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-   -   Quiet CD??? (http://www.focusfanatics.com/forum/showthread.php?t=303595)

Besbro 12-03-2012 03:49 PM

Quiet CD???
 
Hello, I have one CD that for some reason plays quieter than the rest. It is an old cd. My question is if I turn my volume up to 15 and this CD is still quiet, is the same amount of power running thru my speaker wires as when I have a different louder CD playing at volume 15? Is the power output of the amp determined by the volume knob or the output at the speaker?
Thanks!

Kipp 12-03-2012 05:41 PM

yeah, the headunit puts out the power based on what the colume is set at. it's just the recording quality on the cd that's making it quiet. is it a burned cd by chance?

Besbro 12-03-2012 06:09 PM

No, not burnt. Just old...

Besbro 12-03-2012 09:09 PM

So if my volume is at 15 on my hu and the output level on my soem4 (loc) is at max the power running thru my speaker wire is the same as when I turn the output level on the loc to low and leave the hu volume at 15? With the loc output on low the music is much quieter...

blackraven456 12-03-2012 09:58 PM

Depending on how old the CD is, this is easily explained. Originally when they were introduced CD was considered an audiophile medium and thus the mixes of the tracks put on them contained a higher dynamic range. Today's CD's are often over compressed and thus sound louder at lower volumes. It's the same trick TV stations use when loud commercials come on over a quieter show.

freemind 12-04-2012 08:12 AM

^Encoding.

The Killers CD Hot Fuss is a fine example of compression while, The Kings Of Leon's Only By The Night is an example of a nicely recorded CD.

This is why I still have the same copy of Enya's Watermark that I bought in 1989.
It is very dynamic.

Elizabeth 12-04-2012 10:03 AM

The reply about the power and volume is wrong.
The volume controls the signal going to the amp. the amp will always increase the (volmue controlled variable) incoming signal by the same amount. The power put out from the amp is directly related to the power of the signal coming into the amp.
So, in effect, the volume control 'controls' the amount of power being put out by the amp at any time.(dependent on the level of signal into the volume control too)
Only a class "A" amplifier would be running at full tilt no matter what.
Car amps are NOT class "A" amps.
So the amplifier is always outputting the power corresponding to the signal input, as controlled by the volume knob. [screwy]
I hope this is totally as confusing as it seems... [dunno]

Added: and yeah, a lot of old CDs do not have nearly as much compression. Compression is squeezing the dynamic range, so the soft parts are way louder, and the loud parts well, just stay loud. Also many older CDs were not made with the volume as high as possible. They used to believe in dynamic range. No so anymore. Now it is all about being a loud as possible at all times..

Besbro 12-04-2012 10:28 AM

So to summarize, the louder the music coming out of the speaker, the more power running thru the speaker wire, regardless of the volume knob.

Thanks!

Kipp 12-04-2012 10:52 AM

more or less, yes. the headunit and amp (if applicable) are capable of multiplying the input power level to a certain point. the issue here is that the input source (the cd) has a weaker input signal. the amp is still multiplying that up to a higher level, but isn't as high as what a stronger source would be. think of your multiplication tables. (random numbers btw) 2 x 12 = 24 vs 3 x 12 = 36. the amp is the constsant and the cd is the variable that changes the output.

Besbro 12-04-2012 11:00 AM

Clear as day, I love the multiplication analogy, that makes total sense! The reason for all these questions is I installed my amp (95 watts rms per channel) and components (ID CXS 6.5 2 ohm version) last weekend and failed at running nes speaker wire into the doors. I spliced into the factory wiring and have approx 4 feet of factory wire active on both sides. I am paranoid about it. I played it at a moderately high volume for an hour and then checked the stock wire, it was totally cool to touch, not warm at all so I am guessing it will be ok. Still paranoid though. I know a few other forum members have done this successfully. The comps sound awesome by the way!!!


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