Need help understanding "performance" graphs

[smihalik]

I'm trying to understand what I'm looking at when I see a speakers frequency response, or other performance variable, mapped onto a graph. Is there anywhere I can go to have this explained to me? For example, I understand what frequency response is, but what does +-2db mean exactly? I have too many other questions and i wont ask them all here. I need it explained in lamens terms. I'm not a sound engineer...(obviously)

 

[Midcow2]

I'm trying to understand what I'm looking at when I see a speakers frequency response, or other performance variable, mapped onto a graph. Is there anywhere I can go to have this explained to me? For example, I understand what frequency response is, but what does +-2db mean exactly? I have too many other questions and i wont ask them all here. I need it explained in lamens terms. I'm not a sound engineer...(obviously)

dB is decibel and is used to measure sound level loudness

Here is a typical sound decibel scale:

Threshold of Hearing 0 dB
Rustling Leaves 10 dB
Whisper 20 dB
Normal Conversation 60 dB
Busy Street Traffic 70 dB
Vacuum Cleaner 80 dB
Large Orchestra 98 dB
Walkman at Maximum Level 100 dB
HT system at full blast 105 dB
Front Rows of Rock Concert 110 dB
Threshold of Pain 130 dB
Military Jet Takeoff 140 dB
Instant Perforation of Eardrum 160 dB

It is a logarithmic scale +3dB is a doubling of sound levels.

An easy way to make you HT system sound its best is to equalize the sound of all speakers from the listening point by using an SPL (Sound Pressure Level) meter. They cost about $50 from Radio Shack. http://www.radioshack.com/search/index.jsp?kwCatId=&kw=digital spl&origkw=digital SPL&sr=1


Hope this a laymen enough of an explanation

Good luck!

MidCow2

 

[Rickster71]

Try this:
http://forum.ecoustics.com/bbs/messages/34579/131062.html

 

[smihalik]

I know what a dB is. I'm sorry, I wasn't clear in my question. Lets take my LCR for example:

±2 dB from 110 Hz - 20 kHz

What if it said ±4 dB from 110 Hz - 20kHz? or ±1dB etc...

 

[smihalik]

Try this:
http://forum.ecoustics.com/bbs/messages/34579/131062.html

Thank you. Exactly what I was looking for.