What I love about this dude is he's a proper scientist but doesnt seem to realise it. He starts out by admitting his limitations and the limitations of his testing. Then he identifies, isolates, and carefully controls his variables one at a time. He enters the testing phase with a total open mind and considers everything regardless as to what his intuition might tell him. He carefully records his methods so others can try to replicate his results. He delivers his conclusions impassively by looking at the real outcome with no regard for any prior bias. Then he opens up his tests to a wider audience to invite their comments and review. Dude knows the scientific method inside out

This guy is the guitar snob killer. What a legend.

Eventually you will have to play the tackle box through the foam cab using the no-body/no-neck Tele. I love the experiments you do!

This guy seriously built like a dozen different cabs in his backyard just for this video. That's dedication. Bravo

In 20 minutes you've undone decades of marketing by guitar cab manufacturers to justify crazy prices for a wooden box. Hats off to you!

You are a hero of the guitar community. No hyperbole.

No one will ever create such a thorough and clear demo of this stuff ever again, this is actually a masterpiece

This man is a genius. He does not fall for advertisement and "this is known", he experiments and learns himself. These videos will make so many "audiophiles" and audio companies really angry, since they clearly demystify all their mambo-jambo. The consumer on the other hand learns what really is important and where money is wasted or not. Very well done :)

Jim deserves his own little wing of the Rock n' Roll Hall of Fame for his tireless work in busting myths and answering the important questions.

This man is a national treasure and must be protected at all costs.

At one point (17:13 to be exact) you say "I'm just a musician, I don't know anything about physics...". I beg to differ. Here's a quote from wikipedia: "Experimental physics is a branch of physics that is concerned with data acquisition, data-acquisition methods, and the detailed conceptualization (beyond simple thought experiments) and realization of laboratory experiments. It is often contrasted with theoretical physics, which is more concerned with predicting and explaining the physical behaviour of nature than the acquisition of empirical data." By that definition, I would say that you are an experimental physicist, and a good one at that. Love your videos, carry on.

The styrofoam cab has no business sounding that close to the Orange cab. This is hilarious. Cab makers have to be ripping their hair out at this. Excellent work. You conducted experiments exactly as one should, and were not afraid to say "this didn't affect the outcome as I hypothesized, so I moved on". Truly the mark of a mature experimenter. Well done.

Incredible. I spent a whole day building a 1x12 because the thought of spending $650 for a plywood box was ridiculous. Stoked with the results

Electrical Engineer here: The impedance *can* effect the sound as it *might* change the way your amp interacts with the speakers, but that depends on the amp. So it might be that in your case the amp could handle all impedances well, while other amps might handle them differently. Impedance mismatches can certainly also effect the frequency graph (e.g. try running a High-Z Piezo into an low-Z preamp vs running the same thing into a High-Z-Preamp). But with amps it really depends how the output section is built, e.g. a change in impedance might form a different "passive filter" with any internal capacitance of the amp, etc. However I don't think impedance is a big factor in the sound of an cab typically. It might affect the effectiveness (how much levels you get out of the whole thing), but not so much the sound as long as your amp-cab combination is within spec : ) Some additional thoughts: You looked exclusively into the frequency domain which was a really interesting (and worthwile) exercise. But be aware that the time domain also exists (REW can do waterfall plots). Some of the changes you made might not have shown big changes in the frequency graph, but might have affected how the cab handels short impulses, percusive sounds and such things in the time domain, which in turn might affect things like the perceived "tightness" of a sound. I believe the biggest changing factor there would still be the speaker itself, unless you are building some boomy bass-reflex thing replacing the hole in the back with a pipe or something. But if you have the speakers around still, looking at how they "ring out" when fed with short pulses might be an interesting thing to look at as well. Your work is really gold, thanks.

As an engineer, I love this no-hype systematic approach. Do yourself and everyone else a favor and make cabinet impulses of all nine of your cabinets and monetize this content even further. I'd buy it.

The acoustical principle that's causing the effect with making a hole or opening the back is called "helmholtz resonance". There is a caclulation to find the relationship between the boosting or cutting frequency and the size of the opening.

I have never sent a PayPal to a content maker…until now. This was absolutely incredible and so well done. I cannot believe how much work you put into this and how valuable this debunking of mojo voodoo secret sauce actually is. More please!

Jim's not only a great guitar tone mythbuster, but he's got awesome video storytelling chops. Super engaging end-to-end.

35 years of playing and working with these things, and 3 of your videos made me feel like I am beginning again. Subscribed!

I typed "how a guitar cabinet affects tone into the search" and thought I was in for a wild goose chase but this was the first video that came up and it was perfect.

You legend. You just demolished about a million different tone myths in less than 20 minutes. I couldn't tell much difference between polystyrene cab and orange cab tbh at the end! Amazing.

What was the atmospheric pressure ? Were they oriented to north or south ? Was it full moon ? (Your videos are great !)

I am totally exhausted and drained just watching the amount of work YOU did for this video.

"... so I did the work..." I love that this is repeated so often. I wish more folks making videos like this would reference this thought more. Not everything requires us to duplicate so much work of anyone before us in order to learn, but if we really do want to do well at anything, at some point(s) there will be lengthy, arduous work we'll have to do to reach our goals and beyond. KZfaq is an amazing resource, Jim is gift, and after watching his work, we still have plenty to do.

Your conclusion is correct. The air inside the cab acts like a spring and a dampener on the speaker cone. Depending on the volume of the cabinet, this can dampen or boost certain frequencies. Furthermore, the geometry of the cab creates standing waves inside it, which oscillate at specific frequencies, acting in or out of phase with the speaker, boosting or dampening certain frequencies. It's a pretty complex topic that I haven't look at in well over 10 years. Guitar cabs are pretty simple, but you wait until you get into Hi-Fi subwoofer design, with tuned tubes, tuned enclosures, and passive speakers. Also, Eminence Audio still have a cabinet design simulator.

Jim "So I Did The Work" Lill...Thank you for doing what the rest of the internet is unwilling to do (myself included) and what companies most likely would not want to share. This is beyond impressive!!

60's Fender 2x12 cabinets had insulation installed to absorb some of the frequencies bouncing around inside the cab. This insulation is often used in hi-fi speakers to improve frequency response... would love to see you go down that rabbit hole!

I think this is by far my favorite video in this series. Besides musical instruments, my other hobby is hifi speakers. The construction of the speakers determines what kind and size cabinet it should be on, plus sealed vs ported affect on bass response. Your closing statement hit the nail on the head.

Great practical testing! Your conclusion at the end is spot-on and is related to a phenomenon called acoustic impedance - this is similar to electronic impedance in that the speaker cabinet acts like a transformer to match the impedance of the speaker to the impedance of the air, which combined with phase shift and diffraction effects results in the response you see from different speaker cabinets. What's really fascinating about this is you can measure a change in electrical impedance of the speaker coil when you change the acoustic impedance by mounting it in a cabinet. It's pretty well-understood what affects the response of a speaker cabinet, so I see this topic as more of an education issue. Speakers are relatively easy to model mathematically and you can get about 90% accurate from design equations that use the parameters of the driver and the speaker cabinet. This is easy using a graphical program like Hornresp or Akabak. The mystery of speaker design/sound is mostly limited to guitar cabs at this point due to tradition and superstition running deep in the industry, which stands in stark contrast to the scientific approach used in modern PA equipment. But like you observed, as long as your speaker cabinet walls are suitably stiff, only the volume of air and dimensions of the baffle and any ports matters (besides which speaker driver you've selected). A huge issue with guitar speakers is they don't typically publish all of the driver parameters, so the only way to accurately design a cab is to measure the driver yourself in most cases. Measuring the driver parameters is pretty easy with some cheap test equipment. Also worth measuring is polar response (as you rotate around the speaker), as baffle diffraction and such have a huge effect on how the speaker sounds around the room, especially for cabs with multiple speakers. If you'd like to to a follow-up video doing some more in-depth tests to explore the science/process behind speaker design I'd be happy to help! With regard to your 5:20 tests, the transition from closed-back to ported and into open-back depends on the cabinet volume and the driver parameters. At a conceptual level, your test represents the following conditions: 1) With no holes, the system comprises the speaker driver (with its mass and springiness) with a spring formed by the air in the cabinet attached to the rear of the speaker cone (sealed/closed back). This is a second-order system that provides 12dB/octave of rolloff in the bass. The main issue with designing a speaker cabinet concerns what to do with the wave that comes off the back of the speaker cone, which is 180 degrees out of phase with the front wave and will cause destructive interference. A sealed cabinet resolves this by simply trapping the rear wave, preventing it from canceling with the front wave. This results in a boosted bass response compared to a speaker with no cabinet, and the spring of air inside the sealed cab provides protection for the speaker driver by resisting large excursions. 2) With a few holes, another mass on a spring (a port) is attached to the sealed system. The air in the holes you drilled act as a single mass that bounces against the spring of air inside the box. This is exactly the same effect that makes a bottle whistle when you blow across the opening or causes an acoustic guitar to emit bass from its soundhole, Helmholtz resonance. As you probably know, you typically add a port to boost bass response on a speaker. I think in your case the speaker driver just has an unsuitable motor for actually driving a port, so you mostly just saw the decline in low bass response associated with ports, but if you look at the red plot at 5:56 there's a boost in the bass response where the port tuning is as good as it's going to get for this driver. If you mounted a speaker with a more powerful motor (higher magnetic field strength) and stiffer cone, then it would produce a lot more bass, likely at the expense of mid and high response. A fun modification to an acoustic guitar is to actually tape a tube into its soundhole, extending the bass response but decreasing the volume. The tuning frequency is proportional to the area of the port and inversely proportional to the depth of the port. An intuitive way to think about this is a longer port hole provides more travel distance for the air in the port, lowering the tuning frequency because a longer wave is needed to push and pull the air in and out of the port. Don't let the velocity of the air in the port confuse you either - the sound waves always travel at 343m/s, so the velocity of the air in the port is only related to the amplitude of the sound. A larger diameter port hole allows more air to move, but also must be proportionally longer to provide the same tuning frequency, so ports are made as small as possible without having excessive turbulence. If a port is too long it also causes secondary resonances that sound bad in the midrange. With a port attached, the speaker behaves almost the same at high and mid frequencies as in a sealed system, but as the frequency approaches the resonance of the port the speaker driver itself actually stops moving, instead transferring all of its energy to the mass of air in the port and setting that into motion. This is the acoustic impedance phenomenon you hinted at in your conclusion - the ported enclosure presents a favorable impedance that allows the driver to do more work at the port tuning since the enclosure is allowing the speaker to push harder than it would be able to otherwise. The result is increased bass response at the tuning frequency of the port (mostly limited by port turbulence and thermal capacity of the speaker driver), but now there's a hole in the box, so below the tuning frequency of the port the bass disappears twice as fast as in a sealed system (24dB/octave, a fourth-order system). The speaker also receives no protection from overexcursion at low frequency, so a high-pass filter is usually required. 3) With the larger full-width cutouts, the box is effectively open, eliminating the extra springs in the system so the speaker is basically equivalent to being mounted on a flat baffle. Any resonance is from the speaker's own mass and suspension. This is called open baffle loading and results in a dipole speaker. Bass response is poor due to destructive interference of the front and back waves, with the mid response determined by baffle dimensions and the resulting diffraction. Frequency response changes dramatically as you walk around the cab due to diffraction and interference effects. The response pattern is similar to a figure-8 microphone. Siegfried Linkwitz has some fascinating insight and designs on dipole speaker design, which can help inform you when positioning open-back cabs. The same loading condition can also be achieved by mounting a large speaker into the wall of a room, but the bass response is actually good because the rear wave is discarded outside of the room - this configuration is called infinite baffle. Open and infinite baffle are both dangerous to the speaker driver for the same reason as a ported cabinet - nothing prevents the speaker from being driven past its limits at low frequencies besides its own suspension. It's also worth mentioning transmission line cabinets to help understand how a ported cabinet creates more bass. If you imagine a ported cabinet, but make the port the size of the baffle and lengthen it until you get the low frequency you want (so the speaker is a long tube), this is a transmission line. The length of the tube is 1/4 the wavelength of the lowest frequency you want to tune the speaker to. This results in a very messy response (comb filtered), but between the first and third harmonics of the tuning frequency you get a massive increase in amplitude and efficiency compared to almost any other type of speaker. The reason for this again comes back to the speaker cone simultaneously emitting a wave at 0 degrees in front and 180 degrees in back. At the tuning frequency (first harmonic) we know the rear wave is delayed by 1/4 wavelength, or 90 degrees, so the result is the front and rear waves are now only 90 degrees out of phase and will thus partially add instead of cancel. The act of delaying the rear wave creates constructive interference at the tuning frequency, so we're just making better use of the energy that's already there. This is actually what a ported speaker cabinet is doing - introducing phase shift to the rear wave from the speaker driver by time delaying it so it can add to the front wave, but only at a specific frequency band because this time delay would need to grow longer as frequency goes down. The same delay phenomenon is part of why you don't see transmission line designs very often. Unlike a ported cabinet, which behaves like a sealed cabinet above the tuning frequency, in a transmission line the phase rotates 90 degrees for each harmonic. So the second harmonic results in 0 degrees phase difference and max addition, third harmonic is 90 degrees just like the first, but the fourth harmonic is now 180 degrees out of phase and cancels completely, which is very inconvenient because this is typically in the midrange unless you've built a very large subwoofer. In literal terms this means you get a speaker that only has a frequency response from 20Hz-60Hz, 40Hz-120Hz, etc., but it is extremely efficient and loud in that range. The other main reason you don't see these is size - a transmission line tuned to 30Hz is almost 3m long to achieve 1/4 wavelength. Transmission lines are actually the simplest type of horn loudspeaker and provided a good foundation for understanding how those work.

What you've encountered with the hole thing with the low end slowly coming back up is the idea behind bass reflex cabinet designs - stick a specific length of pipe in that hole and you get _way more_ low end from a helmholtz resonator.

You're incredible, thanks for all of your hard work on these videos!

Top effort Jim. Thanks for your work and dedication.

As you were going through the 12 factors I was thinking "too bad he didn't make a cab out of something crazy like plastic or concrete". And then you came with the Styrofoam. Phenomenal work, man.

Super impressed with the work that went into this video.

Man I love your videos, they have so much hard work put into them and you seem so honest and genuine.

Fascinating, excellent work!!!!

Thank you for doing the work! The Helmoltz frequency is what describes that "complex relationship between bass response and the size of the opening in the back panel". This is a well documented phenomenon where a hole in an otherwise closed volume can lower it's resonant frequency. This is why sub woofers often have ports. It's also why the size of the hole in an acoustic guitar is very important

Great work - puncturing all those myths that guitar players love to tell each other about "golden tone". Keep up the good work!

Wow... hats off to you Jim! This was a fascinating journey....you really put in the work on this one, really enjoyable thanks.

You rock dude, love your experiments !!

Every time you say "So I did the work" it put a smile on my face. You are one of my new favorite channels because of this. Not wasting everyones time talking or theorizing about what might be causing things, or regurgitating what others online say about what causes things. You just put the work in to track down the results, no matter how time consuming or tedious it may be. I hope you can find plenty of new topics to perform these sorts of tests on for guitar and music as a whole because it's super interesting having all of the myth broken down

This is like Project Farm for musicians. "We're gonna test that!"

Love these tests. Thanks duder.

This is such a quality video! You cover absolutely everything with quality!

“So I did the work”. Heck yeah you did. This was epic. There’s another guy on here, Johan Segeborn, that has a ton of videos comparing the sounds of speakers. Mostly Marshall cabs and greenbacks. But even amongst them there are significant differences in tone. It’s amazing how little attention is paid to speakers and cabinets. When they’re really the key to tone imo. No doubt everything in the chain has an affect. But speakers and cabs are way overlooked for how much they do to the sound.

Jim, your blind test right at the end with “which do you think was which?” was the perfect listening test!

I have been enjoying everyone of your videos about what makes tone!

This hits all my buttons. Great stuff Jim!

Great work Jim! Of course, it's only a matter of time until they start making cabs out of "toan foam"...and there will be a line of suckers to buy it. As you said, it's just physics. Anything that shapes the sound waves and their path to the mic, shapes the sound you hear in the end. You can get more noticeable tonal change by simply moving the mic around on any given cab than by owning 12 different cabs. Sadly, that doesn't sell cabs, so it is ignored in favor of various and sundry gimmicks. Thanks for keeping them honest. Cheers!

This is literally a guitar community treasure. Make a patreon or some way to support your amazing efforts.

The work you put into making these videos is mind boggling. Well done Jim - your videos are fantastic.

This is insane and I love it!!!! My new favorite channel

I think what you are doing in these videos is just fantastic. You are basically approaching tone with no preconception at all, like a science researcher would do. Awesome.

I absolutely love your scientific experiments, no BS, no "mojo", just measurable facts.

You are so thorough and hard working. Crazy work and documentation here.

The amount of work that went into this video is impressive. Thank you for your service!!!

I can only imagine the amount of work that went into this! While other people criticize your results, you're the one actually testing, and putting in the work while they just philosophize on how you must be wrong. Keep on doing what you're doing. It's very much appreciated.

The fact that you didn't reveal which was which at the end speaks for itself. You didn't need to because it doesn't matter, they sound so similar that the difference is completely negligible if there even is one. Great work!

You really did the work!! Amazing to find out that you actually did build a dozen of cabs for these tests!!

Outstanding job Jim!

I'm curious how much these differences apply once you start backing the mic off of the speaker and get more of the room in the mic signal. I'd think the speaker amount and straight vs slant would have a much bigger effect as you start pulling the mic out. The styrofoam cab was pretty fucking mind-blowing though holy shit. Really gives you something to think about for live situations that are usually only close mic'd anyway, might as well just build a cab that is the best combination of lightweight/portable and sturdy to make touring and setup much easier. Great video! This definitely took a lot of time and dedication and it shows!

This reminds me of an interview with Mark Bartel who was saying he thinks of his speaker cabs as acoustic instruments and is very focused on the way standing waves inside a cab can build up. Volumetrically, understanding the air movement inside the cab and allowing for it to get out in the right ways seems like fair pursuit.

wow, that's lots of work done for 1 video, thank you for it!

Wow... again a lot of work with very interesting results! Thank you for that!

Jim must be the hardest working man in showbiz. Not necessarily on stage... but certainly in the wood shop. Give this guy a hand to get him the subscriber and view counts he deserves.

Dude, you're a lunatic😄 I can't believe how much work you've put into all of these videos. Truly a priceless service you've provided, and an amazing groundwork to build off. I hope that the message gets through to enough people that they don't need to keep jumping through so many hoops and spending so many thousands of dollars on things that don't affect the sound they're after. It's great to be able to focus on what really matters.

Jim, you are awesome. Thank you for putting these comparisons together.

love this video series so much!

Obviously, lots of work went in to this - not just in building and filming but in all the thinking and managerial work of editing it into a cohesively formatted presentation. Kudos on all of that and the bits that can't even be put into words. As a sound engineer, both studio and live, for 27 years now and a woodworker for even longer I will say a few things that will likely make you want to kill me. First thing. It's not just the cab, it's the room. Take any cab into 3 differently sized spaces and, using the same amount of power at the same ''volume'', you will get different EQ responses. The diaphragm of any mic can only behave relative to its environment, like a goldfish grows smaller in a smaller bowl but place it into a larger bowl and it will grow larger, it's directly proportionate. Increasing the power to a given cab in a larger space. that initially sounds thin in that space but beefy in a smaller space, does several things that resemble torque curves seen from combustion engines but to the sustain of whatever resonances that cabinet otherwise has. The changes have to do with how voice coils are built and the mass/size of the driver relative to the power and air resistance in the room. The cabinet's construction will either perform great in a 7x11 bathroom or a 16x 24 bedroom or a 3x4 closet, but likely only one of them, and if it does will likely then be trash on a stage. I have my beliefs, I'm sure you will have yours, but there DO exist specific parameters at play as to how to use these phenomena either for or against your patience levels and/or sanity breakdown threshold. Second thing. Pine or spruce face plates, full-stop. The mid range frequencies at play in electric guitar are very similar to the low mids of a violin. To dissipate them so that none of them ''stand'' you need to avoid both thin/flimsy and dense/rigid faces. The point being you want to reduce cabinet resonance, which do feed back through the face plate, but not leave it dead. I've tried at least 10 different face materials and pine has been the best overall. Double it up to 1.5'' and leave the mounting ring the speaker fits into at .75''. Think about what is going on when a snare drum shell is mic'd (ie from the side). That shell is definitely audible and it sounds totally different than either the batter side or snare side, same as the back and side materials of an acoustic guitar make a difference. The pine/spruce face just sends sounds wave through it FAST and consistently - without adding noticeable ooompf to bass notes. Third thing. Close micing ain't always it. I've gotten great results at 5' on cabs that just sounded trash within 2-6'' in any space. If the mic is always within 2'' and the volume is always above 95db then don't even bother unless you're just doing a solo performance as any other band instruments will negate 99% of any nuance the cab COULD ever offer. Once you get out around 1.5' the cabinet material begins to matter A LOT.

Absolutely fantastic, good job dismantling decades of marketing mythology. I love this series

Well done. That was a lot of work. Lots of good info too.

I totally absolutely agree with your conclusion. Great work. Looking forward to more of your videos.

Mega props for incorporating frequency analysis into these tests! This is some solid science my guy.

You work deserves a Nobel Prize and you should be inducted into The Hall of Fame!

great series of videos! certainly learned a lot. awesome.

Oddly entertaining & Well produced video. Its obvious that A tremendous effort went into creating this video, and it turned out terrific.

Please, please keep making these videos! Incredible!

This has GOT TO BE one of the best, most informative vids on youtube land I got to watch the past year. Mann ! 👏👏💪

This video is absolutely legendary. What an amazingly thorough experiment you've conducted here.

Man, the amount of work you put in here is insane, thanks for the insanity, great video.

Not gonna lie, I only heard differences for like four of those 12 changes, but that styrofoam cab at the end was an awesome demonstration of the take-home message. Well done sir.

This series is legendary. Magnum opus level stuff.

Really appreciate all that effort!

Jim, I so appreciate you doing the work to demystify all this. Only sorry I didn't see this one for a full year.

I rarely comment on videos, but this was excellent work, so it deserved you knowing it. I can't wait for more of these tests. Keep up the great work!

The strips of wood on old amps are diffusers and disperse the treble frequencies wider in the room. The treble frequencies gradually disappear the further you move off-axis from the speaker cone.

the video ending is WONDERFUL! great job :)

This is amazing, and the best video you've made since the electric guitar one. I love how you've gotten more analytical about experimentation and measurement, and the Pink Panther guitar cab is pretty awesome!

Another great video! Really love your scientific approach on all these experiments.

These videos just keep getting better and better. The amount of work that goes into the experiments is one thing, but tracking every result, organizing it, and presenting it via brilliantly executed audio/video cuts is extremely time consuming and labour intensive. I'm excited about where this channel will take us as you move on from guitar to Pro Audio in general. I think it's important to mention that your content is not only highly entertaining, it truly is a public service. Thank you!

You are awesome. A lot of work has been done, it is clear and it is a game changer. Cheers from France!

Talk about an ambitious project! Thank you for doing this!

This video is exactly why I like KZfaq and all the amazing people who make such awesome videos for everyone to enjoy and learn! Huge thanks, man, it’s really cool!

well - not only did you do a LOT of work, you also had a method to what you were doing and are good at explaining what you did and point out the results you felt/got. Excellent job!

Thank you for your hard work!

The work for this video…you’re amazing

Man when you make a video you go HARD... Fun to see all of this compared. Personally, I play a Marshall plexi through a rather unusual 4x8 cab with celestions, this video again confirmed that I really need to upgrade to a 4x12. As for the slanted vs straight cab thing, as you said it doesn't matter when you're miking it up close, but it very much matters in a live situation. Because 2 of the 4 speakers are slanted upwards in slanted cabs, they have a much bigger sound dispersion, allowing you to hear yourself better if you're standing within 3 feet of your amp (say, on a small stage), and allowing your band to hear you well too. If you're in the same position on stage playing a straight cab, because of the somewhat limited sound dispersion and your head being above this area, you cant hear yourself well, so you turn up your amp. All the while, your band members standing further away can hear you just fine, so by turning it up you're just pissing them off (ask me how I know).

I play guitar probably one every other month - these videos are still instant watches for me. Great stuff.

This is just "wow" all of the time spent but huge results thanks so much for doing this, now it's time to go build my own cabs

These videos are always awesome. I hope it encourages people to not only be open, but also innovate in better areas that will give us more awesome tones.