More > JRiver Media Center 23 for Windows
Sonic Sculpting Speakers with Shelving Filters
blgentry:
--- Quote from: drmimosa on July 09, 2017, 05:46:08 pm ---This immediately made me think of the Harmon House EQ curve, which I've read about but never implemented.
https://www.innerfidelity.com/content/acoustic-basis-harman-listener-target-curve
--- End quote ---
Interesting. I own a pair of headphones that were modeled after the Harmon Olive curve: The NAD HP50s. They are sublime. Very non-fatiguing, yet somehow rather detailed also. Not as detailed as many other headphones, but definitely not lacking in sparkle at all. They're very seductive. (If an audio device can be described with that word...)
--- Quote ---Suppose I would like to make a stock decending "house" EQ curve that cut 1db per octave across the audible spectrum, for a total of 8db slope from (say) 65htz to 16khtz.
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It would be neat if MC had a DSP filter to do arbitrary slopes like this. What you're essentially asking for is a low pass filter at 65 Hz with a 1 dB/octave slope. A low pass filter with an arbitrary slope, would be pretty neat to play with; particularly for this type of application.
--- Quote ---If I understand your post correctely, the following high shelf filters could accomplish this curve.
...
--- End quote ---
Yes, I think that will work. It won't be exactly a straight line sloped filter. But it should produce approximately the response you're looking for.
--- Quote ---I may be missing something in my understanding of the Harmon curve and usage of it as well. 8db seems a bit much for a cut, so -.5 db may be a better value for each shelf for a -4db slope. The paper I linked to specified a -6db slope as preferred by listeners.
--- End quote ---
You can certainly play with it and see what you think. You might find that making some custom adjustments to the overall downward slope work better with your room or speakers. There are lots of possibilities for how you could use this general idea.
--- Quote ---Also, how significant is the Q value in the shelf filters?
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I believe the Q value affects the curved part of the response. The part that's near the knee frequency. The higher the Q, the steeper the slope of the curved part. I wouldn't mess with the Q to start with. I'm far from an expert; this is just my understanding and my advice.
Good luck with your experiments! :)
Brian.
mattkhan:
You can use rephase to look at how arbitrary filters sum, see attached pic for an example
a few things to note;
- the jriver dsp window asks you to enter a Q value for the filter but it is actually S so the Q value entered in most other apps does not directly translate to the jriver value (it would be better IMO if jriver changed this to actually accept Q). You can convert from Q to S though, one easy way to do it is to paste this formula into https://www.mathpapa.com/algebra-calculator.html and enter values for Q and gain (d in the formula below)
1/((((1/Q)^2-2)/((10^(d/40))+1/(10^(d/40))))+1)
- as Elvis133 says, such a target curve is intended to be a target for your room not the source material, use it to adjust your room response to that target not the source material
jtconte:
Thanks for the excellent write up, Brian!
adiebear:
--- Quote from: mattkhan on July 11, 2017, 06:16:35 am ---You can use rephase to look at how arbitrary filters sum, see attached pic for an example
a few things to note;
- the jriver dsp window asks you to enter a Q value for the filter but it is actually S so the Q value entered in most other apps does not directly translate to the jriver value (it would be better IMO if jriver changed this to actually accept Q). You can convert from Q to S though, one easy way to do it is to paste this formula into https://www.mathpapa.com/algebra-calculator.html and enter values for Q and gain (d in the formula below)
1/((((1/Q)^2-2)/((10^(d/40))+1/(10^(d/40))))+1)
- as Elvis133 says, such a target curve is intended to be a target for your room not the source material, use it to adjust your room response to that target not the source material
--- End quote ---
Oh dear! Alphabet soup (Q. S etc.)and mathematical formulae do my head in. The concepts I get. How to implement dsp on my own? Not so much. I wish I could borrow Brian and others in this thread o sort out the finer bass bits (a pair of Vandy 2wq subs and Eminent Technology LFT8b's in a fairly well treated room). I'm just using Alan Parsons' test tones and combination sweeps over and over and dropping or raising certain frequencies according to my ears (eek!). Now and the I use a friend's high end system (Vivid Audio Giya G1 Spirits for example) as a reference.
Sounds pretty good to me, but could sound better I'm sure. Sigh.
Wilderness:
--- Quote from: blgentry on July 02, 2017, 04:34:59 pm ---Over the past few years I've tuned a handful of speaker systems using mostly shelving type filters. In several cases I've done this directly with DSP Studio in JRiver MC. You might be wondering why would I use shelving filters. Or you might be wondering what a shelving filter even is.
Shelving filters are very simple. Think of the frequency response of a system as a straight line from left to right. The lows are on the left, the highs are on the right. A shelving filter pushes one end of the line up higher than the other. So a high shelf filter at 5000 Hz, would push up all the frequencies from 5000 Hz up to 20,000 Hz up higher than the rest. Or pull them down if you specify a negative value.......
This is my new tuning method of choice for speakers and headphones. I think it works quite well.
Thanks for reading.
Brian.
--- End quote ---
Brian,
I can't thank you enough. I had been having a terrible problem with wince-inducing sibilance with "s" sounds and even worse with "t" sounds for more than a year. I tried adjusting speaker toe in, purchasing new cables, etc., but those changes only helped a little. With your advice about shelving in JRiver, I finally solved the problem.
Here are the high shelf settings I used for my bright system:
-3 dB 2000 Hz.
-4 dB 5000 Hz.
-5 dB 7700 Hz.
I set a separate parametric equalization at -6 dB. at 9000Hz.
I am very pleased with the sound I am now getting. The sibilance is gone, and I am getting more beautiful bass undertones with acoustic guitar. Sweet!
I owe you a premium beer and/or gourmet lunch, which wouldn't even begin to repay you for the money you saved for me. I was going to spend thousands of dollars for new audio equipment without any guarantee of success. Maybe I'll see you at an audio show next year.
P.S.: I think JRiver should feature your advice about shelving. Many audiophiles have the same problem with sibilance that I had. They would be so grateful if they could solve their problems with sibilance with shelving.
Allan
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