Contact Miking Real Drums.
There is no doubt that electronically synthesised drums and percussion have grown in popularity second only to their keyboard counterparts over the past few years, and are likely to be with us for a long time yet. The reasons for their success are pretty obvious; portability, ease of set up, consistent sound quality (excellent in the case of expensive, digital sampling systems), with the 'plug-inability' of any electronic instrument. Microphones, with their cluttering stands and ambient problems, seem to play little part in today's modern sounds. But when is a mic not a mic?
I recently took a look at a means of picking-up real drums, both in the studio and on stage, using the C-ducer flexible contact mic. If it were possible to discretely 'DI' signals from drums, then the convenience of an electronic kit would be combined with the obvious advantages of real drums.
My interest in the C-ducer started after seeing a Jam concert last year when I was mystified to hear a thunderous sound coming from Rick Buckler's Premier kit with only three cymbal mics in evidence! Investigation revealed that each drum had been fitted with a pair of these strip mics. Rick and the sound crew were evidently pleased with the results as this set up had been used already for two major tours.
I took myself around various small studios that were using the C-ducer on drums to get some impressions from inside the control room. The results were enlightening to say the least! With the strip mic stuck around the inside of the shell of each tom (double-headed drums need the bottom head removing and the cable passed through the breather hole), the response was quite remarkable - a faithful reproduction of what each drum was doing (including stray rattles), if anything the sound was a little larger than life, but clean and with plenty of punch.
I was brave enough to try to compare the sound from the monitors with what I heard with my ear really close to each drum. Nobody actually hears live drums like this, of course, but it was still surprising that any transducer mounted this way on a drum shell should produce such an accurate sound. The monitor sound was very 'upfront' as one would expect with the time delay reduced to virtually zero, but it was quite easy to add the feeling of space, if desired, by means of a delay and mixing in some room ambience.
Generally, everyone I spoke to seemed happy with the ease and convenience of the system and on most of the house kits the C-ducers were left in place once their optimum positions had been found. Positioning the strips needs a mention at this point, however. Being flexible, there is no problem in following the curve of the shell, but noticeable differences in response can be had according to how far up the drum the strip is stuck. Close (say ½") to the playing head gave a lot of attack or click and, as one moved down the drum shell, resonance began to predominate. This sensitivity to positioning gives the C-ducer user plenty of scope to extract good, usable sound from the instrument before moving on to desk equalisation.
The C-ducer CX6 drum system comprises a 6:6 preamp with a set of six 8" long strip mics, housed in a neat transit case. The strips plug into the preamp via ¼" jacks and the individual, transformerless outputs are XLR type 600 ohm balanced at line level. A small screw adjustment is provided on the rear of each channel to adjust down to mic level. The CX6 preamp derives its power either from the phantom source of the desk or, where no phantom power is available, via a special AC power supply. A special bass roll-off facility is also incorporated on each channel to tune out unwanted hall resonances in large PA work.
What about the separation, so essential in today's multitrack techniques? Remember that here is naturally generated audio picked up with what is essentially a vibration transducer. To the question, could the C-ducer match the almost total separation between channels of a drum synth, the answer was, frankly, no - crosstalk between the mechanically connected drums being the drawback. But this effect was virtually eliminated by fitting gaskets, cut from an inner tube, between the shells and mounting lugs of the offending toms, which hung off the kick drum post. This simple modification is evidence of the C-ducer's ability to be almost wholly sensitive to sound by contact with strong rejection of airborne vibration. As mentioned later, I managed to get almost total separation between a pair of bongos using this same decoupling technique.
The bass drum sounds I heard with C-ducer were fine except on one occasion when accompanied by what sounded like the number 22 siding at Crewe. This turned out to be a squeaky pedal, soon cured with a drop of oil. The sound of the various bass drums I heard seemed to vary considerably depending not only on where the C-ducer was attached, but also on damping, tension and the thickness and material of both the shell and head. In spite of all the variables the sounds we got by judicious EQing and experimentation inside the drum were again rather remarkable considering that this piece of thin plastic was doing the same job as a chunky AKG D12, and for a lot less money. Having said that, I also heard the C-ducer and D12 together, which was stunning and yet another story.
Talking to C-Tape themselves, it seems that the C-ducer is not recommended on snare due to early trials not yielding an accurate enough sound. I understand, however, that certain persevering recordists and musicians have, nonetheless, achieved highly usable results. One electronic recordist played me a tape of electronic drums and keyboards, pointing out where they had used a real snare drum (C-duced) to drop in a short press roll that the drum computer was incapable of simulating; the tiny overdub blended perfectly with the electronic snare sound. I also know of one 'name' group that insist on using C-ducer - only on the snare! There's simply no accounting for taste ...
I thought another revealing area to investigate would be the Latin percussion family. How did one approach congas, bongos and other hand drums with C-ducer?
The recommended positions are straightforward enough, but turned out to require a little more thought and experimentation. Using a vintage pair of ASBA congas for a gig, I stuck an 8" strip to each lip as shown and plugged a commoned stereo ¼" jack into the C-ducer LP2, a smaller battery powered preamp. The stereo input socket takes the bifurcated pair of C-ducers and the output is via ¼" unbalanced jack - ideal for unbalanced mixer inputs and combos. A 'pan' pot is also provided to balance the two levels.
Through the PA system the results were immediately impressive: loads of attack on the slaps, punch, penetration and clean with it. I was so pleased with all that power, that I only realised it had got the better of me when the electric bassist asked me to turn down! So much for feedback fears.
When I next tried a new set of Latin percussion congas in the studio, I began to realise what people meant when they said 'it can be a bit fiddly getting it right on certain instruments'. The Latin percussion congas are fibreglass and frankly I didn't like the sound I got off the rims anything like as much as with the old wooden ASBAs. It was 'cardboardy' with very little resonance. I then stuck the C-ducers inside the congas as per tom toms and everything changed. There was now a splendid ringing attack, very little mid and an enormous bass boom to the sound. A heavy roll-off from 250Hz and some 10dB of mid lift resulted in a nice, natural sound with a lot of presence.
The bongos were really easy. The same set up was used as for drums and the flat percussive sound was pronounced good. Obviously there is no chance of the player moving off-mic with this system, since each drum is picked off direct. I also used this test to check out the crosstalk between the two bongos via their joining block and found there to be only about 5dB of separation between them on a good 'thwack'. Sandwiching a pair of rubber gaskets between the block and shells reduced the crosstalk to virtually zero.
Finally, I made a few interesting tests on some of the more unusual percussive instruments: kalimba (surely you know a kalimba?), tablas and steel drums - and found out how Coca Cola cans with the Penguin Cafe Orchestra are C-duced, but that's for another time...