I made a DIY sub kick mic recently.
Here’s some photos, commentary and sound clips from my experience.
The neighbors were throwing out a turntable/cassette/radio all-in-one console unit from the 1980’s complete with speakers mounted below the tape deck. I brought over my crowbar. Soon I had the speaker panels off and was on my way. When I tore off the speaker covering I found a woofer and tweeter on each side with passive crossovers. What had looked like a third tweeter, was merely an empty hole (maybe an acoustic port hole, probably just window dressing). There was silver paint around all the mounted speakers that, when masked by the screen, made them look more impressive (see pic). Clearly, this model was not designed to sound good, but to be cheap (fyi brand: Magnavox). From my research, plenty of people had success using junk woofers as well as brand new subs. I decided to give it a shot despite the cheap make of the speaker. Budget was the number one concern for me on this build – and I was off to a good start.
Putting it together was very simple. There’s quite a bit written about the process on various web sites, but if you’re looking for the most comprehensive guide, I’d recommend Gabe Herman’s. I used this as a starting point and made some additions (mic clip/mount, pop filter, in-line attenuator) and subtractions (on-board attenuation circuit) for my build. Basically, you mount the speaker in one of those concrete-forming tubes, cut to the appropriate size and multi-layered.
If you can find a free speaker the whole thing won’t cost you much. Aside from the tools and adhesive/solder, I spent about $5 for the XLR jack and $7 for one piece of form tubing. With some resourcefulness you should be able to put something useable together without having to buy anything else (maybe not even these!).
I wired up one of the tweeters for fun, too. The tweeter fit nicely in the rubber end cap for 3” PVC pipe. I just cut a hole in the cap for tweeter and secured it further with coarse screws. After soldering on an XLR connection to the speaker cable, it was good to go. I had some cheap, used XLR connectors lying around, so all I had to purchase was the PVC piece and rubber cap – about $8 total.
I didn’t have any expectations. So when I ended up with two usable mics, I deemed it a worth while venture.
Recently, I threw up my two experimental mics at a drum session (drummer – Chris Woodruff).
The sub kick works pretty well. It gets a good, powerful, low frequency thud. I didn’t see a whole lot of amplitude in the 30-45hz range, but there was a good amount between 45-65hz (centered at about 53hz). I think this is largely due to the natural resonance of the bass drum, but I’d be willing to bet the woofer wasn’t designed to put out frequencies lower than about 40hz, so I couldn’t expect it to pick up much down there. In the least, it’s a dark, thick sounding mic to blend with some others when you want to augment that ‘punch you in the chest’ thud. I don’t have enough experience with the Yamaha Sub Kick to testify on how mine compares. It might be good on a bass cab or under a tom as well, I’ll have to try. The signal was hot, and I used a -20db pad to knock it down before the mic pre.
The tweeter I mounted on the track lighting over the drum kit as an overhead/room mic that I crushed with an EL-8 Distressor going to tape. It sounds like I expected – a trashy room mic. But I was surprised at the range it picked up and reasonable amount of definition. It could be used to give the drums some grit in the right context.
Here are links to samples, I kept the volumes conservative:
Sub kick only – raw with no processing
Sub kick with EQ/Compression and tweeter mixed in lightly
Tweeter through EL-8 Distressor