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Audyssey Room EQ Review

Sal1950

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As far as the house curve, you can try but not many have succeeded in improving on the curve created by Dynamic EQ via the program.
I wouldn't classify DEQ as a "house curve".
A house curve will normally introduce a tilt to the FR with a rise in the bass and a dropoff in the treble but can actually be any FR alteration that the user prefers and remains constant at any volume.
DEQ, fletcher munson curve, or plain ole "loudness button" as it used to be called varies the FR with volume level and normally introduces a boost to both the bass and treble ranges as level falls below some per-determined point.
Some users are known to actually use both together. Not as crazy as it seems at first blush. ;)
 

Chromatischism

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To me, it's a house curve, only better because it corrects based on volume level. Many people don't know that a house curve is only valid at one level, +/- a few dB.
 

Sal1950

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To me, it's a house curve, only better because it corrects based on volume level. Many people don't know that a house curve is only valid at one level, +/- a few dB.
I understand but we do need to have some reasonable definitions for various terms in audio.
House Curve "Preference", and Fletcher Munson "Correction" really are two different things.
The first based on person preference, the second based on the science of human hearing.
Just sayin
 

peng

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I understand but we do need to have some reasonable definitions for various terms in audio.
House Curve "Preference", and Fletcher Munson "Correction" really are two different things.
The first based on person preference, the second based on the science of human hearing.
Just sayin

That is true by definition, sort of, but still, you could be both right depending on the context. For example, the so called Harman curve is clearly based on "preference" as found in the Harman studies, and from based on what Dr. Olive said about the level used in listening tests, the so called Harman curve might have been based on levels below reference. If that's the case then Audyssey's DEQ curves that vary with volume level may actually work similar to the Harman curve(s) (+/- obviously..) at the listening level(s) Harman used in their study (or studies?). So in a sense, all such curves could be said as based on personal preference as well as on the science of human hearing.:)
 

Chromatischism

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That is a good point – I would have to see what dB level was used in the studies as that definitely affects how much bass people will add.
 

peng

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That is a good point – I would have to see what dB level was used in the studies as that definitely affects how much bass people will add.

He mentioned 78-80 dB, B weighted but that's for headphone. Someone may know how to contact him for the same info but for their studies on speakers.

 

Galz

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That is a good point – I would have to see what dB level was used in the studies as that definitely affects how much bass people will add.
It's not just the level, but the level relative to the level at which the content was mastered. You need both numbers to figure out how much compensation is needed purely due to level, before adding the room effects to the equation.

In general, assuming no loudness compensation used/needed, as far as I'm aware the need for a "house curve" comes from the fact you want your speakers to sound "right" in your room and do it by using a microphone that registers reflections and direct sound in the same way, while your ears actually separate the reflected sound from the direct sound (at least to some degree, and at least at the higher frequencies). The shape of the target curve tries to compensate for that difference (ears vs microphone), at in the best way that is possible by just changing the curve.

At the higher frequencies adjusting the target curve might still not be good enough, though, depending on your room, and you might have to just limit the correction frequencies to avoid poor correction at higher frequencies that you couldn't "fix" even with a better target curve.


Seems like some mix in loudness compensation into their target curve, even though it seems like that isn't the original purpose of a target curve, simply because their system doesn't provide a workable loudness compensation or that the available loudness compensation is not satisfactory.
 

Newman

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That is true by definition, sort of, but still, you could be both right depending on the context. For example, the so called Harman curve is clearly based on "preference" as found in the Harman studies, and from based on what Dr. Olive said about the level used in listening tests, the so called Harman curve might have been based on levels below reference. If that's the case then Audyssey's DEQ curves that vary with volume level may actually work similar to the Harman curve(s) (+/- obviously..) at the listening level(s) Harman used in their study (or studies?). So in a sense, all such curves could be said as based on personal preference as well as on the science of human hearing.:)
The Olive experiments were at a sufficient level that ’quietness compensation’ does not come into play.

So, not a factor.
 

Sal1950

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That is a good point – I would have to see what dB level was used in the studies as that definitely affects how much bass people will add.
Audyssey DEQ provides the option of setting the "0" db level.
Maybe already covered here?
DEQ.png
 

Galz

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I also like to select 15 dB for some extra bass but without twhomping the whole house.

The value chosen here mostly represents what level whoever mixed the original content was listening at. For movies, often 0 is the best choice (although as I understand, nowadays it's not so much a given fact). For much else, 10 is usually a good value. But there aren't any rules (except for movies, and even then it seems like the rules are sometimes broken). Of course, if you don't use DEQ and rely on your house curve, you might have even more trouble adjusting it on the go for different content. Eventually, as far as I understand, the loudness correction depends on the difference between the mastering level and the actual level, so as long as that difference is constant you could keep the same curve. But of course, there is no way to guarantee this difference is actually constant even if you always listen at the same level.

Seems like the only way to never need loudness compensation (or be able to keep a constant one integrated in the target curve) is if you always (or at least when caring about the quality) adjust the volume level until everything sounds balanced. Although for for different content that level could end up being a different one.

The only way I understand of to find the dynamic EQ offset needed, is to find the level at which everything is balanced, set the offset to that value (hopefully it's close to either 0, 5, 10 or 15), and then adjust to the desired listening level. Or just set the desired listening level and try find the offset which makes everything sound the most balanced. Of course, at least for me, it's often difficult to decide what's "balanced", because it's not always obvious how much bass was originally intended, although in some extreme cases it's easy to tell if the bass is overdone.

In the end, I just set it to 0 for movies and 10 for everything else, and forget about it unless something sound really off.
 
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Sal1950

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As I mentioned before, there's no rule against using a House Curve and DEQ together.
Using a preference House Curve created in something like the Editor app that sounds correctly balanced to you at 0 db, and then using DEQ to introduce the F-M curves (not exactly I know) can work very well in combination.
 

Chromatischism

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As I mentioned before, there's no rule against using a House Curve and DEQ together.
Using a preference House Curve created in something like the Editor app that sounds correctly balanced to you at 0 db, and then using DEQ to introduce the F-M curves (not exactly I know) can work very well in combination.
IMO you'll get way too much bass if you do that. As far as I can tell, DEQ works based on a table of values and it's assuming you're starting from the flattened bass response of the Audyssey correction. Remember, all of these features were coded years before D+M came up with the editor app.
 

Galz

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IMO you'll get way too much bass if you do that. As far as I can tell, DEQ works based on a table of values and it's assuming you're starting from the flattened bass response of the Audyssey correction. Remember, all of these features were coded years before D+M came up with the editor app.

If a house curve is depending on the room (with no additional bass boost for "taste") then how could DEQ assume somethin about it? It won't know your room gain or the required house curve slope. Then if that's still not enough bass then the bass can be boosted to taste. But at least theoretically (according to my understanding) you shouldn't have too much bass if you just raise the bass according to your existing room gain.
 

Sal1950

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IMO you'll get way too much bass if you do that.
It would depend on the amount of boost you added into the House curve,but
Using a preference House Curve created in something like the Editor app that sounds correctly balanced to you at 0 db
It should still sound balanced to you with DEQ at lower levels if the F-M human perception curves are correct.
Try it, you might like it. ;)
 

Chromatischism

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If a house curve is depending on the room (with no additional bass boost for "taste") then how could DEQ assume somethin about it?
In all of my systems, Audyssey has targeted a flat bass response, and achieved it.

DEQ was designed to work in conjunction with those EQ filters. It applies set dB boosts at different parts of the bass curve, variable with master volume level.

If you start with a boosted bass curve, DEQ will pile onto that. And, your own adjustments can only be ideal within a very small master volume level range, going against what DEQ is trying to do, like putting together apples and oranges. You'll have to test your own system, but if I did that, I'd have way too much bass, and my adjustments especially wouldn't work as well if I had to use a Reference Level Offset as a result of having too much. Because I find the DEQ slope to be perfect, it's best to just raise the sub levels rather than alter the curve.
 

Galz

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You seem to be working under the assumption is that a house curve (at least its bass portion) is purely for boosting bass to compensate for loudness. I'm quite unsure that is actually true, though, as if it was, why would some rooms need a different curve than others?

Raising the sub levels like a bad way of changing the curve, so I don't see how that helps with anything.
 

Sal1950

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If you start with a boosted bass curve, DEQ will pile onto that.
Yes it would, that's what DEQ does, but that's what a user tells the AVR it prefers thru the use of a boosted house curve.
Either the science behind F-M human hearing perception is correct or it isn't.
If it is, what ever you choose to start with as your preference balance at 0 db with sound the same to you at -30db.
 

Chromatischism

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You seem to be working under the assumption is that a house curve (at least its bass portion) is purely for boosting bass to compensate for loudness. I'm quite unsure that is actually true, though, as if it was, why would some rooms need a different curve than others?
It certainly is, because it is the "house" that has the greatest effect on the bass region.

Raising the sub levels like a bad way of changing the curve, so I don't see how that helps with anything.
Not at all. Nearly all Audyssey users raise sub levels to very good results. I don't believe the curve should be modified much beyond the flattening by EQ, otherwise you are introducing a sound that is only going to be right within a narrow volume range. And I mean like +/- 2.5.

"House Curves" are themselves an adjustment made to get to an ideal sound that is specific to a room, and it is done as a final target. DEQ is also a final target, so they will add together and overshoot. I don't believe they should be combined UNLESS your adjustments are made to the curve with DEQ already on. Then you are working on the final response.
 

Galz

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Of course if you listen with DEQ you should perform the listening tests to check your curve with DEQ on. What I'm saying that I'm not sure if you set your low frequencies to match your room gain, if that would actually result in excessive bass with DEQ on or not. I suspect it shouldn't. But then again it seems like the low bass level is very much a personal taste thing.

In any case, I don't see which problems you are solving by raising the subwoofer level over modifying the low frequencies by changing the curve. The subwoofer has a crossover filter applied so you are basically raising the low frequencies with a very specific curve when you turn up the subwoofer, and in addition you get that extra level just from the subwoofer and not your speakers. If you create a curve for your speakers and subwoofer so that they match at the crossover you can get a similar or better effect (better because you have more control on the actual curve, so at the very least you can get a very similar result to just raising the subwoofer level).

I find saying DEQ is meant for a flat curve and then raising the subwoofer on top of DEQ to be in contradiction with each other.
 
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