The Audyssey MultEQ Editor app users thread (with facts and tips)

P

PENG

Audioholic Slumlord
Sorry if it came across as disagreeing. I don't think we are :) I just had a couple of points to add which you actually do already touch on...
1-Take in room measurements before and after audyssey. Make sure to either average several measurements in a similiar configuaration as your audyssey measurements, or even better in my opinion use the MMM (moving microphone method) of your listening position. A lot of those small variations at higher frequencies go away the more measurements you take.
2-Looking at speaker measurements and correcting the speakers using detailed measurements (such as from Harman, or Audiosciencereview) might be the best way to do correction. I'm not currently doing this, but this is what @Jon AA is talking about. According to tool as noted in the image, the series of bumps that are in all of the measurements are the ones that can be EQ'd.
3-And I just wanted to point out to compare your before measurements with what Audyssey measures. Audyssey will do boosts/cuts based on what the Audyssey measured (even if those measurements aren't accuate). I had a situation where Audyssey boosted high frequencies when I wanted Audyssey to cut. It did this because the origianal measuement didn't seem to be very accurate based on my MMM REW measurements. As you have already mentioned it is essential to measure what Audyssey has done.
Sorry if it sounded like I was disagreeing with you. Audyssey does exactly what you tell it to relative to what it is measures and is really great at it. I think people can fine tune their results for sure using what you have described.
Thank you for clarifying this. In fact, I have no problem disagreeing or agreeing to disagree with knowledgeable and open minded people like you and Jon AA, but I am merely curious about if there is something I missed or got lost in the back and forth, before agreeing or disagreeing. Based on my hundreds of REW plots, I also recognize that Audyssey, and Dirac Live (I must emphasize I was using the trial versions only) were unable to "correct" my speakers in room response at my MMP to better than 9 dB p-p with no smoothing in the 15-200 Hz range, let alone the higher frequencies.

I can say, and must emphasize that their (at least Audyssey for sure) could do the correction to within 2 dB p-p for the same range (in my room) if fed with the actual results measured by REW/Umik-1. So I would assume that logically speaking, Audyssey's algorithm to create the FIR based minimum phase filters are likely not the bottleneck, but the mic and the measurement/data collection part is. Do you follow my logic? Or you have another "logical" explanation.

Now that I am happy with +/- 1.2 dB 20-110 Hz, I am going to start working on editing it slope up towards 15 dB, by perhaps 2 dB, and then will on the FL/FR to extend the flattened part to about 300 Hz.

1590679661783.png
 
D

DJ7675

Junior Audioholic
Thank you for clarifying this. In fact, I have no problem disagreeing or agreeing to disagree with knowledgeable and open minded people like you and Jon AA, but I am merely curious about if there is something I missed or got lost in the back and forth, before agreeing or disagreeing. Based on my hundreds of REW plots, I also recognize that Audyssey, and Dirac Live (I must emphasize I was using the trial versions only) were unable to "correct" my speakers in room response at my MMP to better than 9 dB p-p with no smoothing in the 15-200 Hz range, let alone the higher frequencies.

I can say, and must emphasize that their (at least Audyssey for sure) could do the correction to within 2 dB p-p for the same range (in my room) if fed with the actual results measured by REW/Umik-1. So I would assume that logically speaking, Audyssey's algorithm to create the FIR based minimum phase filters are likely not the bottleneck, but the mic and the measurement/data collection part is. Do you follow my logic? Or you have another "logical" explanation.

Now that I am happy with +/- 1.2 dB 20-110 Hz, I am going to start working on editing it slope up towards 15 dB, by perhaps 2 dB, and then will on the FL/FR to extend the flattened part to about 300 Hz.

View attachment 36505
Yes, I definitely follow what you are doing here and that is a really great result. Doing either an average REW measurement or MMM measurement before and after like you are doing is really getting excellent results. I look forward to your next step of adding some tilt to that smooth measurement.
While this is a loaded question, in particular since it is impossible to do an a/b test... but how does it sound? Do you think you can notice an improvement?
 
Jon AA

Jon AA

Audioholic
Appreciate your post and look forward to your write up on a process to use Audyssey in the manner you describe. I’ve got 3 Revel M16 and between Harman’s measurements and Amir’s measurements at ASR it would be a fun project. Just so I understand correctly, I would use Audyssey to fine tune the speaker with Audyssey (using ratbuddy). The M16 has good directivity so it would be a good example of a speaker that could be “corrected”, correct?
OK, I can give the Cliff's Notes of the process to get you started. Yes, the M16's are quite good so you should end up with very good results. And you have the huge advantage of anechoic data for that speaker as a sanity check on your measurements.

1) Make sure you have a good Auydssey calibration measurement-wise (mic placement was good, individual measurements in Ratbuddy look reasonable, speaker distances, etc, are where they should be). You won't want to be starting from scratch because you think one of your measurements in the original Audyssey file may have been messed up.

2) Measure your speakers. If you can drag them and your AVR outside, that's great, middle of a big room OK, but as-placed in the room is probably the most practical for most people. Keep in mind, as boundaries get closer, the less you can trust data at lower frequencies. Even in the middle of a large room, the floor bounce will wreak havoc on your measurements, so don't even think about doing anything in the lower midrange with these measurements unless you can do it outside with the speaker up in the air.

Make sure you're using a calibrated mic with the correct calibration file. For this I use the 0 degree file with the mic pointed at the tweeter. Use a tape measure to accurately place the mic.

For most speakers, I think 1 meter on axis with the tweeter is probably the best place to take measurements for high frequencies. With larger towers, farther measurements may be advisable but this makes it more difficult to eliminate reflections from the measurements. You want to use gated measurements to eliminate reflections as much as possible. You can look at your impulse response to give you an idea of where the large reflections are coming into the signal, but even the smaller reflections will influence the results somewhat. This is an area where experimentation and using some judgement comes into play. Try different measurement techniques--distances and gating lengths--and compare them until you arrive at a technique you're comfortable with (feel you can trust the measurements--they're repeatable!) in the frequency range you want to fix.

I've ended up using 1m distance and 4ms gating as a standard. I haven't used REW for this in a while, but with Omnimic here are the results you get with 4ms gating:

GatedBlended.jpg


The pure gated measurement (in black) in Omnimic as you can see flat out stops at 600 Hz, and looses resolution above that for a while (which is why outdoor measurements with longer gating times are needed to actually evaluate a speaker full range). The brown line is "blended mode" which blends the gated measurements at high frequencies with steady-state measurements at lower frequencies. That's the one I use as I think the increased resolution in the 800-1200 Hz range is helpfull and they're both basically identical above that.

Once you've figured out a technique you want to use, it's time to take measurements for real. While a single on-axis measurement is OK to get you started quickly if you just want to test the process and will basically give you the same results with a really, really good speaker, in most cases you're going to want to do a listening window measurement. Many speakers with horns and most coaxial speakers will have anomalies exactly on-axis that disappear in the listening window. Naturally, you don't want to correct those.

For various reasons, I think the full CEA 2034 listening window is a bit bigger than necessary for the purpose of calibrating the direct sound, so I typically do a smaller "calibrating window"--basically on-axis, up/down 5 degrees, left/right 10 degrees. But that's entirely up to you to do what you feel is best for a particular speaker.

Note, for all measurements, make sure DEQ is OFF! DEQ can be great set to preference when listening, but you don't want it on when you're measuring for calibrations.

The first measurement you want to take, is one with Audyssey switched OFF. Do this only after calibrating though, so that it's level is the same as with it on. Then do the same with Audyssey On. I don't think it really matters when doing this method whether you pick Ref Rolloff #1 or #2, I got in the habit long ago when trying to draw new curves of using Rolloff #2 because it's more linear at the top end. But whatever you pick, stick with it.

3) Calibrate! Once you've taken the measurements, you've done the hard part. Now you can finish up at your computer.

First look at the curve with Audyssey off to see what your speaker naturally does and make some decisions on how to fix it.

LFDirLW.jpg


There's an example (different speaker than the above BTW). The first thing you need to decide is your target. I'd suggest for most speakers simply aiming at a flat response is going to give the results that will be preferred by most people (we'll talk about variations later). If aiming for a flat line, you need to decide where to put it.

For this speaker I decided since it has a nice flat and smooth area from about 1100 to 2000 Hz that averages exactly 80 db, that would be the target.

Unfortunately, with Audyssey at high frequencies, it's all or nothing. If you have a speaker that measures perfectly flat with just one flaw (bump or dip), you can't just fix that. It's all or nothing. So while the curve above with Audyssey off is informative about what to do, you can't fix it. You can only fix the Reference curve. With such a speaker that will likely mean "undoing" what Audyssey did instead of simply fixing the one spot.

So, add the reference curve measurement:

LFDirRefLW.jpg


Here, the red line is the Reference curve measurement.

First off, you can see how Audyssey can screw up a pretty good speaker at high frequencies. This is a controlled directivity speaker which doesn't have excessive room reflections, and you can see by aiming for a flat in-room steady state response for most of the curve, it ends up boosting the upper midrange and most of the treble well above flat in the direct sound that will be headed to your ears. That makes the speaker sound excessively bright. One would be much better off limiting the correction of this speaker to bass frequencies than correcting full range with the standard reference curve.

So for this speaker, most of the deviation from the reference curve you type into Ratbuddy will be fixing what Audyssey screwed up.

To identify the new control points, first zoom in on the upper frequencies such that you make the Reference measurement really ugly. I find it easiest to literally print it out and draw your target line on there for reference. Simply put a dot at each "inflection point" along the curve:

ControlPointsRed.jpg


(I ended up deleting the bottom few points from that out of the file.) As you can see that is zoomed in such that each line is only 1 db so it looks really bad, but it allows you to be precise in the adjustments needed.

That may look a bit scary--I plan on doing more experiments with applying a little bit of smoothing and using fewer control points. Most of those small deviations won't be audible so there is probably a point of diminishing returns so you don't need to add 60 or so points. Be careful of smoothing though--it can cause undercorrection of the bumps and dips. But if you want to get a super flat curve as was posted above, this will do it for you. Frankly, I find it impressive XT32 is able to fix such small deviations. But the first time or to you try it you may want to only try a few points to make sure you're doing everything correctly.

It is my understanding, that there really isn't a downside to adding more points with Audyssey as there may be with adding a bunch of PEQs with other types of filters and processing. XT32 uses more than 10,000 control points to make up the reference curve. So rearranging 5 of them instead of 50 doesn't mean any reduction of processing of the signal (making it more "pure"). Like I said, with this software it's all or nothing, so you might as well do a complete job if you've made it this far.

For each dot location, simply measure the frequency and how far it needs to go to get to your correction line and enter that as a control point in Ratbuddy.

But if you just do something like the above, with a stack of control points as shown here in Ratbuddy:

RatCapture.jpg


Results like this are possible:

RF4hDir1m.jpg


This shows the Audyssey off in brown, on with the above corrections in black.

The best thing about doing this at high frequencies, is that EQ actually works! At low frequencies, many deviations are caused by room modes, SBIR effects, etc. Some of those can't be fixed by EQ at all, and for some it'll only partially help which can lead to frustration when things don't respond as you tell them to. But at high frequencies, if you follow the above method, Audyssey pretty much does exactly what you tell it--and will nail it on the first try!

There are exceptions though--as noted before, acoustical interferences caused by a bad horn/waveguide (or even a good one above a certain frequency), coaxial speakers and various design flaws of more conventional speakers, etc, may not react well or at all to EQ. If you find a spot in the response that doesn't correct properly, and you've added the control point and its correction properly, it's probably best to just leave it. Throwing gain at something like that isn't going to fix it.

That brings us to other reasons to deviate from a flat line. If your speaker's natural response has a huge dip or massive rolloff at the top end, you may think twice about trying to flatten those things all the way out. If it's bad enough Audyssey may limit you anyway, but you may not want to push them that far, particularly for a speaker with dome tweeters which may have limited headroom. I don't think a few db of boost is the end of the world (Audyssey will surely do it all by itself) as long as you're mindful you will be eating into the speaker's headroom and distortion may become audible a bit sooner. If you know you often listen to the speakers close to the limits of their capabilities, especially to the point of hearing distortion, you want to be really careful about not boosting much if at all. Keep in mind, the proper way to judge how much you're boosting is not the number you put into Ratbuddy, because that's relative to the Reference Curve. Compare the final correction to the response with Audyssey Off to see how much you're actually "boosting."

Other reasons to deviate from the flat line are as simple as personal preference. You may like more of a rolloff at the top end. If so, that's fine--just draw it in and correct the dots to that line instead. You may want a more "laid back" sound in which case you could put a bit of a declining slope into the curve. You may like the "show winning detail!!!!" of a speaker with a big rise the last couple of octaves. That's fine too, the goal is to get the sound you like. This amounts to the second portion of what Kevin Voecks describes in their "Anechoic EQ" where you're using smoother tone-control type adjustments to taste after fixing the "flaws" of the speaker (smoothing out the resonances) with quasi-anechoic data.

The research does tend to point to most people preferring flat direct sound in this frequency range, so that's where I recommend most people start for most speakers. It's a very sensible target that should sound quite good to everybody.

Keep in mind, this does not mean your steady-state in-room measurements will be flat. They should not. They will have a downward slope to them.

This can be clearly seen by in-room measurements of the above result:

LF4hBMAve.jpg


In a larger room (with a longer listening distance) the slope will be more, with a speaker that beams at higher frequencies there will be more of a rolloff, etc, but that's OK.

And if the in-room measurements aren't perfectly linear, and they probably won't be with most speakers, that doesn't mean you did anything wrong. That's due to your speaker's directivity index not being linear. That's OK--it's the best you're going to get out of this speaker because you can't fix the directivity issue with EQ. And now you know, if you flatten out the in-room curve with that speaker, you'll be screwing up the direct sound. The direct sound is generally the most important. The above speaker has exceptionally well controlled constant directivity which is why it remains linear in the in-room measurements.

Something else to check after you're done with in-room (steady state at the MLP) is to make sure the high frequency portion blends smoothly with the midrange. If you choose your "target line" poorly, you may see a sort of "step" where the high frequency EQ kicks in if you corrected to a line that is too high or too low. In this case you can simply add or subtract 1 db or whatever the error looks like from all the high frequency control points. Your in-room curve should smoothly go from the point you left the reference curve to high frequencies.

A couple more notes:

This operation is separate from what you do in the bass region. Whether you leave that flat, add in a "Harman preferred" rise at the bottom, etc, is up your preference. You can try different things on the bass while leaving your high frequency EQ intact by using different copies of the file you made. You can add control points in Ratbuddy out of order. I've found it's a good idea to save the file, open it and save it again before trying to use it though (sometimes it seems to take an iteration or two of that before puts the points in the correct order).

That should be enough to get you up and running. Man, if this was the "Cliff's Notes" version, the full version explaining all the theory and giving references, etc, is really going to take a while!
 
Last edited:
P

PENG

Audioholic Slumlord
I know, that's why I am not quite ready to tackle, or even just experiment with frequencies above a few hundred Hz. To do up to 120 Hz it took minutes to flatten it to within +/- 1.5 dB or better with Rutbuddyssey + Excel as I have shown you. That's fantastic enough for me, for now.:D
 
D

DJ7675

Junior Audioholic
OK, I can give the Cliff's Notes of the process to get you started. Yes, the M16's are quite good so you should end up with very good results. And you have the huge advantage of anechoic data for that speaker as a sanity check on your measurements.

1) Make sure you have a good Auydssey calibration measurement-wise (mic placement was good, individual measurements in Ratbuddy look reasonable, speaker distances, etc, are where they should be). You won't want to be starting from scratch because you think one of your measurements in the original Audyssey file may have been messed up.

2) Measure your speakers. If you can drag them and your AVR outside, that's great, middle of a big room OK, but as-placed in the room is probably the most practical for most people. Keep in mind, as boundaries get closer, the less you can trust data at lower frequencies. Even in the middle of a large room, the floor bounce will wreak havoc on your measurements, so don't even think about doing anything in the lower midrange with these measurements unless you can do it outside with the speaker up in the air.

Make sure you're using a calibrated mic with the correct calibration file. For this I use the 0 degree file with the mic pointed at the tweeter. Use a tape measure to accurately place the mic.

For most speakers, I think 1 meter on axis with the tweeter is probably the best place to take measurements for high frequencies. With larger towers, farther measurements may be advisable but this makes it more difficult to eliminate reflections from the measurements. You want to use gated measurements to eliminate reflections as much as possible. You can look at your impulse response to give you an idea of where the large reflections are coming into the signal, but even the smaller reflections will influence the results somewhat. This is an area where experimentation and using some judgement comes into play. Try different measurement techniques--distances and gating lengths--and compare them until you arrive at a technique you're comfortable with (feel you can trust the measurements--they're repeatable!) in the frequency range you want to fix.

I've ended up using 1m distance and 4ms gating as a standard. I haven't used REW for this in a while, but with Omnimic here are the results you get with 4ms gating:

View attachment 36848

The pure gated measurement (in black) in Omnimic as you can see flat out stops at 600 Hz, and looses resolution above that for a while (which is why outdoor measurements with longer gating times are needed to actually evaluate a speaker full range). The brown line is "blended mode" which blends the gated measurements at high frequencies with steady-state measurements at lower frequencies. That's the one I use as I think the increased resolution in the 800-1200 Hz range is helpfull and they're both basically identical above that.

Once you've figured out a technique you want to use, it's time to take measurements for real. While a single on-axis measurement is OK to get you started quickly if you just want to test the process and will basically give you the same results with a really, really good speaker, in most cases you're going to want to do a listening window measurement. Many speakers with horns and most coaxial speakers will have anomalies exactly on-axis that disappear in the listening window. Naturally, you don't want to correct those.

For various reasons, I think the full CEA 2034 listening window is a bit bigger than necessary for the purpose of calibrating the direct sound, so I typically do a smaller "calibrating window"--basically on-axis, up/down 5 degrees, left/right 10 degrees. But that's entirely up to you to do what you feel is best for a particular speaker.

Note, for all measurements, make sure DEQ is OFF! DEQ can be great set to preference when listening, but you don't want it on when you're measuring for calibrations.

The first measurement you want to take, is one with Audyssey switched OFF. Do this only after calibrating though, so that it's level is the same as with it on. Then do the same with Audyssey On. I don't think it really matters when doing this method whether you pick Ref Rolloff #1 or #2, I got in the habit long ago when trying to draw new curves of using Rolloff #2 because it's more linear at the top end. But whatever you pick, stick with it.

3) Calibrate! Once you've taken the measurements, you've done the hard part. Now you can finish up at your computer.

First look at the curve with Audyssey off to see what your speaker naturally does and make some decisions on how to fix it.

View attachment 36849

There's an example (different speaker than the above BTW). The first thing you need to decide is your target. I'd suggest for most speakers simply aiming at a flat response is going to give the results that will be preferred by most people (we'll talk about variations later). If aiming for a flat line, you need to decide where to put it.

For this speaker I decided since it has a nice flat and smooth area from about 1100 to 2000 Hz that averages exactly 80 db, that would be the target.

Unfortunately, with Audyssey at high frequencies, it's all or nothing. If you have a speaker that measures perfectly flat with just one flaw (bump or dip), you can't just fix that. It's all or nothing. So while the curve above with Audyssey off is informative about what to do, you can't fix it. You can only fix the Reference curve. With such a speaker that will likely mean "undoing" what Audyssey did instead of simply fixing the one spot.

So, add the reference curve measurement:

View attachment 36850

Here, the red line is the Reference curve measurement.

First off, you can see how Audyssey can screw up a pretty good speaker at high frequencies. This is a controlled directivity speaker which doesn't have excessive room reflections, and you can see by aiming for a flat in-room steady state response for most of the curve, it ends up boosting the upper midrange and most of the treble well above flat in the direct sound that will be headed to your ears. That makes the speaker sound excessively bright. One would be much better off limiting the correction of this speaker to bass frequencies than correcting full range with the standard reference curve.

So for this speaker, most of the deviation from the reference curve you type into Ratbuddy will be fixing what Audyssey screwed up.

To identify the new control points, first zoom in on the upper frequencies such that you make the Reference measurement really ugly. I find it easiest to literally print it out and draw your target line on there for reference. Simply put a dot at each "inflection point" along the curve:

View attachment 36851

(I ended up deleting the bottom few points from that out of the file.) As you can see that is zoomed in such that each line is only 1 db so it looks really bad, but it allows you to be precise in the adjustments needed.

That may look a bit scary--I plan on doing more experiments with applying a little bit of smoothing and using fewer control points. Most of those small deviations won't be audible so there is probably a point of diminishing returns so you don't need to add 60 or so points. Be careful of smoothing though--it can cause undercorrection of the bumps and dips. But if you want to get a super flat curve as was posted above, this will do it for you. Frankly, I find it impressive XT32 is able to fix such small deviations. But the first time or to you try it you may want to only try a few points to make sure you're doing everything correctly.

It is my understanding, that there really isn't a downside to adding more points with Audyssey as there may be with adding a bunch of PEQs with other types of filters and processing. XT32 uses more than 10,000 control points to make up the reference curve. So rearranging 5 of them instead of 50 doesn't mean any reduction of processing of the signal (making it more "pure"). Like I said, with this software it's all or nothing, so you might as well do a complete job if you've made it this far.

For each dot location, simply measure the frequency and how far it needs to go to get to your correction line and enter that as a control point in Ratbuddy.

But if you just do something like the above, with a stack of control points as shown here in Ratbuddy:

View attachment 36853

Results like this are possible:

View attachment 36854

This shows the Audyssey off in brown, on with the above corrections in black.

The best thing about doing this at high frequencies, is that EQ actually works! At low frequencies, many deviations are caused by room modes, SBIR effects, etc. Some of those can't be fixed by EQ at all, and for some it'll only partially help which can lead to frustration when things don't respond as you tell them to. But at high frequencies, if you follow the above method, Audyssey pretty much does exactly what you tell it--and will nail it on the first try!

There are exceptions though--as noted before, acoustical interferences caused by a bad horn/waveguide (or even a good one above a certain frequency), coaxial speakers and various design flaws of more conventional speakers, etc, may not react well or at all to EQ. If you find a spot in the response that doesn't correct properly, and you've added the control point and its correction properly, it's probably best to just leave it. Throwing gain at something like that isn't going to fix it.

That brings us to other reasons to deviate from a flat line. If your speaker's natural response has a huge dip or massive rolloff at the top end, you may think twice about trying to flatten those things all the way out. If it's bad enough Audyssey may limit you anyway, but you may not want to push them that far, particularly for a speaker with dome tweeters which may have limited headroom. I don't think a few db of boost is the end of the world (Audyssey will surely do it all by itself) as long as you're mindful you will be eating into the speaker's headroom and distortion may become audible a bit sooner. If you know you often listen to the speakers close to the limits of their capabilities, especially to the point of hearing distortion, you want to be really careful about not boosting much if at all. Keep in mind, the proper way to judge how much you're boosting is not the number you put into Ratbuddy, because that's relative to the Reference Curve. Compare the final correction to the response with Audyssey Off to see how much you're actually "boosting."

Other reasons to deviate from the flat line are as simple as personal preference. You may like more of a rolloff at the top end. If so, that's fine--just draw it in and correct the dots to that line instead. You may want a more "laid back" sound in which case you could put a bit of a declining slope into the curve. You may like the "show winning detail!!!!" of a speaker with a big rise the last couple of octaves. That's fine too, the goal is to get the sound you like. This amounts to the second portion of what Kevin Voecks describes in their "Anechoic EQ" where you're using smoother tone-control type adjustments to taste after fixing the "flaws" of the speaker (smoothing out the resonances) with quasi-anechoic data.

The research does tend to point to most people preferring flat direct sound in this frequency range, so that's where I recommend most people start for most speakers. It's a very sensible target that should sound quite good to everybody.

Keep in mind, this does not mean your steady-state in-room measurements will be flat. They should not. They will have a downward slope to them.

This can be clearly seen by in-room measurements of the above result:

View attachment 36855

In a larger room (with a longer listening distance) the slope will be more, with a speaker that beams at higher frequencies there will be more of a rolloff, etc, but that's OK.

And if the in-room measurements aren't perfectly linear, and they probably won't be with most speakers, that doesn't mean you did anything wrong. That's due to your speaker's directivity index not being linear. That's OK--it's the best you're going to get out of this speaker because you can't fix the directivity issue with EQ. And now you know, if you flatten out the in-room curve with that speaker, you'll be screwing up the direct sound. The direct sound is generally the most important. The above speaker has exceptionally well controlled constant directivity which is why it remains linear in the in-room measurements.

Something else to check after you're done with in-room (steady state at the MLP) is to make sure the high frequency portion blends smoothly with the midrange. If you choose your "target line" poorly, you may see a sort of "step" where the high frequency EQ kicks in if you corrected to a line that is too high or too low. In this case you can simply add or subtract 1 db or whatever the error looks like from all the high frequency control points. Your in-room curve should smoothly go from the point you left the reference curve to high frequencies.

A couple more notes:

This operation is separate from what you do in the bass region. Whether you leave that flat, add in a "Harman preferred" rise at the bottom, etc, is up your preference. You can try different things on the bass while leaving your high frequency EQ intact by using different copies of the file you made. You can add control points in Ratbuddy out of order. I've found it's a good idea to save the file, open it and save it again before trying to use it though (sometimes it seems to take an iteration or two of that before puts the points in the correct order).

That should be enough to get you up and running. Man, if this was the "Cliff's Notes" version, the full version explaining all the theory and giving references, etc, is really going to take a while!
Thank you for taking the time for the write up. This is really excellent. What I like about this:
1-The process goal is to eq the speaker to flat on axis.Then when measured at your listening position you naturally get that downward slope the Floyd Toole/Harman research shows people prefer.
2-Even if someone doesn’t want to follow this process, you show how Audyssey can destroy a good speaker by forcing a flat curve measured at the listening position. I think this illustrates why for most it may be good idea to not eq above a 300/500/1K.
3-EQing at higher frequencies only using the Audyssey mic I think can cause audyssey to “fix” issues that aren’t there when measured with a better mic. Making corrections based on measurements with a better/calibrated mic seems to be important at higher frequencies to get good predictable results.
I look forward to giving this a try. Appreciate the “Cliff Notes” version :)
 
P

PENG

Audioholic Slumlord
Do you think you can notice an improvement?
I can only say I am very happy with the bass response right now, without the Harman recommended curve at the low end that I don't have the time to try yet. Whether it is an improvement as such I cannot say, there is no way to do an AB comparison. The bass sounds clear and tight.
 
S

shkumar4963

Audioholic
OK, I can give the Cliff's Notes of the process to get you started. Yes, the M16's are quite good so you should end up with very good results. And you have the huge advantage of anechoic data for that speaker as a sanity check on your measurements.

1) Make sure you have a good Auydssey calibration measurement-wise (mic placement was good, individual measurements in Ratbuddy look reasonable, speaker distances, etc, are where they should be). You won't want to be starting from scratch because you think one of your measurements in the original Audyssey file may have been messed up.

2) Measure your speakers. If you can drag them and your AVR outside, that's great, middle of a big room OK, but as-placed in the room is probably the most practical for most people. Keep in mind, as boundaries get closer, the less you can trust data at lower frequencies. Even in the middle of a large room, the floor bounce will wreak havoc on your measurements, so don't even think about doing anything in the lower midrange with these measurements unless you can do it outside with the speaker up in the air.

Make sure you're using a calibrated mic with the correct calibration file. For this I use the 0 degree file with the mic pointed at the tweeter. Use a tape measure to accurately place the mic.

For most speakers, I think 1 meter on axis with the tweeter is probably the best place to take measurements for high frequencies. With larger towers, farther measurements may be advisable but this makes it more difficult to eliminate reflections from the measurements. You want to use gated measurements to eliminate reflections as much as possible. You can look at your impulse response to give you an idea of where the large reflections are coming into the signal, but even the smaller reflections will influence the results somewhat. This is an area where experimentation and using some judgement comes into play. Try different measurement techniques--distances and gating lengths--and compare them until you arrive at a technique you're comfortable with (feel you can trust the measurements--they're repeatable!) in the frequency range you want to fix.

I've ended up using 1m distance and 4ms gating as a standard. I haven't used REW for this in a while, but with Omnimic here are the results you get with 4ms gating:

View attachment 36848

The pure gated measurement (in black) in Omnimic as you can see flat out stops at 600 Hz, and looses resolution above that for a while (which is why outdoor measurements with longer gating times are needed to actually evaluate a speaker full range). The brown line is "blended mode" which blends the gated measurements at high frequencies with steady-state measurements at lower frequencies. That's the one I use as I think the increased resolution in the 800-1200 Hz range is helpfull and they're both basically identical above that.

Once you've figured out a technique you want to use, it's time to take measurements for real. While a single on-axis measurement is OK to get you started quickly if you just want to test the process and will basically give you the same results with a really, really good speaker, in most cases you're going to want to do a listening window measurement. Many speakers with horns and most coaxial speakers will have anomalies exactly on-axis that disappear in the listening window. Naturally, you don't want to correct those.

For various reasons, I think the full CEA 2034 listening window is a bit bigger than necessary for the purpose of calibrating the direct sound, so I typically do a smaller "calibrating window"--basically on-axis, up/down 5 degrees, left/right 10 degrees. But that's entirely up to you to do what you feel is best for a particular speaker.

Note, for all measurements, make sure DEQ is OFF! DEQ can be great set to preference when listening, but you don't want it on when you're measuring for calibrations.

The first measurement you want to take, is one with Audyssey switched OFF. Do this only after calibrating though, so that it's level is the same as with it on. Then do the same with Audyssey On. I don't think it really matters when doing this method whether you pick Ref Rolloff #1 or #2, I got in the habit long ago when trying to draw new curves of using Rolloff #2 because it's more linear at the top end. But whatever you pick, stick with it.

3) Calibrate! Once you've taken the measurements, you've done the hard part. Now you can finish up at your computer.

First look at the curve with Audyssey off to see what your speaker naturally does and make some decisions on how to fix it.

View attachment 36849

There's an example (different speaker than the above BTW). The first thing you need to decide is your target. I'd suggest for most speakers simply aiming at a flat response is going to give the results that will be preferred by most people (we'll talk about variations later). If aiming for a flat line, you need to decide where to put it.

For this speaker I decided since it has a nice flat and smooth area from about 1100 to 2000 Hz that averages exactly 80 db, that would be the target.

Unfortunately, with Audyssey at high frequencies, it's all or nothing. If you have a speaker that measures perfectly flat with just one flaw (bump or dip), you can't just fix that. It's all or nothing. So while the curve above with Audyssey off is informative about what to do, you can't fix it. You can only fix the Reference curve. With such a speaker that will likely mean "undoing" what Audyssey did instead of simply fixing the one spot.

So, add the reference curve measurement:

View attachment 36850

Here, the red line is the Reference curve measurement.

First off, you can see how Audyssey can screw up a pretty good speaker at high frequencies. This is a controlled directivity speaker which doesn't have excessive room reflections, and you can see by aiming for a flat in-room steady state response for most of the curve, it ends up boosting the upper midrange and most of the treble well above flat in the direct sound that will be headed to your ears. That makes the speaker sound excessively bright. One would be much better off limiting the correction of this speaker to bass frequencies than correcting full range with the standard reference curve.

So for this speaker, most of the deviation from the reference curve you type into Ratbuddy will be fixing what Audyssey screwed up.

To identify the new control points, first zoom in on the upper frequencies such that you make the Reference measurement really ugly. I find it easiest to literally print it out and draw your target line on there for reference. Simply put a dot at each "inflection point" along the curve:

View attachment 36851

(I ended up deleting the bottom few points from that out of the file.) As you can see that is zoomed in such that each line is only 1 db so it looks really bad, but it allows you to be precise in the adjustments needed.

That may look a bit scary--I plan on doing more experiments with applying a little bit of smoothing and using fewer control points. Most of those small deviations won't be audible so there is probably a point of diminishing returns so you don't need to add 60 or so points. Be careful of smoothing though--it can cause undercorrection of the bumps and dips. But if you want to get a super flat curve as was posted above, this will do it for you. Frankly, I find it impressive XT32 is able to fix such small deviations. But the first time or to you try it you may want to only try a few points to make sure you're doing everything correctly.

It is my understanding, that there really isn't a downside to adding more points with Audyssey as there may be with adding a bunch of PEQs with other types of filters and processing. XT32 uses more than 10,000 control points to make up the reference curve. So rearranging 5 of them instead of 50 doesn't mean any reduction of processing of the signal (making it more "pure"). Like I said, with this software it's all or nothing, so you might as well do a complete job if you've made it this far.

For each dot location, simply measure the frequency and how far it needs to go to get to your correction line and enter that as a control point in Ratbuddy.

But if you just do something like the above, with a stack of control points as shown here in Ratbuddy:

View attachment 36853

Results like this are possible:

View attachment 36854

This shows the Audyssey off in brown, on with the above corrections in black.

The best thing about doing this at high frequencies, is that EQ actually works! At low frequencies, many deviations are caused by room modes, SBIR effects, etc. Some of those can't be fixed by EQ at all, and for some it'll only partially help which can lead to frustration when things don't respond as you tell them to. But at high frequencies, if you follow the above method, Audyssey pretty much does exactly what you tell it--and will nail it on the first try!

There are exceptions though--as noted before, acoustical interferences caused by a bad horn/waveguide (or even a good one above a certain frequency), coaxial speakers and various design flaws of more conventional speakers, etc, may not react well or at all to EQ. If you find a spot in the response that doesn't correct properly, and you've added the control point and its correction properly, it's probably best to just leave it. Throwing gain at something like that isn't going to fix it.

That brings us to other reasons to deviate from a flat line. If your speaker's natural response has a huge dip or massive rolloff at the top end, you may think twice about trying to flatten those things all the way out. If it's bad enough Audyssey may limit you anyway, but you may not want to push them that far, particularly for a speaker with dome tweeters which may have limited headroom. I don't think a few db of boost is the end of the world (Audyssey will surely do it all by itself) as long as you're mindful you will be eating into the speaker's headroom and distortion may become audible a bit sooner. If you know you often listen to the speakers close to the limits of their capabilities, especially to the point of hearing distortion, you want to be really careful about not boosting much if at all. Keep in mind, the proper way to judge how much you're boosting is not the number you put into Ratbuddy, because that's relative to the Reference Curve. Compare the final correction to the response with Audyssey Off to see how much you're actually "boosting."

Other reasons to deviate from the flat line are as simple as personal preference. You may like more of a rolloff at the top end. If so, that's fine--just draw it in and correct the dots to that line instead. You may want a more "laid back" sound in which case you could put a bit of a declining slope into the curve. You may like the "show winning detail!!!!" of a speaker with a big rise the last couple of octaves. That's fine too, the goal is to get the sound you like. This amounts to the second portion of what Kevin Voecks describes in their "Anechoic EQ" where you're using smoother tone-control type adjustments to taste after fixing the "flaws" of the speaker (smoothing out the resonances) with quasi-anechoic data.

The research does tend to point to most people preferring flat direct sound in this frequency range, so that's where I recommend most people start for most speakers. It's a very sensible target that should sound quite good to everybody.

Keep in mind, this does not mean your steady-state in-room measurements will be flat. They should not. They will have a downward slope to them.

This can be clearly seen by in-room measurements of the above result:

View attachment 36855

In a larger room (with a longer listening distance) the slope will be more, with a speaker that beams at higher frequencies there will be more of a rolloff, etc, but that's OK.

And if the in-room measurements aren't perfectly linear, and they probably won't be with most speakers, that doesn't mean you did anything wrong. That's due to your speaker's directivity index not being linear. That's OK--it's the best you're going to get out of this speaker because you can't fix the directivity issue with EQ. And now you know, if you flatten out the in-room curve with that speaker, you'll be screwing up the direct sound. The direct sound is generally the most important. The above speaker has exceptionally well controlled constant directivity which is why it remains linear in the in-room measurements.

Something else to check after you're done with in-room (steady state at the MLP) is to make sure the high frequency portion blends smoothly with the midrange. If you choose your "target line" poorly, you may see a sort of "step" where the high frequency EQ kicks in if you corrected to a line that is too high or too low. In this case you can simply add or subtract 1 db or whatever the error looks like from all the high frequency control points. Your in-room curve should smoothly go from the point you left the reference curve to high frequencies.

A couple more notes:

This operation is separate from what you do in the bass region. Whether you leave that flat, add in a "Harman preferred" rise at the bottom, etc, is up your preference. You can try different things on the bass while leaving your high frequency EQ intact by using different copies of the file you made. You can add control points in Ratbuddy out of order. I've found it's a good idea to save the file, open it and save it again before trying to use it though (sometimes it seems to take an iteration or two of that before puts the points in the correct order).

That should be enough to get you up and running. Man, if this was the "Cliff's Notes" version, the full version explaining all the theory and giving references, etc, is really going to take a while!
Excellent write up. Thank you.

I see that Ratbuddy allows us to create a custom target curves for both front left and front right speakers.

I also see that MultEQ sends both front left and front right curves to the Denon 3500.

But I can only see one front curve in the MultEQ.

Do you know that it actually does transfer separate left and right front target curves to the AVR?

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Jon AA

Jon AA

Audioholic
Yeah, the MultEQ app only shows and allows you to edit the target curve for speaker pairs. So don't mess with that section of the app when using Ratbuddy.

The EQ is different for each speaker, obviously, and Ratbuddy allows you to alter the target curve for each independently. You can see the results in the MultEQ app by looking at "Room Correction Results" where there will be differences for L&R if you put them there.
 
S

shkumar4963

Audioholic
Yeah, the MultEQ app only shows and allows you to edit the target curve for speaker pairs. So don't mess with that section of the app when using Ratbuddy.

The EQ is different for each speaker, obviously, and Ratbuddy allows you to alter the target curve for each independently. You can see the results in the MultEQ app by looking at "Room Correction Results" where there will be differences for L&R if you put them there.
Thank you.

You said, "Yeah, the MultEQ app only shows and allows you to edit the target curve for speaker pairs. So don't mess with that section of the app when using Ratbuddy."

Did you mean, "don't mess with that section of the app when using, MultEQ?

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Jon AA

Jon AA

Audioholic
I just mean if you have different target points entered for the L and R channels but then try and modify the curve in the MultEQ app, I have no idea what would happen--would your modifications apply to both L&R, would that erase differences between the L&R that were there before? I have no idea...but I do know if you make the changes in Ratbuddy they will be correct for each channel.
 
S

shkumar4963

Audioholic
I just mean if you have different target points entered for the L and R channels but then try and modify the curve in the MultEQ app, I have no idea what would happen--would your modifications apply to both L&R, would that erase differences between the L&R that were there before? I have no idea...but I do know if you make the changes in Ratbuddy they will be correct for each channel.
Thanks. I got it now.

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S

shkumar4963

Audioholic
I just mean if you have different target points entered for the L and R channels but then try and modify the curve in the MultEQ app, I have no idea what would happen--would your modifications apply to both L&R, would that erase differences between the L&R that were there before? I have no idea...but I do know if you make the changes in Ratbuddy they will be correct for each channel.
Based on your experience, how much SQ improvement have you seen by doing this technique?

Was it as per your expectations?

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Jon AA

Jon AA

Audioholic
The improvement possible depends entirely upon the speaker you're correcting. If your speaker is naturally relatively flat on-axis it could be rather subtle (though, as mentioned above, Kevin Voecks said even the top of the line Revel speakers can benefit from high resolution anechoic EQ at high frequencies), if it's really bad it could be transformative, and everything in-between.

It doesn't necessarily track with price of the speaker either--many really, really expensive speakers are not very flat on-axis being "voiced" to set the apart from the crowd with their "house sound" so one shouldn't think spending a lot of money guarantees a perfect speaker.

And keep in mind, speakers that have very poor directivity control may certainly be improved substantially, but there's only so much EQ-lipstick can do with a pig. ;)
 
S

shkumar4963

Audioholic
The improvement possible depends entirely upon the speaker you're correcting. If your speaker is naturally relatively flat on-axis it could be rather subtle (though, as mentioned above, Kevin Voecks said even the top of the line Revel speakers can benefit from high resolution anechoic EQ at high frequencies), if it's really bad it could be transformative, and everything in-between.

It doesn't necessarily track with price of the speaker either--many really, really expensive speakers are not very flat on-axis being "voiced" to set the apart from the crowd with their "house sound" so one shouldn't think spending a lot of money guarantees a perfect speaker.

And keep in mind, speakers that have very poor directivity control may certainly be improved substantially, but there's only so much EQ-lipstick can do with a pig. ;)
Thank you. With that in mind, and since XT32 is so widely available, do you think it could be available as a custom SQ improvement service by a home custom installer?

I assume, once perfected, it would take about 2 hours for a pair of speakers. Would it be worth for a homeowner to spend an additional $200 to $400 to get such an improvement?

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L

Lattiboy

Enthusiast
Hi all,

I’ve read through this thread with great interest, and posted a question in the main forum yesterday, but I think I need the advice of you lot, as so far the only thing I’ve been told is Audyssey is garbage and I shouldn’t use it


I have an issue (on both the Marantz 6012 and Denon 3500H) where I get a constant bass distortion from my left speaker when using Audyssey with my external DAC. I’m running it into the CD input RCAs. On both receivers!

I figured it was a line level input issue, but even after setting the source input to -10db the distortion remains. Also, if I use Airplay or other digital inputs the distortion isn’t present

To make things even weirder, when I run the DAC in “pure direct” mode there is no distortion, even at incredibly high SPLs.

I’ve attached a photo of my room correction results.

I’m running a Marantz SR6012 into two NAD 2400thx power amps, driving my NHT Classic Four speakers, being aided by two Infinity Sub R12s. The external DAC is the D1+ tube DAC from Maverick Audio.

the distortion is present even with “L/R bypass” or Flat is selected, which makes no sense. I’ve also attached my levels post calibration.
 

Attachments

Pogre

Pogre

Audioholic Warlord
I had time this morning so I played with ratbuddyssey to tweak a little bit above the crossover point on the front speakers. I think I got my arms around it now. It'd be nice to have a Q feature instead of typing in all those anchor points, but it did help me.

06-19-20 FR.jpg


76 dB is the target here, because when I tried 75 dB REW kept telling me 85% of the sweep was above the target goal. So instead of fighting it I just raised the target 1 dB. I figured it's bass, so it can't hurt. I tapped out at +/- 2 dB from 125 hz and down, and +/- 3 dB from 200 hz and down. This is with 1/12 smoothing. That's better than what I usually get above 90 hz and I think I can get it even closer. Another day perhaps. I've had enough fun for 1 day, lol.
 
S

shkumar4963

Audioholic
Hi all,

I’ve read through this thread with great interest, and posted a question in the main forum yesterday, but I think I need the advice of you lot, as so far the only thing I’ve been told is Audyssey is garbage and I shouldn’t use it


I have an issue (on both the Marantz 6012 and Denon 3500H) where I get a constant bass distortion from my left speaker when using Audyssey with my external DAC. I’m running it into the CD input RCAs. On both receivers!

I figured it was a line level input issue, but even after setting the source input to -10db the distortion remains. Also, if I use Airplay or other digital inputs the distortion isn’t present

To make things even weirder, when I run the DAC in “pure direct” mode there is no distortion, even at incredibly high SPLs.

I’ve attached a photo of my room correction results.

I’m running a Marantz SR6012 into two NAD 2400thx power amps, driving my NHT Classic Four speakers, being aided by two Infinity Sub R12s. The external DAC is the D1+ tube DAC from Maverick Audio.

the distortion is present even with “L/R bypass” or Flat is selected, which makes no sense. I’ve also attached my levels post calibration.
This is very interesting. I have 3500h. And I get the same issue but only on my right front speaker.

And we know why. Audyssey is seeing a dip at about 200 Hz in my case and 350 Hz in your case and is trying to provide a boost of 7 dB in my case and about the same in your case. Clearly, our speakers distort when one frequency is boosted that much

I thought that it was because I had a bookcase next to my right speaker but listening to your issue, it may be that our 3500h are malfunctioning.

Very interesting.



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L

Lattiboy

Enthusiast
This is very interesting. I have 3500h. And I get the same issue but only on my right front speaker.

And we know why. Audyssey is seeing a dip at about 200 Hz in my case and 350 Hz in your case and is trying to provide a boost of 7 dB in my case and about the same in your case. Clearly, our speakers distort when one frequency is boosted that much

I thought that it was because I had a bookcase next to my right speaker but listening to your issue, it may be that our 3500h are malfunctioning.

Very interesting.



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To be clear, this happened on BOTH the SR6012 and the 3500. Can’t be a hardware default unless I’m having the greatest coincidence in human history :)
 

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