Today's Top Stories:
 Roland's new M-100FX mixer!
M-100FX
The perfect small-format mixer for the home and project studio, the M-100FX allows you to plug a number of devices from your studio into its analog inputs and route them to your computer via the digital I/O and/or USB interface! Roland delivers once again with BIG studio, innovative tools that fit with just about anyone's budget!No Interest On Sweetwater Purchases Until January... 2005!
Sweetwater is offering an incredible deal that you simply can't afford to pass on. Purchase gear using Sweetwater's All Access credit card from now through August 4th and you won't have to pay any interest as long as you have it paid off by January 2005! Yes, that's right 2005. Purchases must be over $499. Call for more information!
Around The Web
KNZAudio has created Midifier that allows you to control your MIDI devices with audio. According to KNZAudio, Midifier is the first real-time audio-to-MIDI plugin. It converts monophonic audio tracks to MIDI and faithfully extracts the pitch and envelope of the audio data and generates MIDI notes on-the-fly. Midifier is a PC, VST plug-in that is only available from KNZAudio.
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| Compact Disc |
| A Compact Disc (see also CDDA in our WFTD archives), is a small optical disk on which data such as music, text, or graphic images is digitally encoded. It is essentially a digital medium that is read by a laser. Some of the original standards of the audio CD, such as the 44.1kHz sampling rate, 16-bit depth, size and finished minutes (74 minutes at that time), were decided upon as early as 1979 by Sony and Phillips. While prototypes were shown as early as 1979, the Compact Disc technology was introduced by in large in Europe and Japan in the fall of 1982. 30,000 CD players were sold in the US in 1983, and by the end of the decade CDs were outselling vinyl as a popular music delivery format. An audio CD is specified by Red Book standards, which define information such as lead-in, lead-out, table of contents and more. While there are other standards used by other forms of data stored on CDs, they all are derived from Red Book in one way or another. The compact disc is read by a laser that receives a series of digital pulses from a track of bumps as it follows a spiral track from the middle of the disc outwards. The track width is tiny at just 0.5 microns wide, with 1.6 microns separating the tracks. The CD initially rotates in the player at 500 rpm as the laser reads the inner tracks; the speed slowly decreases to 200 rpm as the outer tracks are read. This keeps the data rate constant as the laser traverses the disc and is known as CLV (Constant Linear Velocity). |
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| Why do speakers appear to lose their power over distance? |
Q: "I've heard that speaker will "lose" their power over distance. Why does this happen?"
A: The full depth of this question can't really be covered in the confines of inSync, but there is a short, basic answer. For the most part, this is due to the fact that while copper is a very good conductor of electricity, it isn't perfect. It has a certain amount of resistance, determined primarily on its cross-sectional area (but also by its purity and temperature). This wiring resistance is "seen" by the amplifier output as part of the load; if a cable with a resistance of one ohm is connected to an 8-ohm speaker, the load seen by the amplifier is 9 ohms. Since increasing the load impedance decreases current flow, decreasing power delivery, we have lost some of the amplifier's power capability merely by adding the series resistance of the cable to the load. Furthermore, since the cable is seen as part of the load, part of the power that is delivered to the load is dissipated in the cable itself as heat. (This is the way electrical space heaters work!) Since Ohm's Law allows us to calculate the current flow created by a given voltage across a given load impedance, it can also give us the voltage drop across the load, or part of the load, for a given current. If a given cable has a certain amount of resistance to current flow per foot (a common way for them to be rated) then naturally greater lengths are going to add to this, which is what causes the loss to accumulate over greater lengths of cable. The natural follow up to this question is how can this power loss be minimized, which we'll cover in another inSync Tech Tip of the Day. |
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