PDM wins the

Award!

 
PDM wins the

Award!

 
Read our ATM
user report in

Frequently Asked Questions for PDM

Controlling PDM

Do I need a PhD to operate PDM?

A GED will do just fine! If you can press 2 buttons, you can operate Program Delay Manager.

Do I need a computer to use PDM?

No. PDM is fully functional as a stand-alone system.

Can PDM be controlled over a network?

Yes. PDM has a built in web server which allows you to control it from a browser over your local area network.

Can PDM interface with station automation systems?

Yes. PDM can work with your existing automation system through the use of GPIO (contact closures). Custom solutions may be possible in the event that you have unique needs or requests. Please contact us to discuss.

Can PDM receive and send contact closures?

Yes. PDM comes standard with a built in 8x8 opto-isolated GPIO system. Contact closure inputs and outputs may be assigned to a variety of useful functions. To help you configure your system, we also supply a GPIO test utility that allows you to fire outputs, and view input statuses. In addition, PDM interfaces with Livewire™'s GPIO over IP system.

What happens when a contact closure comes in to fire an ID or Liner, but PDM is running? Won’t the ID fire at the wrong time?

No. PDM’s sophisticated GPIO features allow you flag a contact closure to a piece of audio as it comes in, so that it fires a closure when that audio plays out. Contact closures stay in perfect sync against the audio

If necessary, how can I upgrade the internal software?

At this writing you will need to contact 25-Seven Systems, and provide an IP port allowing us to perform a remote update over the Internet. We are currently working on a software upgrade to help automate this process. In the future you will simply be able to “check for updates” from your PDM’s front panel, provided you have Internet access.

 

Audio Quality

How does PDM compress and expand audio?

We use variable-width analysis windows to simultaneously check the pitch, tempo, and spectral characteristics of the audio. Additional algorithms are applied to preserve musical rhythms and stereo placement. Our proprietary software is the product of years of research into the advantages and pitfalls of other time-compression algorithms.

What is the sound quality of your compressed audio?

It’s amazingly transparent. We recommend you hear it for yourself. At low rates, you simply don’t know its there. At higher rates, things may seem sped-up, but you don’t hear the glitches, artifacts and grunge that you do with other systems. There is absolutely no change in pitch, ever. Whether you notice it or not becomes really quite content dependent. If you speed up someone who speaks really fast naturally, you may feel his/her speech is just unbelievably fast. But if you are speeding up a snore-inducing talk show guest, even 20% can sound fine, even preferable.

How much audio can PDM store?

PDM can buffer up to ninety seconds of stereo audio.

My station uses watermarking technology. Will PDM pass audio watermarks?

Yes. 25-Seven Systems conducted tests with a leading digital audio watermarking technology company at the request of a major corporate broadcaster. We ran multiple passes of watermarked test material through our system, at various rates. They reported having “no issues” with our system, even at our highest rate of time compression. We are happy to repeat the experiment for any other provider of watermarking technology.

How good is the analog sound quality?

Converters run PCM linear 16 bit/44.1 kHz, and measure ≥94 dB dynamic range, frequency response ± 0.5dB, 20 Hz - 20 kHz at all levels. In other words, it's CD quality.

What about digital audio?

PDM comes standard with digital I/O, user selectable AES or s/pdif. PDM can accept sample rate inputs of 32, 44.1 and 48kHz. Default operation is 44.1kHz, 16 bit linear PCM.

 

Interfacing

What audio connectors does PDM have?

XLR male and female connectors for balanced stereo analog, and AES digital audio. The Livewire version transfers audio over the network, but also provides connectors for analog and S/PDIF monitor output.

What other interfaces does PDM have?

8x8 GPIO (contact closures) on a DB25 female connector, and a built in web server, accessible over an RJ45 network connector.

What about audio over IP?

PDM fully supports Axia Livewire™.

Can I drive PDM from my station’s master clock?

Yes. Point PDM at an NTP (network time protocol) server, and it will automatically adjust the unit’s internal clock, which is displayed on the LCD. This NTP server can be located on your station’s LAN, or can be on the Internet.

Wait, I was talking about digital audio clock rates, not time clocks!

Oh! PDM will sync to whatever valid external rate is coming in on the AES input, even if your audio source is analog. That sync signal gets passed to the digital output. If you don’t supply a digital input, PDM uses its own internal 44.1 low jitter digital source.

 

Technical and Form Factor

 

How large is PDM?

It's 1RU (rack units) high, and measures 19" W (with rack ears) x 13.5" D x 1.75" H (483 x 343 x 44mm).

How much power does it require?

PDM has an internal 100-240 VAC high-efficiency, self adjusting regulated supply, typical consumption 32 VA.

What about heat dissipation, cooling requirements, maximum operating temp?

PDM does not generate much heat, but its important for it, and any electronic equipment to stay cool. We advise you to mount PDM in a well ventilated cabinet, and to make sure the unit’s rear panel vents are not blocked. For best results, operating temperatures should not exceed 55C/130F internal, 40C/105F ambient.