Audio Systems: what is the meaning of clip (inrush audio peak)limiter, fidelity system, voltage swing

Question
QUESTION: hi
i want to know the meaning of clip limiter (inrush audio peak limiter) and how it work?
1 - whether it indicate that amplifier getting overloaded to its maximum capacity?
2 - whether it indicate that speaker getting overloaded to its maximum capacity?
3 - whether it indicate that amplifier or speaker getting overloaded to its maximum capacity?

ANSWER: Clipping in amplifier terminology is when the input signal drives the output to its maximum voltage swing.  The voltage swing is determined by the rail voltages being fed to the push-pull output or final stage of the amplifier.

Here is what a pure sine wave input looks like at the power output circuit when driven slightly past the clipping point:

http://en.wikipedia.org/wiki/File:Clipping_1KHz_10V_DIV_clip_A_5ohms-1-.jpg

This is a good discussion of amplifier clipping.

http://en.wikipedia.org/wiki/Clipping_(audio)

There are many ways of detecting the clipping point.  The best way is to listen to it as the clipping causes lots of distortion AND can cause damage to a speaker.  Especially tweeters whose power handling capacity if often much less than the other speakers in the system.

Happy listening.



---------- FOLLOW-UP ----------

QUESTION: hi,
i am not able to understand the technical language so i would like to ask above mention question repeat and i hope you will answer in simple language so that i can understand easily.

ANSWER: First, please tell me why you are interested in clipping point and why you think you need to have a clip detector in your system?  They are usually used only in professional sound systems of complex design.  If you are speaking of home type high fidelity system for recorded music playback then you really would not need or want a clipping detector in the system.

If you are running a large scale public address music system you may wish to employ such devices to keep the risk of damaging a loudspeaker as low as possible.

So, let me hear back from you what kind of application you are thinking of so we can discuss at your level of interest.

Thank you.

PS:  Inrush current limiting is different technology topic from audio clipping detection or limiting.  Inrush current is often used to define the peak current when filament of lamp is first turned on.  In amplifier could be warmup current to amplifier and does not relate to loudspeaker connection.  Speaker system does not have inrush current.



---------- FOLLOW-UP ----------

QUESTION: yes i am running large scale public address music system so you can proceed to my question in simple language and also explain inrush audio peak limiter soft start in detail.

Answer
First, inrush is the extra amount of energy required during the first few milliseconds after turn on.  It takes a few milliseconds to maybe a second or two for the internal charging up of the capacitors and settling down the circuits for normal quiescent operation.

I think the inrush peak limiter you are talking about may be the current increase and slight instability of the amplifier if the input signal asks for more power than it can deliver;  the peak signals are clipped due to the output power being pushed  beyond its capacity.  It may then draw uneven power from the two dc power lines to the audio stages.  Thus a peak detector/limiter would prevent serious overloading of the circuits.

A limiter apparatus is a device that will watch the audio input signals and prevent them from exceeding preset levels.  If the db level in a music playback signal is to not exceed a predetermined level then with a db meter in the acoustic space and a test signal the limiter can be set to not allow the acoustic level to go over that setting.  If the limiter is used for preventing overload and excessive potential damage to the audio power amplifier or loudspeaker system then the limiter can be set for the maximum level just before the danger point is reached.

Often a dynamic limiter/compressor is combined in order to keep the music signal higher during low level passages and lower during the loud passages. Thus it compresses the dynamic range of the music being reproduced.  

http://en.wikipedia.org/wiki/Dynamic_range_compression

It is a very common apparatus for commercial audio systems.

A strict limiter is explained here:

http://en.wikipedia.org/wiki/Limiter

There are many commercially available devices that will do all kinds of creative actions to the signal under question.

For recording studios the same equipment but with more specific tasks defined as needed by the recording engineer or musician.  

If you are building a system and want advice on which components you will need for your system I suggest you visit a commercial systems equipment seller such as Sam Ash (who has good, well trained experts in the equipment you may want to use in your system(s).

Hope this helps.