The first video to properly explain why AlNiCo, Ferrite and Neo guitar speakers sound different?!!

[@NINEWALKING]

Part 1. First thing I want to mention is that first guitar amplifiers were combos and those have had speakers without permanent magnets. As you know there were tubes only. There were no transistors available. Speakers have had so called field coil. It was used to generate magnetic field instead of the permanent magnet but cleverly it doubled as the choke as well. Two birds with the one stone sort of the situation. How to all the other things. Most of the stuff mentioned is kinda right but it is way more complex than that. First we have to establish the rule that guitar speakers and cabinets are not designed same as home speakers, as PA speakers, as studio monitors or subwoofers. They use different materials for the cabinets and different calculations for the cabinets. Very same thing regarding design is true for the drivers them self. When we design guitar speaker it does not mean we want or need to design perfect speaker with best characteristics. Those perfect things would be win for other types of speakers where superior damping and cooling and less mechanical loss would make them “sound” better and increase the power handling. For example for most of the other speaker types we want die cast baskets with less as possible surface that is parallel to the back of the cone to restrict as little as possible the free movement of the cone. We want more linear Xmax. We want ventilation everywhere. We want super stiff but light as possible membrane. We do not care much about the reproduction of the top end because other drivers will take over. We do not care about the damping factor because amplifiers are transistor based and can take way more current back than the tube amplifiers. We want string magnetic field that does not change. Now with the guitar speakers we play all of the range with single big driver. Your typical 12” driver right? Well take almost any other type of 12” speaker and play full range signal true it. It does not work. Top end is gone. Weight of the membrane/cone, stiffness off the membrane, coating of the membrane, material of the membrane will define what frequencies you can play. Surrounding and spider will dampen some frequencies as well. How come guitar speakers can play top end than? Well they do it with a simple trick based on imperfection of the cone. Actually most of the top end is played by the middle of the speaker and the dust cap itself. Paper cone damps high frequencies and they get lost until the reach from the voice coil to the surrounding of the cone and the basket. You have to understand that the actual movement of the membrane is not the same for all of the frequencies. Tweeters are small and move fractions of the millimeter at normal levels and still make for example 97 dB at one meter. For the same sound pressure 12” subwoofer has to move way more. So when we understand that we now know that during guitar playing cone moves in heretic way and is moving more for lower tones and at same times it shakes making other higher frequencies. But point is that it does not need to move as much to play top end loud. In your typical other type of drivers for other purposes you do not want membrane to play top end and you want to prevent hectic movement of the cone and parasitic vibrations so you dope the cone to demo them or you choose materials that are damping those vibrations but play perfectly ranges that they should play leaving the space for the other drivers to play they part. Now dust cap is highly misunderstood part of the speaker and especially in the guitar speakers it has huge effect on the tone and the performance. The first usage is in the name and simple to understand. It keeps the dust out of the motor of the speaker. Second one is cooling usage. It literally pumps air around the voice coil and true the. Pole peace and basket vents if they are in the speaker. Third is dispersion of the top end frequencies. Smaller more pointing bullet shaped dust cap has wider top end dispersion. But it captures less air and makes the pumping cooling effect less. Dust cap material and size also influences mechanical damping of the speaker a lot. Even more with speakers that have no pole ventilation. And lastly dust cap weight influences resonant frequency of the speaker. Now once again in the other usage speakers we want the dust cap that cools the best and adds the smallest possible amount of mechanical damping. Sure we like cooling in our guitar speakers but that’s not our main thing. We are happy with lower power handling speakers as well. They sound alive and often have nice tone. Now mechanical damping is something we can tune but we necessarily do not want to remove it in the guitar speakers while it is part of the tone of some speakers. Material can be solid paper and that has no give. But some speaker use textile dust caps with different level of how much air can go true it. They are still filtering dust but reduce somewhat mechanical damping especially of the bigger dust caps and they play top end differently often even letting middle of the cone play it and they just let those high frequencies true like the grill cloth. We need stiffer suspension of the cone to prevent loose low end and help play other frequencies. We need spider that will accommodate such cone movement as we get in the guitar speaker. We use stamped still baskets and those also add color to the sound. They reflect back to membrane and they are increasing yet again damping of the cone movement. Holes are just to small so they are slowing down the cone. But that makes guitar speaker sound way it does. Plus stamped still baskets vibrate and color the sound somewhat with that as well. Some early guitar speakers have had tons of small openings and back was opened only 50 percent. Those were not so efficient speakers but those have had their specific tone for sure. Next to a all of those mechanical damping we have electrical and magnetic damping that’s very much connected with each other and interacts with everything else. Let’s look at them separately so we understand what’s happening better. When we send signal to the voice coil we make it move in the magnetic field. We profit from that effect because we generate mechanical force that moves the membrane and give us the sound. But every coils that moves in the magnetic field inducts current as well. This is sort of action reaction thing. That inducted it generated power has the opposite direction and is sent back to the amplifier. Amplifier has to be able to handle it. Damping factor of the amplifier describes its capability to absorb this current and deal with it. This is directly related of the output stage impedance. Higher it is less current it can take an lower the damping factor gets. Why is this important? Well amplifier that can’t take that current back is fighting with it and can’t control movement of the cone good even if the speaker and cabinet are really good. Therefore in audiophile world amplifier with higher damping factor will be more accurate. Now transistor outputs have way lower impedance especially when they use many parallel transistors. Tube amplifiers have output transformers and do not like current coming back to them. Even in home audiophiles tube amplifiers people use small drivers with small voice coils and even wide band drivers to avoid generating return currents by many voicecoils in parallel and to avoid complexity of what happens with those currents and passive crossovers. Just remember bigger voicecoils generate more return currents. Louder you play you generate more return current.

[@tobymoorhouse]

This video inspired me to take the plunge and buy a set of Neodymium speakers for my new guitar amp.. against the wealth of evidence in forums that Neos sound too bright and brittle. This is an opinion mostly formed by KZbin comparison demos I imagine. In my experience you need to change your amp settings to account for the higher level of detail in the upper mids and high frequencies when using Neo. If you don't, they sound unusually bright. Unfortunately in the name of keeping things fair most demos keep the same amp settings when changing speakers and end up biasing their results towards the most common speaker type of that demo (usually Ferrite). Neodymium speakers are the perfect choice for those wanting an honest sound out of their amp (my point of reference for my own comparison was EVM12L/G12H vs 18Sound 12NMB420/Mojotone Neo through a Ceriatone SSS using a Strat)

[@Funkussionist]

Thans Alex. Great to hear your brief but informative summary. I currently use 2 amps, one into a neo the other into ceramic. They sound different but complimentary. I'm glad you mentioned eddy currents, they're an important factor affecting the siZe and direction of forces in electromagnetic systems.

[@vincentevansbass]

Very informative as always, rapidly becoming my favourite channel to watch

[@bwvideo0905]

Well done video sir, thank you. Subscribed.

[@BarefacedAudio]

Welcome aboard!

[@ctimlock]

Incredibly interesting, absolute champion.

[@riangarianga]

Thank you very much for your coverage of this topic! I enjoyed the way you presented it. It's something I would have liked to investigate more in depth myself. You provide a nice starting point to anybody willing to follow that route.

[@Splattle101]

I've used lots of AlNiCo speakers from Weber, and some of their ferro ceramic jobbies. I also use some greenback style Celestions. My subjective experience is that the AlNiCo speakers are brighter and more articulate, and the ceramics are louder and have more bass. In the case of the Celestions, they're MUCH louder. One of my favourite sounds was with two amps: a 5E3 clone running a 12" Celestion greenback, and a Champ clone running a 10" AlNiCo in mono. The sag and compression of the 5E3 contrasted nicely with the stiffer single ended amp. The AlNiCo 10" reproduced lots of attack and detail, while the Celestion thumped and growled. I built a master vol. into the 5E3 to help balance the loudness and it was a glorious combination.

[@Scoots1994]

I don't think the eddy currents are just "against" the intended movement of the speaker. It is sometimes against it which causes distortion by reducing movement, and it is sometimes with it which also causes distortion by increasing movement ... it muddies the response in both directions. If I remember my physics from several decades ago anyhow.

[@summersendband]

Such a good explanation 👍 thx

[@BarefacedAudio]

Glad it was helpful!

[@MegaTubescreamer]

its one of those`nitty gritty` invaluable ingredients in the whole sequence of creating the key to finding or discovering tones people love, guitarists want that, but probably never consider for a nanosecond what they`dig` about tone, has to be dug up, and processed probably by slave labour blood sweat & tears, ,thanx alex ,, for being so enthusiastic, its truly appreciated 👍

[@egoncorneliscallery9535]

Alex, that was super informative! I have noticed speaker 'fatigue' when pushing it at prolonging high output levels. I had assumed this was more a thing of alnico speakers but it seems ceramucs are more prone to that. Suffice to say that all the other speaker elements play a big part. Celestion made the alnico blue to go into the Vox ac30 and they are glorious when pushed. Other, Fender old alnicos tended to blow in the early 1960s and often replaced by more robust ceramics. They mightve just been more robustly built and i think the elements of Alnico became scarse. Push a greenback and they get a sag. That IS a certain sound some people like. Another thing to consider is the way an amp's output transformer interacts with a speaker. That push and pull thing. I often use 2 10" drivers, one alnico and one ceramic. They both have their strengths and weaknesses. This for electruc guitar. For bass the mix and match does not work well for obvious reasons.. Thanks again Alex for your deep dives!

[@egoncorneliscallery9535]

Sorry for the typos. You cannot edit your post afterwards.

[@geoffkeeler5106]

Another good video Alex, and the first time I've heard an attempt to explain these phenomena. You continue to provide a bullshit-free approach to loudspeaker design, entirely in the Barefaced tradition. Looking forward to many more, thanks again!

[@PooNinja]

I’d love a quantum talk but that gets complicated fast

[@Herfinnur]

WAT!? Edit: Ok, on the third listen I got past the confusing bit and into the practical bit, and now I better understand the confusing bit; thank you for this! I love to use Softube's 'Celestion Speaker Shaper' plugin, and now I understand why choosing one of the two different Ferrite options and increasing the 'Boost' leads to a more full, booming sound. It would be interesting to find out whether magnets could be combined in a speaker design. Specifically AlNiCo and Neodymium

[@tonys.4657]

So...heating up your speaker will get you the compression and sag everyone is chasing with turning up tube amps? Is the tone more related to heat than power? This is fascinating! 😁

[@PedalScience]

Great video! Thanks

[@mrfivethirteen8919]

Alex, thank you very much for your always amazing efforts to deal with insights of physics indeed. Royal Engineers are supposed to greet themselves still with Glasgow handshakes for letting you leave for your civilian career. You are serving the country of finer guitar and bass sounds. I didn't consume all of your lectures, but as far as I remember one bit is always being taken constant: the electricity. Though amps likely work with transformators to mitigate impact of regional voltage and amperage, doesn't this detail influences the reaction of a driver aswell, does it? Is it a proper assumption using the same amp and cab in the USA, GBR or DEU may lead to a slightly different sound?

[@JR_Taylor]

Right away im reminded of the insane clown possy

[@roberthastings708]

And I subscribed today. I appreciate you. I've seen pooninja comment on your chnl and on Dylans. So I'm not the only one ...thanks again.

[@Factless_Wonder]

He said quantum and flux!! We're going back - to the future!!!!

[@leftyo9589]

only if you have a delorean that can manage 88mph!! LOL

[@hoboroadie4623]

@@leftyo9589 I only ever rode in my friend Karla's Deloren in town, and the little five cylinder or whatever it is did sound rather insubstantial, but I never really thought of the era, emissions controls were not quite sorted, were they?

[@hoboroadie4623]

L I B. I did not know that AlNiCo Magnets had heat proof character. 🤔

[@leftyo9589]

magnets cant work, and bumble bee's cant fly.

[@gushutchinson8758]

Magnets Magnetson ? Alex on Mastermind, the swivel chair . Specialist subject: Sound investment Something makes it move From the bottom to the top Alex doesn't care who you are Or what size you are- He's going to magnestise ya! Every colour of day Once he starts Magnet your day from dark ! Sun Zoom spark Don't let it get away Once it starts Which hands got it? The bottom or the top? Neither hands got it Just got it Hope it dont stop Does it start at the bottom ? Or does it start at the top? Dont let it get away Do you think you hold it once it starts ? I'm going zip up my guitar then ,when I've gone too far I'm going to zip down my guitar Sun zoom spark SUN ZOOM SPARK

[@HyperBlueZYZ]

Thanks for doing the math and the hard work for us 😂. #youdaman

[@Scoots1994]

If you step away from the guitar speaker area and move over to the hi-fi "audiophile" area the debates are the same but with less voodoo logic being employed because BIG money has been spent there to confirm and clarify the behavior of every component of the system used to "reproduce" the sound, but they use amplifiers and cables and speakers and cabinets just like guitarists do.

[@NINEWALKING]

Part 2. Now again we have our worlds and in it what we have sort of works for us. Now how that all in the Part 1 has anything to do with magnets you ask? 😂 Well any current spent or generated has its magnetic field. That field interacts with speakers engine. Now we need to understand that ceramic magnets came from the bean counters requests. Fact that engineers made them sound good is something completely different. They are electrically non conductive. But they also conduct heat way worse. Hence they tend to accumulate the heat and need cooling. But even absence of good cooling has its sound because it adds compression. Ceramic magnets came in as cheap solution. They are massive and heavy because they are not efficient. They are fragile as well. As any other ferrite core they shatter on smallest mechanical interaction. Now need and absence of money meant people have had to make workarounds. So to generate better power absorption and stronger field they made them big and heavy. Then they started pole and chassis venting but those did not came in guitar speakers always. What is very important to understand is how magnets structure is designed. Pole peace’s and how magnetic field work in the speakers is often misunderstood. Ceramic magnet is sandwiched by two metal plates. Back plate has pole peace that brings polarity of the back of the magnet forward to the front pate. Front plate is like washer or doughnut. We fix magnet structure to the basket using that plate as well. So it’s a disk with hole in it. It’s thickness determines usable depth of uniform magnet field of the magnet structure. Space between it and rear plate pole peace is the home of the voice-coil. The only part of the whole magnet structure that positive interacts with the voice coil is that space, that ring formed slit between the front plate and the rear plate pole peace. Rest of it is providing magnetic force and cooling. Now indeed both signal current and generated return current will again generate inductive currents in anything metal in their proximity. Here comes the importance of the back plate and it’s pole peace material and construction. Ceramic magnet is further away and it’s diameter is huge compared to other type of magnets. Saying it is not electrically conductive is not 100 percent true. In that powder mix we do have iron but it is surrounded by isolator. That iron takes the magnetic charge and becomes magnet. Luckily that powder is so fine and so far away that we do not need to bother about any eddy currents in them plus everything is isolated by the ceramic so there is no possibility to generate much current. What is the problem place is first and most the back plate pole peace. It is iron based metal to be able to conduct magnetism from the back to the front. Currents generated there are losses and turn into heat and affect the control capability of magnet controlling the movement of the voice coil and there for the cone. Then we understood that drilling the pole peace for the ventilation and cooling purpose has changed how those eddy current were generated and how they interact with the voice coils and even how much return current is generated. Some companies even started incorporating damping rings made of copper into the top of the pole peace controlling where and how those currents are generated. Now again that did not mean all of that came into the guitar speaker designs. Not that designers do not know it but they shape the tone by using or not using some things and tuning the tone to their liking. But all of those choices define unique tone of the each speaker. Like M and H magnet size in early Greenbacks. The same cone and voice coil, basically same speaker could take more power because of the magnet size and weight. Simply more thermal reserve and more cooling due to the mass and more surface. But it changed the tone as well. I bet they didn’t expected that one. Simply stronger magnet controls the cone and the voice coil more effective resulting in less distortion of the sound and different top and bottom response. So point being you can’t generalize speaker tone by just one thing because everything matters and can turn the tables sometimes. What everyone could hear is that some speakers are better for clean and not for gain sounds. Or the other way around. But some perform good in both. Some seem to lack top end in gain sounds but actually have excellent top end in clean scenario. Look at the Eminence black shadow for Mesa and EV 12L for Mesa. Both massive ceramic magnets speakers. Eminence has no top end when in high gain scenario but has when clean and in low gain scenario. While EV 12L has top end always. Both ceramic magnet speakers with what looks from outside similar construction. But yet they are so different. And then came Celestion 90 Watt version for Mesa with smaller magnet and it brought more top end. So you cannot say this magnet will do always this. It is way more complex. Look at the first Celestion Alnico Ruby. It was very dark always. Clean and overdriven. Now they changed it a bit and added some more middle growl and some top end. But it stays non typical Alnico speaker. Even Alnico Cream is not as bright as the Blue, 100 and the Gold are. Lastly power rating is also influential in the tone. Compare Creamback M and G12-65 Heritage. Lot of times similar power rating speakers sound similar. Lower power speakers tend to be more alive and often bright with looser bottom. There is something with sensitivity as well. But that’s another huge story for another time. Companies change stuff as they learn or depending on the feedback. Look at the Copperback. It came first without pole vent and as 2,5 kg. Then it got pole went and became 2,3 kg. It opened up an started sounding better to my ears. I am not sure what they have done to it next to adding that pole vent. But they made it sound better. So my advice is to take every speaker with the open mind and judge it on its tone disregarding what construction it has. Plus we all hear different and we all like different tone. So most important thing is that we like how that speaker sounds with our rig and with us playing it. The only important thing is that we like it. No matter what it is or how much it costs. Look at the PRS using V type. One of the cheapest models. Sounds good to people who chosen it in the PRS and people who bought those amplifiers.