Audio Processing

FM, AM, Mic & Internet Audio

Wheatstone Audio Processing

Deliver sound so good, you can feel it. Bring it on with Wheatstone's ultra high resolution Vorsis processors for voice, AM, FM on-air or streaming. Sound that's loud, yet detailed. Only Wheatstone offers processors with the surgical precision of 31-band processing for audio detail that sings! It’s the Vorsis advantage and it's all inside: brilliant highs, articulate vocals, bold bass…ambience. If you need sound shaping for FM, AM, HD, television, webcasting, podcasting, mastering or live audio, this is the place.

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Wheatstone At NAB: Booth C755

There are less than two weeks until NAB! Make sure you visit Wheatstone/Audioarts in Booth C755. We're working feverishly to finish up some ridiculously exciting new stuff that will, as usual, revolutionize the way you work.

And don't miss Dave Breithaupt's presentation:

Stranger in a (Very) Strange Land: Ethernet Switches in Your IP Audio Network, What You Need To Know

Sun. April 12, 5:00 PM - 5:30 PM,  S227

What's in an Ethernet switch? Audio, control, access -- just about everything if your radio operation runs on an audio over IP network. So, what should you know about this strange IP apparatus that holds so much importance as your stations' main audio router?

Dave Breithaupt covers the essentials of Ethernet switches used in audio over IP networks, from what to look for in a switch capable of always-on, realtime multicast streaming to edge and core topologies that provide optimum network access. He talks about packet loads and switch fabrics for mitigating IP packet losses, gives examples of multicast tables and IGMP groups, and discusses managed versus unmanaged switches. He covers how standards such as AES67 affect your switch selection, and touches on new advances in switching technology by companies like Cisco that will affect audio networks going forward.

In closing, he finally answers that recurring question of who should handle the station's switches, the IT guys or the audio guys.

LPFM. Going Pro.

LPFM B_Pro_1400You can’t be a professional football player without throwing around a few Wilson footballs.

In fact, the footballs that have passed from one NFL great to another have come out of Wilson’s Ada, Ohio, factory, where they’re stitched inside out, steamed and laced to exact specifications, and inflated to 13 psi before being sent off to play the game.

If you’ve just joined the broadcast big leagues and have acquired your first LPFM construction permit, you can guess where we’re going with this. In almost all cases, it’s better to go with a professional broadcast console than to try to get a music store mixer to pass as one.

 

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A professional broadcast board will give you logic buttons on each fader so you can stop and start sources. It’ll provide speaker muting that mutes monitor speakers when your mic is on, eliminating the possibility of feedback. A broadcast board will have a straightforward way to output programming to air and streaming at the same time, and a means for controlling an ON AIR tally light to alert others that you are currently on the air with a live mic. It won’t have too many controls that provide opportunities for your guest operators to do harm to your program. Nor will it require you or your weekend talent to have to figure out what bus assignment goes where.

It will give you a simple interface to the task at hand: broadcasting. Broadcast consoles are made to easily handle music from a PC and to cue up mics and listener calls, which is why the broadcast console is a much more intuitive work surface for most LPFMs.

On the other hand, sound reinforcement boards are made for live sound applications requiring lots of hands-on sound shaping of source feeds. With this come the many knobs and buttons for equalizing, filtering and mixing handfuls of feeds – all of which is going to cost in you complexity.

Checking in with iHeartMedia Portland

iHeartRadio A_2560-MC
We dropped in on iHeartMedia in Portland recently to revisit a WheatNet-IP audio network that has been in operation since the seven-station cluster moved to Tigard, Oregon, in September 2012. Director of Engineering Chris Weiss showed us around the 17-studio, 25,000-square-foot facility and talked about life with audio over IP.

He recalled a recent remote at the Rose Quarter stadium for the Portland Trail Blazers (basketball sportscast) that involved all seven stations at the same time – an impossible feat before IP audio networking. “It was more a staffing issue; could we have enough promotion and programming staff to handle all this? But from an equipment standpoint, it was easy,” he said.

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At the center of the operation are the audio network’s core Cisco switches, which are bonded together on a backplane in the TOC, with gigabit/second connections to every other switch and element in the network. “Everything works better at a gig, especially NexGen (automation),” commented Weiss, who monitors network traffic on a regular basis. Normal NexGen traffic hovers around the 100 Mbps mark, whereas on the fiber connection to the hub point for all the cluster’s transmitter sites, Weiss routinely sees steady traffic at about 150 Mbps. “150 megabits. That freaked me out at first because you never see that kind of bandwidth solid on a circuit. But that’s what it takes because it’s running all this AoIP back and forth, and we run a video feed for the Trail Blazers over that,” he said.

The operation includes 56 WheatNet-IP I/O BLADEs, 49 audio drivers, 23 Wheatstone M2 dual-channel mic processors to handle 46 microphones, and 13 control surfaces all connected through a WheatNet-IP audio network.

Look for details in the recent issue of Radio magazine, which features the iHeartMedia Portland facility as its cover story in the February issue.

View the embedded image gallery online at:
http://wheatstone-processing.com/index.php#sigProGalleria3d99162483

Gigabit Ethernet. Just the Facts.

Gigabit LargeNumbers don’t lie. That’s what your friendly police officer will tell you when he clocks you going 70 in a 35 mph zone. But, this isn’t entirely true when it comes to the speed of Gigabit Ethernet networks.

Most of us assume that Gigabit Ethernet links transfer data at one gigabit/second, or 10 times faster than 100Mbps Fast Ethernet.

But, in fact, a Gigabit Ethernet cable contains four twisted pairs of wires that are each clocked at 125 Mbps. What the "Gigabit" actually means is that a gigabit of information (data payload plus overhead) can travel across the cable in one second. Because of the efficiency of the modulation scheme and the use of all four pairs in both directions, instead of a pair each way as is the case for Fast Ethernet, Gigabit Ethernet is effectively 10 times faster than 100BaseT (Fast Ethernet).

At an order of magnitude improvement over Fast Ethernet, Gigabit Ethernet allows the audio network to deliver many more packets that much faster and therefore mitigate some issues.

 

The Gig on Latency

Take latency. Latency in an IP audio network is the delay between when audio enters the system and when it comes out. Every audio network has some latency because it takes a small but measureable amount of time to take analog audio in, convert it to digital, construct the AoIP packets, transmit them across the network and then reverse the process at the other end. In any IP system, the transit time across the network of an individual piece of data is not guaranteed or predictable. Ethernet networks are designed to avoid data collisions (which happens when different bits of information try to occupy a wire at exactly the same time) by squeezing out packets in between other packets in a multiplexing process controlled by the network switches. You just don't know when "your" packet is going to get there. The IP audio network deals with this by using temporary storage in buffers on each end. It fills up a pool of information on the transmit side so there is a ready source of data whenever the switch is ready to send a packet. Likewise, it fills up a pool of data on the receive side so there is enough data to carry you over the breaks when the network is busy sending someone else's packets.

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As long as the transmit and receive buffers fill and drain at the same rate there is no interruption in final data delivery. The buffers absorb the variance in packet delivery. The catch is that for this scheme to work, the buffers are designed to be half full of data on average, so as to be deep enough that the data in the buffer never runs out or overflows during the worst-case variance in packet timing. This means that the receive data can't start playing out until its buffer is half full or the scheme won't work. The length of time it takes to fill the initial buffer half full is a main part of latency.

What does this have to do with Gigabit Ethernet, you might ask? Just about everything, actually.

Because a gigabit link is 10 times faster with 10 times the throughput of Fast Ethernet, packets can get to their destinations faster. Furthermore, the large capacity of the link allows for many more packets to traverse the network without risk of congestion and collisions and delays by the switches trying to find an opening on the wire for a packet. Because there is less concern with congestion, packets can be made smaller and more of them can be sent more frequently. Thus, buffers can be smaller and therefore, latency can be decreased. On the flip side, less link capacity often means larger data payloads, which can be necessary to ease congestion in lower bandwidth environments but at the unfortunate expense of increased latency.

Big Capacity

From the system perspective, the capacity of a link is all-important. As advertised, Gigabit Ethernet can reasonably handle 10 times the capacity of Fast Ethernet. For example, whereas you might push the upper limit of your Fast Ethernet link at 16 stereo audio channels, a Gigabit Ethernet link will be able to easily do 160 stereo audio channels.

One hundred sixty audio channels might seem like overkill in your studio, however it doesn’t take long for signals to add up. The more you ask of your audio network, the more it will need capacity to handle busses and foldbacks, backup sources, mixes, and headphone streams -- not to mention control and monitoring signals. If you want to automatically switch between live assist and dayparts, for example, that takes something like a utility mixer (which is part of our WheatNet-IP BLADEs) to switch them at the right time and level – plus the capacity to handle that switching. Put a few I/O devices in a studio and pipe their audio over a link to your rack room and the channel count goes up quickly.

It’s a given that you will probably need to run more than 16 audio channels through a link at one time. Any time you add more capability onto the system beyond a basic input or output channel, that’s when you need capacity. It’s also nice to have enough of it available for when you want to add something like an audio clip player or multiband audio processing to a network I/0 unit (which we did recently with the introduction of our new BLADE-3 I/O units). Having the available channel capacity allows us to add in the new features and functions that enhance the power and flexibility of the system without running out of network resources.

There’s also the flip side of capacity, or what happens when you run out.

As you add more channels to a link, the possibility of dropouts is increased until they are commonplace and you hear them routinely. It’s a logarithmic function up to the final cliff, not linear.

In fact, there’s a lot at play in the audio network that affects the quality of the end result. IP audio networks are highly stressed, running much more traffic than initially expected. That’s why it makes sense to use a topology (Gigabit Ethernet) that is more tolerant of the workload IP audio puts on it.

For example, the bigger the switch capacity, or what is referred to as switch fabric, the more packets it’ll be able to move. Just as on the Ethernet link itself, IP audio network switches should be sized and configured to handle the amount of traffic you're going to throw at them -- both today and five to 10 years from now when you'll ask your system to handle the new features we haven't even dreamed about yet.

By using Gigabit Ethernet links and switches you'll have the highest capacity, lowest latency, most future-proofed system available today.

The Curious Behavior of Radios

CarRadio LargeLouder is better! Crank it up! Well, not so fast...

Ever wonder what your listeners' FM radios sound like when your station is knee deep in the loudness race and the modulation monitor is always pegged? Our audio processing development guru, Jeff Keith, wondered about that too.

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So, during one quiet week at the Wheat processing lab, he decided to find out. He selected 15 radio receivers that most represented the majority of radios out there in use, and got out his trusty modulation analyzers, signal generators and other assorted test gear. He ran audio sweeps of de-modulated and de-emphasized FM audio and plotted SMPTE IM distortion of the receiver’s audio output as modulation was raised, among other tests. His main goal was to discover distortion trends in radios during 110% or more modulation. Here are a few of his findings, the details of which will be presented during the upcoming NAB Broadcast Engineering Conference (BEC).

  • The more recent the radio model, the more intolerant of high modulation it is likely to be.
  • Newer AM/FM/HD radio IC chips detect high deviation (over-modulation) and often, in an attempt to fix the problem, create unpleasant audio effects.
  • Many consumer receivers have restrictive intermediate frequency (IF) bandwidths, which can mean perceptibly distorted audio even when tuned to a normally modulated station. The IF bandwidth of one radio measured was barely 100kHz wide at the 3dB point.
  • Half of the receivers tested added significant IM distortion at modulation levels as low as 120%.

Jeff Keith’s paper “The Curious Behavior of Consumer FM Receivers During Hyper-modulation” will be published in the 2015 NAB Broadcast Engineering Conference (BEC) Proceedings and presented during the NAB Engineering Conference, Sunday, April 12.

A Look at Leighton

Leighton-1-420Our Darrin Paley says he couldn’t recall a moment when someone wasn’t sitting in front of a microphone as he snapped these shots of the Leighton Broadcasting studios during his recent visit to St. Cloud. Designed by Rob Goldberg, who is well-known in the area for his signature studios, the control rooms and newsroom for four Leighton stations (KCLD-FM, WILD-FM, KCML-FM and KNSI-AM) are networked and controlled through the WheatNet-IP audio network.

Leighton Broadcasting also has stations in Detroit Lakes and Grand Forks. The group’s Director of Engineering, Tony Abfalter, says he has just about every one of our BLADE I/O access units, and a good many of our control surfaces, including E-1s, L-12s, IP-12s, LX-24s and SideBoards. The group was also one of the first to receive our new FM-55 audio processor, in addition to owning AirAura X3 and AM-10HD audio processors.

Wheatstone BLADEFEST

Enhancing System Performance

September 2014: Wheatstone's WheatNet-IP Engineers get together to try and break a huge system assembled to be representative of all our control surfaces, many, many BLADES and processors, as they'd be used in a very large installation. In the process, they make the products faster, better, and stronger. We called it BLADEFEST. And the engineers who took part were our BLADE RUNNERS...

The above video documents the process. The article below (expanded here) appears in the Jan/Feb 2015 edition of Radio Guide Magazine. 

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Beyond 4K at CES. The Internet of Things.

CES LasVegasWhat at CES 2015 could possibly interest a couple of audio network nerds?

Well, yes, gadgets of course. But there was also this: the Internet of Things (IoT). One analyst counted 900 exhibitors with IoT products there. Thermostats, coffee makers, watches, jewelry, dog collars, ovens, smart sports apparel … baby bottles. All connected to the Internet of Things.

It’s a great concept, this idea of connecting appliances (not to mention, that new 4K TV) to the internet and controlling them through your smartphone or laptop. 

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Processing Tip

erickson rackHere's a helpful tip from Wheatstone Processing Guy Mike Erickson on keeping track of presets:

"One thing I try to remember to do when I'm making presets for a new install, or adjusting presets on a processor that's already online, is to date the presets. This not only gives you a good track record as to when you created that perfect sound, but it also allows you to go back if the PD complains that the processing ‘sounded better last week’ ... you'll know what preset to go back to even if you didn't physically write it down! Saving presets with the dates allows you to do the processing version of ‘System Restore.’ Also, it's a good idea to back up your presets. ALWAYS! I recall a Memorial Day failure of a processor in Market #1 going back almost 7 years ago. The backup switched on via silence sensor and I was able to swap out the main with another of the same model we had on the shelf and load the custom presets. Within an hour, we were back sounding as good as you could get with that box! The PD was nervous while I was swapping hardware that we wouldn't sound the same because all the presets were lost on the hardware. If I hadn't backed up the presets, weeks of work would have been down the drain.”

This tip is brought to you by our new FM-55 audio processor, which is so easy to adjust from the front panel, you might want to save and date presets for the presets.

The Scoop on Codecs for IP Audio

CodecIllustrationUsing the Internet for audio distribution makes sense, but the problem is a little like the holiday rush at the Post Office.

There are simply too many packets of data for the pipeline.

You need a codec to bit-reduce the audio stream. So what’s it going to be? AptX, Opus, G.722 or AAC, and if so, which version of AAC? We asked Charlie Gawley from Tieline, “The Codec Company” and a Wheatstone technology partner, to fill us in on Opus, the EBU ACIP standard, and how the AES67 factors into the use of codecs for IP audio delivery.

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Hand it Over, Internet

WheatTie CLOUDS 420If you’re thinking about handing over program distribution to the public internet, Brian Kerkan of Crawford Broadcasting has some advice for you.

Do yourself a favor and oversubscribe on bandwidth if you’re not able to set up a guaranteed QoS network, he says. His group in Detroit is paying around $100 a month for 20 megabits/second upstream.

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Crawford Denver Upgrades with WheatNet-IP

hoppWriting in the October 8, 2014 issue of Radio World, Amanda Hopp of Crawford Broadcasting in Denver described her recent production studio upgrade using WheatNet-IP Audio-over-IP networking. You can download a reprint of the article below, courtesy of the publisher.

icon Building an AoIP Network with BLADEs (947.19 kB 2014-11-21 15:40:29)

Oh, The Voices -- Part II: Adjusting for Taste

SteveDove Altby Steve Dove, Minister of Algorithms

The most basic, and arguably the most powerful, tool for getting vocals to sound good is equalization.

It has two primary uses, to correct for errors or for artistic effect. Compression and limiting also can be useful for adjusting vocals, as I cover in some detail below.

But first, this PSA: The worst judge of microphone processor settings is the one doing the talking. Most folk swoon over massive proximity effect bass and vertigo-inducing compression in their own headphones, to extents that would be ludicrous on-air. Someone other than the talent should do the equalization and dynamics adjustments, thank you very much.

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Oh, the Voices (Part 1)

Steve DovePart I: Tidying Up Talent Vocals
By Steve Dove, Wheatstone Minister of Algorithms


The microphone processor has long been important but in recent years it has become vital. Mainly this is due to the recent trend of referencing audio to 0dBfs (the maximum signal level in a digital system) rather than the cozy old nominal 0dB VU. 

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Mike Erickson is THAT Processing Guy

Mike Erickson_2012a_800

AirAuraX3 420NAB FM55 670Writing in the October 15 issue of Radio World, Wheatstone's Mike Erickson describes what it's like to be "that guy," the one who arrives in town with an audio processor under his arm and delivers on the promises.Here's a reprint, courtesy of Radio World.

 icon Mike Erickson is That Processing Guy (824.47 kB 2014-11-12 11:58:38)

Wheatstone Holiday Video Greeting

HolidayVideoThumb

It's that time of year again, and with the winter chill comes the warmth of our now-traditional Wheatstone video greeting card. (I must say that Mike Harris and the surface-mount department have absolutely stolen the show this year!) From our Wheatstone family to yours, we'd like to wish you peace and joy this holiday season, and a very happy and prosperous 2015.

Outta Control!

AgileScreenBuilder 2560We’ve just started to ship our new Screen Builder app, and already the many uses for this software app that lets you create custom screens for the WheatNet-IP audio network are rolling in.

Our new Screen Builder app has faders, meters, labels, buttons, clocks, timers and other widgets that you can arrange on a PC screen and program to create your own custom control interface for level adjusting, monitoring and more.

Chris Penny from Agile Broadcast in Australia told us about this interesting application for Screen Builder. (Shown in the photo at left: click to zoom in.)

  

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"The screen I built for this studio is for a producer. It allows IFB in to the right channel of a host/guest headphone by simply pressing on their chair. The ‘dot’ in front of the chairs (on the desk) lights up to show the mic is switched ON. Buttons to the right give the producer full monitoring of all outside broadcast lines in the facility, and he can talk to any remote talent by pressing the IFB button for the desired line. Group talkback to all guests is available by pressing ‘talkback all guests;’ or to every headphone by pressing the ‘Roosevelt’ button (Roosevelt is the name of the studio). A source selector on the left side of the screen allows the producer to monitor a variety of program sources, and a PC button mixes in the producer’s Internet computer to the monitor mix. Additional controls include delay DUMP (which illuminates when delay is full) and Aircom, which sends the producer’s talkback microphone to the On Air mix via an AirAura processor (to colour the sound so it mimics an intercom/ and control dynamics)."

Other uses for Screen Builder include monitoring transmitter levels and logic at various sites, locating and controling all hardware in the audio network, and monitoring studios in different locations.

Here's a quick video from Wheatstone's VP/Technology, Andy Calvanese, describing Screen Builder.

Let us know your ideas for Screen Builder. Email us at This email address is being protected from spambots. You need JavaScript enabled to view it..

Quick Stop at WXXI

Web WXXI_FM_SCOTT_REGAN_2560-v2From time to time we check in with our customers to see how things are going. This month, we found the folks at WXXI AM/FM/TV in good spirits and busier than ever.

Kent Hatfield in charge of audio operations for WXXI television and radio showed us around the facility, which has clearly seen a lot of changes since the Rochester, New York, pubcaster set up shop with ten Wheatstone D-9 and G series consoles networked into a Wheatstone TDM system 12 years ago.

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Audio Performance Testing on the Cheap

AudioPerformanceOnTheCheap 420by Jeff Keith

There’s nothing like a little audio performance testing to cap off a hectic week at the station, especially if you don’t have to haul out the heavy (read “expensive”) equipment to do it.

There are two main things I like to test: the flatness of the frequency response and the distortion added by equipment in the air chain. For this, you’ll need clean test signals, and a way to measure those signals after they’ve passed through the air chain.

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3 Things You Need to Know About Network Switches

SwitchPlate 420You’re about to embark on a social experiment.

You’ve selected the perfect control surfaces and the audio network is almost laid out for your new studios. Everyone and everything speaks broadcast and, so far, you haven’t had to take up IT as a second language. But now you’re about to drop a couple of network switches into the middle of it all and you’re worried that things could erupt into a civil war between this newer IT world and the radio cavalry.

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