Volume setting vs amp work load

[Bevan]

i'm wondering what is the essential difference between having

1) receiver vol at 80% and sub vol at 50%, and
2) receiver vol at 50% and sub vol at 80%

i'm guessing that even though spl's might be the same, that 2) might cause the sub to work more having to amplify a lower level signal? this might maybe be why its often recommended to set sub vol to between 10 and 12 o'clock?

but what i'm really wondering, as i have a sub that is challanged in the spl department, is why shouldnt i set my source to +10db, my receiver to +10db, and my Outlaw ICBM(when i get one) to +10db, and then only have to set my sub to say 8-9 o'clock to get the volume i need.

whats the dissadvantage, if any, to amplifying the signal a much as possible before it gets to an amp?

thanks in advance

b

 

[Buckle-meister]

i'm wondering what is the essential difference between having

1) receiver vol at 80% and sub vol at 50%, and
2) receiver vol at 50% and sub vol at 80%

i'm guessing that even though spl's might be the same...

They wouldn't be the same SPL.

For 1, if 80%=50% (i.e. same SPL), then for 2, the receiver will have gotten quieter, but the sub will have gotten louder!

Regards

 

[j_garcia]

It's the same either way, if you are talking about calibrating to the same SPL level. The sub ultimately does the same amount of work in the end to achieve that SPL. Too low of a voltage though may cause a few problems - 1) the sub may turn off during quiet passages and 2) very low input voltage with the sub turned way up means the distortion component is also higher. Everything is amplifed, bad as well as good, so background signal noise will now be louder.

Every room is different, so a 12'oclock blanket recommendation doesn't work. I use the rule of thumb of starting with 50% gain on the sub and seeing how that translates to the receiver's setting. If it's close to 0 on the receiver, I say adjust the sub so that the receiver is at 0 and then you can do any subsequent tweaks via the receiver only. If 50% gain requires a large adjustment up or down at the receiver, then it's time to find the point at which they agree without having the sub's level turned up too high (I wouldn't run my sub at 75% gain).

If you set all of your devices to +10dB you will get +30dB at the sub, will you not?

 

[Snap]

Jgarcia is right. I would never run my gain settings above 75%, even my pro audio stuff, the amps gain s not going to be set above 75%.

Do the stuff J Garcia said to do. Set the gain at 50% and start your calibration from there. The closer to "unity" you can get the better off you are. "Unity being 0"

The cleanest sound you can get is if you can get your sub settings around Unity, and the sub no more than 50%.

Good tips Garcia!

 

[Bevan]

thanks.

seems there are no free lunches then. will keep it at 50% where it is at the moment.

b