# Over-amplification of sub?



## ndurantz (Aug 10, 2008)

Hi All,

I recently got all the pieces in place for my new computer set up:

Source: Digital files on Mac Mini ==> optical out to FiiO D3 ==> RCA out to Parasound Z-Pre ==> RCA out to Parasound Z3 ==> speaker terminals to Orb Mod1's ==> RCA passthrough to Mirage Omnisat 8 sub LFE.

As I was listening the other day, I turned off the amp and noticed I could still hear audible sound from the track I was playing coming through the sub. Is this normal? And if so, am I "over" amplifying the sound to the sub?


----------



## wgmontgomery (Jun 9, 2011)

From what I read in your post, this _is_ normal. The preamp is sending a _separate_ signal to the Parasound amp AND the subwoofer's amp. Turning-off the Parasound amp will only kill the sound to the Orb speakers; the sub is still getting a signal from the preamp and is doing what is should-amplifying it. You need to turn-off the preamp (and maybe the source), too.


----------



## ndurantz (Aug 10, 2008)

wgmontgomery said:


> The preamp is sending a _separate_ signal to the Parasound amp AND the subwoofer's amp.


Thanks for the reply. I am probably showing my ignorance here, but if I am only running one set of RCAs from the pre-amp to the amp then running RCAs to the sub through the passthrough RCA jacks on the amp, how is the pre-amplifier sending a seprate signal to the sub? Does the LFE work its way back up the chain to the pre-amp based on the freq. crossover I set on the sub?


----------



## tshifrin (Nov 24, 2011)

The key phrase is "pass through" connection; the amp passes a signal through even if it's powered off (I think). It would be the same as using a "Y" connector, the signal travels through on the pre-amps power.
It's normal (happens in my system too), and gave me an interesting perspective on what the sub was actually oding.

Tom


----------



## wgmontgomery (Jun 9, 2011)

tshifrin said:


> The key phrase is "pass through" connection; the amp passes a signal through even if it's powered off (I think). It would be the same as using a "Y" connector, the signal travels through on the pre-amps power.
> It's normal (happens in my system too), and gave me an interesting perspective on what the sub was actually oding.
> 
> Tom


Correct; that's what I gathered, too.


----------



## ndurantz (Aug 10, 2008)

Thanks, fellas. Appreciate the info!

Sent from my iPhone using HTShack


----------



## wgmontgomery (Jun 9, 2011)

Not a problem; we are here to help!!


----------

