[geoffire]

I found this off this website while I was researching line arrays:
http://www.gtaust.com/filter/05/07.shtml

Awsome info everyone should see.
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More on the Ear

The human ear also is not sensitive to very high frequencies or very low frequencies. This is the origin of the “smilie curve” you may see on some equalisers set by people listening to music. (Check out any graphic EQ that returns from hire to a karaoke gig). The tendency is to boost bass and high frequencies. It might make music sound good but it will make live speech harder to understand, especially in a reverberant or noisy environment.
Loudness Contours

For the benefit of designers, way back in 1956, a couple of guys called Robertson and Dadson developed a graphic representation of free field equal loudness contours of pure tones. It shows how we hear a range of pitches. It is a frequency response graph of our hearing:

In the development of the loudness contours, a person listens to a sweep of frequencies across the frequency spectrum and sets each to what they hear as the ‘same volume’. As you will see, what we consider the same volume in each frequency band varies considerably in power required to amplify each frequency to the same perceived dB level. This will vary from person to person. In other words, we do not all hear the same.

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So... Tuning for the most natural sound would follow that curve? or is that already compensated for in the recordings?

 

[npdang]

I think you're confusing 2 separate issues... the sensitivity of the ear vs. frequency and spl, and reproducing a signal exactly as it was recorded.

 

[ArcL100]

*shrug* either way I almost always bump bass and treble in the car, in the home, or on the pc - whether that's due to limitations in the source or environment or listener, you tell me. It just sounds lousy otherwise.

-aaron

 

[geoffire]

well if you could tune your setup completely flat with a MLS setup, that would reproduce the sound exactly as recorded, but would it sound as intended?

If I'm understanding this right, At low listening levels you may not be able to hear the lower frequencies all together even if it is in the recording and your setup is tuned flat.

 

[raamaudio]

When I first bought an RTA I spent two long days tweaking to get a perfectly flat response first then a nice curve like the example in the RTA manual.

Then I had a very gifted tuner have a go at it, 45 minutes later the settings looked nothing like what I had done.

But, it sounded 10 times better

An RTA is a good ball park tool to find major problems with then you need to put it aside and tune by ear, a well trained ear being better of course, I still need help after all these years.

Rick

 

[geoffire]

This is talking theoretically of course, the final answer is what your ears like, but interesting none the less

 

[ArcL100]

Lol in my experience, whether tuning a car or tuning the stereo, theory, like Rick stated, should only be considered a starting point.

-aaron

 

[npdang]

Depending on the speaker, listening environment, etc. boosting bass and treble could be the "correct" thing to do.

FR plots do not tell the whole story... in other words a flat frequency response doesn't necessarily mean that you are reproducing the recording accurately. It very much depends on understanding how/what you are measuring.

I guess the whole point is that if you played the recording at it's intended level, it will/should sound correct. Lower, or higher volumes deviate from that. Imagine trying to record a live performance. Why should it sound the same at lower volumes as it does at it's original one? Equal loudness contours tell us that it shouldn't... if it did, then it would sound weird when played back at it's original level.

 

[Derek]

i've always enjoyed my car flat from 1k on up to 20k......and a little boost down low....

 

[300Z]

Depending on the speaker, listening environment, etc. boosting bass and treble could be the "correct" thing to do.

FR plots do not tell the whole story... in other words a flat frequency response doesn't necessarily mean that you are reproducing the recording accurately. It very much depends on understanding how/what you are measuring.

I guess the whole point is that if you played the recording at it's intended level, it will/should sound correct. Lower, or higher volumes deviate from that. Imagine trying to record a live performance. Why should it sound the same at lower volumes as it does at it's original one? Equal loudness contours tell us that it shouldn't... if it did, then it would sound weird when played back at it's original level.

I agree 100%...

I have worked in Recording Studios setups with proper flat FR and it always sounded spot on just like it should... That's a lot more to it than just a "flat FR"...

 

[Jim85IROC]

I think a big reason why a measured flat response may sound bad is because our ears do a very good job of ignoring a lot of the effects caused by the environment you're in... mainly the "room effects". When you have a conversation with a friend, his voice is recognizable whether you're outside, in your kitchen, or in a home theater room. In each case, his voice would measure much differently, yet he basically sounds the same to you. The same thing happens with your music, so when you use an RTA, you're basically trying to equalize the response back to "flat" when in fact, quite a bit of the frequency response variations are due to room interraction, which is something your ear has learned to largely ignore. By equalizing that out, what you're left with is a very uneven direct response, although your power response may be flatter.

 

[foley316]

Smile curve = Fletcher-Munson Curve

 

[montyburns]

I don't know if its exactly a smile, but I imagine the fletcher-munson curve is why many people like a 'BBC dip,' though I imagine it was not created for that purpose.
Anyone have any thoughts on a correlation between highly compressed music and popularity of the smile curve? EDIT: I'm referring to dynamic compression of recordings, not Mp3s

Smile curve = Fletcher-Munson Curve

 

[SQ_Bronco]

This is interesting...

http://en.wikipedia.org/wiki/Fletcher-munson_curve

 

[foley316]

The fletcher munson curve shows where the human ear is most sensitive therefore the smile curve is what most people use because it tends to be the most pleasing.

 

[npdang]

A smile curve is not more pleasing sounding Imo... it's just used because most speakers out there have poor treble and bass extension.

I know alot of speakers also have a BBC dip to control for a peak in the response off-axis.

If you're playing a recording back at it's original level, a flat response will almost always sound the most accurate.

 

[geoffire]

I see what your saying npdang, how are we to know the level to play the recording though? in a car where the noise level is varying is it even possible to achieve?

 

[npdang]

I see what your saying npdang, how are we to know the level to play the recording though? in a car where the noise level is varying is it even possible to achieve?

You would tune your system flat, so that the speakers reproduce the recording exactly as intended. The point is not to have a flat listening response at the ear, but to have the speakers reproducing the recording without bias.

However, if you only listen at certain levels (say really loud or really soft) I could understand that you'd want a BBC dip or boosted bass levels.

 

[MarkZ]

I guess the whole point is that if you played the recording at it's intended level, it will/should sound correct.

This is assuming that the engineer had the same things in mind that you do.

 

[fugyaself]

well if you could tune your setup completely flat with a MLS setup, that would reproduce the sound exactly as recorded, but would it sound as intended?

Thats the main problem right there. We dont know how records get produced from each producer. Some might enhance certain aspects of the recording so that it sounds good over the radio or on standard crappy stereos. Look at Dirty South rap for example. Very bass heavy so that it has some presence. Play it on a flat system and you have too much bass IMO.

This is why the idea of SQ is losing its impact for me.