Distortion and clipping vs. percieved loudness [Archive] - Audio & Video Forums

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salad 419
01-07-2007, 06:54 AM
Alright, I'm not good at explaining my concepts, so hopefully some of you more seasoned and wordy folks can change my concept into words and a nice clean question, but I'll try my best.

Why does a "not so" clean reciever (super cheap) sound louder than one with clean power?

What attributes to the room filling mud? Can't really explain this part, but it seems like all the tones are reverberated and you're surrounded in sound. Amost like the feeling of being in a bath tub of warm water. Is it the clipping of the sine waves that limit the dynamics, added Harmonic Distortion, or both?

I recently upgraded recievers (post coming soon) and from the Super Crappy one I had, it took my ears a good 5 hours to realize that I was playing the thing LOUD. It was so clean and musical.

I guess another way to put this is that on most of older equipment when you turn it up to where it starts noticably clips/distorts and then back it off a touch so it doesn't sound as bad, it sounds loud.

Anyway, there's my hillbilly findings. I just wanted to know "why"????????

Mr Peabody
01-07-2007, 09:16 AM
I understand what you are saying and agree. I'm not sure why but my guess is that when the music gets to the point of distortion it becomes more offensive to our ears, something tells our brain to back off. Where when we hear a loud clean signal we don't get that alarm unless it's to the point something hurts. Unfortunately, it seems some people are void of this alarm or their ears can tolerate more abuse than mine.

I also don't know why a distorted signal gives the perception of filling the room more unless it's the total lack of control by the amp we pick up on. The sound no longer has a form, you can no longer depict the bass line, or most any other detail, it just sounds like a loud diffuse mess.

When I had my Krell system hooked up, I'd be listening at what I thought was a good listening level and I didn't realize how loud it was until some one would come into the room to say something.

Wireworm5
01-07-2007, 09:56 AM
From the time you were a baby 'til now your brain has learned how to interpret sound. It picks up subtle clues to loudness and lets you know by either pain or irritability that your ears are in danger. That's when we cover our ears, flea from the sound or yell it's too loud! Turn it DOWN!
With a high end system however these subtle clues of distortion aren't there until the amp/receiver starts to clip. So your brain doesn't have a reliable benchmark to judge the loudness. So you need to use an spl meter to measure this. In time with listening experience you can tell approx. what 90db or louder sounds like on a high end system.
On my system I cannot tell when the amps are starting to clip without the aid of the clipping lights. When a receiver starts to clip its an indicator that amp/receiver has reached it's power limit and there is no point to increasing the volume other than to add distortion and possibly damage speakers or amp.
However a distorted wave from the source will also cause amp/receiver to clip. I am not sure of the explaination for this. But this kind of distortion is potentially more damaging to equipment than running out of power.
Years ago I had an early model Moog synth. hooked to my receiver. Just from distorting sound waves to make cool sounds I fried something in the receiver.
To answer the second part of your question I'm not sure what you mean. The room is as important as any other component in your system for acheiving good sound. Too lively and you get an echo effect that makes speech hard to discern an irratiable. Too dead and you have to crank the volume to hear detail. Acoustic treatment helps abit to focus the sound and you can hear even more detail.
I find depending on the room that you want the volume to be just loud enough to interact with your room when critical listening. Too loud and the sound smears overloading your brains ability to process detail.
Just my .02 cents

basite
01-07-2007, 12:49 PM
I understand what you are saying and agree. I'm not sure why but my guess is that when the music gets to the point of distortion it becomes more offensive to our ears, something tells our brain to back off. Where when we hear a loud clean signal we don't get that alarm unless it's to the point something hurts. Unfortunately, it seems some people are void of this alarm or their ears can tolerate more abuse than mine.


agree, but then why do teens and some other people like the super loud 'noise' at parties and in disco's then? I assume that most of these events don't have decent sound...

I also notice that, since I moved my speakers from the bed to the long wall in my room that the signal sounds a little clearer, and that I play louder without it sounds like it is loud, although it is...


Keep em spinning,
Bert.

Mr Peabody
01-07-2007, 01:15 PM
Yeah, those are the ones I'm talking about:) Seriously, I think most clubs probably do have a thumping system, probably more along the lines of a Pro audio system. Another aspect of listening to loud music is the physical sensation you get. You can feel the air excited. If you have ever listened to electrostats and paid attention, you noticed something missing. Itwas that physical aspect that you get from dynamic speakers.

The moving of your speakers is just another example of how important the listening room is to the performance of one's gear. Maybe the first location had more reflections that effected the clarity and also those reflections are as bad as distortion when it comes to assaulting our ears.