Speakers: Ceramic, Alnico, and Electrodynamic....a Basic Discussion

This video is a basic discussion of the construction and function of three types of audio speakers: Ceramic, Alnico, and Electrodynamic. Topics include voice coils, wattage, impedance vs resistance, electromagnet vs permanent magnet, voice coil testing, effects of signal polarity on cone motion, field coils, and humbucking coils. To demonstrate construction principles, a speaker is dissected and the component parts are examined and explained. This presentation is best suited to individuals seeking a basic understanding of audio speakers.
Here is a link to the 1940 National Dobro video: • 1940 National Dobro Am...
Here is a link to an EIA Code site (to identify speaker and component manufacturers): www.thespeakershop.com/speaker...
If you enjoy videos featuring classic vintage tube amps, jukeboxes, bizarre homebuilt electronic marvels, and clear, concise technical presentations, then please subscribe to my channel. You will gain immediate access to 100 additional videos, and (if you activate the service) you will be notified each time a new video is posted. Thanks for watching !!!

[@quarryfield]

I just learned more about speakers in 25 minutes that I have in all my 62 years of doing other stuff. Thanks, Uncle Doug and Rusty :-)

[@UncleDoug]

You're welcome, QF. We're glad the videos are informative :)

[@jaysorensenIBEW]

Absolutely, same here. Just took the right guy to come along.

[@timothyandrews2157]

I don't know how I missed this one Uncle Doug, but now 9 years later I've enjoyed this vid. as much as if I'd seen it then.

[@UncleDoug]

Glad to hear it, Tim. Thanks for watching :)

[@GRobLewis]

A few things I learned working at Cerwin-Vega (many years ago): 1. We always called them "spiders" even though they don't look like arachnids. Interesting to learn the source of the term! Their main purpose isn't to keep dust out, but to keep the voice coil centered in the magnetic gap. 2. Besides burning out the voice coil, another cause of failure due to excessive power is overexcursion, which can cause the voice coil form to "bottom" in the magnetic structure, often ruining it (you'll typically hear a loud "crack" if this happens). Open-back cabinets do nothing to prevent this, though you're right that the stiff suspensions of guitar speakers make it less likely. Still, playing a bass with a powerful amplifier through guitar speakers in an open-back cabinet is inviting trouble! 3. Overheating the voice coil may not melt the wire, but it can soften or burn the glue holding the coil together, allowing the coil to "throw a winding" into the gap. Time for a new voice coil. 4. Magnet size by itself is overrated. My boss used to ridicule the ceramic magnets found in cheap speakers as "dried mud". They could advertise heavy magnets when what actually matters is magnetic field strength.

[@UncleDoug]

Excellent comments, Rob. I had a personal experience with #3 fairly recently. Thanks !!

[@KittraKittra]

Fascinating.

[@damonztube1]

Your Presentation of "Speakers: Ceramic, Alnico, Electrodynamic....a Basic Discussion" is excellent I've been on a quest to discover the reason behind the magic of Alnico magnets I climbed to top of the mountain to receive wisdom and Uncle Doug bestowed Thank you

[@UncleDoug]

It was a pleasure, Damon. I'm glad you enjoyed it.

[@renemichelnunes]

I can not resist the charm of the old bad boys and his tones... this is precious info thanks Doug and Rusty with your wishbone :)

[@UncleDoug]

You're welcome, Rene. We're glad you enjoyed the video :) ^. .^

[@2angelitolv]

Thank you Doug for taking the time to make these videos. They are very enlightening for us, the amateurs.

[@UncleDoug]

+Angel Escobar You're welcome, Angel. I'm glad the videos are helpful :)

[@djvycious]

This video, like your others, is so informative and in a short period of time has taught me so much about how guitar amplifiers work. You rock Uncle Doug!

[@UncleDoug]

Cameron Walker Thanks, Cameron. Rusty and I are glad you're enjoying our videos. Best of luck with your continued study of tube amps :)

[@JoseCavendish]

Thank you Uncle Doug. Your videos have been so useful to me. I restored my dad old technics speakers. Thanks for your time and teachings.

[@UncleDoug]

You're welcome, Jose. We're glad the video was helpful.

[@daveogarf]

LOL! Back in the '60s, I built my own speaker cabinet with a Lafayette 15' woofer and a mid-horn and horn tweeter. The woofer looked just like the speaker featured at the very beginning of this vlog! What a nice memory trigger - Thanks!

[@UncleDoug]

You're welcome, Dave :)

[@billvrijens306]

What a beautiful presentation. A pleasure to watch and listen to.

[@UncleDoug]

Thanks so much, Bill. Rusty and I really appreciate your nice comments.

[@TheCarablanco]

Y'know, I thought I knew just a little bit about speakers after modifying or replacing elements in almost every speaker system I've owned over the past 40 years. Doug, you beat me with a stick, and gladly so. I had no idea how in-depth one could get in this oh-so-not-sometimes-esoteric medium. Hats off to you, sir! ~ S ~

[@UncleDoug]

Wow....thanks so much, TC. Rusty and I really appreciate your kind appraisal, and wish you all the best (or "beast" in Rusty's case :)

[@TheCarablanco]

Uncle Doug You recall our exchange concerning those old ceramics out of your previous project. You are absolutely right, they don't hold their age at all. Somehow I was hoping that . . . never mind. It is what it is.

[@UncleDoug]

Greetings, "Paleface" (if my rudimentary Spanish is correct). Yes, I recall your inquiry about the Newcomb speakers. I believe they are a good example of speakers designed purely for midrange, with small voice coils & magnets, and cones with rather soft suspension. Which is fitting, since the Newcomb E-20 was a public address amp. On their best day, they were probably incapable of accurately portraying frequencies below 200 or 300Hz. This is not a result of their age, but rather their design. On the other hand, the Jensen C12Q in the video is quite the opposite. Once the voice coil has been replaced and despite its age, it will function as well (or better) than many new speakers, due to its significantly larger VC & ceramic magnet, and much stouter cone suspension.

[@Skellingtor]

This helped me save a pair of vintage pioneer speakers destined for the dump. One dead tweeter and one dead 12inch sub in the other. Found replacement coils and followed Uncle Doug's video and got them back up and running.

[@UncleDoug]

That's great to hear, S.

[@BicycleJoeTomasello]

A classic Uncle Doug, miss Rusty. I love your new format. Time marches on! A humbucker coil, you learn something every day.

[@UncleDoug]

Thanks, Joe. Glad you enjoyed it :)

[@DaMaxchi]

Thank you so much for creating/posting this video. In the past, I tried to read about speaker design but had a tough time visualizing and interpreting the typical speaker cutaway drawings that you see in books. Your video is so much more effective in explaining the various speaker components. Well done!

[@UncleDoug]

+DaMaxchi You're welcome, DM. Rusty and I are really glad the videos are helpful.

[@andrewpearce5477]

My son and I love your channel. Great information.

[@UncleDoug]

+Andrew Pearce Thanks, Andrew. Rusty and I send you and your son our best regards.

[@compulsor5853]

As always, thank you for taking the time and effort to produce these videos for all of us eager learners, you're a great resource for all of us want to be luthiers and amp Smyrhe's! Wonderful job.

[@UncleDoug]

Compulsor You're welcome. Thanks for all the kind words. Rusty and I are glad you enjoy our videos.

[@knoxpruett1889]

Excellent indeed!

[@jayster.k.wiseguy]

that was a very loving approach to what we always have wondered~ pressure needed, or we have failures, sorta like backpressure for the engine~

[@bullthrush]

Understanding is a wonderful thing, and your videos bring it to a new level. Rusty must have underestimated how much more there is to learn about speakers.

[@UncleDoug]

Thanks, BT. Like most 16-year-old's, Rusty thinks he knows it all.....and that the world revolves around HIM. Hopefully, SOME day he'll grow up, move out, and get a job. THEN he'll discover how little he REALLY knows.....Oops, sorry, I had a flashback to a family discussion back in 1963 :))

[@billd3692]

Excellent videos, I really appreciate hearing the history of how the magnetics evolved. Interesting info on the hum-bucker coil.

[@UncleDoug]

Thanks, Bill......glad you enjoyed the video.

[@Barracuda48082]

I started my hobby with several name brand tube televisions and radios from the forties, fifties, early sixties. Hunts, Arvin, Whitney and some of the call letters of the station were embossed on the old ivory buttons. Most of these vintage units contained electro magnet or dynamic field coils and the sound was amazing. During that era..I came across a type of tweeter on a tube hifidelity radio turntable unit that I had never seen...a thin curved or arc of metal mounted to a flex plate with what looked like either carbon fiber or bakelite fingers behind the arc that had one wire connected to the arc and one the the carbon fingered bracket. A huge transformer was mounted on the 12" speaker and fed both the woofer and this unique tweeter through what I read as a non polarized capacitor and a ceramic wire wound resistor with a n adjustable slide ring wiper, which may have been the beginning designs of r c filtering?? My guess circa 1958, 1960 ..no loctal or octal tubes for dating..all 7 and 9 pin if I recall correct. 6beg, 6bag, 6v6g, 12ax7 philco and sylvania tubes. Now nearing retirement the itch is back to restore some of these older recievers and maybe ham radio versions.. who knows. I posses a set of vintage hard bound tv radio repair cyclopedias and manuals from the early fifties an pristeen shape that is up for grabs..

[@UncleDoug]

That tweeter sounds like quite a piece of engineering, Gary.....almost like a mini-plate-reverb for high frequencies :) Thanks for your interesting comments. Perhaps a viewer will be interested in your offer of manuals and books. Best of luck.

[@theHAL9000]

Not even sure how I came to watching this video but so interesting and well presented. Have much better general understanding of speakers and that makes for 20 mins. very well spent. Thanks!

[@UncleDoug]

Thanks for watching, Hal.

[@billmoran3812]

When I was a kid, my dad wanted to wire remote speakers to out old RCA radio/phono. I remember it had a transformer and a wound magnet coil on the speaker, so I didn't mess with it. I finally learned how those old speakers worked! Thanks for a great video.

[@UncleDoug]

+Bill Moran You're welcome, Bill. We're glad the video was helpful :)

[@TucsonBillD]

As usual, another well done explanation, Doug. And that Lafayette speaker really takes me back (about 50 or so years...). Keep up the good work!

[@UncleDoug]

+Bill Daniels Thanks, Bill.....glad you enjoyed it :)

[@L.Scott_Music]

Got a full life with so much to do... and it just got fuller after discovering this channel. Uh oh.

[@UncleDoug]

Join the club, LS. Rusty and I are busy from dawn to dusk, and never seem to be finished.

[@andyk295]

Thanks so much-so very informative. I had an old 40's 35mm moviola editing machine that had an electrodynamic speaker and I nearly electrocuted myself checking it out. It had an exciter lamp tube that measured about 410 volts at one of the connections. I learned to leave it alone since it worked well enough. Very loud !! I didn't have a schematic or diagram of the components. Uncle Doug your videos are the best !!

[@UncleDoug]

Thanks so much, Andy. Be careful !!

[@Woodys_Hobbies]

You're a great teacher Uncle Doug!!!! Thank you!!!

[@UncleDoug]

Thanks for the nice comment, Woody.

[@jungblutjm]

Excellent Excellent Excellent!!! Rarely seen such a great educational value.

[@UncleDoug]

Thanks so much, J-M. Rusty and I really appreciate your nice comments :)

[@EDKguy]

The talk of turkey magnet sandwich and can of tuna is making me hungry! Great video! I appreciate you sharing your knowledge and I like your sense of humor too.

[@ScottTheNews]

Excelant description of speaker types! Thank you!

[@UncleDoug]

+ScottTheNews You're welcome, Scott.....glad you liked it :)

[@subjectiveone1937]

Thanks, Uncle Doug! You taught this layman some interesting speaker knowledge that I hadn't known before. I came across a pair of JBL 4312 Control Monitor speakers and my mind started wondering about how these things worked.

[@UncleDoug]

You're welcome. Hopefully, now you know how they work, SO :)

[@BertusJ]

always insightful videos, thanks Doug and Rusty

[@UncleDoug]

You're welcome, Bert, and thank you for the kind words :)

[@OfficialSERFATRON]

This feels like a master class, thank you for sharing your genius.

[@UncleDoug]

You're welcome, OS. Thanks !!!

[@cornhuskbag]

Hi Uncle Doug and Rusty, Wow, another great video, Rusty obviously already knows to much about speakers. It is a good thing the cones are made of paper rather then rawhide, vellum, and or held together with hide glue! Any how, thanks a lot for this video. All generations today are fortunate to have a person like you who takes the time to educate! I wish there was another way other than using words to thank you? Kind Regards, Steve

[@UncleDoug]

Thanks so much, Steve. It's always great to hear from you. Yes, it is indeed quite fortunate that speakers and Tolex aren't made of tasty, chewable material.....Rusty would probably have eaten my collection by now.

[@VegasCyclingFreak]

Very interesting video, I didn't know much about those old field coil speakers until I watched this.

[@UncleDoug]

Glad you liked it, VC :)

[@GaitaPonto]

Great video. I wish I watched it a couple of years earlier, when I was trying to identify the speaker that came in my Victor projector speaker cabinet.

[@UncleDoug]

+Gaita Ponto Thanks, GP.....glad you enjoyed it :)

[@johngeddes7894]

A very thorough overview!

[@UncleDoug]

Thanks, John :)

[@noreaction1]

Your videos inspire me to learn electrical engineering on the free MIT courseware online. You're a very good teacher

[@UncleDoug]

Thanks, NR. By all means, pursue your goals.

[@Elix1rify]

Yes! Fantastic! I've actually just gone deep into the speaker-world.. This will be a joy to watch!

[@UncleDoug]

Have a safe trip, Elix.....I hope it's an enjoyable one :))

[@Elix1rify]

Uncle Doug This was great. Nice Jensen save! Thank you for putting this video together! :)

[@UncleDoug]

You're welcome, Elix......glad you enjoyed it :)

[@ronniewall1481]

Very nice job sir

[@CassetteMaster]

Very nice presentation! Another interesting speaker type is the balanced-armature.

[@UncleDoug]

Thanks, CM. I am not acquainted with the speaker you mentioned.

[@rayvoorhies7180]

I just stumbled across this video. I learned a lot. We need a part two on horns and tweeters. Usually the tweeter burns out first in a bookshelf speaker. The better bass guitar cabs have horns. Some trivia. I grew up in Hope AR (25 miles from Texarkana) a mile from the original Klipsch company. This was early 70's not too long after he started. I had no idea what revolutionary speakers Paul Klipsch designed. What a wasted opportunity to beg for a job, any job just to be around this man and his work. At that time, Klipsch was in a run down, area of old, empty warehouses and a chicken processing plant. I used to play in and explore those abandoned warehouses. I don't know if Klipsch has moved since then. I'd assume they probably have.

[@UncleDoug]

I agree, Ray, about the lost opportunity to learn from the master. I specialize purely in vintage guitar amps and circuits, so I'm probably not the best source of videos on HiFi accoutrements, but I will keep your suggestion in mind for the future. Thanks !!!

[@alvagoldbook2]

Another great and very informative video, Uncle D! I've never heard of electrodynamic speakers before! A very cool history lesson!

[@UncleDoug]

Greetings, Alva. It's always good to hear from you. Now, when you look at the speakers in many old radios, jukeboxes, and amps you will know why they have four wires instead of two :))

[@kosborne1963]

Thank you SO much for posting these vids. It's like a college course conducted by a particularly interesting professor.

[@UncleDoug]

You're quite welcome, Ken. I'm glad you're enjoying the videos, and really appreciate the kind words :)

[@yaboymintz]

Despite the fact I am too clumsy to work on my own amps (I wouldn't dream of doing anything my 64 Concert myself,) I enjoy watching your videos and learning the technical aspects about the gear I love!

[@UncleDoug]

Greetings, MDM. I'm a great fan of Fender Concert amps, particularly the earlier models.....you're a lucky guy to have one. Take care of it and by all means don't feel compelled to work on it if you're not comfortable doing so. Thanks for watching !!! :) ^. .^

[@tubical71]

As for 13:50 and up, this is *very* true for especially Vintage speakers. Some of them just have 4 screw-holes even when they are 12 inch diameter speakers.... So be save and tight it up very gentle and always tight it up cross sides. Thanks for this little but major detail description:)

[@UncleDoug]

You're welcome, TC. I found this out "the hard way" a long time ago. Even a minor bend in the speaker basket can result in non-alignment of the voice coil.

[@brainseagle]

well appreciate the presentation and learning of the filter choke use of the field coil and the humbucker. The independent power supply in field coil radio cabinets are a bit daunting. Inspiring stuff, look forward to more.. Appreciate the knowledge being shared. Thanks.

[@UncleDoug]

You're welcome, Anthony. I'm glad you enjoyed the video :)

[@Terribleguitarist89]

I love these videos, and the fact that you sound like my Uncle Roger who got me into Amateur Radio and guitar amp teching only makes them that much better.

[@UncleDoug]

Thanks, TG. Glad to hear it :)

[@guyanderton]

These videos are fascinating, really informative. Thank you so much for doing them.

[@UncleDoug]

Thanks, Guy. We're glad you enjoy them.

[@MrMac5150]

The best videos I have ever seen. thumbs up.

[@UncleDoug]

Thanks so much, Mr. Mac. Rusty and I are glad you enjoy our videos :)

[@MrMac5150]

Fantastic

[@hoofbags]

Hi Uncle Doug. This is an extremely interesting movie. I learned so much by watching it. I never really took much notice of speakers before, just check that the impedance is correct and usually looking for as big a magnet as possible. You mention that alnico magnet speakers are more expensive to produce, and I now know why. I build battery valve amplifiers of small wattage and I fitted a ceramic speaker into the cabinet. I wasn't very impressed with the volume of my latest build. I found an alnico speaker of similar dimensions, ohmage, and connected it externally to the amp: a considerable increase in volume resulted. Alnico are clearly more sensitive than ceramic in most instances, it would seem. I can't fit the alnico into the cabinet, unfortunately because, although the frame hole spaces are identical, the magnet protrudes out towards the back, making it impossible to close the cabinet. Thank you so very much for the very useful information. I will subscribe. (o:

[@UncleDoug]

You're welcome, HB. We're glad the video was helpful. Thanks for watching and subscribing :)

[@Leftlanedave]

Love all your videos uncle Doug your a great teacher sir!

[@UncleDoug]

Thanks, Dave. I'm glad you're enjoying the videos :)

[@FransvandenBergeMuziekschuur]

This is a great explanation.

[@UncleDoug]

+Frans van den Berge Thanks, Frans. Glad you liked it :)

[@Graywoolf25]

Thank you for sharing your knowledge. I really appreciate you spending time on making this video.

[@UncleDoug]

It is our pleasure to do so, Pablo :)

[@JoelzombieThomas]

I wanted to let you know I love the emphatic chopstick and finger tapping when you point at things while you're talking about it. It shows a healthy level of obsession. Keep it up! Oh, and thanks for finally explaining the way a field coil works. Next I'll be curious to learn the specific need and purpose for filter chokes in certain amp circuits since you pointed out the field coil speakers double as filter chokes. Also I must check into why the hum bucking coils don't cancel each others' electromagnetism if they cancel one another's hum...

[@UncleDoug]

Thanks, Joel......I guess I was a percussionist in a previous life :) Coils offer impedance to AC, but allow DC to pass freely.....thus they are of great value when trying to produce clean DC and resist and/or eliminate the unwanted AC ripple (hum). Hum bucking coils work just like output transformer windings in push-pull amps to eliminate or reduce hum. Since the hum is present at the same frequency in each of the out-of-phase windings, it tends to cancel itself out. Electromagnetism is not affected by this......both fields coexist.

[@barryseaman7863]

Very informative.I worked for Radio Shack nearly 40 years ago and never got very much of the theory side of speakers. interesting to see an RS speaker in the video.

[@UncleDoug]

Barry Seaman Thanks, Barry. Glad you liked it :)

[@leomonster1973]

Today I learned what a field coil is.... Thank you Uncle Doug

[@UncleDoug]

You're welcome, Rick.

[@jaym4958]

Thank you for sharing a lot of the little unknowns, just thank you.

[@UncleDoug]

My pleasure, Jay :)

[@budandbean1]

Another super video Uncle Doug. Up to now I thought I knew about speakers. Turns out I had a general idea and that came from my class books oh, thirty years ago. This is great info to have! Thanks Uncle Doug,

[@UncleDoug]

You're welcome, Buddy. Rusty and I are glad to hear that the video was helpful and informative. Thanks for watching !!!

[@budandbean1]

Hey Uncle Doug, as I was looking at some of the schematics and was wondering if you had done a video on Chokes and how they work. I'd love to see one like your Power Transformer video. Thanks, -buddy

[@UncleDoug]

Buddy, filter chokes are simply coils of wire that act as inductors by creating a magnetic field which blocks the passage of alternating current while allowing direct current to pass easily. They are used in the power supply to smooth out AC ripple in the rectified high voltage DC that is going to the tube plates.

[@GREGLUHOWY]

Once again, Very Informative & straight forward explanation.

[@UncleDoug]

Thanks so much, Greg. Glad you liked it :)

[@nickvanmaarth680]

Fascinating stuff! I was looking for info about the speakers in my Music Man 210 HD 130. Thanx very much for a great class. :-)

[@kolinevans9127]

Awesome and very inspirational thanks for sharing this.

[@UncleDoug]

Glad you enjoyed it, Kolin :)

[@chrisfite6217]

Awesome. I learned a ton! Thank you for sharing.

[@UncleDoug]

Chris Fite You're welcome, Chris. Glad you liked it :)

[@jlucasound]

Already have one! (Beer). That was me! Thanks Uncle Doug.

[@ciguat3ra]

Great video. thanks for sharing !

[@UncleDoug]

You're welcome, Cig. Thanks for watching :)

[@bigdicky11]

Great vid as usual Uncle Doug.

[@UncleDoug]

Thanks so much, Richard. We're glad you liked it :) ^. .^

[@tonykennedy9798]

Thank you Doug that makes perfect sense now. My plan is to build it as a 2x12. I will therefore buy 2, 16 ohm speakers and dispense with the extra speaker jack. I had not noticed the disconnect on the second jack when an extra speaker is input. I guess there is a lot of conflicting advice on the net. I do however, trust the numbers and your explanation. Many thanks and kindest regards from the UK.

[@UncleDoug]

+Tony Kennedy You're welcome, Tony. If you intend to build it as a 2 x12, then two 16 ohm speakers in parallel would be perfect. It's always best to have a proper impedance match between output tubes, output transformer, and speaker(s).....no matter what some people may advise on the net. If they want to take chances, then so be it, but it's irresponsible when they encourage others to do so too.

[@barnabyjones8333]

Thanks so much for this and all your videos. They/you rock! My first amp as a kid was a cheap tube amp (maybe Danelectro) with an 8" speaker with a transformer attached to it. I decided to stuff a 12" 8 ohm speaker in the cabinet with no knowledge of matching the circuit. No idea what that little transformer was for. Turned it on and rocked out for about ten minutes until the amp smoked itself to silence. Great fleeting sound! Ha ha

[@UncleDoug]

A lesson learned about matching speaker to OPT impedance :)

[@fartknocker132]

Thanks so much for these videos Uncle Doug. I love my JBL D120s and EVs etc. in my guitar amps......but always wanted to know how the heck they work...now I know!

[@UncleDoug]

You're welcome, FK :)

[@davea.8499]

ALWAYS A PLEASURE TO WATCH YOUR CLASS/LECTURES.

[@UncleDoug]

Thanks so much, HA. Rusty and I appreciate your interest and input :)

[@davea.8499]

I have an old Jenson alnico speaker that I am going to try that voice coil surgery that you mentioned..great idea wish me luck.

[@UncleDoug]

Good luck, HA :)

[@davea.8499]

Thanks Ill need it.

[@bigjohn75]

another great vid uncle doug

[@UncleDoug]

Thanks, John.....glad you enjoyed it :)

[@dwightward4956]

Well done, and very informative. Thank you.

[@UncleDoug]

You're welcome, Dwight.

[@davgold496]

Great video.

[@UncleDoug]

Thanks, Dav :)

[@felixred3261]

Great content Mr. Dough. Appreciate it man.

[@UncleDoug]

Felix Red Thanks, Felix. Glad you liked it :)

[@felixred3261]

Uncle Doug You're welcome.

[@GretschenMunch]

Fantastic!

[@UncleDoug]

Thanks, GM :)

[@diversifieddame9682]

Thank you, that was really neat... I learned so much about speakers and their history just now from you :)

[@UncleDoug]

You're welcome, DD :)

[@BrandonBuckaudioanarchy]

A couple of niggling clarifications. The material used for suspension at the outside of the frame is called the surround, whether it's foam or paper or cloth. And the cloth wires used to attach the coil wires to the terminals are called tinsel leads. And I've enjoyed your videos thus far. Keep up the good work!

[@UncleDoug]

Thanks, Brandon. We will :)

[@alessandroattianese1830]

Instructive, interesting and nice video. Thank you very much! Grazie ❤

[@UncleDoug]

Glad you liked it, AA. Be sure to subscribe to receive new video alerts.

[@onemancarnage]

As always great video, lots I didn't know about speakers. Very interesting. Thanks again.

[@UncleDoug]

You're welcome, Bryan. Glad you like it !! :)

[@SkroboElMagnifico]

Thank you for sharing your knowledge.

[@UncleDoug]

+Sebo Skrobo You're welcome, SS. Thanks for watching :)

[@silgamur7479]

quite interesting video, thank you for sharing!

[@UncleDoug]

My pleasure, Vicente.

[@hernancoronel]

Thank you Uncle! Very interesting and enlightening lesson.

[@UncleDoug]

You're welcome, HC.

[@zoomfotoboothsmsp9913]

Fantastic! Thanks so much!

[@UncleDoug]

+Zoom Foto Booths MSP You're welcome, ZFB :)

[@mrmoon7484]

Great learning video

[@UncleDoug]

Thanks, Mr. M :)

[@Qassu78]

Thanks for this video Uncle Doug! Concider me stupid but I really did learn something new. I had no idea that electrodynamics were used before permanent magnets. For me electrodynamics have always meant those huge flat high-voltage grinding electrostatic panels.

[@UncleDoug]

Hammu78 You're welcome, Hammu. I would never consider anyone stupid who actively seeks knowledge. Rusty and I are glad you found the video informative. Thanks for watching :)

[@petegonewild2022]

Very nice. Thank you

[@UncleDoug]

+pete carter You're welcome, Pete :)

[@RPSJR100]

I have the same Lafayette speakers like the one u opened with got them in a set w a Lafayette pa tube amp that sat in the bottom of the speaker boxes that clamp shut when put together to make one big speaker box fyi thanx for all the info for me to learn i appreciate your good work

[@UncleDoug]

You're welcome, SR. It seems like a good speaker.....very well made. I wish it had come with an amp, like yours. Best of luck :)

[@tsypherd76]

Thanks Uncle Doug!

[@UncleDoug]

You're welcome, Thomas.

[@seankerrigan1627]

Oh man I love this stuff... basically I'm having to endure my own ignorance, realise the weight of it as both an impeller and a detractor. I haven't done this stuff for ages and, with that chasm of time between, on one hand it's almost as if I've given myself a time for the ideas to actually be understood but at the same time realise a sense of stubbornness I'd used to bolster myself, back in those dim and dark days, just to go forward. Gosh... let's hope this time around I take more time to appreciate the ignorance I undoubtedly have now and use it to find that sense of intuition where I might know it's actually making other futures even more difficult... maybe that's what wisedom and humility actually are? Cheers utmostly Mr Uncle Doug! As an aside I did some pickup making way back then, any old wire and any old magnet, but I did kinda notice a difference within the makeups of different magnets creating fields. Alnico, as it were, seemed somewhat more attune to the human ear and felt unable to be precise as frequency went both higher and lower whereas something like neodinium, those little pellets of it were starting to become available, felt more precise in the sense that in something like a bass pickup it was very much able to give clear lows whilst also bringing a very clear 'fingerwork' sense, but in the mids it felt sterile ... interesting.

[@UncleDoug]

Thanks for sharing your ruminations, Sean. Best of luck with your renewed interest in speakers and tube amplification.

[@stefanvaneylen9488]

Great explanation About speaker types . Just what i needed. Thx!!

[@UncleDoug]

You're welcome, Stefan.....glad it was helpful :)

[@SaxJockey]

Many thanks, very interesting to see the physical arrangement of the voice coil and it's location between the magnetised core and plate. This video helped clear up the evolution (Alnico > Ceramic). I bought a used Jensen C10Q (re-issue made in Italy), probably different to the original USA ones, but still a nice speaker. Subscribed!

[@UncleDoug]

Thanks for subscribing, SJ. I have found the new Italian Jensen's to be excellent speakers :)

[@erichelsinkimusic]

Good stuff, just what I was looking for. Thanls for upload!

[@UncleDoug]

You're welcome, Eric :)

[@professortwang]

Fantastic video you are a master teacher! You talk about the decision to move from alnico to ceramic as being a financial one. I also read that alnico contained strategic metal that was in short supply during WWII which contributed to the need for another magnet type.

[@UncleDoug]

Thanks so much, Troy. You make an excellent point about the limited availability of the Nickel, Cobalt, and Aluminum during the war, and the fact that after the war, the Ni and Co were primarily available from countries with controversial labor practices (see Adam Rainstopper's comment below). Both of these factors provided additional impetus for the shift to ceramic magnets....and the continued expense of obtaining these materials probably contributes to the high cost of Alnico magnets and speakers today.

[@altonrex6495]

This is the first of your videos I've seen... boy do I have some tube time in front of me now! Thanks so much for bringing the old school gear and theory into focus for us. p.s. now I know why I love my old 12' alnico Utah so much! lol

[@UncleDoug]

Welcome aboard, Alton. Only 139 videos to go :) You're welcome for the videos.....we're really glad you found our channel and hope you enjoy them all.

[@howardskinner4916]

A bit of dirt or rust in the voice coil can completely stop a speaker from working. A New Year's eve gig in a small town in Wyoming was almost affected by such a thing. The horn of a PA speaker stopped working. No replacement was available. I carefully removed the driver from the horn and sprayed electronic cleaner into it because it was all I had. I re-assembled the horn and much to my surprise it worked! It worked for the rest of that tour, too. Be prepared!

[@UncleDoug]

Good point and an excellent on-site repair, Howard. Thanks !!!

[@kindanyume]

NIce vid for beginners.. they can learn a ton for older equipment in short order from this video format. won't make them experts etc but thats hardly the idea.. it will easily help educate newbs however which is a big bonus imo

[@UncleDoug]

Thanks, K2 :)

[@volvo09]

Awesome info with the early spider design!

[@UncleDoug]

Glad you liked it, V09.

[@tomwilliamson5287]

Very informative well explained, thank you.

[@UncleDoug]

You're welcome, Tom.

[@terrydixon1272]

Very informative.

[@UncleDoug]

Thanks, Terry.

[@denniswalsh8476]

Great video..... this is fun stuff. Possible orgin of using the term "spider" for the speaker's rear suspension. In the world of round mechanical stuff.... the occasional part the manufacturer may call a "spider" is usually a device that's a round part, usually with legs from the larger diameter OD rim to the smaller duameter ID hub, (like a wagon wheel). A solid, disk-like part, without the legs, is usually called a diaphragm. The most common function of either is keeping inner parts and outer parts aligned concentrically. A speaker spider's primary function is to keep the coil former centered in the magnet's annulus and concentrically aligned with the rear speaker frame (and allows normal cone travel). The speaker's sorround or front suspension maintains the concentric alignment of the front of the speaker cone ( and travel). The very old open speaker spiders MAY have allowed the voice coils to run a little cooler.... but the coil former was exposed, dust and dirt could eventually be an issue. New disk style fiber "spiders" close that path to dust and dirt.

[@UncleDoug]

+dennis walsh Thanks, Dennis, and thank you for the very informative input.