A high audio engineer explains NPR’s signature sound

2023-03-08 18:10:29

What makes NPR’s broadcast sound so crisp and brilliant, whereas many native public radio stations have a bassier, boomier tone? Adam Ragusea, host of our podcast The Pub, needed to search out out, so he not too long ago interviewed the man who ought to know greatest — Shawn Fox, senior director of audio engineering at NPR. That is an edited transcript of the interview, which first appeared on The Pub #17.

Present: How did you provide you with what’s been described as NPR’s “secret sauce”?

Fox: Oh, the key sauce! Once we had been in our very early design phases of our new constructing, that was one of many issues that got here up in a short time — ensuring that we proceed on with the NPR sound. There was a complete detailed evaluation of what was that sound? When it comes to the phenomenon of with the ability to hear the distinction between native and nationwide audio high quality, there are many causes for that. All in all, what our native stations do and what we do at NPR are very shut if you examine it to a few of our business brethren. However sure, you’ll be able to hear that distinction.

Present: What’s ingredient quantity one of many secret sauce? Is it the NPR studio microphone?

Fox: The NPR sound has so many tentacles. If we’re simply specializing in the studio facet, which was really the simplest factor, all of it begins with the microphone. We use a easy Neumann U87 microphone because the house-standard microphone in any respect of our amenities. They’re costly, however that’s what we’ve used for years.

Within the new constructing, we knew we had the previous microphones — and microphones don’t die except someone actually works laborious at it — and we had extra amenities, so we purchased a number of extra. Nevertheless it actually comes right down to the U87 with the bass rolled off.

Present: The bass rolled off? Might you clarify what meaning?

Fox: Positive. The U87 and most higher-end microphones have two switches on the again. One is a polar sample, which is the route of the microphone, and the opposite one is for the bass roll-off. When the bass is rolled off, you’ll be able to’t hear the decrease frequencies of my voice. The microphone itself takes them away.

And once I flip that change, you get these decrease frequencies. That is what they name flat mode; there is no such thing as a attenuation.

Present: It takes out frequencies beneath what number of hertz? We’re speaking actually super-low stuff, like beneath 150 or 200 hertz or so, proper?

Fox: Actual low stuff, someplace beneath 250 or so.

Present: Sure, however if you happen to’re at a station and form of annoyed with the bassy, boomy sound you get in your studio mic, and you’ll’t get the engineering employees to do something about it for you, one factor that you could possibly do your self is to look on the mic and see if there’s a bass roll-off change, and switch it on.

Fox: Yeah. I wouldn’t attempt to give attention to making an attempt to repair the studio, as a result of there’s a complete completely different aspect of the acoustics with the studio. The explanation NPR got here to this commonplace — and this was many years in the past — was as a result of most of our listeners are consuming in an vehicle or with one thing else within the background. Again within the day, and even to a point now, you roll down these home windows and listen to these low rumbling frequencies. We needed our voices to get above that in order that they might be clear, open and comprehensible to enhance our storytelling.

We got here to that conclusion principally as a result of most of our customers had been listening to Morning Version and All Issues Thought-about within the vehicle to and from work. And now, as extra of our content material is heard on headphones from iPhones and all of the digital sides of that, we found that persevering with with that is helpful, as a result of there may be nonetheless that acoustic outdoors noise. Nevertheless it’s not a repair for a studio. That’s the entire different aspect of why our sound is a bit completely different. We need to make it possible for we work with our on-air expertise, our reporters and our hosts.

We’re followers of being close-miked, and P-pops come into play there. However we make it possible for we’re inside a foot of the microphone and often loads nearer — shut to 6 inches — in working with any of our on-air expertise. That’s one other aspect that goes into it.

Present: The factor about getting nearer to the mic is proximity impact, proper? The nearer you might be, the extra bassy you might be. So why doesn’t that occur to your individuals?

Fox: That’s the place the bass roll-off additionally comes into play, and we additionally actually work with them in order that it’s not head-on immediately into the microphone. It’s extra to the facet.

Present: In the event you think about the air popping out of your mouth as a column, you need that column of air not going straight into the microphone however at a diagonal, type of off to the facet of the microphone.

Fox: That might be correct, sure. That’s the place we choose it.

Present: So going again to particular sauce and its substances, we talked about a few issues. We talked concerning the microphone, and also you’re utilizing the U87. In my expertise, the commonest studio mic at stations is the Electro-Voice RE20.

Fox: The previous RE20.

Present: That mic tends to have form of a heat, bassy, virtually gauzy sound to it that, for my part, doesn’t work so effectively on the radio. So there’s the microphone, there’s the roll-off change on the microphone to make it possible for the bottom frequencies come off, there may be the efficiency side of expertise getting proper up on the microphone however speaking a bit bit to the facet of it in order that the Ps don’t pop. I might assume that it’s additionally necessary to have a pleasant pop filter on there as effectively. What’s the following ingredient within the sauce?

Fox: It’s the precise studio itself; it’s the development of the studio. We’ve got a really low-reverberant studio, and we make it possible for there aren’t numerous strong partitions. We need to take out the sound of the surface newsroom. Most of our amenities are all centrally situated inside, proper in the course of our newsroom, so we ensure they’re remoted so that you don’t hear the rest however the particular person talking.

And a fast observe on the RE20 — I’m a giant fan of the RE20. I do see numerous stations utilizing it. I by no means veer away from anyone utilizing the RE20. It’s a unbelievable microphone. If we’re making an attempt to be a bit cost-conscious, we’ll usher in RE20s. They’re a very good equal for the Neumann U87. However at stations I do see lots of people utilizing the RE20 and in that flat place, as a result of that low-end bass attenuation on the RE20 can actually be problematic at most stations.

Again once I labored in Detroit, we had been an RE20 station. And numerous on-air expertise — and we get a bit little bit of this right here at NPR — likes to sound a bit bit extra authoritative, and so they hit the microphone into the flat place to get that bassy sound. In Detroit, we used epoxy to carry all the switches right into a place in order that couldn’t occur once more. And, actually, we do see that sometimes right here. We’ll hear one thing bassy and we’ll run as much as the studio and, positive sufficient, someone switched it.

Present: That’s hilarious.

Fox: So if you happen to’re a chief engineer at a station that makes use of RE20s and also you’re getting actually indignant at your on-air host for switching it, simply get some Tremendous Glue or epoxy; it’ll be nice.

Present: That’s a comparatively straightforward repair. When it comes to getting your studio to sound good in order that it’s shielded from outdoors noise with soundproofing, you additionally want sound diffusion to make it possible for the announcer’s voice is just not echoing across the room. Are there low cost fixes that may be pursued? Or in case your studio is already constructed out, are you simply form of caught with it?

Fox: No, there are some little issues. Over the previous 10 years, you see extra laptop screens all through each broadcast plant. And sometimes that microphone is actual near the pc display: Relying on how shut, you’ll be able to really hear among the digital interference off the pc display. The pc display is the massive subject. Whether it is just a bit too near that microphone, your voice is reflecting off of it.

Present: Proper, as a result of it’s a clean laborious floor that displays sound.

Fox: Sure, this is without doubt one of the issues I regularly see. One other factor for engineers or anyone at a station to do is to enter the studio, flip the microphone on, crank it to 11. Don’t speak — so that you don’t blow your ears out — and hearken to the sounds of all of the followers that you’ve got within the room. That is one problem that we’ve had for many years right here. You’re by no means going to get it to zero. You’re by no means going to get it fully silent. Nor do you actually need to, as a result of with a purpose to get it silent you’ve acquired to maneuver numerous tools out, and there’s numerous price with that.

However if you happen to’ve acquired a CPU [central processing unit] proper subsequent to the microphone or considerably shut, transfer it two ft elsewhere and conceal it underneath a cupboard. That helps out fairly a bit.

After which there are numerous studios constructed for 2 microphones that might be arrange with six microphones for a chat present. There’s not a lot you are able to do; simply attempt to area that out a bit higher. These are the largest issues that I see regularly.

Present: I haven’t really visited the brand new NPR facility but, however within the previous one on Massachusetts Avenue, one of many issues that all the time struck me was the sheer measurement of the on-air studios, which is counterintuitive since you’d suppose that the larger the room the extra echo you’d get. However with the proper baffles and diffusion and all of that, the scale permits all of the completely different mic positions to be unfold out actually far aside, thus decreasing any bleed from one mic into the following.

Fox: Our previous headquarters on 635 Massachusetts Avenue was an ideal plant; it served our wants effectively for 20-odd years. You noticed the massive studios, however we constantly had issues with bleed in a few of our smaller offline manufacturing studios. We resolved that in our new constructing on North Capitol Avenue. We made the offline manufacturing studios larger. The precise on-air studios are bigger than 635, however we had been in a position to begin with a clear slate and actually put in numerous effort and time working with our acousticians and our studio designers to make it possible for we had outlined what the key sauce was and that they might design round that.

Present: Are there another components of the key sauce that you simply haven’t revealed but, or are these issues that you’ll take to the grave?

Fox: Nicely, chatting with the general public radio group, one of many issues that we don’t do is course of our sign heading to the stations. We maintain it as pure as potential. This has been up for some debate for the longest time, however as we presently stand we don’t compress; we don’t alter our sign leaving the studio to the satellite tv for pc and hitting the stations.

We all know that our over 600 stations and all their listeners have completely different wants. So we attempt to give the purest sound to the stations in order that they will manipulate it for his or her market, with various levels of success. We’ve got talked about, particularly with our newscast unit, possibly beginning to slide a bit little bit of compression into that. We haven’t performed it but, and I don’t know if we are going to, however giving that pure sign through the satellite tv for pc to our stations might be the final aspect to the sauce.