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 :-)

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.

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

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 :)

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 ~

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.

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

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!

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.

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

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.

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

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!

My son and I love your channel. Great information.

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..

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

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.

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

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

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

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

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!

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.

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.

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.

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.

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.

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

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.

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

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.

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!

Interesting & informative! One thing I've always wondered about AC waveforms ending up pushing/pulling a cardboard cone is the conveyance of 'Timbre'. I understand harmonics & sound synthesis, but still, on an old vinyl LP, how does an oboe or piccolo tone come thru with strings & horns, with just a needle scraping sides/going up/down? Analogous, yes. But still, 1 needle or 1 read head or 1 bitstream ultimately goes to paper cones pushing air against my eardrums. Oboe timbre still there. Miraculous! God does love us!

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

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

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

Wow! Great Video! I just hope you don't run out of subjects to cover. Another 100 won't be too much to ask for, would it? When I was in Tronics school I worked a summer at a Goodwill reclaim action center in the electronics dept. I was always working on tube radios and TVs. One day a pair of beautiful Altec home stereo speakers came in and I tested them and found nothing wrong. So I boxed them up and send them to the store(in the same building) that my first wife worked at and at lunch told her to buy them for us. When I got off work I went to the store to get the speakers, my first wife told me this story. A man came in to the store and saw the speakers and asked if he could hook them up to see if they worked. He was asked if he knew how to test them the correct way and he replied he did, so he was left alone to try them out. A short time later my wife heard a loud pop and some of the lights in the shop went out so she ran to see what it was and after the smoke went away she found the man had cut off one end of an extension cord and had put the bare wires on the speaker terminals and plugged the other end in to a near by wall outlet. We'll my wife asked if he was gonna pay for the speaker and he replied, No! This speaker don't work! Thanks for these incredible videos. And tell Rusty to slow down on his chewing. Don't want him to lose his teeth!

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 !!

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!

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!

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!

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.

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,

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

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.

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:)

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

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:

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

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.

The best videos I have ever seen. thumbs up.

I always thought the name "Spider" was coming from "Spider web", because it act like a spider web with the spider (the voice coil) in the center, waving but acting like a suspention. And like always, thanks for all the videos, I'm curently re-watching all the videos! ;)

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.

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!

ALWAYS A PLEASURE TO WATCH YOUR CLASS/LECTURES.

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

Excellent indeed!

Another outstanding informative and entertaining video. I think much of "electronics for guitarists" is watered down and often incorrect-its a pleasure to watch your videos, good info is worth its weight in gold. I've become a vintage speaker junkie, and although they look cool and are historically accurate-its really all about the sound they get. I wonder if modern manufacturing would even be capable of making such speakers these days. I think back to all those vintage recordings I love, and on occasion when I get that sound with old speakers/amp's-you kinda know you are hearing the real thing as it was made to be heard. Keep up the good work, Im moving on to your speaker repair video next.

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.

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!

always insightful videos, thanks Doug and Rusty

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

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...

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

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.

A very thorough overview!

Awesome info with the early spider design!

Excelant description of speaker types! Thank you!

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

so f* good description about how a speaker works... nice to got here and learned more about them in such a very precised way, thank U 4 posted it!

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

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

Very nice job sir

Well, Uncle Doug, I found out what was causing the buzzing on low A and E notes. Bad news..I bought a brand new Weber 12 alnico and proceeded to warp the heck out of it! I really didn’t think I tightened it too much. Good news... I rotated it 90 degrees and tightened it not as much and it works great ! I really didn’t warp it much. I exaggerated for effect. But I can make use of the raw volume of my Ao 44 and the pine cab I built for the Weber ,now! They all sound great together.Almost TOO good. Feel like I shoulda paid about $500 more than I did for the rig! Stay safe out there!

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

Once again, Very Informative & straight forward explanation.

Doug. I just wanna say how great these videos are. I can't kiss enough butt. you know they are informative but they also are a grand departure from the usual self subservient fodder put forth by my fellow Generation Y'ers. on a personal note, I suffered an incredible personal tragedy this year and have enjoyed the comfort your videos ( and voice ) have brought me in tough times. I usually watch them late at night on my iPhone and have viewed almost every one. it feels good to get the mind on other things. I write this as my infant daughter lays next to me. she just fell asleep watching this video. apparently she comes from the Rusty school of compliments. anyways. thanks, and keep them coming.

Grab a beer, sit down and enjoy! I knew I was going to like this video, even before it started ..

Well done, and very informative. Thank you.

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

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.

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

Great vid as usual Uncle Doug.

Great content Mr. Dough. Appreciate it man.

Wow, why didn't I know all of these things? Thanks, Doug.

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

This is a great explanation.

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

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

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

Awesome and very inspirational thanks for sharing this.

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

I was going to add an after dinner speaker to my quiet, at home evening amp. Guess I'll rethink that... Gracias, señor.

WE thank you for the incredible amount of time & preparation you must need to compile such high quality, interesting videos. And I feel almost ashamed to post a comment since I see that, on top of that, you also take the time to respond to a lot of them ! I have only one question : I am going to replace a 15 speaker in a Fender Excelsior amp (the original speaker is very not very good and underpowered). Problem : this original speaker has no polarity mark. Is polarity relevant in a 1-speaker amp? (I've been told it doesnt, that I could put any wire on any terminal of a single speaker) , but if it does, how do I know which wire from the amp section is the hot one (they are both black) to connect to the new 15 Eminence (which does have a polarity marking) ? BTW, I started watching your canal by viewing your fine vid on pine cabinet construction, since the Excelsior baffle design actually bars maybe 1/5 of the speaker hole area. I might have to build another cabinet since I'm expecting some trouble with the new speaker which is not only better, but also much more powerful (100W against 15 w for the original speaker !). I suspect the greater air flow will need full free space to avoid any parasite vibration (I know from a previous similar experience). Cheers

Getting ready to try and find voice coils and cloth surrounds to try and fix the alnico woofers in my dads kenwood speakers from when he left the service. Hope to keep that original sound.

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

Very informative well explained, thank you.

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

another great vid uncle doug

What causes distortion to occur in the speaker. I like the celestial greenback for its distortion. Vs. the vaunted jobless e series which is crystal clear. Thank you for passing on your knowledge. Hi to the Jack!