There's an old parable about "focus"......
It's late at night, and a person walking along the street sees another fellow carefully searching the ground under a street lamp.
Guy #1: Hi; what are you doing? Can I help you somehow?
Guy #2: I'm looking for my car keys; I seem to have dropped them.
Guy #1: I'd be glad to help you; where did you have them last?
Guy #2: Over there (points to a car parked about a half block away - in a very dark part of the street).
Guy #1: I'll be glad to help you, but, if you dropped your keys over there, then why are you looking for them
HERE?
Guy #2: Because this is where the light is!
If you're wondering what in the heck this has to do with amplifiers..... I'll tell you.....
The value that determines how loudly an amplifier will play at a given volume setting is the gain.
The amplifier itself has a certain gain structure - which determines how much power it will put out with an input signal of a given voltage going in.
The preamp or pre/pro has a gain structure, which determines how much it will boost or cut the level of the signal coming in when you set it to a particular number.
Together these two determine what setting on the preamp will produce a given loudness - in your room - with your speakers.
The particular numbers involved are often meaningless or arbitrary.
The 29 dB gain on our power amps means that the voltage you put in will be boosted by 29 dB (so, for 1 V in you will get a certain power out - this is independent from the
MAXIMUM output power of a certain model).
Our XMC-1 happens to be calibrated in dB of gain (so, if you set the XMC-1 to 0 dB, the signal going in will be passed with no boost or cut - which is sort of a standard meaning for "0 dB" - in some circles).
The dB gain scale is also traditionally negative - with 0 dB being "reference" and lower levels being expressed in "minus dB" - which us why -20 dB is quieter than 0 dB.
The dB scale is also set up so that the difference from -10 dB and -20 dB should be the same proportionally as the difference between -40 dB and -50 dB - which works well for audio.
If we'd wanted to, instead of reading from -96 dB to +11 dB, we could have had the display read from 0 to 10.... or from 0 to 100... or from -9346 to +492... and it wouldn't make much difference.
The actual range of the control is 107 dB so, if we wanted to accurately represent the dB scale, and stick with dB, it would have to be two numbers that are 107 dB apart.
And, as I mentioned before, having a gain of x1 represented by "0 dB" is enough of a standard that it's worth using.
Now, back to our parable........
We use the volume control to adjust the level when we listen to music, and the number it's set at is nothing more than a handy reference - so we can remember where we like to set it
on a certain piece of equipment, when it's connected to other certain pieces of equipment. It really doesn't matter in the least whether your favorite listening level happens to be
-26 dB, or +11 dB, or 47, or even 9346.3 ..... and long as knowing that number helps you set it to the same place next time, and to have some idea how much you're changing it when you dial it
higher or lower; most of us grow accustomed to what the numbers mean on our equipment pretty quickly. We happen to like the "minus dB scale" because it actually has some technical meaning,
but which way you choose to do it, and which number you end up being set to really doesn't matter at all....
And thinking about whether the number setting that happens to work for you, and whether it's different than the one that happens to work for someone else, is really just a distraction....
Of course, if the number scale shows you that you've reached the top setting, and your system still isn't loud enough, then the number has served to inform you that the gain structure
of your system isn't sufficiently high to satisfy your needs. However, as long as you can get your system to play as loudly as you want it to before "the knob runs out of range", then everything
is just fine. Incidentally, within certain limits, gain is not "hard to do" or "expensive". When you design circuitry, with all else being equal, there is usually a tradeoff between gain and noise,
and keeping the gain lower generally results in a circuit that's quieter. However, there's no other valid reason to suggest that something with a higher (or lower) gain is "better".
We could have made the gain on the XMC-10 times higher, or a hundred times higher, or ten times lower, and it wouldn't have cost more to design or build.
We chose the value that gave the best overall combination of useful output level and lowest noise.... there's nothing more to it than that.
Two more things worth noting:
1) The idea of not wanting to set the control "too near the top" comes from the old days - when some equipment actually would tend to distort when you set its volume control near the top of its range.
This isn't really an issue with most modern equipment - like the XMC-1.
2) Because the volume control sets gain rather than output power, it's quite possible that your amplifier will be at maximum power when the volume control on your preamp is set at 30% or 40%.
However, if that's the case, then it
DOES NOT mean that your system will have more power - or be "more dynamic".
All it means is that, if you turn the volume control above the number where your amplifier is delivering its maximum power with your current input signal, you will cause your amplifier to distort -
which will make it sound bad - and quite possibly damage your speakers (or even your amplifier).
I also have an AV7702 with Crown pro amps. At a volume level of 70 I'd be blasted out of the house! I'm using all RCA connections even though the three amps have XLR inputs. I doubt if there is much difference between XLR and RCA in the gain department. I wouldn't expect any sound quality difference so I won't be using XLR cables. My normal listening levels are around 45-50 for TV and movies. IIRC the Crown amps all have gain of 26db. I just don't remember where I read that and it isn't listed in the specs. The Emotiva amps are either 29 or 32db - a bit hotter than the Crown amps but that isn't a big difference.
I just watched a bit of an old favorite DVD - Lord of the Rings to get a feel for the Marantz since I just got it today. The Fellowship of the Ring. I've always found myself adjusting the sound when the action gets heavy. I was ranging from 48-55 while listening/watching the movie. The Crown amps have a bit more power than the XPA series amps but the effect on volume is minimal - probably 3db or less at the listening position. Speaker efficiency also has a marginal effect.
Have your run Audyssey? If not and you haven't been into the speaker level menu they should be at 0db trim. No gain or attenuation on any one channel. The full range is from -12db to +12db. That is 24db - not insignificant and leaves lots of 'room' to pair up very powerful amps with less than powerful amps. 0db is where the trim was on mine before I started farting around with it. Had to boost the center and both surround levels.
I just got it today and so far I'm impressed. Two channel sound is quite good - probably not quite what the Sherbourn 7030 I just sold has but its very close. So far it sounds great - can't imagine that will change.
If the numerically high volume number bothers you just set all your speakers at +12db. Mine are all pretty close to 0db with my smaller sub (12" sealed) set to +4db as well as the adjustments I mentioned above. If I hiked them all channels up to +12db 40 on the volume would be just about right. What that number is for is just a reference for you so you can find the level you like so you don't get blasted out of your chair when you fire up the audio.
