Audio TX Communicator
Communicator is a very simple system to use. In this section, you'll find answers to the most common questions, but do email us if there's something you can't find here!
1. What is AudioTX Communicator?
AudioTX Communicator is a combination of products in one. We call it a broadcast audio transmission device. It IS an ISDN Audio Codec, but can ALSO send and receive live audio over a standard PC network, over the Internet using ADSL/DSL/Cable Modems/Leased lines etc, or over larger networks like ATM, T1, T3...
OK - so you know what an ISDN Audio Codec is? An ISDN Codec allows you to make a live audio connection over ISDN lines. Broadcasters and pro-audio studios use ISDN Codecs to link studios, for remote broadcasts and also for studio-to-transmitter links. Because of the limited data bandwidth available over ISDN, all codecs use compression. The three most popular forms (in order of most regular usage) are MPEG Layer 2, MPEG Layer 3, and G.722. All of these are supported in AudioTX.
Typically, an ISDN Codec comes as a dedicated hardware device - you plug in audio at one end and an ISDN line at the other. AudioTX Communicator is a software-only solution. This brings several key advantages:
- It's low in cost.
- It's portable - because Communicator will run on a Laptop, you can take it with you anywhere.
- It's easy to use - Communicator has an auto-detect algorithm built in... so when you make a call or someone calls you, the system recognizes the type of codec, the compression used etc and just connects you - no fuss!
2. What PC Specification do I need to use AudioTX Communicator?
Communicator is written to be a very efficient program and will run on a Pentium 266 with 32MB (Win 98/NT) or 64MB (Win 2000). However, we recommend a Pentium II 300 system or above as a minimum spec if you are choosing a machine to install on. Processor speed in MHz is not the only factor - different manufacturers' CPUs in our experience have differing floating point abilities which affects the speed at which AudioTX can encode and decode audio. In order of efficiency (best first), these are:
AMD Athlon, Intel Pentium III, Intel Pentium II, AMD K6-2, Intel Pentium I and AMD K6.
The system runs on Windows 98, Windows NT and Windows 2000 - generally, we'd recommend Windows 2000 if you have a free choice.
3. What about the hardware or cards I need - Sound, ISDN or Network?
Broadly, Communicator has been designed to work with any Windows compatible sound card and any CAPI 2.0-compliant ISDN board. We have a recommended list and guidelines on Sound and ISDN cards in a separate section of the site. In practice, almost all Sound cards work fine - but there are some important criteria involved in choosing the right card for a professional audio application - these are outlined in the guide.
For ISDN cards, we do recommend that you go for one of the cards we have on our recommended list... happily, these are the most widely available cards from the biggest ISDN manufacturers and low in cost. Again, see the guide. (CAPI is a standard specification that ISDN board manufacturers use - you should also check that the card is capable of making 'Bit Transparent' connections.)
Network cards: all cards - both Ethernet and other larger scale networking hardware - will all work as long as they offer an IP-based networking connection to the Windows operating system. Communicator will simply try and connect you over networks by attempting to link to the IP address you enter as a destination or by using Windows DNS to resolve any hostname you enter.
4. We love the idea, but is a software ISDN audio codec really reliable and stable enough for, say, a 3-hour remote broadcast?
Definitely!
One of the most fundamental principles used in the design of Communicator was that it should be as reliable as a hardware codec solution.
Communicator is a professional broadcast-quality audio tool, and works as one, rather than a toy!
5. How good is the audio quality?
With our recommendations on audio cards (see the guidelines on Sound and ISDN cards) or any decent professional audio card, you should get excellent sound quality.
6. What's the transmission (coding) delay?
As an ISDN Codec, very low - in fact, our tests show the delay to be shorter than any other ISDN product on the market today. expect around 25-50ms in G.722 mode, and between 65 and 100ms in MPEG 2 or 3 stereo mode.
On a good network (i.e. over your existing Ethernet network, private circuits, ATM, etc.) transmission times are slightly shorter than those shown for ISDN above.
In 'Internet' network mode, expect delays of between 0.5 and 2 seconds - Communicator automatically detects the available bandwidth for the connection during handshaking and uses as short but safe a delay as possible.
7. What ISDN codecs is AudioTX Communicator compatible with?
Pretty much any and every available codec.
That includes our entire range such as the CDQPrima and PrimaLT series, the CDQ1000, 2000 and 2001,as well as all other leading manufacturers' codecs.
Communicator is compatible with MPEG Layer II, MPEG Layer III, G.722 and G.711 protocols at 64 or 128 Kbits - that's one or two ISDN "B" channels.
