Footbass??

[Shoeman]

I just came across a vid demo-ing the Footbass stompbox.   Anybody know anything about these?  I'm thinking its not really an effect pedal, more like some sort of mic or pickup in a box.  It seems to require no battery or power.   I think one would be great to have..and if I can build instead of buy.....

[bcalla]

I'm not familiar with that specific pedal, but I think you're talking about something to give a bass drum sound when tapped.  I've seen a DIY version with a piezo pickup installed in a wooden wedge.  Seems pretty useful for a solo performer.

[ashcat_lt]

There are several ways to do it, and each has its own issues, but yes you've got the basic idea. 

A straight microphone is probably the least desirable, because it's more likely to feedback to more frequencies.  The resonant properties of the inside of the box will tune it some, but the mic responds to the movement of the air in the box, which doesn't necessarily have anything to do with your stomping on it.  Even if it doesn't feedback, you'll have bleed from other instruments on the stage.

A piezo pickup (properly installed) will only respond to the actual movement of the stomping surface.  This is much better.  You can still get feedback at the resonant frequency of that surface, though, if it's undamped, just like with piezo pickups in a guitar.  More importantly, a piezo is essentially a capacitor which creates a high pass filter with the load.  That is, it passes higher frequencies more easily than low, but it's really the low frequencies that we want from this thing.  We want the thump, not the tap-slap.  So we have to push it to a very high impedance input (sometimes even higher than most pedals or guitar amps, almost always higher than a microphone or line input) and usually end up wanting to filter out the higher frequencies along the way somewhere.

If you've got a ferrous metal stomping surface, you can use a magnetic pickup just like we find on a guitar.  This will again only transduce the movement of the surface, but will still tend to feedback at the resonant frequency of that surface for the same reason as the piezo.  The benefit here, though, is that this pickup is an inductor, and so creates a low pass filter where the piezo makes a high pass.  It doesn't really need any special consideration to get the thump through, and lower load impedances automagically help us kill the tap-slap.  From the little bit of info I found on the Footbass page, I suspect this I what they're doing.  The case is metal, and they mention high output and hum-resistances which makes me think it's a humbucking pair of coils, probably in series, just like the typical HB in a guitar.

[Granny Gremlin]

I was looking at one of these things to use for solo shows, but nothing seemed to satisfy. There's a number of commercial offerings that are OK but a bit expensive for a glorified piezo in a wood block. I did try to mess around and make one but nothing seemed to sound very good, at least not without running it through a pedalboard first, which defeated the purpose - more gear to carry.  Then I chanced across this in my local used gear shop and jumped on it:



The brown rectangle is the built in stomp trigger (a piezo under there), but I made my own external one (there's a jack for ext trig) by putting a piezo into a tapered piece of foam stuck in the heel of that sneaker there.

The device itself is an 808 kick sound  with nice tweakability.

I thought I saw a schem for it online when I got it but I can't seem to find it now.  Suppose it don't matter too much because obviously it'd probably need some sort of proprietary ROM for the sample sound source and I'm not sure how easy that would be to come by.  If you wanna try searching the company that made it is called Health Club. 

Demo/rundown: http://www.matrixsynth.com/2010/01/not-namm-health-club-music-boomin.html

Oscillation mod demo (no desc of mod): http://www.matrixsynth.com/2010/11/this-boomin-can-self-oscillate.html

[ashcat_lt]

I was looking at one of these things to use for solo shows, but nothing seemed to satisfy. There's a number of commercial offerings that are OK but a bit expensive for a glorified piezo in a wood block. I did try to mess around and make one but nothing seemed to sound very good, at least not without running it through a pedalboard first, which defeated the purpose - more gear to carry.  Then I chanced across this in my local used gear shop and jumped on it:



The brown rectangle is the built in stomp trigger (a piezo under there), but I made my own external one (there's a jack for ext trig) by putting a piezo into a tapered piece of foam stuck in the heel of that sneaker there.

The device itself is an 808 kick sound  with nice tweakability.

I thought I saw a schem for it online when I got it but I can't seem to find it now.  Suppose it don't matter too much because obviously it'd probably need some sort of proprietary ROM for the sample sound source and I'm not sure how easy that would be to come by.  If you wanna try searching the company that made it is called Health Club. 

Demo/rundown: http://www.matrixsynth.com/2010/01/not-namm-health-club-music-boomin.html

Oscillation mod demo (no desc of mod): http://www.matrixsynth.com/2010/11/this-boomin-can-self-oscillate.html

I think you could probably get away with single oscillator just running constantly into a VCA that either follows the input envelope, or is controlled by an envelope triggered by the piezo input.

[Granny Gremlin]

Input envelope would be useless with the Boomin (a raw piezo like that, either my shoe trigger or the built in pad, gives no sustain whatsoever).  If anything it would be triggering an envelope based on the decay knob setting.  The Sens knob is a trigger sensitivity adjust for the ext trigger ("Sound In") so you can technically trigger this thing with just about anything that puts out audio (e.g. bass vs just a comparatively binary piezo, though I haven't tried that yet).  I assume that the pad is set to max Sens (bypasses the pot at least) because I need to almost max out that knob when I use the shoe or I get the occasional missed hit.

[anotherjim]

Worst thing about these things is that I know them as "Stompboxes". I was searching for DIY designs for these when I first discovered this here website. Believe it or not, I never heard "stompbox" used to mean "fx pedal" before that!

I ended up doing my own design, but have found the piezo triggering erratic. Sounded ok in a crunchy chipsound kick way since it involved abusing CMOS logic. Needs more work though.

[PRR]

> the Footbass stompbox

THE Footbass is a box you stomp, with a pickup inside.

He calls it a "stomping pad", *not* a "stompbox". (Yes, it is in a box.)

Also called "a cigar foot Texas stompbox, ellis box pedal, porchboard cajon, stomp board, foot stompbox, Wazinator Wuzinator percussion box, Stompin foot stompbox, rhythm box, hand drum, bass drum, bass drum pedal, hand pedal, beat box, timber stompbox, foot stompbox, percussion instrument."

Any fool can build that. Some of those nicknames may give you ideas. (Go to Texas and start ripping-up porch boards?) It may not work WELL, but you did it yourself.

Doing PA, the percussionist wanted me to mike her box. In a small practice room live it was a very impressive woody boom. Outdoors on concrete, we could not get a satisfactory thud. And I've had some experience miking strange instruments. It takes time to work out the amplification technique.

I think the FootBass guy musta got obsessed with the idea and spent many-many-many hours trying different structures and pickups. The finished device may be "simple" but getting there is a long road.

If you are a working musician, probably best to just buy his FootBass. (Note that he has a few at lower price.)

If you are DIY-crazed, of course you will collect boards and boxes and pickups and work out your own approach.

He has notes about speakers, which may be an important point.

[Beo]

I tried to recreate one of these:
http://porchboard.com/pbmirco1.html


Here's the (expired) patent information:
http://www.google.com/patents/US5627336

I got a 7$ proximity sensor from amazon, wasn't sure if it was a proximity switch type, so I took it apart trying to get an analog signal I could boost... but no luck. I think a key part of this design is the metal bar (length, thickness, material) and the mounting to tune the frequency. Interesting that it's completely passive. I saw a two man band in dublin using one of these, and during chorus parts, the extra thump really added a lot. If anyone finds a way to replicate this design, please share! 300$+ is a lot to spend on something that should be fairly easy do build... if the right sensor could be identified. The designer was an automotive engineer, and the sensor is supposedly related to auto.

[Shoeman]

Woah.  Thanks everybody.  I have spare humbuckers, pedal boxes, and all kinds of wood working scrap crap in my shop.  Guess I'll get to tinkering.  I think Paul hit it on the head.  Simple in theory, not so much in execution if you want a decent sound.   But I got time and ambition and a spare bass amp for real thump. 

[Granny Gremlin]

I thought I saw a schem for it online when I got it but I can't seem to find it now.  Suppose it don't matter too much because obviously it'd probably need some sort of proprietary ROM for the sample sound source and I'm not sure how easy that would be to come by. 

Aaaaaaaaaaand I was so wrong.  Looking at some completely unrelated stuff I came across this schem for a 808 kick circuit.  Looks like you can just add a piezo trigger on the front there and off you go. 

http://www.ericarcher.net/wp-content/uploads/2014/07/tr-808-bass-drum-diy-project.pdf

[j2dac901]

Did anyone get a diy porchboard working with the proximity sensor?