Originally Posted by Cvetan1
Here is a question... Since I do not know what a "clipped" signal to the speakers sound like, how do you know when you're clipping?
As has been pointed out, the quality and clarity of music starts degrading rapidly when clipping commences. Kbarnes clearly has plenty of experience with very clean powerful systems. As the music gets louder with them, the music simply gets somewhat louder, without any changes to its basic character.
If you could play computer files I could provide you with downloadable files with and without clipping. You could play them at lower levels and hear what clipping sounds like in total safety.
What I feel compelled to add is that clipping is not the only reason why there are changes in sound quality as you turn your audio system up.
Your speakers have limits that are similar to amplifiers. However, there is less consistency. For example, subwoofers in particular are prone to have audible distortion due to running out of something called Xmax or linear travel. Usually this barrier to loud clean sound is less sudden than clipping in power amplifiers. It can actually happen with woofers, midrange speakers, and tweeters as well. Because it is less sudden and less sharply defined, it is not as obvious. However it also causes the sound quality to change as opposed to simply becoming louder.
While not a nonlinear effect like clipping and running out of Xmax, room acoustics can cause a perceived change in sound quality as loudness increases. Rooms that have too many reflections can seemingly "load up" and become unpleasant to listen in at high volumes.
Finally the human ear itself has well-defined limits. The ear is most effective at resolving different sounds around 85 dB SPL. Below 85 dB SPL sounds tend to disappear into audible thresholds. Above 85 dB the mechanical components of the ear become can become quite nonlinear. Above about 105 dB at midrange frequencies, the ear may be damaged, either short term or long term. The ear has far more tolerance for loud sounds at low frequencies. For example at 70 mph the SPL of wind buffeting inside a car at low frequencies can exceed 120 dB SPL.
How do you know you have enough power?
To be absolutely sure that you have enough power, you set up a means to view a graphical representation of the voltage across your speaker's terminals, and examine the graphical representation of the voltage across the speaker terminals for clipping.
Here are some examples of clipped music:
The areas where there is flat-topping near the top and bottom of the picture above represents clipping.
The above picture (annotated Fig 1) shows a number of areas where there is clipping, some labelled "peak clipping", and others notable because the signal reaches maximum Y or minimum Y.
This is a good read, as I was prepared to buy a much larger external amplifier than whats included in my Denon 4520. I sometimes like to listen to my Salk Veracity ST's loud, but I don't know if I'm doing harm to them or not, which makes me scared to crank them up. (Rated 4ohm, 88db sensitivity, 250watts at 4/ohms)
4250 spec: 150 W + 150 W (8 Ω, 20 Hz – 20 kHz with 0.05 % T.H.D.)
From a ratings standpoint, I don't find http://www.salksound.com/veracity%20st%20-%20specifications.htm
to be particularly helpful. The system contains 2 Seas E0049-04S W16NX001 type speakers that have a long term rating of 80 watts. http://www.seas.no/index.php?option=com_content&task=view&id=66&Itemid=90
So 150 watts could be pretty safe. The ratings on the RAAL 70-20XR midrange tweeter are proprietary so what they can do is questionable.
Depending on how you use them, they are probably safe with your AVR, but may not be safe with significantly more powerful amplifiers. This comment is contingent on use with a good subwoofer crossed over in the 60-80 Hz range.Edited by arnyk - 9/9/13 at 5:51am