Germotiva
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Post by Germotiva on Mar 28, 2021 15:27:47 GMT -5
I have put my diagram over yours. maybe you understand me what I mean about your analysis. The Magenta Signal to 2 kHz. The Sub-out from allstereo is Open In the higher area. Disconnects not clean.dad through the Micro also records these frequencies. If you only use the separation of the RMC and not the DSP. With the additional separation of DSP it becomes cleaner. But then the phase is not correct if you do not pay attention. For example, I have to use the separation of 12dB in the RMC and set a separation in the DSP with 12dB so I come to 24dB separation. So that the phase of separation of the 24dB setting of the Midbasses is correct. Sorry i Hope you Understatement me....Technical English is really difficult in the translation.🤷♂️😔
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Post by ttocs on Mar 29, 2021 16:47:35 GMT -5
I have put my diagram over yours. maybe you understand me what I mean about your analysis. The Magenta Signal to 2 kHz. The Sub-out from allstereo is Open In the higher area. Disconnects not clean.dad through the Micro also records these frequencies. If you only use the separation of the RMC and not the DSP. With the additional separation of DSP it becomes cleaner. But then the phase is not correct if you do not pay attention. For example, I have to use the separation of 12dB in the RMC and set a separation in the DSP with 12dB so I come to 24dB separation. So that the phase of separation of the 24dB setting of the Midbasses is correct. Sorry i Hope you Understatement me....Technical English is really difficult in the translation.🤷♂️😔 I know it can be difficult to translate the ideas. I am not understanding what I should be looking at, so I don't know if there is a problem. Should the curves be lower?
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Post by ttocs on Mar 29, 2021 17:09:16 GMT -5
Speaker Placement is First on the list of things that improve the system! I've been working on a deep dip between 60-70Hz when both Fronts play the same signal. Over the last few months I have tried using absorption panels and bales of rock wool, but nothing was showing more than a tiny improvement that would also be good for when each speaker is playing by itself. An improvement is only workable when each and both are improved. I've been seriously avoiding moving the Front speakers because there is a lot going on when the subs are taken into account, but today I move the speakers. I started moving just the two stacks of subs, but then saw the need to move the speakers which had the greatest impact. So now the speakers have been moved 7" farther away from the front wall and the subs a little more than that. It's a work in progress, but the initial result is pretty major. This is a before/after plot. All I did was move the speakers and run Dirac, then check with REW. I made no other tweaks.
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Post by leonski on Mar 29, 2021 21:28:30 GMT -5
What you have is a standing wave issue........room mods might not help this. Instead? speaker placement might help..... amcoustics.com/tools/amrocto help visualize, check out the link. Even DIRAC won't help because if it turns 'up' the bass to fix this dip, EVERYTHING gets the same bump...... PLEASE NOTE: By moving the speaker you not only helped the LF DIP but the 2nd harmonic of that, at DOUBLE the frequency and again higher p.......ALL THREE DIPS are related.
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Post by ttocs on Mar 29, 2021 22:07:13 GMT -5
What you have is a standing wave issue........room mods might not help this. Instead? speaker placement might help..... amcoustics.com/tools/amrocto help visualize, check out the link. Even DIRAC won't help because if it turns 'up' the bass to fix this dip, EVERYTHING gets the same bump...... PLEASE NOTE: By moving the speaker you not only helped the LF DIP but the 2nd harmonic of that, at DOUBLE the frequency and again higher p.......ALL THREE DIPS are related. Well, in this case it's really a cancellation when both Left and Right Fronts are playing a Mono signal. I believe it's from a reflection while both are playing. With the speakers in the previous positions I've always been able to get a good response when Each speaker is on its own, or, when Both speakers are playing, but not for EachAndBoth after using Dirac. So unfortunately it is Dirac that messes things up. I have dialed in the settings for the speakers/subs many times getting good results, even going as far as trying to get slightly worse response for "each" speaker so that the "both" response would be improved after using Dirac. But each time, Dirac would make "each" speaker look great, but "both" continued to have that dip. In other words, I was trying to fool Dirac into a calibration that would be better for when both speakers are actively playing the same signal. I'm a big advocate of speaker placement! It's free and has the greatest impact on the system. When I placed the speakers in the positions they've been in for almost two years, it was pre-Dirac. So this dip didn't show up until I started using Dirac. I was able to tame some of the dip with the subwoofers that are now used as extra woofers for the Fronts, but was not able to reduce the dip more than just being 10Hz wide - which is half the width it was, but the depth never changed, it was always an abyss. And yes, that's a great point about the harmonics! Another improvement that I'm hoping will show up in measurements is having moved a null that is about a foot above our heads when seated watching movies. I only found it when using 9 mic points when using Dirac, so I avoid it with a tighter pattern and only use 7 points max. When I've been asked about what I think are the top five most important considerations in setting up a system, the first three on the list are speaker placement.
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Post by leonski on Mar 30, 2021 1:44:44 GMT -5
Standing waves can 'cancel' or 'peak'......you can get a double DIP or BUMP.
I'd PERSONALLY unplug the DIRAC. sounds like WAY more trouble than it's worth. And this based on reading thru nearly 180 PAGES of posts.
Many people DO get good results. I've a standing offer to go WITNEsS this setup and cal run, but not takers.
the Harmonic behavior of the result is your CLUE. Next would be to determine the MODE of the reflection. Too ocmplicated to go into here....but you SHOULD look it up.
Than mmove ONE Of the subs to a non-cogging location and try again....
And BTW? At least for MUSIC, everthing below about 80hz or so is MONO, anyway.
Wavelength of 70hz? about 16 feet. Take that into considerataon when moving ONE sub.
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Post by ttocs on Mar 30, 2021 8:01:37 GMT -5
Next would be to determine the MODE of the reflection. Too complicated to go into here....but you SHOULD look it up. Than mmove ONE Of the subs to a non-cogging location and try again.... Please do elaborate about the MODE of the reflection, this is the right place to do that. It's actually not the subs that are the problem here, it's the Martin Logan Expressions themselves. The moving isn't complete yet, but once it is then the treatment phase restarts. I found one placement for treatment that worked pretty well, even more than the amount of dip that's left, so I think things are pretty close.
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Post by leonski on Mar 30, 2021 16:24:59 GMT -5
In SIMPLE terms? You have sound bouncing around. It can bounce 2-wall.....Up /Down OR Left / Right OR LENGTHWISE in the room.
It can bounce off 3 walls... In nearly any adjacent combination. 4 wall bounces and more are possible, but each diminishes the effect.
This all reacts to form a series of 'standing waves'.....which can either be peaks or dips.
Longer freuqencies get more problematic.
Please find the Harmon White Paper on Multiple Subs.....a HIGHLY regarded and oft-quoted paper which will give you plenty of sub-isssues to chew over. Also? Find one of the MANY room mode calculators. Some have neat graphics which will help VISUALIZE what they are giving the math for. It's a pretty neat process and pretty soon YOU'LL be seeing sound as well!
Does this help? I tried to not get TOO deep into stuff I barely understand, but the drift is clear. Bass is the worst to get right.
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KeithL
Administrator
Posts: 9,902
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Post by KeithL on Mar 30, 2021 16:55:51 GMT -5
I feel a need to point out that you are providing an excellent example of the logic behind using "subs and satellites". Most of the problems you are seeing are due to interactions between those two front speakers and the sub at low frequencies. The logic is simply that, if you only had one speaker making low frequencies, then there would be no interactions between speakers. Then all you would have to deal with would be interactions between that one speaker and the room.
And, since low bass is non-directional, you would have the freedom to put it wherever in the room worked the best. And, since that was a separate speaker than the speakers making the midrange and high frequencies...
You could put those speakers wherever they sounded best in terms of things like imaging and sound stage. But, once you have large front speakers, you now have multiple subs... And, even worse, two of them are pretty much forced to be in spots that work the best for midrange and treble.
(Which is rarely the best spot for a sub.) This is why many people compromise by simply using their main front speakers as large when listening to music (with the sub off). You're sacrificing some very low bass performance for a perfectly smooth transition between the midrange and bass and the best imaging.
(Presumably it is high quality stereo recordings where things like sound stage and phase response will actually matter the most.)
And using a sub for movies - with the front speaker set to small. You're avoiding low frequency interactions by ONLY using the sub for those...
But now you have a crossover, and the transition between the main speakers and the sub, to worry about. (But since most movies and most surround sound music are usually multi-tracked and heavily processed - phase isn't as critical for those.)
It's when you try to optimize for both situations that things get dicey...
(Like trying to design a truck that works well climbing mountains... but also won't spill your drink in the back seat.)
Speaker Placement is First on the list of things that improve the system! I've been working on a deep dip between 60-70Hz when both Fronts play the same signal. Over the last few months I have tried using absorption panels and bales of rock wool, but nothing was showing more than a tiny improvement that would also be good for when each speaker is playing by itself. An improvement is only workable when each and both are improved. I've been seriously avoiding moving the Front speakers because there is a lot going on when the subs are taken into account, but today I move the speakers. I started moving just the two stacks of subs, but then saw the need to move the speakers which had the greatest impact. So now the speakers have been moved 7" farther away from the front wall and the subs a little more than that. It's a work in progress, but the initial result is pretty major. This is a before/after plot. All I did was move the speakers and run Dirac, then check with REW. I made no other tweaks. View Attachment
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Post by leonski on Mar 30, 2021 17:00:59 GMT -5
I feel a need to point out that you are providing an excellent example of the logic behind using "subs and satellites". Most of the problems you are seeing are due to interactions between those two front speakers and the sub at low frequencies. The logic is simply that, if you only had one speaker making low frequencies, then there would be no interactions between speakers. Then all you would have to deal with would be interactions between that one speaker and the room.
And, since low bass is non-directional, you would have the freedom to put it wherever in the room worked the best. And, since that was a separate speaker than the speakers making the midrange and high frequencies...
You could put those speakers wherever they sounded best in terms of things like imaging and sound stage. But, once you have large front speakers, you now have multiple subs... And, even worse, two of them are pretty much forced to be in spots that work the best for midrange and treble.
(Which is rarely the best spot for a sub.) This is why many people compromise by simply using their main front speakers as large when listening to music (with the sub off). You're sacrificing some very low bass performance for a perfectly smooth transition between the midrange and bass and the best imaging.
(Presumably it is high quality stereo recordings where things like sound stage and phase response will actually matter the most.)
And using a sub for movies - with the front speaker set to small. You're avoiding low frequency interactions by ONLY using the sub for those...
But now you have a crossover, and the transition between the main speakers and the sub, to worry about. (But since most movies and most surround sound music are usually multi-tracked and heavily processed - phase isn't as critical for those.)
It's when you try to optimize for both situations that things get dicey...
(Like trying to design a truck that works well climbing mountains... but also won't spill your drink in the back seat.)
Speaker Placement is First on the list of things that improve the system! I've been working on a deep dip between 60-70Hz when both Fronts play the same signal. Over the last few months I have tried using absorption panels and bales of rock wool, but nothing was showing more than a tiny improvement that would also be good for when each speaker is playing by itself. An improvement is only workable when each and both are improved. I've been seriously avoiding moving the Front speakers because there is a lot going on when the subs are taken into account, but today I move the speakers. I started moving just the two stacks of subs, but then saw the need to move the speakers which had the greatest impact. So now the speakers have been moved 7" farther away from the front wall and the subs a little more than that. It's a work in progress, but the initial result is pretty major. This is a before/after plot. All I did was move the speakers and run Dirac, then check with REW. I made no other tweaks. View AttachmentThe advantage? Music RARELY needs any frequency below mid-20s. I can think of ON bit of organ music which benefits from 16hz. The exception Based on the chart TTOCS posted, it is REFLECTION and interaction of bass. The harmonic relation of the dips seals it.
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Post by ttocs on Mar 30, 2021 18:13:01 GMT -5
I feel a need to point out that you are providing an excellent example of the logic behind using "subs and satellites". Most of the problems you are seeing are due to interactions between those two front speakers and the sub at low frequencies. The logic is simply that, if you only had one speaker making low frequencies, then there would be no interactions between speakers. Then all you would have to deal with would be interactions between that one speaker and the room.
And, since low bass is non-directional, you would have the freedom to put it wherever in the room worked the best.
And, since that was a separate speaker than the speakers making the midrange and high frequencies...
You could put those speakers wherever they sounded best in terms of things like imaging and sound stage.
But, once you have large front speakers, you now have multiple subs... And, even worse, two of them are pretty much forced to be in spots that work the best for midrange and treble.
(Which is rarely the best spot for a sub.) This is why many people compromise by simply using their main front speakers as large when listening to music (with the sub off). You're sacrificing some very low bass performance for a perfectly smooth transition between the midrange and bass and the best imaging.
(Presumably it is high quality stereo recordings where things like sound stage and phase response will actually matter the most.)
And using a sub for movies - with the front speaker set to small. You're avoiding low frequency interactions by ONLY using the sub for those...
But now you have a crossover, and the transition between the main speakers and the sub, to worry about. (But since most movies and most surround sound music are usually multi-tracked and heavily processed - phase isn't as critical for those.)
It's when you try to optimize for both situations that things get dicey...
(Like trying to design a truck that works well climbing mountains... but also won't spill your drink in the back seat.) Keith, this is all well and good but there's several things to consider here. The dip does not exist when running the Expressions with or without the subwoofers using USER EQ. The dip only shows up AFTER running Dirac. Moving the stereo subwoofers around does not change the dip much at all, barely noticeable. But moving the Expressions has a big impact on the depth of the dip. In all speaker/sub positions the dip does not show up until a Dirac filter is enabled. Prior to setting up the the Expressions with dedicated twin stereo stacks of subs, the dip caused by using Dirac was about twice as wide. Using the subs I was able to tweak that to what it shows in the plot above. Moving the Expressions, with or without the subs, is what is changing the depth of the dip. I'm not a stranger to having the electrostatic speakers far from the front wall, two years ago they were 5' out, but when I came upon a way to have it all I grew accustomed to living life without the speakers dominating the room. With that said, I guess I'm going back to a little in-between. The strange thing is that I've added the subwoofer in the rear of the room to the Left/Right Fronts and Dirac kept wanting to keep that dip when mono is played through both Fronts. The other strange thing is that I can make it such that the dip is gone even using a Dirac filter, but the response from each channel playing alone is worsened. Bottom line is that things are going in the correct direction by moving the speakers. USER EQ still is ok, Dirac seems to be playing nice and hopefully will be doing so after more moving.
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Post by leonski on Mar 31, 2021 0:07:12 GMT -5
Than I'd look to microphone placement.....you are placing one of 'em in a peak / peak area which DIRAC compensates for by driving that frequency and harmonics DOWN.....producing the 'dip'.
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Post by ttocs on Mar 31, 2021 7:43:21 GMT -5
Than I'd look to microphone placement.....you are placing one of 'em in a peak / peak area which DIRAC compensates for by driving that frequency and harmonics DOWN.....producing the 'dip'. Sorry, it's just one mic location, so it's a comparison of multiple DIRAC EQ's with the mic in one spot, the same spot that produced the plots using two different DIRAC EQ's posted Monday. When testing things it's always just using one mic location.
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Post by leonski on Mar 31, 2021 13:42:06 GMT -5
Than MOVE the one location. You appear to have a standing wave issue.......
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Post by ttocs on Mar 31, 2021 17:22:22 GMT -5
Than MOVE the one location. You appear to have a standing wave issue....... There is no standing wave until Dirac makes that happen. I will not setup my system solely based upon what Dirac does. It needs to operate with and without it. I really need to stress the point that there is no notch or dip without Dirac. Dirac is creating that dip all on its own.
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Post by leonski on Mar 31, 2021 17:30:35 GMT -5
1. Set it up without dip 2. Unplug DIRAC 3. Enjoy your system 4. Don't obsess about 'measuring' stuff.
What with DIRAC would cause such behavior? the Harmonic relation is very off-putting and makes me wonder...... Some unfortunate reaction going on here which needs experiment to overcome....
I wish I was near enough to drop by and watch the process and learn.
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Post by ttocs on Apr 1, 2021 13:34:53 GMT -5
What with DIRAC would cause such behavior? the Harmonic relation is very off-putting and makes me wonder...... Some unfortunate reaction going on here which needs experiment to overcome.... I wish I was near enough to drop by and watch the process and learn. I don't understand everything Dirac does, but it uses phase quite a bit so my guess is that because it does not know that two speakers or subs will be working together it only corrects each speaker by itself. So when the combinations come into play is where the oddities can appear. The same thing occurs with subwoofers, which is why it would be nice if we could use the Dirac Live Bass Control that's not available yet for our processors. This week, everything in the entertainment area is up for grabs. Everything is on the move. Nothing is sacred. And, like I've known for a couple years now, what's good for the Left is not good for the Right. So the desire this week is to try something I've known for quite a while but my OCD wouldn't let me try, and it's known and espoused by the speaker setup gurus, Asymmetrical Setup. Put each speaker where it wants to be to sound its best, then use toe/tilt/etc to get the imaging correct. Hop on a plane and come over! Although, you might get frustrated with all the back and forth, up and down, left and right, rinse, repeat. Pete and Repete were on a boat, Pete fell overboard, who was left? Repete Pete and Repete were on a boat, Pete fell overboard, who was left? Repete . . . . . .
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Post by leonski on Apr 1, 2021 19:46:50 GMT -5
TEST? When you are in the condidtion of the bass 'dip'?
Flip the phase switch on ONE of the subs........than check for the dip.....if that's even possible.
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Post by ttocs on Apr 1, 2021 21:33:31 GMT -5
Flip the phase switch on ONE of the subs........than check for the dip.....if that's even possible. There's 5 subwoofers involved. It's easy to Invert, or change the phase incrementally of anything and everything. The wide, deep dip only shows up when I ran Dirac before having moved the speakers a few days ago, but I'm past that now, it's a not much of issue "mostly" as the plot shows. I'm now just trying to improve the efficiency of the bass by moving everything where the most gain shows up, and things are going in the right direction. In fact, it's getting close to the point where the gain of some of the subs needs to be reduced again. There's more than 10dB increase just from moving things, including the MLP. I'm basically finishing what I did not do a few years ago because I didn't want to sit as close to the tv as I'm probably going to do now, but there was another logistical reason that no longer exists due to a change in floor plan, so now is the time to complete the task. I'm in Phase 492A (completely meaningless), using room treatment panels, moving them in and out while also moving the speakers and furniture to see the effects. It's quite interesting that the biggest bang for the buck comes from just leaning a couple of absorption panels against the left and right sides of the tv, perpendicular to the wall, so they are straight out from the front wall. I always thought they would be better near or in corners, 2-walls, 2-walls&floor, floor&wall, etc. Another thing to note is to use the tv panel itself as a tuning device. Mine is on a mount that will swing out away from the wall and tilt, and this has an effect, so much so that I'm going to use some absorption behind it to see if that also has an effect. The tv is something I'd rather not utilize, but, who knows? Waterfall plots show some issues, some of which I can't do anything about, like the highway that's less than a mile away and causes quite a bit of low frequency rumble up. Right now it's quiet in the neighborhood, always is at night. Everything in my house is off, so as I'm writing this I decided to run RTA. 14Hz is showing as being 50.8dB SPL. Maybe it's possible that this might be a contributor to some of the little notches that don't go away completely? Things can get really smoothed out, but there is almost always a downward portion of the curve at or near the same frequencies, the "Tune Of The Room" so to speak. So in the last measurement run I did an hour ago there is a tiny notch at 56Hz, a multiple of 14. hmmmmm. I'm going to start tracking the room noise each time I run measurements, because I've noticed that the notches are at different frequencies on different days. Maybe it's just environmental? This would mean that close enough is close enough. Get the big stuff figured out and leave the rest alone. Anyway, what I was originally leading up to is that I'm in Room Treatment Mode for the next few days. I have a lot of material that's been sitting around for a few years and now have the gumption to do something with it, so I'll be making more panels.
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Germotiva
Minor Hero
Alter Mann über 50 aus Deutschland
Posts: 90
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Post by Germotiva on Apr 2, 2021 3:08:16 GMT -5
I also find a good idea. to reverse the phase in the SUBS. If Dirac rotates the phase at a certain frequency from the measurement. Could this be the mistake. Can you please show a WTF measurement of the subs / 24db and midbasses / 24db.
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