Reason for loudness frequency effects ?

[vasyachkin]

i understand why ear is more or less sensitive at various frequencies.

i do NOT understand why relative sensitivity of ear to different frequencies depends on loudness.

anybody know ?

in case of listening to music this may be an effect of masking due to ambient noise ?

but equiloudness curves weren't arrived at by testing against background noise were they ? so then that can't be the explanation.

perhaps masking effects due to ambient noise require bass equalization in ADDITION to whatever equiloudness curves would suggest is needed ?

[djg]

And why don't they put loudness switches on receivers anymore?

[billfitzmaurice]

i understand why ear is more or less sensitive at various frequencies.

i do NOT understand why relative sensitivity of ear to different frequencies depends on loudness.

anybody know ?

So a sleeping mother will be awakened by her crying child, and so that hunters unable to see each other can hear each other. The ear is most sensitive in the bandwidth of the human voice, and the brain is hardwired to hear human voices even at very low levels, in effect filtering out less important frequencies.

[maynardg]

Bill, I was going to say "because it is adaptive", but you beat me to it.

[madmallard]

So a sleeping mother will be awakened by her crying child, and so that hunters unable to see each other can hear each other. The ear is most sensitive in the bandwidth of the human voice, and the brain is hardwired to hear human voices even at very low levels, in effect filtering out less important frequencies.


to listen for sabertooths?

[vasyachkin]

that makes sense Bill.

i guess you simply don't need to hear thunder bass at 0 db :)

[billfitzmaurice]

to listen for sabertooths?That too. It obviously worked, we're still here, they aren't.

[vasyachkin]

That too. It obviously worked, we're still here, they aren't.

there is a funny T-Shirt with Osama bin Laden saying " i am still free - how about you ? "

:)

[jcapodieci]

i understand why ear is more or less sensitive at various frequencies.

i do NOT understand why relative sensitivity of ear to different frequencies depends on loudness.

anybody know ?

in case of listening to music this may be an effect of masking due to ambient noise ?

but equiloudness curves weren't arrived at by testing against background noise were they ? so then that can't be the explanation.

perhaps masking effects due to ambient noise require bass equalization in ADDITION to whatever equiloudness curves would suggest is needed ?
The following link is to a general discussion of the human auditory perception curve. Nothing seems to be linear, even speakers. The designed 'flat' spectral response standard everyone tries to reach should only be viewed as a reference point, then make adjustments to meet your own ear's preference. :)
http://replaygain.hydrogenaudio.org/equal_loudness.html

[jcapodieci]

i understand why ear is more or less sensitive at various frequencies.

i do NOT understand why relative sensitivity of ear to different frequencies depends on loudness.

anybody know ?

in case of listening to music this may be an effect of masking due to ambient noise ?

but equiloudness curves weren't arrived at by testing against background noise were they ? so then that can't be the explanation.

perhaps masking effects due to ambient noise require bass equalization in ADDITION to whatever equiloudness curves would suggest is needed ?
Sorry for all the off comments. Here's two reasons for loudness-frequency non-linearity: Cheaper drivers exhibit different response characteristics depending on the voice coil position to the magnet. At low power, the coil is near it's resting position. At high power it's several mm further away. The design of the cone and surround will determine it response characteristics. Secondly, cheaper drivers do not vent heat as well. In this case the voice coil and magnet will physically change after 15 to 30 minutes of 100 Watts or more power being applied. At lower power levels, the heating effect is much less noticeable. The bottom line is that the selected driver needs to have a track record of continuous power levels similar to that at which you intend to use them. Be very sure that if continuous high power usage is the plan, that the drivers are intended for that kind of continuous usage. They need to be properly vented with sufficient heat sinks to keep them stable - especially if they're contained in small un-vented enclosures.

[Jason]

And why don't they put loudness switches on receivers anymore?

Actually, the "loudness button" is making a new come-back, although it's considerably more sophisticated this time around.

There are several companies that are coming out with new loudness compensation products aimed at providing more or less a "variable loudness button". Audyssey and Dolby both have new products out now that not only adjust the EQing at varying volume levels, but they also adjust the relative volume of surround speakers in a surround sound setup. As volume decreases, our sensitivity to sounds to the side and behind us also decreases. I believe there are some THX functions that behave similarly. However, the Audyssey and Dolby solutions are supposed to be the best and supposedly don't introduce weird artifacts (i.e. they don't suck and you might actually use them!).

There are a couple of interesting interviews from the Audioholics SOTU event here:
Audyssey Dynamic Volume (http://www.audioholics.com/news/trade-show-coverage/videos/audyssey-dynamic-volume-interview)
Dolby Volume (http://www.audioholics.com/news/trade-show-coverage/videos/dolby-truehd-dolby-volume-interview)

[brianpowers27]

I believe that my Harman Kardon avr247 uses this type of logic when you run the speakers through Logic 7. It definitely changes the EQ to compensate for lounness. This is a good thing.

The article that was mentioned earlier on the relative sensitivity of frequencies points out one thing to me. The eas is most sensitive around the 3khz rnage and is sensitive from around 1k to 5k at all loudness volumes(http://replaygain.hydrogenaudio.org/equal_loudness.html)

It seems logical that a crossover is not placed in this range would be best. Phase errors and frequency response should be more easily detectable throughout that range.