Michael Graves

This author has written 1385 articles

Audio Sample Rates: Terminology vs Application

I’ve recently started to develop a grumpy streak with respect to the use of certain terminology with respect to telephony. Maybe telephony isn’t exactly the right word, let’s say that my unease arises from some odd terms surrounding audio quality in the context of communication. I think that some of the language needs to be more application sensitive.

A few years ago the world was a simpler place. The “Plain Old Telephone System” (aka POTS) was definitely a narrowband medium. Where “narrowband” implied digital sampling at 8 KHz and a useful audio channel of 300 Hz – 3,400 Hz.

Some people using more advanced systems enjoyed “wideband” audio. Wideband in that case was defined as a 16 KHz sampling yielding a useful audio channel of 50 Hz – 7 KHz. The TIA-920 standard, which I have referenced previously, spells this out. A variety of audio codecs can deliver this capability including; AMR-WB, EVRC-WB, G.722, G.722.1, CELT & Opus.

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A Gigaset With A Blacklist & The FTC’s Robocall Challenge

Gigaset-C620AEarlier this week I saw a press release detailing a new model of Gigaset cordless DECT phone. This new model, known as the Gigaset C620A, isn’t even SIP capable so normally I wouldn’t give it the time of day. However, the release placed unusual emphasis on one particular feature…a blacklist function intended to reduce the impact of nuisance calls.

Nuisance calls have been on my mind lately, not so much because we get them…because we generally don’t suffer such a problem. They’ve been on my mind because ZipDX’s David Frankel has been railing against the outcome of the FTC/FCC sponsored Robocall Challenge intended to crowd source a solution to the problem of such calls.

David entered that contest but was not one of the winners. He made some inquires about the judging criteria and scores, but met with resistance. In fact, David’s experience following up on the scoring was pretty bad. So much so that he’s been pursuing the FTC and FCC for more details. His efforts in this pursuit made it into The Wall Street Journal on June 25th.

While the contest was over some time ago, there was a Senate hearing on the subject just last week.

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An Interesting History Of Headphones

k240studioSome time ago I stumbled upon a nice article that proposed to be something of a history of headphones. It’s a fairly good effort on the part of the author. However, I would like to add my two-cents in reference to a couple of missing items that I think are significant.

When I was in school in the mid-1980’s I was studying music recording and broadcasting. I spent a lot of time in and around various recording studios around Toronto. The single most common headset that I saw at that time was the AKG K240 Studio monitors. These were the reference grade dynamic headphones used in many facilities at that time.

The K240s are genuinely, big-ole, cans. A circumaural headphone with a semi-open design they sound great, even today. They can be cleanly driven to excessive volumes if required. Fairly efficient, they can even be powered by a cell phone or iPod.

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Sightdeck: High-End Compositing & Virtual Sets Meet Telepresence

SightDeck_AdMore and more it seems that things from long in my past are recurring in the present day. To give you some context, you should know that in the early ‘90s when I was working as an editor in video post-production I became very familiar with blue/green screen techniques.

At one point I was editing commercials for a large Canadian supermarket chain where the President was blue screen composited against close-up shots of the products. We made tremendous use of Ultimatte gear as well as Ampex’s Spectrakey.

Jump twenty years into the future when this I see that Telepresence Options is highlighting Sightdeck, a live presentation facility for telepresence applications. Sightdeck is from iMatte, a company created by the founders of Ultimatte. Warning, iMatte’s web site is a study in lame.

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Shields Up! New Protection For Our Androids

True to his offer last month, Ed Tyson of Expert Shield sent us a sample set of his companies protective garb for mobile devices. Last week we received a package with kits for each of our Nexus 4 cell phones and my Nexus 7 tablet. My devices are now cloaked in these new wares, but I have to to take Stella’s Nexus 4 captive for long enough to dress it in a similar fashion.

Applying any screen protector requires a certain amount of skill and care. There’s not much opportunity to lift and reposition the clear and somewhat wobbly layer once it’s been applied. One must take care that it’s not applied in a skewed manner.

In some regards application of the screen protector is easier on the larger tablet than the cell phone. First, the tablet is larger, making it easier to align the item to the face of the device. Secondly, the tablets doesn’t have as many little openings and sensors that must align with irregularities in the perimeter of the screen protector.

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Extending Our Whole House Audio To The Back Yard

audio-trioLike many people we have a wooden deck at the back of the house into the back yard. It has long been my intent to extend our ability to play music to the back yard, but it has only recently com to pass. It’s essentially the next step in my long standing plans to deploy Whole House Audio, a project that recalls some of the earliest posts to this site.

As I described so long ago, we love our Logitech Squeezeboxes. They still form the basis of how we play music around here, even though Logitech has abandoned the product line. In fact, when my one Squeezebox Touch died I was inspired to purchase another Squeezebox 3 on E-bay, just to have a spare.

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