How to implement loudness?

[AaronDC]

Hi. I do a lot of low volume listening and I am really Jonesing for loudness on my setup. I have Klipsch Cornwalls and a pair of SVS SB-3000 subs. I'm driving it with an NAD C658 Streaming DAC preamp which has Dirac Live via an NAD C268 power amp. Unfortunately, the NAD does not have a loudness button (nothing does these days it seems). I tried to use the Tone Control feature on the NAD C658, but it doesn't really do the job. I was thinking that maybe I could upgrade to Dirac Live - Full Range and try to make my own Fletcher-Munson curve on the Dirac software. Another way I thought of was to find a device that I could put between the preamp and the main speakers and the two subs. I don't know what that would be, especially given my four channel setup. Variable compensation based on volume would be ideal, but I don't think that's something I can hope for unless NAD implements it on the preamp.

Any suggestions?

Thanks!
Aaron

 

[Daverz]

The RME ADI-2 DAC has a loudness control implemented in DSP. CamillaDSP implements this in software:

GitHub - HEnquist/camilladsp: A flexible cross-platform IIR and FIR engine for crossovers, room correction etc.

A flexible cross-platform IIR and FIR engine for crossovers, room correction etc. - HEnquist/camilladsp

github.com

 

[Triliza]

As @Daverz said CamillaDSP can do it, I have done it with CamillaDSP on Moode running on a Raspberry Pi (400). Does anyone knows if CamillaDSP implementation is optimal, some other parameters we can try?

filters: loudnessvol: type: Loudness parameters: ramp_time: 200.0 reference_level: -25.0 high_boost: 7.0 low_boost: 7.0

Edit: @AaronDC I see that NAD is a streamer so a Raspberry wouldn't be very useful to you in any way. And it doesn't have an USB input, so you can't use a Raspberry even if you'd want to. Sorry for a not that useful reply.

 

[AaronDC]

Edit: @AaronDC I see that NAD is a streamer so a Raspberry wouldn't be very useful to you in any way. And it doesn't have an USB input, so you can't use a Raspberry even if you'd want to. Sorry for a not that useful reply.

Thanks anyway! I appreciate the idea.

I've been looking at a few things in the pro audio world that might work. Radio Design Labs makes a little unit that is the kind of thing I'm looking for but I'd need four of them plus four power supplies and a voltage controller for them. Not a good solution. There seem to be a bunch of loudness thingies on eBay, but they're kinda sketchy looking. Maybe I could just buy a few old school manual parametric equalizers with a bypass and stick them in the path after the preamp. I switch em on for low level listening and bypass em off for normal volumes. Again, not ideal. I'm amazed that there's no all in one product that does loudness for all the people who dearly miss loudness buttons from the olden days.

Here's that RDL thing: https://www.rdlnet.com/product.php?page=123

 

[Daverz]

As @Daverz said CamillaDSP can do it, I have done it with CamillaDSP on Moode running on a Raspberry Pi (400). Does anyone knows if CamillaDSP implementation is optimal, some other parameters we can try?

The high boost should probably not be the same as the low boost.

I think it would be more optimal to follow the equal loudness curves,

Equal-loudness contour - Wikipedia

en.wikipedia.org

but I don't know of any hardware or software that does it this way. I think they all use the simple low and high boost.

 

[AaronDC]

Ideally, yes. I did this self-test online to check my own personal equal loudness curve. My result was basically the same as the Fletcher-Munson equal loudness contour. So cool to see it in action on my headphones. Here it is: https://newt.phys.unsw.edu.au/jw/hearing.html

 

[Daverz]

It would be a bit of a hardware and software project (using the CamillaDSP Python API), but the equal-loudness curves could be used to generate fir filters and these could be selected on the fly based on the volume and a loudness setting (that would need adjustment based on the recording).

 

[coonmanx]

Having it change with volume makes it a bit more difficult. I sort of make my own loudness contour using a ten band equalizer. I don't change the volume that often since I live in an apartment and so the volume stays in a fairly defined range. So I set the EQ to that lisening level and it works great and I can always bypass. Often times that is nothing more than a slight bass boost at the low end. My curve is still fairly flat.

 

[JPrufrk]

I find it really odd that this isn't a basic feature of virtually every type of EQ out there. In fact, I use EAPO with PEACE and despite its versatility I'm really surprised there's no loudness feature (unless I just haven't found it). Heck, the Effects panel has "Spatial delay", "Echo count", "Fake stereo" and "Crossfeed filter" among other features, but no "Loudness", though I understand that this isn't an "Effect". I've gotten used to the various non-ideal aspect of my room setup, my speakers, amp, dac, whatever, but the one thing that consistently bugs me is the need to tweak EQ settings when I listen at very low volumes vs. low-but-not-very-low vs. medium etc. It's obviously not just me. I can't afford an RME, but why doesn't PEACE (for example) have a loudness knob? Maybe it is just me and a small handful of others!

 

[NTK]

I find it really odd that this isn't a basic feature of virtually every type of EQ out there. In fact, I use EAPO with PEACE and despite its versatility I'm really surprised there's no loudness feature (unless I just haven't found it). Heck, the Effects panel has "Spatial delay", "Echo count", "Fake stereo" and "Crossfeed filter" among other features, but no "Loudness", though I understand that this isn't an "Effect". I've gotten used to the various non-ideal aspect of my room setup, my speakers, amp, dac, whatever, but the one thing that consistently bugs me is the need to tweak EQ settings when I listen at very low volumes vs. low-but-not-very-low vs. medium etc. It's obviously not just me. I can't afford an RME, but why doesn't PEACE (for example) have a loudness knob? Maybe it is just me and a small handful of others!

Have you tried this?

 

[JPrufrk]

Nope. Will do! Is that an EAPO interface you're showing? I went straight to PEACE and never bothered with that. Thanks.

 

[NTK]

Nope. Will do! Is that an EAPO interface you're showing? I went straight to PEACE and never bothered with that. Thanks.

Yes. That the EAPO Configuration Editor screen.

 

[escape2]

Have you tried this?

The screenshot states "After calibration, volume should only be adjusted via Windows volume control." Sounds like this would not be helpful if one uses a pre-amp to adjust volume.

The way I've implemented rudimentary loudness control in Foobar2000 is by creating three different EQ curves in MathAudio RoomEQ plugin. I then switch between the three with keyboard shortcuts depending on how loud I listen (low, med, high). So no, it's not automatic, and it only applies to audio playing through Foobar2000, but that is how I most frequently listen to music.

Technically, I could configure similar EQ curves in Peace that would be applicable to audio sources other than Foobar2000.

 

[maverickronin]

It's also not really that safe to rely on Windows' volume control either if you have passives (which could be blown out) or actives with high SPL capability (which may protect themselves but still won't be fun for your ears).

You don't really want to have to worry about some random program maxing out the system volume or crashing and outputting white noise at 0dBfs.

 

[Willem]

The RME ADI-2 is level dependent and can be adjusted, because ultimately level also depends on speaker efficiency and room size.

 

[NTK]

The screenshot states "After calibration, volume should only be adjusted via Windows volume control." Sounds like this would not be helpful if one uses a pre-amp to adjust volume.

The way I've implemented rudimentary loudness control in Foobar2000 is by creating three different EQ curves in MathAudio RoomEQ plugin. I then switch between the three with keyboard shortcuts depending on how loud I listen (low, med, high). So no, it's not automatic, and it only applies to audio playing through Foobar2000, but that is how I most frequently listen to music.

Technically, I could configure similar EQ curves in Peace that would be applicable to audio sources other than Foobar2000.

Loudness correction, as implemented in EAPO, adjusts the EQ curve based on the listening level at the listener position (that's what the calibration is for). For it to work correctly, it has to know what the output volume level is. Any manual adjustment will cause the correction to be suboptimal.

 

[escape2]

Loudness correction, as implemented in EAPO, adjusts the EQ curve based on the listening level at the listener position (that's what the calibration is for). For it to work correctly, it has to know what the output volume level is. Any manual adjustment will cause the correction to be suboptimal.

Right. I figured as much. Thanks for confirming.

 

[AaronDC]

Hi. An update here. I learned about dbx's AutoWarmth feature that it has on some of its products. It implements a dynamic loudness curve on lower frequencies. As you turn volume down, the bass boost is increased. As you raise volume, it goes away. You can set the threshold at which it kicks in and the amount of boost. It doesn't seem to boost the higher frequencies, however. I picked up a used dbx ZonePro 641, the cheapest device with AutoWarmth. There are no controls on it. I set it using a computer and put it in the signal chain just before my power amp. Great for late night listening. I have my threshold set at 10 dB and I have a 2:1 curve ratio set on it for now.

 

[gnarly]

Hi, my loudness solution is a bit complicated to implement, but very easy to use. Most folks will probably think it's a bit nuts ...
It's for use with multi-way actives, and dsp.

For each driver section; sub, low, mid, high, and vhf; there is a separate volume control. Along with a master volume control for all.
So the frequency response can be set to flat, or whatever, much like using a multiband equalizer.

Each driver section covers roughly 2 octaves, which in a sense equates to a 5 band equalizer.

The difference between my setup and an equalizer, is that opposed to lifting the equalizer frequency's center with whatever bandwidth or Q chosen, my setup lifts the entire passband up without any taper across the bandwidth. Iow, it's not like a parametric lifting like a mountain top, but it's like lifting the entire plateau. It works this way because xovers are steep linear phase, which also keeps phase flat across the spectrum, allowing relative large level changes.

It's the easiest way to adjust for Fletcher-Munson i've found, especially given a wide range of SPLs, and different listening environments.
(Best room in my house is outdoors, and loud )

It's also the easiest way to simultaneously adjust for the vast tonal differences in tracks stemming from Toole's well described 'circle-of-confusion'. Fletcher-Munson aside, this method has greatly increased pleasure from tracks that clearly had recording studio tonal imbalances a long way off from flat.

The 5 volume sliders, along with the master slider, are like a numerical combination padlock......
it's amazing at whatever level listening, even low, that a certain combination sounds, well..... Bingo!


It all came about by accident, building and tuning multi-way DIYS. During design, it's needed that each driver be able to be controlled and processed individually. I used to ditch the individual controls after full system tuning, but luckily, i tried leaving them in once to play around.
They're here to stay!

 

[dasdoing]

Have you tried this?

Should you use Fletcher-Munson loudness compensation?

If you now have that function, loudness, on your amplifier, you just have to press the button and test. Not harder than that. If you like it or not depends on so many different factors so how can you be able to give advice about that to another person? It even varies based on what music you...

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