Things that go bang – part 2


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Rather fittingly, the pressure is on for me to write this because it’s been quite a while! So lets talk about detonations and real explosions, with a little bit of the science and terminology first.

You’ll remember from part 1 that deflagrations are pressure waves in atmosphere created by the burning of the material. The continuation of the deflagration is due to heat transfer through the material at a “slow” speed which results in increasing air pressures in enclosed spaces.  Now detonations, that we’re covering here are completely different animals. Detonations will occur even in cold temperatures, because the explosion continues through the material due to the pressure wave. The pressure wave itself causes the detonation.

There are plenty of materials that detonate, but I’ll just look at a few big ones for you, so you only get the interesting ones. Starting small with (possibly) the most famous explosive there is – TNT. For those who care, TNT means trinitrotoluene. TNT is a “safe” explosive, because it is quite difficult for it to explode accidentally but the principal reason for mentioning it here is that its’ used as the standard measure for explosive power. Everyone of a certain age will recognise this guy though, who loved (and hated) TNT. (If you don’t recognise Wiley Coyote, you NEED to go and look him up)

Acme TNT

Until 2017, the largest non-nucelar bomb to ever have been used was a conventional explosive bomb used in World War 2 by the RAF, called the “Grand Slam” – a 10,000kg earthquake bomb. The actual weight of explosives in the bombs was only 4,144kg though. Only 42 were dropped during the War, with the first being dropped on 14th March 1945, towards the end of the war. The 4,144kg of explosive was more powerful than TNT, and the blast yield was rated as 6,500kg TNT equivalent. Here’s what they looked like:


But since we’re talking real explosions today, lets go big. 6.5 tonnes is a LOT of weight for explosives. That’s probably 3 times the weight of your car – if not more and you can see the men for scale. But lets go big, significantly bigger than you can comprehend. This bang is from the biggest bomb ever built.

At 8m long, 2.1m in diameter (26′ 3″ long and 6’11” diameter), this thing is HUGE. It weighed roughly 27 tonnes, and to try and explain the enormity of it’s power, I need to explain some simple nomenclature first – sorry!

1 tonne = 1 tonne
1 kiloton = 1,000 tonnes
1 megaton = 1,000,000 tonnes

That wasn’t so scary was it? So far, conventional explosions we’ve discussed have been rated in tonnes. But we’re now going to skip past kilo-tonnes, and straight to mega-tonnes for the biggest bomb ever, which was in fact a hydrogen bomb. I don’t want to go into technical details on this – though I will if any of you would like me to! But this bomb had a yield of 50 Mega-Tonnes. And it could be increased to an ENORMOUS 100 Mega-Tonnes. You’re just here for a picture though, so here you go!

top-tsar-bomba-headThe Tsar Bomba. The red centre is from the explosion itself, and the white ring that dominates the image is actually clouds being made by the explosion. The shockwave was sufficiently high pressure to condense the water vapour out of the air, it literally squeezed the water out of the air. This thing was so enormously huge its impossible to describe. Just try and get your head around the following graphic for the height of the mushroom cloud!

Tsar Bomba Height.png

I better get back to acoustics really. The shockwave was measured circling the globe, not once or even twice. The shockwave was measured around the planet separately three times! It reportedly damaged windows 900km (560 miles) away from the epicentre of the explosion. That means if you blew it up over San Diego (CA), it would damage windows in (and beyond) Sacramento (CA). If you’re on the East coast, that would mean an explosion over Indianapolis would cause damage in Washington DC and also in Kansas City (remember it’s a blast damage RADIUS of 560 miles). Try and let that sink in, because that’s a 16 hour drive from one side of the blast radius to the other…

So yeah, there you go. This biggest, and most ridiculously enormous bomb ever to be detonated on the Planet Earth. So big we can’t even comprehend the scale of the damage this thing could do in it’s 50 Megaton configuration, and it was possible to increase it to a 100 Megaton yield.

I know I’m a blast noise expert but… I can’t comprehend the calculations required to try and work out what’s going on at such an enormous scale and I don’t know anyone who could. I hope you’ve found it interesting though, and if you have any suggestions then please let me know and I’ll see what I can do.


That’s not the sun, it’s the fireball from the Tsar Bomba. And it’s 5 miles across. Enjoy


Things that go bang – Part 1


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I promised you explosions, so I guess I better deliver – and I have to blow my own trumpet a little bit here. That’s a very loud and sudden noise, but I promise not an explosion. I know more about noise from explosions and the propagation of noise from explosions than most people in Britain. That’s enough of that.

If we start fairly small and work up I think that would be ok, don’t you? Of course you do, you’ll just skip to the end to see the big stuff, but I’m warning you… It won’t make sense if you don’t read it all.

These smallest explosions then, well really it depends on whether we’re talking detonations or deflagrations which are slightly different but both can give you a good bang. A true explosion is a detonation, but I’m going to start small with a deflagration. It’s one you’ll probably all be familiar with, but would never consider an explosion – matches. When you light a match, you’ll get a flash of white light in the instant it lights – that’s the deflagration of the phosphor tip igniting.

A much larger deflagration that I’m sure you’ll all think of is black powder. You may be thinking of black powder rifles or, if you’re British, you may be thinking of Guy Fawkes and the gunpowder plot. Either way you’ll be thinking “But that’s an explosion, that’s why they use it. It goes bang!” But it’s easily demonstrable that once again, this is not a detonation.

When you put a pile of black powder on the floor and then touch it with a match, it will go “WHOOSH!” in a puff of smoke and disappear. Burns very quickly. Clearly not an explosion though if it whooshes in smoke like that, it’s like a big match but without the wood to burn and hold a flame. You could of course put it in a box and confine it – and doing this is what made you think black powder is an explosive. Here’s a pile of black powder burning.

Black Powder

Simple physics can tell you why black powder goes bang when you put it in a box. It starts as a solid – which can be very dense. But burning it turns it into a gas, which is much less dense – it takes up a lot more space for the same “amount”. So when it’s confined, the pressure will increase very very quickly until the container fails and all the gas escapes creating the “BANG” that you’re surely familiar with. This pressure can be very significant too – it’s what propels cannon balls, and they were used to knock castles down!

So there’s a tiny little bit about things going bang, without any real detonations. You can approximate a black powder explosion by popping a balloon for example, and you all know that sound. It’s just not as loud as a black powder bang. Real detonations will come up next time, and you’re in for a shock.


Interference Patterns


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This one’s only going to be short, because my entire life is one big interference pattern. I’ll explain, but first for a little bit of high-school physics that I still love – the double slit experiment. Electron Double Slit

From the electron beam gun, a stream of electrons are fired at a screen with 2 narrow, parallel slits, and the result on the second screen is an interference pattern. There’s clearly more than 2 bands on the screen where electrons are hitting. This is due to the wave-like behaviour of electrons, and their ability to interact with themselves as waves do.

Obviously the waves are moving through space, from the gun to the screen, and because there are two slits, when the waves reach the screen they’ll have travelled slightly different distances. Tiny variations, but at the wavelength of an electron, these tiny variations are significant and result in our interference pattern. So lets see how waves do this, why we get some dark bands and some light bands.

Constructive Destructive Interference

You don’t need to worry about the specifics of the “Phase difference”, it basically means that on the left side the two pale waves are identical and on the right side the two pale waves are opposites. The dark red line is the result. Think of it this way, when the wave is up on top of a “hill” or “crest”, it has a value of 1, and when it’s in a “hole” or a “valley”, it has a value of -1.

If the crests line up, you do 1+1 and get 2, the answer is twice as big. Then when you do (-1)+(-1), the answer is -2, twice as big but negative. That’s why the red line on the left is taller than the two pale lines. On the right side, you’re adding 1 and -1 and getting zero, or 0+0 = 0, which is why the line is flat. If we have two waves travelling at different speeds, it gets a little more complicated though. The next image shows how a 55Hz and a 60Hz wave interact with each other. Hope you’re proud, I made it myself.

Interference Pattern.png

Hopefully you can see how the black line changes “height” as the different speed waves interact. Which is what causes the diffraction patterns I showed you before. At 0.1s the black wave is really small, and at 0.2s it’s really big again. This is destructive and constructive interference in action, which is EXACTLY how AM radio signals are transmitted – it’s called Amplitude Modulation. I can write about this another time if you want? Let me know!

Going back to the beginning though, where I said my life is one big interference pattern… If we called the blue line “work”, and the red line “life”, and the black line “blog productivity”… I hope you’re following this. We can see that as life moves forward and the demands of work change, sometimes there are lots of blogs and sometimes there aren’t many at all.

Interference patterns. Bet you never thought your high-school experiments on particles you can’t even see would also describe your life did you? I didn’t. Should have a new blog post coming soon though, on a topic that I’m sure you’ll love. Explosions!

Those Bloody Stupid Exhausts


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Kids and their enormous exhausts on their tiny cars, we all know they’re the scourge of the road! But lets have a little look at the science of the situation and it should certainly make you feel a lot more positive about the whole situation. Believe me, there are reasons you should love to see them. At least if you’re a little bit evil and like to see idiots failing  – and admit it, everyone loves to see others fail! This one doesn’t have many pictures, and it’s not much about acoustics but it has it’s place if that’s what you want to read, otherwise just take a look.

Now you all know the type of thing I’m talking about, and I’ll admit I’m on the side of the fence that says, “Oh for G*ds sake, shush” but bear with me because even if you like big exhausts you’ll find this interesting. You may even have a big exhaust on your car, in which case you’ll definitely find this interesting! I won’t bore you with pictures, but if a little car sounds like a subaru, or aspires to, then you know what I mean.

Big exhausts sound more “throaty”, deeper. This is basic physics. When low frequency sounds have wavelengths of 17 metres, a pipe of 17 metres is required to produce a resonance at that frequency (20Hz in this case). This basic theory holds and scales to say that bigger exhausts – like those found on a Subaru – resonate at lower frequencies so they sound deeper. Obviously as far as most people think and care to be honest and most people don’t care about this much theory! If we delve a little deeper though, I promise only a little, then problems will reveal themselves.

Everyone knows from being a kid, that squeezing the end of hosepipe makes the water squirt farther. This is because the water has to move faster through the smaller hole to maintain a constant rate of flow. I hope you’re still with me, because that’s as bad as it gets! The trouble with this little bit of knowledge is that if you make the hole much bigger, the water can’t move slowly enough to keep the hose full, and cavities of air will open up. In an exhaust system on a car, fresh air obviously can’t get in to fill the gaps in the hosepipes, but it will create gas starvation at the exhaust of the engine. “Big deal” I hear you say. However… Gases absorb heat and transport it away from the engine, everyone knows exhaust gases are hot (as well as toxic).

So a big exhaust will make your car engine hotter. Again, not a big deal you might think. But a hot engine will not run properly. It will put extra stress on the metal of the engine, the components in the engine, the cooling system, will result in a loss of engine power (that’s right, the car will actually get slower!) and will probably reduce the life of the engine. In extreme cases, it may even cause engine failure. Pretty serious (and expensive) issues if you’re a young guy without much money. So at this point, you’re either older and laughing, or younger and crying. If you want some real acoustics issues, these changes in temperature beyond what’s expected in the “normal run of things” will result in changes in the resonances of the engine block and it’s components. This will result in unexpected resonances in the engine which the mounts are not designed for, which will affect the engine, the transmission and even the frame of the car. A simple little exhaust can potentially compromise your engine, transmission and indeed your entire chassis! That would be a complete write off and the car would need replacing. Simple as that.

Now dealing with all these problems. They’re serious problems, but you’ll be pleased to know they’re just as easy to solve as they are to cause, albeit they are another expense. The very simplest solution is a larger air intake to account for the increase in airflow OUT of the engine. An excessively large intake however, will also result in an increase in engine temperature and all of the aforementioned problems. Easy to see why large companies make engines, and not the average people who live next door isn’t it?

An alternative to a larger air-intake which is much more effective, but also more expensive, is to have an engine cooling system which utilises a water-jacket. This ensures a constant flow of water through the engine block and back to the radiator to keep the engine block at a more controlled temperature, although can be susceptible to overheating, particularly on hot days when stationary in traffic for example.

As I’m sure you can appreciate by now, increasing the size of your engine exhaust is not a particularly smart thing to do. ESPECIALLY if it goes against the advice of the engine/car manufacturer. Otherwise you may get very familiar with this symbol!


Now we’ve scared everyone away to rip those huge exhausts off their cars, I’ll share a secret with you. The negative effects are calculable, they are even measurable. They’re only rarely a problem however, beyond the noise. So it seems that we’re going to have to put up with them for a bit longer. At least until Tesla and their electric cars take over the world!

When “bad” harmonics are good


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So I was recording double bass for a piano album to go onto Audionetwork. The particular track I was working on was a quiet, haunting track in B-minor. Originally written a piano only track, the upright bass part I was recording had to fit in and compliment the piano. So I chose to play the part in the “arco” or “bowed” style of playing. This allowed me more complete control over the tone and attack of the notes being played.

The part is, in itself, very simple and the instrument does of course work by taking advantage of standing waves on a string. In this case, connected to the resonating body of the instrument, but still standing waves on a string creating the sound. As all acousticians are taught (and all guitarists) should realise, standing waves on a string are made up of many harmonics. The part trusted to luck slightly, and took advantage of these harmonics that are inherent in the instrument.


Harmonics on bowed instruments are particularly prominent. It is possible to have a limited degree of control over the harmonics when playing bowed, although usually your aim is to get rid of the harmonics to give just the fundamental frequency of the string. This part however has a strong harmonic content and relies on the fundamental sounding before harmonics become the main sound though only briefly, and going back to the fundamental.

These higher harmonics are usually avoided and are often described as “bad”. The stereotypical squealing cat that is the violin is only called so because of these high frequency harmonics and the difficulty of controlling them as a beginner. After a certain degree of mastery has been attained however, they can obviously be used. Although it does trust a little to luck to keep them in check properly, no matter how good you are.

In the picture above however, is someone I was actually lucky enough to see live recently. And I just want to say, he really has MASTERED his instruments. It is of course, Stanley Clarke. This is a guy who knows how to use harmonics and harmonic content to make exquisite music and has learned to control them. Sometimes, these “wolf” notes are perfect though. Nothing sounds quite like a wolf note, and sometimes you need them. A couple of perfect examples are incredibly difficult to play, but things that I’ve loved to work on learning. The masters (in my humble opinion) are Victor Wooten (playing Amazing Grace) and of course, Jaco Pastorius with Portrait of Tracey.


Why Your TV Soundbar Sucks – Part 2


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In Part 1 of this series, I gave some details on why TV soundbars are really rubbish – at least for people who actually care about sound quality. TV soundbars do work, and if you’re not bothered for quality, they’re good enough. If you want something better though, keep reading!

  1. Stereo pair of speakers
  2. Triple speakers
  3. 5.1 surround sound (and more)
  4. Experimental surround sound

The simplest answer is to buy a pair of stereo speakers and plug them into the speakers slot on the back of the TV (or the headphone slot if your TV doesn’t have a speaker socket). I’m not going to tell you how to choose a stereo speaker pair because frankly, it would take months and a hundred full-length blog posts to conclude that it’s subjective. On that note, assuming you’ve got your pair of speakers now, you need to know where to put them. The speakers should have approximately a 60 degree angle between them, and the TV in the middle. This is the “optimum” angle for producing a high quality localisation of sound while watching the TV and is a great improvement over a soundbar.

Stereo speaker pair

Stepping up from there, the obvious thing is to add another speaker. Obviously, that gives you three speakers. The best way of doing this, is simply to add another speaker underneath the TV to be halfway between the stereo speakers. This ensures the distance between the listeners and the speakers is fairly uniform to ensure a good listening experience. An example of this “triple” set up is shown below, but it is quite unusual and won’t add a huge amount to your experience over a stereo system.

Triple Speaker

If you’re wanting to step up from a stereo pair, you’re probably better skipping a triple and going straight to the much more well known 5.1 surround sound system. This is the first system where you are actually surrounded by the speakers for a “true” surround sound system. 5.1 (the name of the system) comes very simply from the 5 “regular” speakers, which surround the listening position and the 1 sub-woofer. The easiest way to show where these speakers go is with the following diagram for an ideal 5.1 layout.


The pair marked with the orange lines and the speaker between that pair are identical to the “triple” layout. The new speakers are the two behind the listener which are, as shown, 110 degrees from the centre-line of the system. All of the speakers are the same distance from the listener still. The speaker that is not on the dotted circle is the subwoofer. It is not on the line because it can be positioned anywhere in the room, and is positioned arbitrarily in the room. This is probably as far as most people are willing to go for that “cinema” feeling of being enveloped by the sounds of the film on TV.

Upgrading from this 5.1 system to a 6.1 system simply involves adding a new speaker directly behind the listener on the dotted circle shown in the diagram. Upgrading again to a 7.1 involves putting 2 off-set speakers behind the listener at 130 degrees from the centre. Again, a step up is to add another “arbitrarily” placed subwoofer to bring the total up to a 7.2 speaker system. This can then be stepped up to a 10.1 (or 10.2, with the second subwoofer) speaker system, or a 13.1 which is available in Japan for example. A 13.1 surround system involves vertical speaker spacing as well as horizontal, which is how the previous systems have worked.


Once you reach a 13.1 surround sound speaker system, it’s becoming quite unwieldy and probably won’t give you much improvement in sound quality over a 5.1 system. It is good for showing off, but realistically, probably wouldn’t improve your enjoyment of watching the TV. Also, it takes up a lot of space in the room, is quite expensive and not practical for a normal living room.

Ultimately, there’s not much of a limit to what you can do with this increase in speakers. The largest system I know to write about is housed at Salford University and is an enormous 2D 112.8 surround sound system. I call it 2D because there is no vertical displacement between the speakers, which you can see below and at the end of the first part of this blog.


This is a different software design compared with the 5.1 (and above) surround sound systems. This is a wave field synthesis setup for research purposes and is quite clearly not practical for a usual living room. This setup does have the advantages as well though. If the software is correctly set-up, this system can handle low frequency all the way down to the bottom of human perception regardless of the size of the room. If the system could be set up to have identical rows of speakers above and below the pictured row, as well as additional speakers on the roof, this would be perfect to listen to. Though obviously, highly impractical and incredibly expensive.

So there you have it. There’s a whole set of options instead of using a rubbish soundbar. If all else fails, and you must watch on your laptop… Buy yourself a really nice set of headphones and you don’t need to worry about the room and practicalities.

What is the Frequency Range of Sounds?


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We’ve all got an understanding of sound, and how some things are higher or lower frequency. When a car goes past you quickly, it’s that familiar sound known as the Doppler Effect which does also occur in light. Sticking with sound though, we all understand the difference between a “rumble” and a “whine” but not as easily understand something being more “red” or more “blue”.

So this leads to the logical question, what’s the highest frequency sound? Or equally, what’s the lowest frequency sound? Well… There’s a lot of things that need to be decided before you can really define the highest or lowest frequency sounds. For a human, the average lowest frequency sound you can hear is 20Hz, and the highest is 20kHz. Some people can hear higher and/or lower than these numbers, but that’s the average values in air. That’s your highest and lowest frequency sounds for humans in air.

For an elephant the lowest frequency is 16Hz – obviously a bit lower than human hearing but they can only hear up to about 12kHz. Mans best friend (an average dog) can hear from approximately 67Hz to an incredible 45kHz. At the high end of the scale, a porpoise can hear from approximately 75Hz to 150kHz. That’s a rough idea of the hearing range of the animal kingdom but that isn’t to say it’s the limits of acoustic frequency.


In electromagnetic waves (“light”), there are long radio waves with wavelengths of multiple kilometres all the way down to gamma waves with wavelengths shorter than picometres (10^-12m, or a millionth of a millimetre). Humans can only see a tiny range of approximately 400nm, which you can see is a TINY proportion of the electromagnetic spectrum.


So what’s the acoustic equivalent of this non-visible sprectral wavelength? It depends on how strict you are about defining “sound”, but lets be relaxed so we can explore the maximal limits of the definition. Starting with the lowest possible sound.

The lowest “sound” in the known universe is a steady hum being emitted by a black hole at the centre of the Perseus Cluster which is one of the most massive objects in the known universe and is found in the constellation of Perseus. The sound being emitted by the black hole has been given a pitch that is roughly a Bb (B-flat) in musical terminology. It is 57 octaves below “middle C” (which is 256Hz) and is roughly a million billion times lower than the lowest frequency a human can hear. The time period of this sound is roughly 10 million years. A speaker playing a middle C moves forwards and backwards 256 times per second, but for this lowest known sound, the speaker would take 10 million years to move forwards and backwards once. That blows my mind.

Now for the highest frequency sound possible. We already stated that a porpoise can hear 150kHz, but we’ve probably all heard of ultrasound scans in the hospital as well. The highest frequencies that most of these commercial ultrasound machines can reach is 20MHz, or 20 million cycles per second. This is already 1,000 times higher than humans can hear. However, a team at the Lawrence Berkeley National Laboratory managed to reliably detect and control ultrahigh frequency sounds, with frequencies in the range of approx. 10GHz. This is on the order of 1,000 times higher than regular ultrasound machines, or a million times higher than humans can hear. This isn’t to say that sounds can’t be higher frequency than this, just that they’re not reliably detected yet.

There’s nothing in the physics to say that higher frequency sounds can’t exist, or lower frequency sounds can’t exist either. It’s just that we haven’t reliably detected them yet. We could be exposed to higher and/or lower frequency sounds regularly but aren’t aware of it because we can’t detect them. So I guess all we can conclude is that we know the highest and lowest frequency sounds so far.

So there you have it, an ultrasound machine in a laboratory, and a black hole in the perseus cluster are the highest and lowest frequency sounds in the known universe at present. So here’s a picture of the Perseus Cluster to keep you inspired while we wait for the next change in the known limits of sound frequency.


Why Your TV Soundbar Sucks – Part 1


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By now I’m sure you’ve seen them in the shops, or maybe you’ve got one. Lots of modern televisions come with built in soundbars, usually below the screen. I have no idea what company makes this particular, it’s just a generic TV with soundbar to illustrate the kind of thing being talked about.

TV with Soundbar

Lets start with the pros of a soundbar though, instead of the cons because there are a few very good reasons to have soundbars for your TV. The most obvious advantage is that with a single speaker location, you can have multiple separate speaker channels at the same time.

Soundbars are also much cheaper than surround sound speaker systems, and usually cheaper than a reasonable pair of stereo speakers as well. Especially if your soundbar is built into your TV! Another advantage of the soundbar over a traditional stereo pair is that a stereo pair has a “sweet spot” where the highest sound quality is, and soundbars largely avoid that. So there you go, a few positives for your soundbar, but now I’m going to tell you why you really don’t want to use one.

Soundbars create their “surround sound” effect by actively directing sound away from the listeners and towards the walls, so the sound will bounce back and surround the listeners. Nice idea, but terrible in practice because the system will be set for an “average” room. Nobody has an average room, in exactly the same way that nobody has the (UK) average 1.8 children. Your living room walls will not be perfectly flat, perfectly parallel, perfectly hard – meaning it will not deflect under any amount of pressure.

All this adds up to a mathematically complicated room, which is further exaggerated by the unknown speaker location AND the unknown listening location. Any shelves, sofa, paintings, furniture, anything at all further complicates things. You just have to accept that your sound system is NOT going to be tuned for your living room. You could do it in theory, but in practice, even using 5-dimensional maths and a really high quality computer, you’re not going to achieve a good optimisation.

Your next issue is one I KNOW you’re familiar with. Think how your laptop speakers sound, or your phone speakers. The word you’re thinking of is probably “tinny”. Without going into excessive details, this is mostly due to the size of the speakers (very small) and the enclosure volume (also very small). If you think about a soundbar, the speakers are not very big, they’re only a few inches across. And they’re usually with a flat-screen TV which means they’re not very deep either, and because you need multiple speakers you also don’t get much space between the speakers. Obviously they sound better than laptops because they’re a bit bigger and better designed but ultimately, they’re always going to a be a bit tinny.

So in part 2, I’ll go into a bit more detail about what to do instead of a soundbar. To whet your appetite, here’s an idea of how far you can take this theory for surround sound in a room. This example is a 112.8 “surround sound”. But more in part 2.


She lives!! The Frankenbass Gets a Soul – Part 4


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So if you’ve been following the series, you’ll have seen that at the end of the 3rd part of the build, which was quite a long day, we had a pickguard ready for putting on the body. In order to test fit the pickguard though, I needed to first fit the pickups into the body.


So as you can see, the pickups all went into the body nice and easy, complete with wiring. If you look carefully between the jazz- and P-pickups, you can see there’s another bit of wood screwed into place. This was to support the VERY narrow piece of the pickguard that goes there and to prevent it being compressed and snapping. Took a little bit of work to get it perfect, but it worked beautifully once it was done. And after drilling the screw-holes in the pickguard, you should be able to see that it’s a beautiful fit onto the body around all of the pickups.


The lines aren’t perfect as it was all done by hand, but a frankenbass isn’t perfect – it’s the hand-made and hand-finished look I was going for. So it was perfect for me. Obviously I needed to take the pickguard off again to make all the holes in it for the controls, but I’ll  leave that to your  imagination because I was about to realise I’d messed up with my beautiful pickguard. Because I had some “ashtray” pick-up covers to put on. So I had to remove the beautiful work around two bridge pickups, which sucked. Look how well it turned out though!


That’s the hard work done! At least, the physical hard work with the drilling and routing, sanding, screwing, shaping… Just the holes into the pickguard which took a while to locate so that I could do all the wiring and then the ridiculous 3 hour wiring job! The wiring took SO long! Having done it, I can easily see where the money goes when you pay a guitar tech to do things properly. I made it work though, and look how the pickups turned out. And if you want to try and imagine how tight the wiring is in the cavity… Well look back at the first picture in this post, compare it with this one, and just imagine all the cables underneath as each pot has at least 3 wires connecting to it.


So there you have it. A p-bass that now does a whole LOAD more stuff. With the rickenbacker style pickup in the neck position, I can get that classic rickenbacker tone, the mellow thumping tones of a p-bass, the bite of a jazz bass pickup perfect for funk, and the really sharp tones from a musicman pickup. I elected to simply wire a volume knob for each pickup (4 black knobs) feeding into master volume and master tone pots.

Took a long time to wire, took a long time to imagine, took a long time to develop, and it took a long time to build. The gist of what I’m going for, is that it took a long time. But I got to spend a week building it it with my Grandad and it was worth every single second. Best of all? Despite my lack of specific wiring knowledge, I managed to solder it correctly and it works! The intonation on it is PERFECT, and it sounds incredible. The frankenbass lives and it’s going to be incredibly useful because, understandably, I’ve never heard any instrument quite like mine. After these pictures, I finally had the opportunity to attach my thumb-rests. Two up front to give a long rest between the neck and the front pickup cover, and a “classic” finger rest below the strings for playing thumb style.

Just stay tuned for the fifth and final part of the frankenbass build where she gets a home and a makeover!


Mosquito Alarms and Deterring Loiterers


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I’m fairly sure that EVERYONE in the UK and most likely everyone who reads this will have come across “chavs”, teenagers who tend to loiter outside shops because they have nothing to do with their time. That’s usually because it’s the holidays in fairness. Nonetheless, kids loitering outside the shops in a group wearing hoodies are inherently intimidating.

I can speak from experience, as the kid wearing a hoody and hanging round with friends. We were just having a laugh, causing no harm and intending to cause no harm. I recognise that my experiences and intentions aren’t everyone elses experiences or intentions. So what do you do if there’s a problem with “youths” outside the shops being problematic? An easy answer is Mosquito Alarms.

What’s a mosquito alarm? Well, all sounds are just vibrations in the air at different frequencies. Everything from the vibration of a black hole which is so close to 0Hz that it’s almost undetectable all the way up to multiple GHz (multiples of 1billion Hz). Human hearing range though, is a relatively concise 20Hz – 20,000Hz. That’s the lowest sound a human can hear to the highest sound a human can hear – on average at least. The crucial thing to know though, is that as you get older, you can’t hear the highest frequencies anymore. Sorry for the poor quality, but here’s an example for you of what I’m talking about.


What this graph shows, is that at 8kHz, an 80 year old needs that sound to be approximately 70dB louder than someone who’s 40 years old. If the graph extended to higher frequencies and younger ages, there would be a similar effect visible at higher between teenagers and 40year olds for example. This is what allows mosquito alarms to work and deter teenagers who are choosing to loiter outside shops, for example.

A very high frequency noise (12kHz for example) can be played at a constant very high level which will not be heard by most of the general public but potentially painful to teenagers. This is all it takes to prevent loiterers because they won’t want to hang around somewhere that hurts.

There you go, simple psychology mixed with simple physiology (and a little knowledge of acoustics or audiometry) can give you a very simple and cheap solution to preventing loitering outside your store while not affecting those who generally, would not be considered loiterers. Ladies and gentleman and all non-binary friends, I give you the mosquito alarm.