Logical Error??? Relation between Output level / Headroom / Efficiency

[totti1965]

Am I making a logical Error???


I don't listen to music very loudly (peaks usually under 83 dB and speakers only 6 feet away). For this reason and because I do some equalizing in the lower bass range (+ 2 dB), I also set Roon's headroom correction to - 6 dB to have some additional headroom for intersample overs.
Does my speaker, with an original efficiency of exactly 85 db/Watt now automatically become one with only 79 dB/Watt efficiency???
I now need four times the power for my speakers to reach my 83 dB peaks at the listening position (4.2 Watts instead of 1.05 Watts) -
Or not?
Where have the remaining watts gone? Is something (3.15 Watts) being converted into heat???
Or does the 85 dB speaker simply remain a 85 dB speaker?

I am a bit confused! Is the headroom correction perhaps just the same as turning the Amp level down a bit, so that nothing really changed?

Peak SPL Calculator

 

[JIW]

Am I making a logical Error???


I don't listen to music very loudly (peaks usually under 83 dB and speakers only 6 feet away). For this reason and because I do some equalizing in the lower bass range (+ 2 dB), I also set Roon's headroom correction to - 6 dB to have some additional headroom for intersample overs.
Does my speaker, with an original efficiency of exactly 85 db/Watt now automatically become one with only 79 dB/Watt efficiency???
I now need four times the power for my speakers to reach my 83 dB peaks at the listening position (4.2 Watts instead of 1.05 Watts) -
Or not?
Where have the remaining watts gone? Is something (3.15 Watts) being converted into heat???
Or does the 85 dB speaker simply remain a 85 dB speaker?

I am a bit confused! Is the headroom correction perhaps just the same as turning the Amp level down a bit, so that nothing really changed?

Peak SPL Calculator

You only reduce the level going into the speaker for the same volume setting. By reducing the level by 6 dB you also reduce the power by a factor of 4. What you need to make up the difference is a higher volume setting or more gain from the amplifiers if the volume has not enough upward range left.

 

[DVDdoug]

Does my speaker, with an original efficiency of exactly 85 db/Watt now automatically become one with only 79 dB/Watt efficiency???
I now need four times the power for my speakers to reach my 83 dB peaks at the listening position (4.2 Watts instead of 1.05 Watts) -
Or not?

No, but you probably need 2dB more power (about 1.5W) depending on how loud the bass is in the mix.

I am a bit confused! Is the headroom correction perhaps just the same as turning the Amp level down a bit, so that nothing really changed?

Yes, it's just turning-down the volume digitally. And since you are boosting the bass by 2dB, you should attenuate by at least 2dB to prevent digital clipping.

 

[Sokel]

What you must consider is not speaker's sensitivity (that remains the same) but power.
There's a difference though by what you exactly do down low.If you just upping with a 3dB self for example you'll need double the power but you will also have a higher level.
Filling a dip on the other hand by 3dB again you will still need double the power but without the level benefit.

For every positive EQ you have to reduce digital signal by at least the same amount and note that this must be calculated as additive depending how you EQ.

 

[unpluggged]

Does my speaker, with an original efficiency of exactly 85 db/Watt now automatically become one with only 79 dB/Watt efficiency???

Sensitivity/efficiency is a characteristic of the speaker itself and does not depend on the equipment/signals that drive it.

I do some equalizing in the lower bass range (+ 2 dB), I also set Roon's headroom correction to - 6 dB to have some additional headroom for intersample overs.

4 dB headroom for intersample overs? Do you routinely listen at full-scale levels? What is your chain and how you control volume? Besides, good DACs are designed to have enough headroom to accommodate for intersample peaking.

 

[Old_School_Brad]

No, boosting the bass by 2 dB means you’ll need 2 dB more power in the boosted range.

You’ll also need to lower the master volume slightly to prevent digital clipping. This reduction means the amplifier will need to provide 2 dB more gain to achieve the same perceived volume as before the boost.

Because of this, the amplifier might eventually reach its maximum gain, not because it lacks power, but simply because it can’t amplify the input signal to the level you’d like. That said, with only a 2 dB bass boost, this likely won’t be a significant issue.

 

[totti1965]

Thanx!

 

[MaxwellsEq]

Does my speaker, with an original efficiency of exactly 85 db/Watt now automatically become one with only 79 dB/Watt efficiency???

There's nothing you can externally do to change the efficiency or sensitivity of a passive loudspeaker. It is entirely constrained by the drivers, cabinet and crossover. Amplifiers, PEQ, tone controls room correction etc. have no effect on a passive speaker's efficiency

You can change a passive speaker's efficiency by taking it apart. You can can change the drivers to be more or less efficient. You can change the cabinet to be more or less efficient. You can change the crossover to be more or less efficient.

 

[totti1965]

There's nothing you can externally do to change the efficiency or sensitivity of a passive loudspeaker. It is entirely constrained by the drivers, cabinet and crossover. Amplifiers, PEQ, tone controls room correction etc. have no effect on a passive speaker's efficiency

You can change a passive speaker's efficiency by taking it apart. You can can change the drivers to be more or less efficient. You can change the cabinet to be more or less efficient. You can change the crossover to be more or less efficient.

Thanks! It makes my decision to take the Topping B100 instead of Topping B200 under the christmas tree more easy!
Obviously: Most of the time I just need ONE Watt peak power - and I would have 50 clean Watts / 8 Ohms with the B100. Nice to have 85 dB efficiency.