Dynamic EQ & Fletcher-Munson Curve

[Robbie010]

Good morning all.

I’m looking for some practical advice / guidance on the settings for Dynamic EQ on a digital crossover in order to implement the Fletcher-Munson Curve (BBC dip).

Last year I setup a 3.1 diy speaker system using a Db-mark digital crossover. At the time, I dialled-in crossover and delay settings and eq’d in-room but didn’t really understand how or why I would use the Dynamic EQ’s on the input. After a little more reading I think I’m getting an understanding of its uses and would like to have a bit of a play around and try to implement a fletcher-munson curve.

As I currently understand it, I would utilise the dynamic EQ’s on the input to boost the low end (<1kHz) and high frequencies (>5kHz) but only between specified SPL’s, the result being a perceived flat response is achieved across the frequency range at higher listening levels, so as not to make the system sound too bass heavy or overly bright at higher listening levels.

Is this correct?

What I’m wondering is how this affects the crossover / EQ setting on the output side?

What is the correct way to go about this, do I have to start from scratch and first implement the desired Dynamic EQ’s setting before re-doing the crossover and output EQ settings?

Has anyone done this before?

Any practical advice?

Thanks.

 

[DVDdoug]

"Traditional dynamic EQ" isn't quite right for loudness compensation...

Loudness compensation should be based on the overall listening level. It should be constant throughout the song/performance even when there are loud and quiet parts. If the band is playing quieter during part of the track it's up to the musicians, conductor, producer, to make sure the frequency balance is correct during the quiet parts.

Old style loudness compensation isn't perfect either because it depends on the volume control rotation without knowing how loud your speakers actually are or how strong of a signal you're feeding-in, etc.

I think there is "calibrated" loudness compensation built into some versions of DIRAC or other room correction that are set-up based on loudness in the room, and then the compensation depends on the volume/gain setting. But it still may not be correct with different sources (if your DVD player is louder than your CD player, etc.) ...I just don't know anything about it.

What I’m wondering is how this affects the crossover / EQ setting on the output side?

As long as everything is linear (no clipping, etc.) it's "links in a chain" and it shouldn't matter if it's on the input or output.

 

[XDM]

Good morning all.

I’m looking for some practical advice / guidance on the settings for Dynamic EQ on a digital crossover in order to implement the Fletcher-Munson Curve (BBC dip).

Last year I setup a 3.1 diy speaker system using a Db-mark digital crossover. At the time, I dialled-in crossover and delay settings and eq’d in-room but didn’t really understand how or why I would use the Dynamic EQ’s on the input. After a little more reading I think I’m getting an understanding of its uses and would like to have a bit of a play around and try to implement a fletcher-munson curve.

As I currently understand it, I would utilise the dynamic EQ’s on the input to boost the low end (<1kHz) and high frequencies (>5kHz) but only between specified SPL’s, the result being a perceived flat response is achieved across the frequency range at higher listening levels, so as not to make the system sound too bass heavy or overly bright at higher listening levels.

Is this correct?

What I’m wondering is how this affects the crossover / EQ setting on the output side?

What is the correct way to go about this, do I have to start from scratch and first implement the desired Dynamic EQ’s setting before re-doing the crossover and output EQ settings?

Has anyone done this before?

Any practical advice?

Thanks.

Loudness Compensation / 'Dynamic EQ' isn't the same as the 'BBC dip', which was never actually intended by the BBC to be in broadcasts (as confirmed by a recording engineer who worked for them, although I can't find the actual reference now).

Denon/Marantz/Audyssey call their idea of a 'BBC' dip Midrange Compensation and that should be disabled immediately (disabling it requires the purchase of a $20 app called MultEQ, they know what they were doing) as it will make your sound very 'thin'.

Ok so back to Dynamic EQ, your understanding of the purpose of the equal loudness curves is correct but you don't need to change your crossovers. Keep those at 80 Hz (or higher). Run Audyssey (using the MultEQ app to disable Midrange Compensation). Enable Dynamic EQ (you can also enable it from the Audio - Audyssey menu).

Audyssey's implementation is highly flawed though because it uses an excessive 'surround boost' in addition to the equal loudness contour, messing with the front-back balance which can't be disabled officially.

Also you'll need to set the offset (the default of 0 is probably too extreme so try -5,- 10).

I've listed some alternative implementations here but none seem to be without flaws https://www.audiosciencereview.com/...dness-compensation.29543/page-12#post-2505588