Thiel Audio Products 1.2 manual Connecting the Speakers, Associated Equipment, Power Requirements

CONNECTING THE SPEAKERS

Speaker wire can be routed through a drilled opening in the mounting surface for a hidden connection. The PowerPoint 1.2 uses 5-way binding posts which accept several types of speaker cable termination. Make sure that all connections are tight.

It is essential for proper performance that both speakers in a stereo system be wired in the same polarity. The speaker’s input terminals are color coded to facilitate this. The wire connected to the red ringed input terminal of each speaker should connect to the respective positive (+) output terminals of the amplifier; the wire connected to the black ringed input terminals should be connected to the respective negative (–) output terminals of the amplifier. The speakers should be connected to the amplifier w ith high quality cable to ensure minimal loss of power and proper control by the amplifier.

ASSOCIATED EQUIPMENT

The PowerPoint 1.2 is a very high quality sound reproducer and will benefit from use with high quality associated equipment. Since it is extremely accurate, it will reveal sources of distortion generated elsewhere in the system. For example, distortion resulting from poor recordings or inferior electronics will be reproduced accurately.

POWER REQUIREMENTS

It is important to have enough power to play at the level you desire without distortion. If high sound levels are desired, the PowerPoint 1.2’s are designed to be used with amplifiers rated up to 200 watts per channel (into 8 ohms). If you play the speakers more loudly than the volume the amplifier can cleanly produce, the amplifier will produce overload (clipping) distortion. The sound will become compressed, strained, and in extreme cases, obviously distorted. This distortion is actually non-musical additional energy and since it is concentrated in the high frequency region where the speaker is least able to handle it, tweeters can be damaged in extreme cases.

Keep in mind that sound quality is usually much more important than sound quantity. There can be large differences in the sonic performance of two amplifiers of equal power, and this is more important than large differences in power. Most everyone will be happier with a 100 watt amplifier of high sonic quality than a 200 watt amplifier of mediocre sonic quality. For this reason, we feel there is no substitute for listening in making your amplifier decision.

The question “how much power do I need?” does not have the simple answer most people expect because it is not determined only by the loudspeaker’s efficiency, but also by the volume desired and the size of the room. If all three factors are average, about 100 watts per channel is required. Each factor can raise or lower this amount by about three times.

1)Usually, people who “don’t like music loud” can decrease their power to about one-half. Also, people who like music loud should increase their power by 2 times or more. Most people fall within a normal range.

2)A speaker with a low efficiency of 84 dB/W-m will require twice the power of an average 87 dB/W-m speaker and one with a high rating of 90 dB/W-m will require only half the power of an average speaker. Usually, high efficiency can be obtained only by trading off sonic quality—there are very few speakers that provide a very high level of both. The PowerPoint 1.2 is of above average efficiency (89 dB) and therefore requires less than an average amount of power for average volume levels.

3)A small room will need less power for a given loudness level than a large room. A very small room of 1000 cu ft (11' x 11' with an 8' ceiling) will require about half the power of an average size room. A large room of 6000 cu ft (20' x 30' with a 10' ceiling) will require twice the average power. If the listening room is connected to another room by a large open area, the required power will increase, but not by the amount of the combined room volume. If the room has a “dropped” ceiling with light panels, the ceiling will be almost transparent acoustically and the space above the ceiling should be added. If the panels are heavy they will act as a more normal ceiling.

With all this in mind, a person who doesn’t like to play music very loudly and has a small room can get quality sound with the PowerPoint 1.2 with as little as 30 watts whereas a person who sometimes likes to play loudly and has a large room may need 200 watts or more.