Cranked the system up to 0 and it hurt my ears . Wondering if any body knows how high on the + side the 990 and the 7500 goes. Using axiom speakers and the louder,the cleaner.

I think it tops out around +5dB or so, although the exact max apparently depends on the channel calibration (too much + trim may pull that maximum setting down some).

You can test without a source playing. My range is -76 to +8.

That's the same volume range I get too.

OK, I've been curious about this, too.

I have the same volume range, -76 to +8 db. So, does this mean, then, that -34 db is half the volume of my amplifier?

thanks,

John

A decibel is not a linear unit - it's logarithmic. That's the way the ear works too. Gonk could probably explain this better, but the point is that what the volume setting controls is the power delivered from the amplifier to the speaker. Of course this corresponds to the loudness of the sound you hear, but not in a simple way. A ten-decibel increase in the volume setting means a ten-times multiplication of the power delivered to the speaker, so if, for example, 70 db on the volume setting, while playing pink noise (equal energy per octave), represents one watt of power delivered to the speaker - and it might, depending on the amplifier, not the 990 - then raising the volume setting to 80 db would increase the power delivered to ten watts and lowering it to 60 db would decrease it to 100 milliwatts. And going on the same scale, 90 db would mean 100 watts and 100 db would mean your amp would be overdriven unless it's a 1000-watt monster, and your speakers would be smoking ruins (remember this is steady-state pink noise I'm talking about, not music!). But, you're asking, what does this have to do with how loud the sound will be? That depends on the sensitivity of the speaker. Outlaw hasn't released the figure for their new bookshelf speaker, but a typical level for speakers other than horns would be around 85 db for a 1-watt input. That's loud enough that 8 hours' steady exposure in a workplace will result in hearing damage. As for "louder" and "softer", people report hearing a 10-db change in the power delivered to the speaker - remember, that means 10 times as much power or one tenth as much, depending on which way you turn the knob - as being "twice as loud" or "half as loud". Merely doubling the power to the speaker (which is a 3-db power level change) is about the smallest change in loudness that's easily noticeable, though in lab conditions people in anechoic rooms with headphones can detect a 1-db power change.
So where does that leave your question? If "half the volume of [your] amplifier" means half the power output, then whatever volume control setting on the 990 drives the amp to its peak (and you and I DON'T know what that setting is), dropping the volume control setting by 3 db will actually drop the amp's power setting by 50%. Surprising but true. (And by the way, amplifiers output audio signals, not sound. Speakers turn those signals into sound. That means only the speaker's output can accurately be said to have volume.)
And reducing the volume control setting by 10 db will make the sound you hear about half as loud as it was before.
There's lots more one could say about this, starting maybe with the sensitivity of the amplifier, but that's enough confusion for one day.
Enjoy whatever you listen to.

I like Cheese




nice answer psyprof1

I agree,

an excellent explanation, psyprof1!!!

I hear what you're saying; thank you!

John

This thread makes me think of something I've always desired. I'm sure others have too. I often wish I had any sort of accurate way to determine the amount of wattage actively being output by my amp. Whether that's max, min, middle, or anywhere in between.
Oh well, the 7500 still gets the job done.

You can always use a device like the Kill-A-Watt to measure the power being consumed by the amp - it doesn't tell you how much of that energy is wasted as heat and how much goes to the speaker.

By the way, good explanation of a very slippery topic, psyprof1.