TOPIC:

Guys,
Our loudness perception of frequencies changes depending on volume setting.
When dirac corrects, does it assume a particular sound level?

What I'm thinking is once you have a preferred target curve, could you modify it based on something like the fletcher-Munson research so that config 1 is for low volume listening and config 4 for high volume and have your target curve compensated according to available research.

But if you were to do this I guess you would want to adjust +/- from whatever level Dirac assumed was the default listening level.

Yes. However in practice I don't find that I really use that feature. I find that one setting seems to work best across all scenarios.

PS no, Dirac just gives you a flat-rate EQ curve at all levels. I'm not aware of it doing amy adjustments based on level.

Dirac doesn't make any particular assumption about listening level, unless you perhaps argue that the default target curve will be more suitable to some listening levels than others.

I do think a different low-volume preset is a good idea if you do have times you listen much quieter than normal. I wouldn't personally get into having 4 different presets as I don't think it's necessary (as normally you can adjust the volume instead) and you'll also risk constantly worrying if you're using the 'right' preset.

Of course, you’re both right. The curves aren’t what’s measured but what’s perceived. Each loudness curve would measure flat. So yes Dirac doesn’t compensate it just aims for flat (+/- target curve). It’s us that hear it being different.

Certainly I think there is value in having a regular and a quiet curve. When I listen at low levels I can hear some really, really subtle things in the recordings but the bass seems weak. At louder levels the bass gets stronger and the subtleties become a little lost.

The other important distinction is between test signals and music. It might be tempting to think that we want EQ to make the response match an equal loudness curve so that say bass doesn't sound quieter than the midband. The reasons we don't is because muscial instruments and mixing engineers mean that in recorded bass frequencies are louder anyway. Use the RTA to see what the spectrum looks like for music some time and you'll see this even if you had applied EQ to give a perfectly flat response.

So if sound engineers/mixers have known about equal loudness since the 30s and the Harman research since (not sure when), shouldn't we be setting a flat curve for any modern recordings? If not, are we not potentially boosting already boosted frequencies?

asx77 wrote:

So if sound engineers/mixers have known about equal loudness since the 30s and the Harman research since (not sure when), shouldn't we be setting a flat curve for any modern recordings?

Short answer no. In that doing anything other than what results in the sound you enjoy most makes zero sense to me.

Don't think in terms of engineers applying boosts BTW. Bass instruments inherently have higher SPL outputs. They have been designed based on how we perceive sound. Any level adjustments at a mixing/mastering stage will also ultimately be done by ear.

"So if sound engineers/mixers have known about equal loudness since the 30s and the Harman research since (not sure when), shouldn't we be setting a flat curve for any modern recordings? If not, are we not potentially boosting already boosted frequencies?"

Hmm..
Hmmm how do I answer this..

It's more complicated than that. Engineers themselves will use equalisers on their main monitors. But the thing you need to understand is that the reason you would use a house curve in the first place is because there are different characteristics to the off-
-axis response of your speakers as well as the Acoustics of the room you are listening in. The on axis response should generally be pretty flat, it's just that in certain environments (like in the car for example), due to the nature of the Acoustics in the car you often need to cut the highs and boost the lows for it to sound flat to your ears.

In reality though, and I can attest this from experience, you can hear that it's been EQ'd like that because you're screwing with the direct response in order to get a flatter power response through a house curve. Before you ever worry about a house curve, it's best to have speakers that are optimized for the room you are in, and to have ideal room treatment.

Assuming you have your room properly treated and a flat response sounds good at moderate to high levels, then all that you would use a loudness contour for is to correct for how loud you are listening since that changes frequency response of your ears themselves.

To cap off:

1) Loudness curves correct for your ears themselves. Those are generally useful across the board. Many audio processors already feature the ability to adjust the loudness Contour depending on the volume setting. Even my car stereo does this - when you turn on the loudness it boosts the bass and highs more and more as you turn it down.

2) A house curve generally exists to "fix" the perceived flatness of a system, which is generally driven by how the off-axis response of the speakers drives the room. A great example of this is in my car I tried using very directional tweeters and I found I had to cut the high quite a bit for it to sound flat, so I switched to wide dispersion tweeters and now I can run the highs much hotter (closer to flat) and it sounds much better that way.

PS forgive the various grammar errors if you noticed them!