Step by step and enthused into the topic. wonderful! Valve old analogue still rules. Thanks Dave.
You say old as if that is a bad thing!! Where do you think experience comes from? Old is good it doesn't need a "but" after it, thanks!
So in love with this videos! Thank youuuuu. I just miss the dynamic design
It is amazing the detail these videos get into.
Dave, these series of videos are GREAT. Better than reading from a book, much more informative, so anyway great stuff and keep them coming!
Please show more things like this!
Dave, thanks for doing these videos, I'm sure they don't get as many views as say mailbag Monday but they have a value in their own right. Just as your videos on Op-map theory.
Curious as to if there were other materials used for the diaphragm before the age of plastics, or did this design arise only after? If so, were the only designs preceding it of the ribbon and carbon-impregnated capsule variety that Doug mentioned in the introductory video #602? EEVblog
What kind of microphone would you need to record elephants who are known to communicate with infra-sound (sub 10 Hz )? Every microphone I've ever heard of dies a horrible death at low frequencies. Would you be in pressure transducer range and would you need multiple microphones to get a high fidelity wide range recording?
You'd probably want to use an accelerometer instead of a mic. You lose the high frequency, but you didn't want that anyway.
Jammit Timmaj I'd just use a bass speaker as a dynamic mic and apply an apropreate bandpass. But using a 1DOF accelerometer is an interesting idea assuming it can pass
metaforest
Any large mass diaphragm would have a low frequency cutoff, so a bass speaker would be good. Just get the amplifier impedance right. A 600 ohm impedance matching transformer might not have the low frequency you're looking for. I was thinking of an accelerometer that would be used for earthquakes.
E-Quakes can have frequency content well into to low KHz, and obviously it has a lot of energy... so the accelerometer needs to have excellent response at very low energies, (e-quake from far side of planet) and not clip at Mag 10+ right on the sensor. COTS devices are no where near good enough for that yet. However for a simple hobbyist bit of kit, take your 3DOF 3Gs accelerator and put it in a 5 Gallon bucket of cement, and bury that about 3 feet underground. That should get you good isolation from surface noise. (except for big trucks, etc)
metaforest
Cool.
How about Noise, I just got a mic in and it humms like hell. Its a Electret SE1000A, had the same problem with the older version SE1000. I thought I could bias it with a 10k Trim Pott? Any one have a cure for this?
hey really trying hard to study sound technology very passionate about it but some of the anagrams e.g puffs and a couple others I didnt understand maths I get circuitry I get powersource etc but puffs etc I don't is there a video to explain them or could u reply please to explain some thanks very much great video very funny love when education is made with humour and is intresting
+traitle87 puff = pF = picofarad.
+Scott Drake thankyou
great video but the end is creepy.
I own an NT1000, did Doug design that one? Can he tell me stories about it?
Creepy Crawlers !!
first