How do AVR's volume display correlate to power output? (1 Viewer)

[papamorff]

Hello,

I'm just getting into the hobby and am curious how power is represented by volume displayed by an AVR.
From what i've read, it's relative to your receiver's max power output (i.e. 90w AVR at 0db is max power/channel driven).

My REAL question is how does that play into an external amplifier?

Like i said, I'm new to the hobby, and I've ordered a pair of RF 7 iii and RC-64 iii that i plan on driving with an Emotiva XPA Gen 3 amplifier in conjunction with a Marantz SR-6015.

If all of this is hooked up, and no adjustments are made via software, is there a way to know what wattage is being pushed to the speakers without connecting any external test equipment?

Do pre-amp channels go off of the same metric that regular, driven channels do (0db is max wattage/channel driven by the amp)?

Any advice on the matter is really appreciated. Thanks!

-Nathan

 

[JohnRice]

The simple answer is, there is no real-world or established correlation.

Believe me. Possibly the most wide spread misconceptions in home audio regard this topic. It’s very compicated.

The good news is, in the end it also doesn’t really matter. What were you hoping to get from that information, if you had it?

 

[papamorff]

Mostly knowledge, I suppose.

I also don’t think it would hurt to know if I’m pushing my speakers too hard. I’d imagine a lot of folks will read that and scoff, but I can’t imagine how knowing a limit, and what percentage of that limit, I’m running them at would hurt.

Thanks for the reply!

 

[JohnRice]

Hello,

I'm just getting into the hobby and am curious how power is represented by volume displayed by an AVR.
From what i've read, it's relative to your receiver's max power output (i.e. 90w AVR at 0db is max power/channel driven).

The thing is, that's not how it works. There's a tendency to get too wrapped up in the idea that a certain volume level always means the same amount of power to all speakers. I'll give you an example. The level of sources will be different. One disc can have a volume level that's higher or lower than another disc. Same with streaming sources. So, let's say you are playing a particular movie, then switch to music that's mastered at a higher level. If you keep the volume set at the same setting, it will be playing louder, and putting out more power for the music that's mastered at a higher level, even though you never changed the volume setting. That's only one variable, and there are several more that come into play.

For you question, Klipsch speakers are rather efficient, meaning they don't need as much power as most speakers. Simply put, they play louder with less power. So they're less likely to strain your receiver. With an XPA-3 amplifier, you'll have far more power available to those three speakers than you could ever use. You'd go deaf first.

You mentioned worrying about pushing your speakers too hard. The more common problem is pushing the amp too hard, where it clips and damages the speakers. If you are using the Emotiva amp and the speakers you mentioned, I can guarantee that will never happen. You could still over-drive the speakers, but I find that incredibly unlikely, as long as things are configured correctly.

I've participated in a couple forum podcasts on this subject. You might find the FIRST ONE discusses some of the things you're asking and dispels some of the misinformation on the topic. The major, common misunderstanding is the difference between power and gain. They are two different things, but it's common to believe they are the same thing. The SECOND ONE goes into some other aspects of amplifiers and such.

 

[Mike Up]

Radio shack used to have a power meter which really was a voltage meter. It was Red LEDs which had the power indication above. I believe the 'wattage' was based on an 8 ohm load. So if your speakers were 4 ohm, figure 2X what it said. I have mine buried somewhere in boxes of electronics.

You can't go by the volume indication because different sources are at different levels where turning up the volume is needed on low level sources. The volume on Denon receivers has enough 'gain' to go above 0 by 18 decibels for a full volume of +18db. Manual states that the lowest level a source may be is 200 millivolts, to get full amplifier output.

 

[Edwin-S]

As far as I'm concerned you will know that either the Amp or speakers are being driven too hard because the sound will start to distort and sound shifty or the speaker cones will.sound like they are "popping" because they are exceeding their maximum limit of extension.

To me the best way to tell is always by ear. Frankly, with modern receiver/amps and speakers the volume will start to feel uncomfortable before the speaker and/or Amp limits are reached in the average room.

 

[Old Dog]

Mostly knowledge, I suppose.

I also don’t think it would hurt to know if I’m pushing my speakers too hard. I’d imagine a lot of folks will read that and scoff, but I can’t imagine how knowing a limit, and what percentage of that limit, I’m running them at would hurt.

Thanks for the reply!

I have been into HT for relatively little time, compared to most here, but also had the same curiosity for a good many years (including during my much longer involvement in HiFi).
John's comments are really "on the ball", but perhaps I can just give some real world info that I have just experienced with my room and equipment, that may give a little insight? -
I recently bought a used amp for my centre channel. It's a "pro" amp and has a feature that I have never come across before - a couple of lights that illuminate when the amp output reaches 2 volts (I had to read the manual to discover what they meant). During listening at my desired level, these lights flicker OCASSIONALLY. With regards to your power question, when illuminated the lights indicates the amp has reached 1/2 a watt output into 8 ohms.
My room is not huge (around 25-30 m2), my preferred volume level is around 75dB, my speakers have a sensitivity of 90dB/watt and are all 8 ohm, except for the centre which is 6ohm, I sit 3 meters away. At this, my AVR displays -25 to -20 dB (depending on disc).
Having efficient Klipsch speakers (certainly more efficient then mine), you are definitely making life easier for your amplifier(s). Not knowing how big your room is (distance from speakers), or how loud you like to listen, makes it rather difficult, but the likelihood is you may well be using far less power than you might think.

Footnote: I recently checked sound level with a meter and combined actual level with AVR readout to see how it compared to Reference Level. It may not have be the most scientific test, but it does seem to stack up and indicate the readout on my receiver can be used as a reasonable guide with regards to Reference Level. Results:

AVR Readout	Max Sound Level	Combined: AVR + MAX
-30	72.7	102.7
-25	78.9	103.9
-22.5	82.3	104.8
-20	84.2	104.2