Parametric Equalizer

LoriQ

LoriQ

Enthusiast
I have a Yamaha RX-V681. It has a parametric equalizer if you want to manually adjust the sound. I don't understand how to use it. I tried searching on the forums here but couldn't find anything. I don't understand what Q means or center channel. I understand what frequencies are. Years ago I had a regular 10 band equalizer and understood that. If anyone could help me understand how to use a parametric equalizer I would very much appreciate it. Thank -you ~Lori
 
Alex2507

Alex2507

Audioholic Slumlord
I think I can answer this. Your old 10 band eq without a Q adjustment is called a graphic eq. The Q adjustment on your 681 makes it a parametric eq. I suspect when you say center channel, you mean the center frequency.

Page 114, #5, give you examples of the setting range and what that means in terms of Q. The narrow range of 15.6Hz to 16.0Hz is referred to as low Q which corresponds to 0.5 but a wide range of 15.6Hz to 250Hz is high Q (10.0).

As you raise the Q, you raise the range of frequencies affected by the EQ adjustment. On a graph the shape of a low Q adjustment would look like a sharp spike where a high Q adjustment would look like a hill with a not very steep incline or downward slope.

Your manual says 4 bands are available for the subwoofer. So you can pick 4 center frequencies and you can adjust the width (frequency range) of the bump or dip you want affected by the EQ.

In setting up your rec'r, start with the auto YPAO and let us know what speakers you have and we'll suggest a crossover point and speaker size settings as those are sometimes not handled correctly by auto eq's. A nice generic setting where a lot of us start is Small on speaker size and 80 Hz for a crossover providing your speakers are rated to about 60 Hz.
 

TechHDS

Audioholic General
I think I can answer this. Your old 10 band eq without a Q adjustment is called a graphic eq. The Q adjustment on your 681 makes it a parametric eq. I suspect when you say center channel, you mean the center frequency.

Page 114, #5, give you examples of the setting range and what that means in terms of Q. The narrow range of 15.6Hz to 16.0Hz is referred to as low Q which corresponds to 0.5 but a wide range of 15.6Hz to 250Hz is high Q (10.0).

As you raise the Q, you raise the range of frequencies affected by the EQ adjustment. On a graph the shape of a low Q adjustment would look like a sharp spike where a high Q adjustment would look like a hill with a not very steep incline or downward slope.

Your manual says 4 bands are available for the subwoofer. So you can pick 4 center frequencies and you can adjust the width (frequency range) of the bump or dip you want affected by the EQ.

In setting up your rec'r, start with the auto YPAO and let us know what speakers you have and we'll suggest a crossover point and speaker size settings as those are sometimes not handled correctly by auto eq's. A nice generic setting where a lot of us start is Small on speaker size and 80 Hz for a crossover providing your speakers are rated to about 60 Hz.
Alex2507, nicely said!! Great info Brother!
On adjusting the high “Q” as I’m sure you know by adjusting “high Q” also will boost the frequency behind and in front of the Q. The EQ adjustment parameters on Yamaha AVR’s are very nice it’s one of the reasons I have a Yamaha unit.

Mike
 
highfigh

highfigh

Seriously, I have no life.
I think I can answer this. Your old 10 band eq without a Q adjustment is called a graphic eq. The Q adjustment on your 681 makes it a parametric eq. I suspect when you say center channel, you mean the center frequency.

Page 114, #5, give you examples of the setting range and what that means in terms of Q. The narrow range of 15.6Hz to 16.0Hz is referred to as low Q which corresponds to 0.5 but a wide range of 15.6Hz to 250Hz is high Q (10.0).

As you raise the Q, you raise the range of frequencies affected by the EQ adjustment. On a graph the shape of a low Q adjustment would look like a sharp spike where a high Q adjustment would look like a hill with a not very steep incline or downward slope.
You have it backward- High Q means the width of the band is narrow and Low Q means it's a wider range.

https://www.rane.com/note101.html
 
LoriQ

LoriQ

Enthusiast
I think I can answer this. Your old 10 band eq without a Q adjustment is called a graphic eq. The Q adjustment on your 681 makes it a parametric eq. I suspect when you say center channel, you mean the center frequency.

Page 114, #5, give you examples of the setting range and what that means in terms of Q. The narrow range of 15.6Hz to 16.0Hz is referred to as low Q which corresponds to 0.5 but a wide range of 15.6Hz to 250Hz is high Q (10.0).

As you raise the Q, you raise the range of frequencies affected by the EQ adjustment. On a graph the shape of a low Q adjustment would look like a sharp spike where a high Q adjustment would look like a hill with a not very steep incline or downward slope.

Your manual says 4 bands are available for the subwoofer. So you can pick 4 center frequencies and you can adjust the width (frequency range) of the bump or dip you want affected by the EQ.

In setting up your rec'r, start with the auto YPAO and let us know what speakers you have and we'll suggest a crossover point and speaker size settings as those are sometimes not handled correctly by auto eq's. A nice generic setting where a lot of us start is Small on speaker size and 80 Hz for a crossover providing your speakers are rated to about 60 Hz.
Thank-you for your reply.

Yes I did mean center frequency. Sorry about that.

Where is page 114?

Oh I've already used the YPAO and have set all my speakers to small with the crossover at 80hz. For my fronts I have a pair of Klipsch 28F. The manual says their frequency response is 35hz-24khz. For my sub I have a Klipsch R12SW. It's frequency response is 29hz-120hz. For my center channel I have a Polk T-30. Its frequency response is 38hz.-24khz. For my surrounds I have a pair of Klipsch bookshelf speakers R-15M. Their frequency response is 62hz-24khz.

I still don't understand what a center frequency is.
 
lovinthehd

lovinthehd

Audioholic Jedi
Thank-you for your reply.

Yes I did mean center frequency. Sorry about that.

Where is page 114?

Oh I've already used the YPAO and have set all my speakers to small with the crossover at 80hz. For my fronts I have a pair of Klipsch 28F. The manual says their frequency response is 35hz-24khz. For my sub I have a Klipsch R12SW. It's frequency response is 29hz-120hz. For my center channel I have a Polk T-30. Its frequency response is 38hz.-24khz. For my surrounds I have a pair of Klipsch bookshelf speakers R-15M. Their frequency response is 62hz-24khz.

I still don't understand what a center frequency is.
If you choose a specific frequency to eq with a parametric eq, say 100hz, that is the center, and the shape of the slope changes on either side of that center frequency ..
center freq.gif
 
Alex2507

Alex2507

Audioholic Slumlord
Page 114 of the owners manual for your Yammy.

The center frequency could just be called The Frequency that you are EQ'ing.

Edit: The page numbers might be different from the website to your paper manual if there is one.
 
Last edited:
LoriQ

LoriQ

Enthusiast
If you choose a specific frequency to eq with a parametric eq, say 100hz, that is the center, and the shape of the slope changes on either side of that center frequency ..


View attachment 25690
Ok, so if I want to boost a specific frequency, how can I do it without affecting the frequencies on each side? What I am trying to do is boost some bass, some mid-bass and the midrange. I'm just afraid I might mess up and end up adjusting the adjacent frequencies.
 
lovinthehd

lovinthehd

Audioholic Jedi
Ok, so if I want to boost a specific frequency, how can I do it without affecting the frequencies on each side? What I am trying to do is boost some bass, some mid-bass and the midrange. I'm just afraid I might mess up and end up adjusting the adjacent frequencies.
Why would you want to boost a very specific single frequency? Generally you want to have the adjoining frequencies affected (and even graphic eq's do this, they're just not adjustable like a parametric eq). Might read this article https://www.minidsp.com/applications/dsp-basics/peq-vs-graphic-eq
 
LoriQ

LoriQ

Enthusiast
Why would you want to boost a very specific single frequency? Generally you want to have the adjoining frequencies affected (and even graphic eq's do this, they're just not adjustable like a parametric eq). Might read this article https://www.minidsp.com/applications/dsp-basics/peq-vs-graphic-eq
Ok I looked at the page you sent me. There are 2 things I don't understand. On that page it says...frequency: the center of the frequency range to be cut or boosted. What do they mean by the "center" of the frequency? The other question is it says...Q: the "sharpness" of the boost or cut, with higher Q meaning a narrower filter. What do they mean by "sharpness?"
 
Alex2507

Alex2507

Audioholic Slumlord
You have it backward- High Q means the width of the band is narrow and Low Q means it's a wider range.

https://www.rane.com/note101.html
I knew that! :D

I did ... for subs. A big bump on the FR coming up from 0 Hz = high q = bad.

My mistake was equating Q with width instead of height on an EQ. Maybe the result of a mental coin toss. Maybe I should have gone with the drugs excuse.

Thank you. The only thing that sucks worse than being corrected is being wrong. ;)

EDIT: Good thing you were paying attention today.

Edit 2: The manual is on a download here from Yamaha:

https://usa.yamaha.com/products/audio_visual/av_receivers_amps/rx-v681_u/downloads.html#product-tabs

I completely misinterpreted what is on page 114 by missing a k in 16 kHz and then further compounded the error by wrongly assuming that the next line was related.

Sorry about that.
 
Last edited:
lovinthehd

lovinthehd

Audioholic Jedi
Ok I looked at the page you sent me. There are 2 things I don't understand. On that page it says...frequency: the center of the frequency range to be cut or boosted. What do they mean by the "center" of the frequency? The other question is it says...Q: the "sharpness" of the boost or cut, with higher Q meaning a narrower filter. What do they mean by "sharpness?"
The center frequency, i.e. the specific frequency at the center of the range that the equalizer will be cutting/boosting. If 100hz is the center frequency, then the slopes would fall/rise from that center frequency. Sharpness think of as narrow (a smaller width of frequencies affected), i.e. the width of the frequencies affected by the filter is narrower (say only 10 hz on either side as opposed to 100hz on either side of the center).
 
KaatheSnake

KaatheSnake

Senior Audioholic
The center frequency, i.e. the specific frequency at the center of the range that the equalizer will be cutting/boosting. If 100hz is the center frequency, then the slopes would fall/rise from that center frequency. Sharpness think of as narrow (a smaller width of frequencies affected), i.e. the width of the frequencies affected by the filter is narrower (say only 10 hz on either side as opposed to 100hz on either side of the center).
The center frequency, i.e. the specific frequency at the center of the range that the equalizer will be cutting/boosting. If 100hz is the center frequency, then the slopes would fall/rise from that center frequency. Sharpness think of as narrow (a smaller width of frequencies affected), i.e. the width of the frequencies affected by the filter is narrower (say only 10 hz on either side as opposed to 100hz on either side of the center).
Howdy there @lovinthehd. How've you been, sir? Haven't heard from you in a while my friend! I guess we're talking about equalization units tonight? I got kicked off Steve Hoffman Forums for being 13. Good grief. SMH.
 
TLS Guy

TLS Guy

Audioholic Jedi
Actually the correct way to think about Q is damping, and that is what it is all about. When thinking about resonance you have to consider how long it is sustained.

Now low Q means damping is high and high Q means is it low.

Take a pendulum swinging on a very high grade low friction bearing. It will swing for a long time. This is high Q.

Now put the pendulum in an oil bath. It will stop swinging quickly. That is low Q.

A snappy sports car with a tight suspension has a low Q suspension. An old family saloon with shot shock adsorbers has a high Q suspension

Now if you grasp this you can understand why I highly dislike high Q speakers, and gravitate to low Q ones, and go to enormous trouble and effort to design them.

Equalizers use R/C resonant circuits in the main. This is my beef with them, as they have to be used very sparingly if at all as they use resonant circuits to carry out their frequency shaping. So they are real quality spoilers, especially when used aggressively.

I'm pretty sure this also applies to programs like Audyssey. Engaging it really spoils the quality of my rig big time. Billy Woodman if ATC has long harped at the fools gold of equalization unless done with extreme subtlety. That is why you can't turn a bad speakers into a good one with equalization.
 
P

PENG

Audioholic Slumlord
Audyssey, Dirac etc., use DSPs, they are digital filters. The manually adjustable parametric equalizers are also digital filters.
Actually the correct way to think about Q is damping, and that is what it is all about. When thinking about resonance you have to consider how long it is sustained.

Now low Q means damping is high and high Q means is it low.

Take a pendulum swinging on a very high grade low friction bearing. It will swing for a long time. This is high Q.

Now put the pendulum in an oil bath. It will stop swinging quickly. That is low Q.

A snappy sports car with a tight suspension has a low Q suspension. An old family saloon with shot shock adsorbers has a high Q suspension

Now if you grasp this you can understand why I highly dislike high Q speakers, and gravitate to low Q ones, and go to enormous trouble and effort to design them.

Equalizers use R/C resonant circuits in the main. This is my beef with them, as they have to be used very sparingly if at all as they use resonant circuits to carry out their frequency shaping. So they are real quality spoilers, especially when used aggressively.

I'm pretty sure this also applies to programs like Audyssey. Engaging it really spoils the quality of my rig big time. Billy Woodman if ATC has long harped at the fools gold of equalization unless done with extreme subtlety. That is why you can't turn a bad speakers into a good one with equalization.
I'm pretty sure this also applies to programs like Audyssey. Engaging it really spoils the quality of my rig big time. Billy Woodman if ATC has long harped at the fools gold of equalization unless done with extreme subtlety. That is why you can't turn a bad speakers into a good one with equalization.
Audyssey, Dirac etc., use DSPs, they are digital... The manually adjustable parametric equalizers are also digital filters so your remarks about the R/C resonant circuits don't really apply.

Below is an explanation by the Audyssey lab, that's about 8 years ago.

You keep making blanket style negative comments about Audyssey and Room EQ software in general, apparently based on your own experience with your equipment/room using the older version (XT). There are much more capable version Audyssey XT32, Dirac Live, Anthem ARC, Trinnov, RoomPerfect and others that a lot of people found effective and in some cases, have facts on their side.

https://audyssey.zendesk.com/hc/en-us/articles/212347763-MultEQ-vs-other-equalization-methods-
  • There are two fundamental differences from every other method available in AV receivers today. The first is that MultEQ is not based on parametric equalization. Parametric equalization relies on a few bands that are centered at certain frequencies. These bands do not provide sufficient resolution to address many room acoustical problems. Also, parametric bands tend to interact so that changes at one frequency have undesirable results at nearby frequencies. Moreover, parametric equalization methods use a particular type of digital filter called Infinite Impulse Response (IIR) that only attempts to correct the magnitude response in the frequency domain. These filters can cause unwanted effects, such as ringing or smearing, in the time domain particularly as the bands get narrower. MultEQ uses Finite Impulse Response (FIR) filters for equalization that use several hundred coefficients to achieve much higher resolution in the frequency domain than parametric bands. Furthermore, by their nature, FIR filters simultaneously provide correction in the frequency and time domains. FIR filters had been considered to require too many computational resources. But Audyssey solved this problem by using a special frequency scale that allocates more power to the lower frequencies where it is needed the most.
    The second major difference is that MultEQ combines multiple measurements to create equalization filters that better represent the acoustical problems in the room. Most other methods only perform a single point measurement and this can result in making other locations in the room sound worse than before equalization. There are some methods that use spatial averaging to combine multiple room measurements. Although this is a step above single-point correction, it does not provide optimum correction when discussing spatial averaging. For example, it is common to find a peak at a certain frequency in one location and a dip at the same frequency at another nearby location. The averaging methods will add the peak and the dip and this will result in an apparent flat response at that frequency, thus causing the equalization filter to take no action. MultEQ uses a clustering method to combine measurements so that acoustical problems are better represented, thus allowing the equalization filter to perform the appropriate correction at each location.
 
highfigh

highfigh

Seriously, I have no life.
Ok, so if I want to boost a specific frequency, how can I do it without affecting the frequencies on each side? What I am trying to do is boost some bass, some mid-bass and the midrange. I'm just afraid I might mess up and end up adjusting the adjacent frequencies.
You can't adjust one frequency and even if you could, the phase shift would cause terrible problems, which is the reason lower Q filters are used in crossovers. However, higher Q can be used in digital filters but they still cause phase shift- all filters delay the signal and when added, phase cancellations occur.

Equalization is often more about removing energy than adding. The beauty of a parametric EQ is that the center frequency, amplitude and width of the range affected (range is the parameter) can be selected, compared with only choosing which band to use and adjusting its amplitude, which may not be exactly where the change is needed.

https://soundbridge.io/parametric-equalizer-2/

 
highfigh

highfigh

Seriously, I have no life.
I knew that! :D

I did ... for subs. A big bump on the FR coming up from 0 Hz = high q = bad.

My mistake was equating Q with width instead of height on an EQ. Maybe the result of a mental coin toss. Maybe I should have gone with the drugs excuse.

Thank you. The only thing that sucks worse than being corrected is being wrong. ;)

EDIT: Good thing you were paying attention today.

Edit 2: The manual is on a download here from Yamaha:

https://usa.yamaha.com/products/audio_visual/av_receivers_amps/rx-v681_u/downloads.html#product-tabs

I completely misinterpreted what is on page 114 by missing a k in 16 kHz and then further compounded the error by wrongly assuming that the next line was related.

Sorry about that.
Q and amplitude aren't related- the Q means the same if it's for a sub or EQ- the higher it is, the more specifically it works, meaning that frequencies to either side are less affected. As TLS wrote, Q is about damping.
 
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