Carbohydrate foams derived from dead trees are not the first material that springs to mind when considering building audio equipment. But really, there’s no reason not to explore new materials for jobs normally reserved for metal or plastic, and when pulled off right, as with this wooden ribbon microphone, the results can both look and sound great.
To be fair, there are plenty of non-wood components in [Frank Olson]’s replica of a classic RCA model 44 microphone. After all, it’s hard to get wood to exhibit the electromagnetic properties needed to turn acoustic energy into electric currents. But that doesn’t mean that wood, specifically walnut veneer, isn’t front and center in this design. [Frank] worked with thin sheets of veneer; cut into shape with a commercial vinyl cutter and stacked up with alternating grains, the wood was glued up with copious cyanoacrylate adhesive to form a plywood of sorts. The dogbone-shaped body was fitted with two neodymium magnets, leaving a gap just wide enough for the microphone’s ribbon diaphragm. That was made from a thin piece of aluminum foil that was corrugated using a DIY crimp roller. Suspended between the magnets and connected to leads, the mic element was adorned with a wood and fabric windscreen and suspended from elastic bands in a temporary frame for testing. The narration on the video below was recorded with the mic, which sounds quite nice to our ears.
We’ve seen ribbon microphones before, as well as wooden microphones, but this is the first time we’ve seen a wooden ribbon microphone. It looks as though [Frank] has more work he wants to do to finish it off properly, and we eagerly await the finished product.
Fun build. I was hoping to see a corresponding low-impedance bipolar preamp design, but I see he just used a transformer.
I wonder how much more signal you’d get if you used a proper flux return path, using an iron metal frame (like the original design) instead of that super-low-permeability wood.
I also wonder what happens when breath moisture (or a temperature gradient) hits that aluminum-copper connection at each end of the ribbon. I suppose the two ends being opposite polarity will cancel the resulting DC out.
You can get iron wood.
I’ll close the door on the way out.
Hard to hear at minus 11dB, once I boosted it that much not bad. I’d like to test it’s up close warmth with my bottom register of announcing. Leave the music under out. You are demoing this for us, it’s like there is a radio on in the next room. I have a pair of Birdcage ribbon mics.
Most people don’t bother to monitor and set things for full audio level. I can’t and won’t mess with my amp-mixer across the room, it’s calibrated for radio and computer with a master that adjusts all 4 channels in surround. The post fade pots aren’t turned up that loud. Everything works great. Num lock mutes the radio, the computer is set for full level and weak sources on YouTube just don’t work. Something’s wrong when you need 10 or more dB of gain at the receiving end. Radio or TV, this don’t happen and a law limits what cable operators can do in running the program feeds low and blasting audio on local insert adverts.
To check the level of the post, whilst playing open Audacity running on Windows and use the left most drop down menu to select WASAPI. Hot things happen now! Recording is possible bit for bit in scale. No soundcard routing. There is no level control as should be. After recording a sample, stop and double click the wave strip highlighting it and go up to effects—amplify—OK. It will give the reading I got just the same everywhere. I’ve never used video editing software, but I do know audio.
With most camera automatic level controls set to record as loudly as possible without clipping – just a dB or two below the max scale for the A/D converter. Combined with most TV and radio using as much compression as they can get away with, the result is the excessive levels we hear most commonly on YouTube and commercial stations these days. It’s unfortunate, since any videographer worth his salt records without ALC, and at a level of 10-12 dB below clipping, which is where the 0 dB mark on most pro camcorders is calibrated. As a result, when someone records audio properly, everyone complains that it’s too quiet. So you have to run compression in your edit, and pretty much destroy your subject’s natural dynamic range in order to keep viewers happy.
I would suggest that demonstrating this with compression would have been worse than useless. It’s unfortunate that someone who knows audio has his system set up in such a way that he can’t (or won’t) control his listening volume.
I do agree with you though, that the music was distracting. And worse than that, I had cranked up MY volume to try to hear the noise level, since this is generally a good way to guess how high the output level is on a ribbon mic. This is important, since ribbon mics are notorious for low output. But with that cymbal in the music bed, it’s not easy to separate it from the noise.
>in order to keep viewers happy.
Most viewers aren’t happy with having to crank up their audio equipment to hear what you say, and then getting blasted with ear-shattering levels of noise to replicate the “real dynamic range” which would include sounds that cause hearing damage if they were reproduced properly.
Or, think of it like this: would you like to view a Youtube video of someone welding steel, where you needed to wear actual welding goggles to avoid getting sandy eyes?
I’m not talking about exceptional situations. I’m talking about long-established STANDARD PRACTICES in A/V recording. Philistines.
It’s annoying enough when commercials on TV are mixed 6 dB louder than the actual show, so you have to reach for the remote to turn the volume down every time (or why TVs now come with automatic gain control). Compression serves a purpose.
Very awesome.
One criticism, if I may –
The baffle spoils it, in my opinion. There’s some really nice craftsmanship shown in the video, but the very opaque baffle hides it, and the white colour doesn’t fit with the wood.
Might be better with a wire mesh baffle (I’ve used one a frying pan splatter filter successfully), or perhaps black nylon tights material? The silver or dark colour would look better with the wood, and either would allow a bit mor visibility of the internals.
Love this construction technique: cutting veneer in a vinyl cutter and laminating it together with superglue.
Another of Frank’s efforts: https://hackaday.com/2021/01/10/wooden-cassette-tape-is-a-veneer-stackup-seeking-a-few-good-walkmen/
Follow-up video with full enclosure:
https://www.youtube.com/watch?v=LIVg17dkSlg