"Your speaker levels should never be in the +."?

brijenjas

"Your speaker levels should never be in the +."
Said by Vr3MxStyler2k3,
in this thread, http://www.polkaudio.com/forums/showthread.php?t=35447
2nd post.

Forgive my ignorance, but why is this so?
Is there a danger of damage to the speakers or AVR with these settings?
Is the sound less bright/more warm at the "-" settings?
I haven't heard the difference with the settings below.

I thought the the speaker levels were adjustable in the receiver to achieve even sound, whether you had to raise or lower the levels.
I had my L/R mians at +3 because of how much louder my center channel sounded, I have since turned them back to 0 and reduced my center to -3.
I have the same "equality of sound" so to speak at these settings.

VR3

Theres no real advantage...

Some theorize that putting the levels below 0 (or starting them there) allows the preamp stage to process a cleaner signal.

I recomend it to everyone...

it is MUCH better to start out with -5 on the mains and get like +1 on the surrounds... than start with zero on the mains and get like 6+ on the surrounds...

Frank Z

Where you start has nothing to do with it. The whole purpose behind calibrating a system is to achieve equal SPL at a predetermined volume level. The Dolby digital standard is 80db and thats typically the reference level for most, if not all receivers that display a DD logo. Yes there are exceptions, my preamp for example, allows me to select any volume level I want as a reference level and then I can calibrate to that point. + or - means nothing, whats important is how close each speaker is to the reference level.

brijenjas

Thanks for the replies.
I suppose i should borrow a meter to measure the SPL.

A related question. I use amps for my main speakers, I have the amp volumes set at midpoint and adjust the speaker levels with the receiver,is this the correct way to do this?

Or is this a trial and error scenario, where I find the sound I like and set it there?
If I set the amp volume too high I'm sure I will get distortion.
Thanks again.

wingnut4772

Well all my speakers ended up being at or under 0 after SPL calibration with the exception of the back two (+1) and the sub (+2 at about 3db hot) so I guess I am ok.

danger boy

my center and surrounds are often calibrated in the low + numbers.. the center more so than the surrounds.. it's not unusual for my center to be + 4 or +5 with surrounds around +1 or +2

Frank Z

brijenjas wrote:

A related question. I use amps for my main speakers, I have the amp volumes set at midpoint and adjust the speaker levels with the receiver,is this the correct way to do this?

Or is this a trial and error scenario, where I find the sound I like and set it there?
If I set the amp volume too high I'm sure I will get distortion.
Thanks again.

What amps are you using? Can't say I've ever dealt with an amp that has its own volume control. Distortion is always a possibility, but it will depend on what type of amp and what it is rated for.

As far as settings go, get an SPL meter and take a look at the following link....
http://www.audiophilia.com/hardware/spl.htm

adam2434

Yep, a SPL meter is the way to make sure you're properly calibrated, especially if your receiver does not have an auto-calibration system.

Several factors will determine the relative level of each calibrated speaker:
Efficiency of the speaker
Position/distance from SPL meter or calibration mic
Room size and layout

Don't worry whether the numbers are + or -, just be sure to get them at the same level on the SPL meter at your primary seating position.

Regarding your amp question, running at the full volume setting will not necessarily cause more distortion. If the separate amps are more powerful than your receiver, you may need to calibrate them down a few notches from your other channels. For example, I run my amps at the full volume setting and my receiver's auto-calibration sets them to -7 to get them at the same level as the other channels. My receiver would power the center and the surround L/R and set them to something like -0.5, +1.5, +2.0, respectively.

The only reason I would reduce the volume on the amps is if they were more noticeably noisy at the highest setting.

adam2434

The volume you referred to may actually be for the input level. That's what it is on my amps.

brijenjas

Frank Z wrote:

What amps are you using? Can't say I've ever dealt with an amp that has its own volume control. Distortion is always a possibility, but it will depend on what type of amp and what it is rated for.

As far as settings go, get an SPL meter and take a look at the following link....
http://www.audiophilia.com/hardware/spl.htm

The amps are AudioSource AMP100. It is in fact a volume control,at least that's what it says over the knob.

Thanks for the link.

SKsolutions

I will add my two cents for what it's worth. When you deal with line level or low level signals (a mic for example), the rule of thumb for an audio engineer is: Set it to 10, and back it off a "smidge". This is to increase the signal to noise ratio in any signal before amplification. As dB is a metric to measure, you can use more absolute measurements that are linear (mV) Increasing the amplitude of a low level signal puts 'distance' between the top of the wave and noise threshold. That's about the best I can remember from days gone by.

So, you should experiment. I have my settings as high as +8 on two speakers, and as low as -1 on another. I say set em high, but keep in mind that some preamps will clip, especially in the digital realm.

Again, my two cents, and my "smidge" might be different than yours. My amp goes to eleven.

Thanks to those that have welcomed me,
SK