Volume rating in - db ???

[stef_000us]

Hello everyone,

This is my first post here but I have been lurking for awhile and learn a lot from the discussion in the forum. I am also new to home theater setup so I got a lot to learn (but I LOVE the sound of it!!!)

Something that still puzzle me is the volume rating on the AV receiver in -Db notation. How does this work exactly? I didn't see any discussion on this topic. Is there any article that I could read to understand this better?

Here's the specifics questions that I am trying to figure out. My receiver is rate 75W per channel (6.1). The volume goes down to -100Db (which is mute). Is that thing a linear scale??? Does this means that at 0db, I should expect 75w per channel? -50db 35Watts? -75Db 18 watts?

Thanks for any info,

Stephan

my setup: front rti70 (large), csi30(small), surrond Rti38(large), sub Cht-10 (xover at 65), AV Yamaha htr-5560.

[pensacola]

There are others on this forum more qualified, but I'll take a stab.
(I'm sure they'll correct me when necessary).:)

I'm sure that scale is more theoretical than actual.
The only thing for sure is that at 0 db attenuation you'd be hearing 75 watts, and at (-)infinity attenuation you'd hear 0 watt.
In between, it gets kinda dicey.

A 3 db increase in volume requires a doubling of power. Conversely, a 3 db decrease would require half the power.
This is impressive, given that the smallest change in volume we can generally detect is around 2-3 db.

Keep in mind that at our "normal" listening level, we are hearing about 1 watt of power. Crank it up, maybe 10 watts. The reason for the extra headroom is to handle the transients of a bass drum--or "thud", in the case of a movie soundtrack. An amp cruising along at around 10 watts would need about 160 watts of power just to reproduce a 12 db peak.
The more headroom--so it goes--the more effortless (and natural) the sound.

The wattage that your amp puts out is always varying depending on the program content (unless it's a steady test-tone). Therefore, you can't really say that you're listening to 20 watts or 35 watts.
Average, maybe.

You can also see how important your speaker's sensitivity can be. Less-sensative loudspeakers require much more power than their highly-sensitive counterparts to maintain the same SPL.

Hope it helps more than hinders.

[stef_000us]

Originally posted by pensacola

Hope it helps more than hinders. [/B]

It sure does help. Thanks.

[PETERNG]

pensacola

great post, very informative...

[mantis]

I think you made a good stab at it.........nicely put.
Here's a little tid bit.Old volume controls was straight analog.Today more and more receiver's/preamps have got away form that.It can be confusing trying to understand the whole db thing...better put negitive db thing.
Most receiver's use the 0db setting as a reference point.This is where is has the best overall performance before distorting but.............and i mean BUT.............this can be extremely to loud if your receiver's power exceed's the room it's in.
This is a whole big disscusion.
But I will keep it short and simple.Turn up the volume to a comfortable level and enjoy.If you have to gointothe positive db scale to achive the desired listening levels then you need more power hince a better receiver.
Don't get to wrapped up in the -db scale..it's still the same as the old analog but it's a little different.
Funny how different companies do it so different.Wasn't like that years ago.

[jeberhart]

The best way to adjust volume is with your eyes closed. Or don't look at the readout. It's about listening at a sound level your ears like, not your eyes or even the db scale. The only thing I don't do is exceed 0 db.

[goingganzo]

i listen to mine at around -20db it is prety loud at that setting i have never turned it past -10

[ward91]

I’ve listened to mine at +18 bd and it sounded fine although it did hurt after a small while usually listen to at -15db

[ward91]

i sent an email to marantz and they replied that my amps ratings are 80 watts between -5 and 0 db ???

[audiobliss]

Hmm. Very interesting, mantis; thanks for the info. I had no idea that was the reference for the db scale on receivers. So, according to the manufacturer, 0 is about as high as you want to go before it starts clipping? Then why do they let you go so high into the positives? My Yamaha will go to +16.5; that's pretty high if 0 is all you want to take it to.



Oh, and btw, I've had mine up to about +15 or so. Almost all the way. Now, only for about 3 or 4 seconds, if that. I don't want to go deaf or mess-up anything. I can't remember how loud I turned it up when I was blowing my old Sony speakers though...hmm.....

[McLoki]

I had thought this was an easy question, as it turns out, everyone has a different opinion on the matter so its a really great one....

My thought was to reference level. When you use a setup disk (video essentials or Avaia) you set it so that at 0db you are running at reference level. (101db peaks from speakers and 115db peaks from the sub - those could be off a few db and could change with speakers set to large or small, but you get the idea)

That way everyone can say what they listen at reguardless of equipment and all be talking about the same relative volume measurment.

BTW - I listen from -25 to -10 depending on the movie and if the wife and kids are home... :D

Michael

[Phil Dawson]

Just a quick note. An increase in 6dB equals a doubling in volume. The other stat is a real kick. It takes a ten fold increase (20 - 200 for instance) in output wattage to double the volume. This means that the 450 or so watts I have going to my fronts isn't even twice as loud as your 80 wpc amp. Oh well it still sounds good and there are headroom issues besides.
Good Luck, Phil

[heiney9]

I'll take a stab here. Decibel (db) is a unit of measure, hence it needs to be measured (w/ equipment) it can of course be calculated but that isn't dead on accurate. So when you see those -db #'s show up this is simply a guide/guage/indicator/marker/reference point and doesn't in any way represent the true db output of you system at that time. And of course each maufacturer is going to have a slightly different gain on the vol. pot so one manufacturer's -28db isn't going to be exactly the same output level as another manufacturer's -28db. They may perhaps differ widely. Much like a gas guage on a car. 1/4 of a tank of gas is going to be slightly different for each make of car.

It's used as an indication of where the output is at that moment and really has no relation to actual decibel measurement. Another thing to consider is the db is a logarithmic expression and the volume control most likely is a linear expression.

FWIW

H9

[Mazeroth]

It's 10db for a doubling in volume, not 6db.

http://www.gcaudio.com/resources/how...eloudness.html

Just a quick note. An increase in 6dB equals a doubling in volume. The other stat is a real kick. It takes a ten fold increase (20 - 200 for instance) in output wattage to double the volume. This means that the 450 or so watts I have going to my fronts isn't even twice as loud as your 80 wpc amp. Oh well it still sounds good and there are headroom issues besides.
Good Luck, Phil

[Phil Dawson]

Traditionaly 6dB has been the accepted value for doubling of volume. There is a fairly recent study out of Princeton (I think) that shows that the figure is (in their conclusion) closer to 10dB. To be safe Bruce and Jenny Bartlett in their book Practical Recording Techniques Third Edition (brand new edition) state "A 6- to 10-dB increase in level is considered by most listeners to be "twice as loud."

[Mazeroth]

After reading what you wrote you kind of contradicted yourself. 10x power equals a +10db gain.

No harm, no foul :)

It takes a ten fold increase (20 - 200 for instance) in output wattage to double the volume.