How can i make a Subkick?

CBlanton

Junior Member
If anyone has the know how or the whereabouts of this precious info, i would be in your debt. thanks.
 

hungrypo

Senior Member
a 'sub-kick' is really just a speaker wired in reverse.
to make one you can take a 6 or 8" speaker cone, mount it somehow (which may be the real tricky part), and rig the speaker wire to a 1/4" male input jack. that'll plug into your soundboard and voila, sub-kick.
 

drumdruid

Member
Yes its like a microphone that only reacts to low end so everything around 50Hz will be up front in the bass drum mix , best is to use a normal kick mic too becuase you dont get much punch out of such a thing
 

hungrypo

Senior Member
Does a sub kick just make a kit kick drum more 'bassier'?
sort of....the frequencies that a 'sub-kick' picks up are super low and in a sense, felt and not heard. if you're going to use a sub-kick, it will only be effective if you're using a sound system that can reproduce ultra-low frequencies. there's no real definition or tone coming from that type of input source. so in a large venue concert setting a sub-kick is there to really 'shake' the room with the beat.
 

hawk9290

Gold Member
as said above, the sub-kick is for improving sound, not capturing it. Using it live or recording in combination with at least 1 other decent kick mic will produce an amazing sound.
Of course, I have found (for recording, at least) that the cheapest way to get that low frequency sound is to send the kick track to an aux track with a frequency generator set at about 50hz on it. That way, it sort of acts like a trigger and responds to the volume just like a subkick. Doing it this way is free (if you have the software).
As for building a subkick knockoff, its not very hard- making it look pretty is the hardest part. Here's an earlier thread on it : http://www.drummerworld.com/forums/showthread.php?p=342385#post342385
 

mikeg

Senior Member
I have seen these for sale by Yamaha, and I've also seen a few that were DIY. I didn't want to spend almost $400 just to see if I like it, so I took the DIY route. I already had an 8" drum that came with my kit, but I never use, so I decided to use it for this project.



I found a cheap 8 1/2" driver and an XLR Mic cable and put it all together. This was surprisingly simple to do.





I'm very happy with the results as well. The added low end is noticeable and it doesn't take much gain to get nice fat signal. I made a recording last night using two Mics. I used a Mic on the snare, and one on the kick, and my DIY Subkick about an inch from the front head.

http://www.outawhack.net/without-sub-kick.mp3
http://www.outawhack.net/with-sub-kick.mp3
http://www.outawhack.net/sub-kick-only.mp3

If you listen to the tracks through small computer speakers, you may not hear much difference.

If you make one, remember to reverse the polarity of the wires going to the speaker. I wired it out of phase the first time and was disappointed with the sound. After reversing the leads, the results were great.

-Mike
 

dkerwood

Silver Member
I've done it for recordings using a wedge monitor speaker flipped up onto its end. Works pretty well, even when it's technically too big of a speaker (15"). Provides a nice low end boost to mix in with the regular kick mic- but only with a badly tuned kick that doesn't provide the low end on its own. I don't think it would be very necessary live, though.
 

mikeg

Senior Member
how did you mount the speaker to the shell? i can see those silver clips... what are they?
The speaker is mounted using the the drum hoop and some old spacers I had left over from when single headed toms were popular. The spacers allowed you to keep the bottom hoop and lug screws on the drum without a bottom head. If you can't find them, they wouldn't be that hard to make.
 

mikeg

Senior Member
I've done it for recordings using a wedge monitor speaker flipped up onto its end. Works pretty well, even when it's technically too big of a speaker (15"). Provides a nice low end boost to mix in with the regular kick mic- but only with a badly tuned kick that doesn't provide the low end on its own. I don't think it would be very necessary live, though.
I think my kick is tuned fairly low, with tension just enough to take the wrinkle out of the batter. The front head is slightly tighter. Our band has a pretty good board, 18" subs, but our sound guy hasn't been able to push the lower end of the kick without bringing in other low-mid frequencies. I haven't had a chance to use this live, but that's what it's for.
 

MusiQmaN

Platinum Member
The inside of a real Yamaha Sub-Kick:



It looks like its a special speaker and not just a standard speaker.

And it works perfect as standalone (im using it to record home recordings)
 

dkerwood

Silver Member
I think my kick is tuned fairly low, with tension just enough to take the wrinkle out of the batter. The front head is slightly tighter. Our band has a pretty good board, 18" subs, but our sound guy hasn't been able to push the lower end of the kick without bringing in other low-mid frequencies. I haven't had a chance to use this live, but that's what it's for.
That's an EQ issue, not mic hardware (assuming that you have a quality kick mic). He's probably trying to EQ you with just the channel EQ knobs. A better solution is to run your kick mic through an outboard parametric or even a 15- or 31-band EQ.

Of course, in your case, you had stuff lying around, and you made it work. Super cool for you. I just don't want people to think that a subkick is the *only* way to achieve a low end boost. Personally, it's an aesthetic thing- I just don't like anything blocking my reso head visually.
 

SoCalMike

Official Drummerworld Photographer
The inside of a real Yamaha Sub-Kick:



It looks like its a special speaker and not just a standard speaker.

And it works perfect as standalone (im using it to record home recordings)
Cool good picture Wes I have been thinking about taking my 10" tom and turning it into a Subkick
 

Aud1073cH

Junior Member
I was also revolted by the $300 to $400 sticker price.

So I made my own, and wrote and Instructable:
http://www.instructables.com/id/SPKR-MiK--How-to-make-a-microphone-from-a-speaker/

I tried to improve on the Yamaha.
- I shock mounted the speaker (they rigidly mount theirs)
- I used a dual coil speaker for slightly different sound options (they don't)
- I added a built in DI box, phase switch, and pad (they didn't)

I also used a microphone mount, to mount to a less expensive stand.

 

John@fhsrc.com

Junior Member
Let a soundman weigh in on this.

Even though the orignal post is several years old, I hate to see too much misinformation go uncorrected.

To begin: the normal range of human hearing is generally accepted by acousticians--those who study both the physics of sound transmission and the psychological perception of that sound--to be from 20 Hz to 20 kHz, though some people extend range that to 16 Hz to 25 kHz. Although, you have to be young, and generally female, and have good hearing to be able to hear 20 Hz to 20 kHz. Most males over the age of 35 can't hear much of anything above 10 kHz. Drummers, other musicians, sound men--like me, who abused my ears by by listening to too much loud rock 'n roll and by working in the oil field, and many others can't hear perfectly well, or at all, in several places across that 10 octave spectrum. Most of us, except for children and a few fairly rare adults cannot hear the entire 20 to 20 kHz spectrum.

To continue: 50 Hz, though in the bass register, is not too low for almost anybody to hear, who is able to hear, unless they have also have a bad dip in their hearing response centered on 50 Hz.

Further: when it comes to our senses, we generally perceive sound in two ways: (1) hearing, through our ears, and (2) tactily, through our skin, which is the body's largest organ. Once a sound wave goes below 20 Hz, we stop hearing it through our ears and start feeling it more through our skin (and internal organs). Thus, sound below 20 Hz is called "infrasonic". We generally "feel" infrasonic sound. (Home theater systems often extend freq' response 1 octave, from 20 Hz down to 10 Hz to enable "earthquake" tremors and other felt, but not heard, special effects.) At lower levels, we normally only hear audible sound. But, we can feel it, if it's loud enough! (Since I I am not a drummer and don't have a bass drum I can't easily do this: I have yet to study the spectrum of a bass drum to see what the lowest frequencies are, to see if any are infrasonic.)

Please don't confuse our ability to feel infrasonic sound with our ability to feel some sound in the audible range--20 Hz to 20 kHz--when that audible sound is at loud enough levels. Most acousticians who study such things, and publish tables, put the threshold of sensation--the point where we just start to feel audible sound--at approximately 110 dB (I believe that is on the C scale, but you probably ought to check!) Any audible sound that is loud enough, can be felt! Which begs the comments and rhetorical questions: "If a tree falls in the forest and no one is around to hear it, does it make a noise?" Yes! "If a tree falls in the forest and no one is around to hear it, does it make a sound?" No! That's because "sound" is not defined the same way as "noise". For discussions of this type, definitions are fairly important. Those acousticians usually don't specify the range of sound we can feel, they don't specify a particular set of frequencies, just the approximate sound pressure level. (I haven't gotten out my SPL meter and measured the level, nor gotten out a frequency meter and measured the pitch, but when my 82-year-old mother leaves the teapot boiling away on the stove--screeching away at a high-pitched "squeal" that makes my ear closest to the teapot, and pointed in that direction, hurt--I know that putting my finger in my ear is protecting my hearing because it instantly eliminates the pain! So, with moderately high to high frequency sounds, what we often feel is pain! I have measured--with a digital meter--using JBL SRX 725 speakers and Crown amps--the minimum level, at a few feet, at which I can feel bass drum beats and bass guitar notes pounding in my chest at 85 dB, C scale. So, one can't always trust tables.)

Contrary to a comment posted elsewhere in this topic, a large speaker is not necessarily undesirable for use as a kick-drum microphone, based on size alone (read further below, far, far below).

If you play a double bass drum set--or get the opportunity to do so--put your fingers on one drumhead while you kick the other bass drum. You'll notice that the second drumhead vibrates every time you kick the first. (This is called "sympathetic-vibration".) Thus, an ideal kick-drum microphone might be an identical kick drum, except for one small "problem": you cannot just attach a coil to the drum head like is done to the corresponding diaphragm in a speaker or microphone. {If I was "hip, slick, and cool," I would use a politically correct and popular, but misused term "issue". I'm not hip, slick, and cool. :D I like being correct better! ;) } That problem is this: a bass drum--or any drum for that matter--has several modes of vibration (thus, an identical drum used as a "pickup", with the same drumhead modes of vibration and same resonances might make an acoustically ideal "pickup", in theory.). For example, if you hit a drum exactly in the center of the drumhead, the head will go in and out. But, at times the outer part of the drumhead--in a circle around the center--is going out while the center goes in, and vice versa. To further complicate matters, sometimes the bottom half of the drumhead goes in while the top half goes out, because the beater isn't hitting exactly in the center of the drumhead. And, a quarter of the head, in a pie-sliced shape, will go in while the opposite pice sliced shape goes out, while the other two quarter-pie-slice pieces on either side go in and out at other, different, but frequency-related times. (That's how you get different tones by playing on different parts of the drumhead.) Thus you just can't make a drumhead pickup by sticking a coil on the drumhead (or, for practical stage use, employ an identical drum that has turned into a drum mike). If you could, then you could plug your acoustical, non-electronic drums into an amp or mixer just like a guitar or microphone. But, you can't; you have to use at least one microphone.

Now, why can we use a speaker as a microphone? Because of the "inverse principle". The inverse principle states that any microphone can be used as a speaker and any speaker can be used as microphone. How can that be? First let's talk about what an inverse is.

In mathematics, an inverse number is any number, that with multiplied by the number which it inverts, equals 1. For example, 1/2 is the inverse of 2. Likewise, 2 is the inverse of 1/2. 2 * 1/2 = 1. 1/2 * 2 = 1.For another example, 1/3 is the inverse of 3 and 3 is the inverse of 1/3. 1/3 * 3 = 1. And so on. Multiplying a number by its inverse "inverts" the first number, always resulting in a product of 1.

A microphone is the inverse of a speaker and a speaker is the converse of a microphone. (For this discussion, I'm discounting esoteric speakers like planars.) A dynamic microphone is generally a coil of wire, which is surrounded by a permanent magnet. The coil is attached to a diaphragm, where the diaphragm is hung or suspended by a spring. The diaphragm moves in and out in sync with the sound wave. A speaker is also a diaphragm ("cone") attached to a coil of wire, and suspended by a spring ("surround"), where the coil is also surrounded by a magnet. Electricity going through the coil creates an alternating magnetic field that pushes and pulls against the magnetic field of the permanent magnet and, therefore, makes the diaphragm move in and out, pushing and pulling on air mokecules, creating a sound wave. In a microphone, the sound waves push the diaphragm in and out, causing the coil to move in and out of the magnet's magnetic field, causing electric current to flow in the coil. In a speaker, electric current flows through the coil, making another magnetic field, causing the diaphragm to move in and out. The diaphragm--or cone--is moved by the coil's magnetic field pushing against, or pulling toward, the magnetic field of the magnet. Because of the inverse principle--in theory--all you have to do to use a speaker as a microphone is to "speak" into it. Because of the inverse principle, all you have to do to use a microphone as a speaker--again, in theory-- is to drive an alternating electrical current through it. In theory!

In practice: Aside from the fact that it would obscure a singer's face on stage--an undesirable characteristic--singers don't use 18-inch woofers for microphones for practical reasons. Primarily, the voice-coil is too big, the magnet too strong, and the cone too heavy for a singer to create a relatively noise-free, useful electrical signal, especially in the mid to high frequency ranges. Similarly, soundmen and others don't use microphones--usually with one-inch or smaller diaphragms--as speakers for bass guitar, keyboard, and drum amps, also for practical reasons. A 1-inch diaphragm cannot move enough air to create a lond enough bass wave (unless you use it as a headphone). An 18-inch woofer does not have the mid- and high-frequency response needed for singers. Though it has a frequency response needed for a singer, a Shure SM 58, or similar microphone, simply can't move enough air to reproduce much sound in the bass register. The electrical current required for just a few SPL--nowhere near the 80-100 SPL C-Scale, "sane" levels, regularly used on stage--would burn out the coil (AKA "voice-coil") of any "conventional", i.e. "normal" vocal or instrument mike like an SM57 or 58!!

Thus, an SM 58, or similar microphone, simply won't work as a bass guitar speaker. Nor will any practical woofer work as a vocal microphone. To get from theory to practical, we have to make compromises; we use relatively big, heavy speakers (when compared to normal mics) for low pitched sounds like those from bass drums and bass guitars, and smaller, lighter microphones for guitars, singers, etc. for higher sounds.

When thinking of drum microphones, a discussion of bass guitar speakers (and amplifiers) isn't out of order: they both have to work with low-frequency sound. They both have to move a lot of air, or be moved by a lot of air. They both require a certain amount of power, either power being put into them or power being taken out of them. There are specialized microphones for amplifying bass guitars and bass drums--other than using an inverted speaker--microphones that have a lower than normal frequency response. However, those microphones don't always have the characteristics that we need or want. So, we use inversions like "Sub-Kicks". Why?! Read on.

You've probably seen a trap set set up in the back of an orchestra in a glass or plexiglass box. That box is there to diminish the amount of sound coming from the trap set, to keep it from deafening the orchestral players in front of it. (I recently heard a drummer, the heaviest hitting, unamplified drummer I've heard in my life. He was playing on a stage which is hung with heavy curtains to cut down on the noise bouncing around. It is in a poorly designed and built auditorium, which required a lot of acoustical work to get rid of the acoustical dead spots in the seating area. I was standing behind him, 15 feet away, and I could feel the thumps from the bass drum, from some of the toms. Like the screaming, screeching teapot, he was beating those things so hard it was making my ears hurt! That's why they put those boxes around trapsets when used in orchestras, to keep hard-hitting drummers from deafening others. (I just saw a Cream documentary where they put the shield around Ginger Baker--at the second of the Madison Square Garden reunion shows--to effectively "turn down" Jack Bruce's dual 8-driver Hartke cabs--if they're the HX810, then "wee Jack" had 4000 watts, 2 kW/HX810 cab with which to make Ginger mad, again!))

A lead singer, a guitarist, a bass player, standing on stage near the drummer, gets the emotional "kick" of those combined pitches, those combined modes of vibration--at loud to very loud levels!--coming from the drums (or bass amp/stack--sometimes TOO emotional--as in Jack v. Ginger in Cream reunion). It takes all of them, the lower pitched frequencies and the higher pitched frequencies, to fully excite both our auditory nerves and tactile senses. Unless he/she has a monitor, the keyboard player sitting half a stage way doesn't get the same impact. To get the same effect in the audience, we soundmen have to reproduce all those pitches at the same levels as what those performers standing, or sitting, near the drums hear and feel. (All musical notes--except for "pure" sine waves created by synthesizers--have a fundamental frequency--usually called the "pitch"--and overtones. Many times those overtones, always higher than or "over" the fundamental, are mathematically related to the fundamental frequency; twice the fundamental which is the first- and an even-harmonic, three times the fundamental which is the second- and an odd-harmonic, etc.. However--as in the cases of bells, pianos, and other instruments--not all the overtones are integer multiples of the fundamental.) That takes both power and low frequency response.

Sound moves through air, because it literally moves the air back and forth, in and out. Soundwaves move through the air from areas of "compression"--where more air is temporarily moved into a small area--to areas of "rarefaction"--where the air is less dense as some air molecules have been moved into an adjacent area of compression. The areas of compression and rarefaction vary, one for each cycle of the sound wave. Low, deep, audible bass sound waves, from approximately 25 to 100 Hz (Hz = cycles per second)--whether from bass guitar, from a synth, or from a bass drum--move a lot of air. Higher pitched audible waves, like from the top end of the guitar or keyboard--say from 2 kHz to 20 kHz--don't move as much air. They don't have to move much air very far because the air is moving back and forth--a much smaller distance--much more rapidly. The areas of compression and rarefaction are much closer together in higher pitched sounds. For higher pitched waves, a small microphone, with a small diaphragm, can react to those short areas of compression or rarefaction, because of the diaphragm doesn't have to move very far. However, with the longer areas of rarefaction and compression in deep soundwaves, the small diaphragm in most microphones soon reaches its limit of movement before the wave has completely moved the diaphragm as far as it should. Thus, the frequency response for microphones with small diaphragms is reduced in the bass register. (If you have not ever seen frequency response charts of microphones or speakers, you should look at a few to better understand these concepts.)

To get a better sound from a bass drum--a more realistic sound, a sound closer to that experienced by those closest to the drummer and by the drummer, him- or her-self, it's easier to use a better suited microphone than to just push and pull faders on an EQ. To get that chest-thumping, pulsing sound that some performers love and that others fear and shield themselves from with Plexiglas, we need good, deep bass response (and good mid- and high-frequency response, from mikes, processors, amps and speakers) at 85 to 100 dB, so we can feel it and hear it (or, at insane levels, 120-130 dB or higher, 100 t0 1000 times as much acoustical output power). The "Sub-Kick"-like microphone has to have better low-frequency response, better response in the bass register. It does have better low frequency response for the same reasons it's not a good vocal mic: large/heavy cone, large coil, and large magnets ("large" in terms of magnetic strength, not physical size; powerful magnets). Unlike a human singing (screaming?) into a woofer producing too little signal, a kick drum produces a usable electrical current because the sound is low enough and the sound waves long enough, and powerful enough, to create useful current from a relatively small woofer in acoustically-/electrically-inverted use.

To increase the frequency response in the bass register, to get stronger electrical signals at lower frequencies, we use a bigger diaphragm which can move farther in response to the longer waves of the low, bass notes. Microphones are not normally made with very large diaphragms. Thus, we use a larger-diaphragm speaker, inverted. The "ideal" speaker--for use as a kick-drum microphone--if we could could make a "drum-pickup" --would be to attach a coil to every area of drum that has a mode of vibration--might be identical in size and construction to the drumhead (giving it the same resonances, the same tone). But, that's where theory diverges from reality; we can't make a practical pickup for acoustic drums (buy some electronic drums instead!). So, we use what works best, which is approximately a 6" woofer.

In theory, we would use a speaker/microphone with perfectly flat acoustical response from 20 Hz to 20 kHz (or whatever "lower" highest frequency of the highest possible overtone is, as that freq' is well below 20 kHz). Those "perfectly-flat" mikes don't exist ("near-perfect" studio-mikes do exist, but are usually too expensive and fragile for live-stage use). If you want to know more, read a little bit about speaker design, about the difference between an infinite baffle, and an acoustic suspension, a ported system, a dipole, etc., especially about the influence of ports on frequency response. The size and shape of a speaker box--any ports, padding, etc.--effects how the speaker works within the box, as a speaker. The same situation occurs with a woofer mounted inside a drum or any other container, when used inversely as a microphone. We use a 6-inch woofer because it's less obtrusive on stage and has good enough low frequency response, because it is a good compromise, because we can get a good electrical signal out of it for the bass drum's fundamental frequency and first 1 or 2 overtones (a "conventional" mic is used for the rest..

(Almost) Next-to-last: in one of the pictures of the originally-posted, non-"Sub-Kick" kick-drum microphone, it appears that the back drumhead has been put back on the drum. That's good! The third recording has too much snare-sound leaking through, good reason to stuff the drum with sound-absorbing material, to avoid phase-addition- and phase-cancellation problems with the snare- and other-drum mics! To make a small drum microphone--a woofer mounted inside a little drum or anything else--better at picking up a bass drum we need to increase the volume of microphone-(drum-)-case. Since we can't practically do that--no one is going to want to look at another bass drum sitting in front of a bass drum--we can effectively increase the volume of the little "drum"-/mic-case or other case by stuffing it full of acoustical padding: fiberglass, cotton batting, AcoustaStuff, etc.

Next-to-last: in the picture of the other kick-drum microphone, it appears that there is an opening between the woofer/microphone and the inner side of the drum case. That opening has to be closed if you're going to have any kind of good frequency response from your woofer/microphone,otherwise, sound waves will travel around the inside of the drum, from front to back, and act on the rear of the microphone/woofer, putting unwanted peaks and valleys in your frequency response. And as noted above, you should stuff the drum, to make it acoustically bigger and extend the low frequency response. (Unless you have some good equipment, the ability to use it, etc., attempting to put a port into the rear drumhead, installing a tube for that port, etc.--to increase the frequency response further--is probably something thing you don't want to get into.) While most microphones are shock-mounted, most don't leave the back of the diaphragm completely exposed. Otherwise, your wiring and mounting looks good, neat and clean.

Finally: people sometimes hear things that are not really there, when DIYing, modding, rodding, etc. For example, I once read a report by an alleged audiophile who claimed he could improve the sound of his expensive home stereo speakers by reversing the speaker wires connecting them to his expensive home amps. (Only if he had a really--I mean really, !REALLY! -- bad connection in one direction--which he fixed by reversing the wires--could he have made any type of substantial, much less measurable, quantifiable difference!) Sometimes other people agree with those types of individuals, when they make such outlandish statements. In many ways, I have "golden-ears" and can readily hear things others can't: slightly out-of-tune pitches, low levels of amplifier distortion at relatively low SPLs, etc. However, I hate to trust anything I can't quantify with a meter. For example, I listened to all three of the posted MP3s, repeatedly, with three sets of headphones/ear-buds, sufficiently loud to hear a noticeable addition of bass/deep-bass. The first set of headphones came with my Dragon NaturallySpeaking package, and could reasonably expected not to have the bass response to "show" any noticeable difference in the first two recordings. The second set, an old set of RadioShack "cans"--albeit award-winning cans! :D--could reasonably be expected to show any increase in bass response. On loud bass drum notes, I can literally feel the air pounding against the outside of my ears with them. The third set--the buds, relatively inexpensive but relatively good Sennheiser CX 300s, which were used because they have the best, flattest frequency response--were most expected to show any increase in bass response. However, I heard so little through the "cans" and through the buds as to wonder "why?". Why make such a fuss about an imitation "Sub-Kick"? If I wanted to take the time, I could get out a frequency response analysis program, my virtual instrument (digital oscilloscope, voltage meter, data-logger, etc.) and measure the actual amplitudes (think "loudness") of the various frequencies, contained in the various drumbeats, in the various recordings. I don't have the time, nor the inclination! However, having listened to the third track--and being able to hear the deeper bass in it--my belief is that you may have just gotten the wrong second recording posted. I was going to use the situation as an excuse to get out some mixing software and remix the first and third tracks together, but, all that software is on a different computer which is not set up at the moment. So…

... Since I'm avoiding more responsible behaviors (house-cleaning, Web-publishing, setting up that other computer ...

… (Once again--no more edits!) Back to bed so I can get up and clean house and work on my Web-site, which is (still) down at the moment.

John Edward Lawton
Full House Sound Reinforcement Company, LLC

PS I did give this post a quick read-through/edit. However, I am fairly tired, in too much pain, disinterested after writing too long of a post, etc. Therefore, you may find all kinds of errors as Dragon NaturallySpeaking doesn't always type what I say.

JEL

PPS if you disagree with my above analysis, please "flame away"! I don't mind. I may deserve it! However, I haven't figured out how to subscribe to this thread yet, so, I'm not really worried. :) (Last edit: figured out, subscribed, still not worried--topic, though still contemporary, is too old.)

J

PPPS

When all else fails, buy a good kick-drum mic and an Earthworks KickPad. Sweetwater's got 'em. Tell Wayne I sent ya.
 
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