Tell us about the layout of the control room.
The control rooms were designed to be, in the term British engineers use, “once past the ear.” That is, the sound comes off the speakers, goes past the listener, then disappears into the background. The rear of the room is very absorbent, and the room overall is flat to very low frequencies. We have a membrane absorber in the walls to absorb ultralow frequencies, and an air gap between the floor and the wall that''s hidden by the acoustic treatment that couples the air volume in this room with the air volume in the basement. That extends the low-frequency response even farther.
We also have very long path lengths in the control room; the longest quarter wave in it is about 45 feet. So the room is designed to be as accurate from the listening position as possible and also to sound as much the same everywhere in the room as is practical. All the reflective surfaces in the room are splayed out and behind the listening position, so from the middle of the room you won''t hear many early reflections at all. There''s also a quadratic residual diffusor in the rear ceiling.
Can you expand a bit on the coupling of the control room with the basement?
There''s a separation between the floor and the wall in the studio A control room [as well as the studio A isolation room and the smaller of its live rooms]. Each of those rooms has a vent between the upstairs air volume and the basement air volume. The vent goes around the perimeter of the room. What''s good about that is that it allows low-frequency waves to hit the wall; the longer wavelengths tend to dissipate their energy down to the basement. But shorter wavelengths reflect back into the room. So you get a nice, bright, supportive sound at mid and high frequencies, but a longer reverb time at low frequencies. You don''t get the buildup of low-frequency energy that you normally get in small rooms.
Did you install anything special in the floors?
The floors are all concrete slab floors floated on 2-inch polystyrene bead board. The board is loosely aggregated polystyrene granules that sort of acts like a sponge. When you pour the concrete pad on top of it, it isolates it from the building somewhat, and then you build the structural walls separately from that floor. That way, footfalls inside the studio and mechanical noise outside the building don''t tend to propagate throughout the rest of the studio.
Tell us about Electrical''s HVAC system.
We have a high-volume, low-pressure (or low-speed) system. There''s a very big plenum, or expansion chamber, that allows the turbulent high-pressure air coming down from the air-handling unit to expand and dissipate its acoustic energy into a big box, basically. From there, it feeds at much lower turbulence through individual ducts that go out into the different studio rooms. So the air comes blasting down from the air-handling unit full of turbulence and duct noise and motor noise, and dissipates all the energy into the plenum. The air then falls out of the plenum into the other rooms. The key there is to have plenty of return area—that is, to have the return doing a lot of the work. So rather than forcing the air into the room through the supply side, you''re drawing it across the room through the return side.
You also installed a special grounding system for the electricity. Can you provide a bit of detail on that?
We have a very fancy (and very expensive, unfortunately) grounding system. We have a cylindrical copper ground stake filled with metal salts. The metal salts percolate into the earth around the ground stake, making that earth more conductive. So over time, the ground stake has lower impedance than when it''s first installed. Then we have a star grounding system for the building. We have an isolation transformer that isolates our AC service from the outside world, and we''ve created our own star-ground, balanced, bipolar power system within the building. So all the isolated outlets have bipolar power on them—that is, instead of having a neutral leg, a hot leg, and a ground line, we have a ground line and hot and cold lines for the AC power. That lowers the ambient EMF from the power lines.
That, by the way, is a very esoteric thing that we did because we were going to have an isolation transformer anyway. We decided to try balanced power just to see if it made a difference. And it does, but in very subtle ways. It''s not something I think is critical.
You have fairly extensive XLR patch-bay connectivity in several rooms. What is the main purpose there?
Those are for outside connection. Some people bring racks of their own equipment in, or someone might want a special sidecar that they want to run the drums through, and having an XLR patch bay allows you to get things from the outside world into our normalled TT patch bay more easily. So those are all wired up as though they were equipment outputs, and they all appear on the patch bay.
We also have tie-lines that go between the two studios so that you can connect studio A and studio B if necessary. We''ve had a few sessions that were massive, where both studios were working on them, and we''ve had to send stuff back and forth between the two. You can also tie one live room into the other control room, that kind of thing.
Since you''re primarily reliant on preamps, compression, and occasional EQ, how often might you use, say, the Eventide or Lexicon processors in your rack?
Well, I primarily use the Eventide as a stereo delay. Sometimes you need to use a stereo delay line on something. And it''s a very simple, 2-in/2-out stereo delay. If you get rid of all the nonsense in the unit, it''s a fine stereo delay and it''s simple to use once you have it set up that way. There''s also a multitap delay patch that I use as sort of a general ambience patch. That''s about it.
The Lexicons, I hardly ever use those. The PCM70 and the PCM60 are pretty easy to use. The PCM80, that thing''s a total pain. We bought that thinking it would be like the PCM70 and we could figure it out fairly quickly. And it''s a total pain in the ass.
A good test for an effects unit is to give it a simple chore and see how much you have to do on the front panel in order to accomplish that simple chore. Like, let''s have a stereo delay line with no feedback, no modulation, no frequency shifting, no autopanning. Just two inputs, two outputs, that''s it. How long is it going to take me to get that? I don''t think that''s possible with the PCM80, because I''ve spent literally hours trying to get there, and I can''t. Or if it is possible, there''s no way to confirm that that''s what you''ve done, because there are a million parameters and you don''t know what the default parameter settings mean with respect to this setting you''ve got. I really detest the “ultimately flexible” effects processors that make it difficult to do simple chores.
How about your subharmonic synth? How much does that get called into service?
That gets used once in a blue moon, like on a metal session where somebody wants extra evil. Then we''ll pull that out.
If you''re recording a string section, how will you mic it?
It depends on whether the string section is going to be the principal music for a given track. Let''s say the band has a song that is principally the string arrangement, and the band is not going to be interfering with it at all, then I''ll try to use the classical technique of using a stereo microphone from the conductor''s position. Maybe with a spot mic for the soloist, if there is one, and maybe with a spot mic to reinforce the cello, for example, in a quartet, or the bass.
I''m working on a big session tomorrow [for the Japanese band Mono] where there will be 15 chairs (basically a triple quartet plus cellos), and the focus of the attention in the song is going to be on the string section. So I can get away with using that classical technique there.
On a pop thing, like a rock band that has fiddles in one part, or “This is where the strings come in,” that sort of thing, I tend to record those things in a more textural, less accurate way. I''ll tend to record the strings closer, so you get more texture out of them. I''m also not as concerned about stereo. People won''t be listening to the strings on their own in this context, so it doesn''t really matter if it''s a gorgeous, lush, ambient, stereo sound for the strings; you just want to make sure that it sounds good when the strings are integrated with the band.
And that''s generally more concerning the texture of the sounds than, say, the stereo spread or the exact balance between the different voices in the arrangement. Because in a lot of cases, you''ll have a bunch of people playing unison and then somebody will come up a fifth or whatever. The written music is often not critical to the song as a whole. Whereas in stuff that''s written specifically for the strings, rather than as an accompaniment for something else, you have to pay a lot more attention to the balance within the ensemble. You have to make sure that you can hear every single element.
For example, for the Page and Plant session [for 1998''s Walking into Clarksdale], we had something like 24 chairs. And the string arrangement was incredibly dense; it had a lot of dissonant and chaotic movement in it. And to make that compete with a rock band without one or the other of them sounding retarded, that was very difficult. In the end, I think it came out okay—the symphonic section definitely sounded best on its own, and the rock band didn''t suffer too much from having to compete with the string section. But getting the synthesis of the two together was very time-consuming. And those were fantastic, topflight players! If it was difficult, that was nobody''s fault but mine.
Do you ever stray from your general miking techniques?
I have done sessions where I''ve had to use just a couple microphones for practical reasons. In one instance, we had an 8-track machine in a cabin, and we only had three microphones. So that determined how we were going to record it. Or other times, for very simple recordings where there''s not going to be a lot of emphasis on the drum kit and it''s just keeping time for a bigger ensemble, then I might go ahead and do a simpler setup there.
You have a fairly unusual microphone in your collection: the Josephson C700A. Can you tell us a little about it?
That''s a fantastic microphone. I don''t get to use it as often as I would like [see Fig. A]. Just because every time I use it I''m impressed by it, you know? It''s just that it takes a little setup. It''s kind of finicky because it has two capsules—a pressure capsule and a pressure-gradient capsule—in omni and figure-8. And by balancing those, you get different shapes of cardioid, but you also get different tonal qualities and different proximity effects. So depending on where the vocalist is, you can sort of zoom in and tune the perfect balance of body and clarity. It''s quite flexible in that regard. But you have to balance those capsules and sum the signal before you can deal with it like a normal microphone.
Finally, one of the more unique things about Electrical studio A''s live rooms is the adobe walls. What led you to use that as a building material? I''d seen a studio in Adelaide being built using the Australian equivalent of adobe bricks. When I saw the walls going up, it seemed like a brilliant solution. They''re physically quite soft, relative to masonry or ceramic bricks [see Fig. B]. If you hit one with a hammer, it doesn''t go “ting, ting,” it goes “thump” and absorbs the energy of the vibration. The surface texture is very coarse, and they don''t lay up in ruler-flat, perfect walls; you end up with some slight undulations in the texture of the walls. They''re slightly porous, and they''re very, very dead. Once an adobe wall is up, you can wail on it with a 10-pound hammer and you''ll just make a little dent.
It''s also really fast to put up. We had a largely untrained construction crew, and we had an adobero come up from New Mexico and teach us all how to throw adobes. In one day, we had the whole crew flying. It''s a supreme construction material for studios, and I''m convinced in the future, all studios will be made out of adobe. At least, they should.