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Post by ttocs on Jan 6, 2021 2:01:02 GMT -5
Things might be getting simpler. Always trying new things led to mixing up the LFE duties a bit today. Looking at the diagram, the Left-1&2 are connected together using High Level, and the Right-3&4 are connected together using High Level. So now, the LFE inputs on subs 2 and 4 are connected to the miniDSP that is connected to the Center Sub LFE Output. Additionally I am still using the subwoofer in the rear of the room, so now I'm calling that one #5. The LFE group is 2, 4, and 5. I know it's confusing with all the different uses so I'll try to clarify. Augmented Bass Subs 1&2 are connected using speaker wire to the Left Front speaker. Subs 3&4 are connected using speaker wire to the Right Front speaker. This allows the bass controls on the Left and Right speakers to be backed off which relieves the dual built-in amps of needing to produce the lowest bass below 75Hz. The reduction is about 15dB at about 50Hz and under. The dual woofers in each speaker can "maybe" do a even better job up to the 300Hz crossover. The point is that the strain of pushing out the lowest octave has been taken away and put onto the subwoofers. Bass Management Since the Center Sub is setup as LFE, all the bass for Small speakers goes to the Left-1&2 and Right-3&4 which are setup as Large in the XMC-2. .1 LFE Channel This is now being sent to Subs 2, 4, and 5. So 2 & 4 are doing extra work by providing LFE in addition to the BM and Left/Right duties. One of the reasons for considering doing all these changes along the way is because the new Martin Logan 1100X subs are so much better than my older Sumiko subs, in every way. They're easier to setup, have lots of controls built-in, just have single drivers in a sealed box instead of having a passive driver which I consider more difficult to setup, and they have more powerful amps. Honestly, I don't know how they are able to measure as low as they do, but they do. I've been watching a few movies to test out how things sound, and there is A LOT more impact with these new subs. In REW the impulse looks way better too. And after running Dirac the decay is better. Everything is better, and everything isn't even finished being tweaked yet. Here is the diagram of the current configuration. This is an REW plot of the current LFE configuration using the LFE channel for the measurement so that's why the upper end gets rolled off.
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Post by ttocs on Jan 6, 2021 19:49:57 GMT -5
This is the simplified wiring diagram for the current setup. The Front Left and Right speakers are setup as Large, and they each use two subwoofers for augmented bass. All speakers except the Front Left/Right are setup as Small. Center Sub is setup as LFE. Bass Management will not send any bass to this subwoofer channel. No other Subwoofer channel is setup in the Processor. Since there is no subwoofer setup as Mono, Bass Management will send all bass for Small speakers to the Left and Right speakers. In my case that means the Left Speaker with Sub-ML1 and Sub-ML2, and the Right Speaker with Sub-ML3 and Sub-ML4. When Bass Management Bass is sent to both Front speakers, the Front Left and Right and 4 subwoofers all produce the Mono bass audio.
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Post by ttocs on Jan 11, 2021 13:49:28 GMT -5
This is a plot from last week. That huge null is a problem. This occurs when both Fronts play the BM Mono signal together. The current plot when both Front speakers play a mono signal together. In some ways this is an improvement. Problem: Bass Management sends all bass from all Small speakers to the Front L&R Large speakers in Mono, so when they both play the mono signal there is a Null between 60-70Hz. Question: How can this Null be reduced or eliminated? Solutions: Move the speakers. edit: YEP!Add room treatments. edit: Nope.Change settings on the speakers to reduce the Null WITHOUT harming the individual response of each speaker when operated independently. edit: Nope.Any one or more solutions can help, but how much? The speakers are not moving, not gonna happen. edit: Well, they can move a few inches each, which is what I did. It’s interaction with the room that is causing this issue. Dirac can’t help with this, well, yes it can to some degree, but it can only aid EACH speaker, not both together without DLBM. Each SOS is phase aligned with the main speaker using a single frequency tone. Changing the frequency results is a change in performance in the frequency response. This also has an effect on the performance when both L&R operate together. Theory: I believe that there may be a “magic” phase alignment that will encourage both speakers to behave nicely and reduce the Null and still allow EACH speaker to perform well. Proposals: I am going to test using a myriad of frequencies for each speaker in hopes of finding a combination where the “stars align”. I’m also going to attempt to use multi-frequency tones - tri-tones - along with RTA in REW to see what occurs when I change the phase of each sub in real time. I have already done a little of this just to see what might happen, but since then I’ve been looking more closely at the phase, group delay, and impulse reporting in REW and while I’m still learning about these things, I think over time I’ll become more aware of what to look for after putting all these thoughts through the meat grinder. edit: Moving the speaker groups closer to where they were before I added the subwoofers helped with the null. I guess my ears weren't too bad after all when I placed the speakers in these spots over a year and a half ago. This doesn't solve all the issues because, of course, I moved the speakers closer together to help with other issues, but does help for when both Left and Right channels are playing the same mono signal.
Tomorrow I'll run ARC on both speakers and the four subs, then run Dirac again.
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Post by ttocs on Jan 12, 2021 13:19:42 GMT -5
To illustrate what can happen with just a little bit of speaker movement just look at the attachments. The Fronts have been 7'-8" apart for over 1-1/2 years. They became located this way after weeks of moving and listening, no measuring. The system has been fabulous with the Fronts located as shown on the plan as being 7'-8" apart. Then, a couple weeks ago, I began moving each Front speaker to improve its performance when mated to its pair of subwoofers. At first, while doing this moving and measuring, I was only considering what was best for each speaker, not the pair. The speakers ended up being as close together as possible without being less than the width of the tv panel, so they could go no farther. Then I began focusing on the pair and what happens with a mono bass signal, and this is where I was being subjected with a null between 60-70Hz and sometimes a bit wider than that. Last night I began moving the speakers apart again and instantly noticed the null being reduced. Right now they are about 7'-3" apart, but will probably go back to the spread I'm used to, but I had to quit and go to bed. This plot was made while the speakers were at their minimum distance. REW sweep with L+R. This is after moving the speakers wider apart. REW sweep with L+R. While it's clear there are still issues, and this is before re-running ARC and Dirac, it clearly illustrates what can happen after moving a pair of speakers a total of only 7". That's 3-1/2" each! So when it's suggested to move speakers/subs a few inches and some would argue that it won't make a difference with low frequencies, here's the proof that it does! The quarter wave of 65Hz is a little over 4', and I moved the speakers 7". This plan shows the widest spread as the starting point, and the minimum spread that the first plot represents, and then of course the speakers were moved back closer to the starting point for the second plot.
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Post by ttocs on Jan 12, 2021 22:50:26 GMT -5
Little bit forward, little bit back, but getting closer with every new clue. Right now it looks as though the Right Group needs some attention. The impulse is pretty messy right now so I know something's up here. I'm going to play with placement and see what becomes of it. Then spread the L&R a few more inches. The Right Group seems to have a lot of effect on what happens when both play together. Left Group, Right Group, L+R Groups.
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Post by ttocs on Jan 14, 2021 10:11:22 GMT -5
I posted this plot last week but it bears being pointed out as a separate consideration when using Large Fronts for Bass Management to send them the Small Speaker bass. The plot shows the bass for the Right Surround channel below 80Hz being at an elevated level when it should be the same as the Right Front bass. One channel, one bass source. If these processors were setup for stereo bass and all the Small Right channels used only Large Right Front it would be perfect. But because BOTH Fronts are used for a single surround channel the bass is artificially multiplied. When using subwoofers connected to the subwoofer outputs, BM sends the Small Speaker bass to one or more of the outputs dictated by the setup. I didn't have too much bass no matter how the subwoofer outputs were setup. Now that BM is sending the bass to BOTH Fronts equally, that bass is being summed and a gain of about 4-5dB is the result. This might be welcome in some systems, but it's too much in mine. I haven't figured a way to adjust this yet as I've got other things to work on for now, but I do want to figure this out.
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Post by hsamwel on Jan 14, 2021 17:34:32 GMT -5
I posted this plot last week but it bears being pointed out as a separate consideration when using Large Fronts for Bass Management to send them the Small Speaker bass. The plot shows the bass for the Right Surround channel below 80Hz being at an elevated level when it should be the same as the Right Front bass. One channel, one bass source. If these processors were setup for stereo bass and all the Small Right channels used only Large Right Front it would be perfect. But because BOTH Fronts are used for a single surround channel the bass is artificially multiplied. When using subwoofers connected to the subwoofer outputs, BM sends the Small Speaker bass to one or more of the outputs dictated by the setup. I didn't have too much bass no matter how the subwoofer outputs were setup. Now that BM is sending the bass to BOTH Fronts equally, that bass is being summed and a gain of about 4-5dB is the result. This might be welcome in some systems, but it's too much in mine. I haven't figured a way to adjust this yet as I've got other things to work on for now, but I do want to figure this out. I think this was the issue I mentioned to Damon. He only told me to lower the BM sub 3db.. Don’t know if this makes it right totally. I asked him specifically about this and what happens with LFE volume in this case. Which should be 10db higher than BM.. I don’t think it’s right, Totally this must let LFE become lower and BM higher in volume.. Even if not huge difference. He just said the difference shouldn’t be noticed.
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Post by megash0n on Jan 14, 2021 19:01:49 GMT -5
I posted this plot last week but it bears being pointed out as a separate consideration when using Large Fronts for Bass Management to send them the Small Speaker bass. The plot shows the bass for the Right Surround channel below 80Hz being at an elevated level when it should be the same as the Right Front bass. One channel, one bass source. If these processors were setup for stereo bass and all the Small Right channels used only Large Right Front it would be perfect. But because BOTH Fronts are used for a single surround channel the bass is artificially multiplied. When using subwoofers connected to the subwoofer outputs, BM sends the Small Speaker bass to one or more of the outputs dictated by the setup. I didn't have too much bass no matter how the subwoofer outputs were setup. Now that BM is sending the bass to BOTH Fronts equally, that bass is being summed and a gain of about 4-5dB is the result. This might be welcome in some systems, but it's too much in mine. I haven't figured a way to adjust this yet as I've got other things to work on for now, but I do want to figure this out. I think this was the issue I mentioned to Damon. He only told me to lower the BM sub 3db.. Don’t know if this makes it right totally. I asked him specifically about this and what happens with LFE volume in this case. Which should be 10db higher than BM.. I don’t think it’s right, Totally this must let LFE become lower and BM higher in volume.. Even if not huge difference. He just said the difference shouldn’t be noticed. Oh my........
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Post by ttocs on Jan 14, 2021 19:06:44 GMT -5
I posted this plot last week but it bears being pointed out as a separate consideration when using Large Fronts for Bass Management to send them the Small Speaker bass. The plot shows the bass for the Right Surround channel below 80Hz being at an elevated level when it should be the same as the Right Front bass. One channel, one bass source. If these processors were setup for stereo bass and all the Small Right channels used only Large Right Front it would be perfect. But because BOTH Fronts are used for a single surround channel the bass is artificially multiplied. When using subwoofers connected to the subwoofer outputs, BM sends the Small Speaker bass to one or more of the outputs dictated by the setup. I didn't have too much bass no matter how the subwoofer outputs were setup. Now that BM is sending the bass to BOTH Fronts equally, that bass is being summed and a gain of about 4-5dB is the result. This might be welcome in some systems, but it's too much in mine. I haven't figured a way to adjust this yet as I've got other things to work on for now, but I do want to figure this out. I think this was the issue I mentioned to Damon. He only told me to lower the BM sub 3db.. Don’t know if this makes it right totally. I asked him specifically about this and what happens with LFE volume in this case. Which should be 10db higher than BM.. I don’t think it’s right, Totally this must let LFE become lower and BM higher in volume.. Even if not huge difference. He just said the difference shouldn’t be noticed. Yeah, you don't want to turn down a sub handling both BM and LFE. When it's just subwoofers handling both BM and LFE I didn't notice excess bass. It's just since I use subwoofers just for LFE and set the Left and Right Subs as None, thus sending BM to the Large Fronts. So, Damon's suggestion won't work for my setup since there's no specific setting for BM volume. Now keep in mind that this only happens for summed mono bass. So when bass for a single channel is sent to two independent channels handling the bass that are not subwoofer channels, that bass gets a free boost. Here's a plot showing the Left Front (Red), Left Surround (Blue), and LFE (Purple). Below the XO setting in the processor the LS begins rising to a max of a few dB higher than LF, and LFE is around 8dB higher than LF.
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Post by marcl on Jan 17, 2021 9:17:53 GMT -5
I think this was the issue I mentioned to Damon. He only told me to lower the BM sub 3db.. Don’t know if this makes it right totally. I asked him specifically about this and what happens with LFE volume in this case. Which should be 10db higher than BM.. I don’t think it’s right, Totally this must let LFE become lower and BM higher in volume.. Even if not huge difference. He just said the difference shouldn’t be noticed. Yeah, you don't want to turn down a sub handling both BM and LFE. When it's just subwoofers handling both BM and LFE I didn't notice excess bass. It's just since I use subwoofers just for LFE and set the Left and Right Subs as None, thus sending BM to the Large Fronts. So, Damon's suggestion won't work for my setup since there's no specific setting for BM volume. Now keep in mind that this only happens for summed mono bass. So when bass for a single channel is sent to two independent channels handling the bass that are not subwoofer channels, that bass gets a free boost. Here's a plot showing the Left Front (Red), Left Surround (Blue), and LFE (Purple). Below the XO setting in the processor the LS begins rising to a max of a few dB higher than LF, and LFE is around 8dB higher than LF. View AttachmentAs one who has been a proponent of separating BM to the mains and LFE to the subs, I apologize for neglecting to point out this issue. I've had this issue from the beginning. Tried to fix it a number of ways over the past several months. Nope, can't fix it. It's not an issue in my system though. I assume most L/R bass is mono below 80Hz, and I adjust the LFE level so it's 10db above the level of BM. I think what would fix this is if bass management were to be stereo and not mono. Small speaker bass for left channels would go to the left front, and right channels to the right front. MAYBE that would fix it. It would be more correct too because some of us have small speakers that go up to 200Hz. But if BM has to stay Mono, the processor should drop it 3db.
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Post by ttocs on Jan 17, 2021 10:42:44 GMT -5
As one who has been a proponent of separating BM to the mains and LFE to the subs, I apologize for neglecting to point out this issue. I've had this issue from the beginning. Tried to fix it a number of ways over the past several months. Nope, can't fix it. It's not an issue in my system though. I assume most L/R bass is mono below 80Hz, and I adjust the LFE level so it's 10db above the level of BM. I think what would fix this is if bass management were to be stereo and not mono. Small speaker bass for left channels would go to the left front, and right channels to the right front. MAYBE that would fix it. It would be more correct too because some of us have small speakers that go up to 200Hz. But if BM has to stay Mono, the processor should drop it 3db. I'm certain Stereo Bass would be a fix because the increase is only due to both fronts summing to play the bass.
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Post by marcl on Jan 17, 2021 11:10:54 GMT -5
As one who has been a proponent of separating BM to the mains and LFE to the subs, I apologize for neglecting to point out this issue. I've had this issue from the beginning. Tried to fix it a number of ways over the past several months. Nope, can't fix it. It's not an issue in my system though. I assume most L/R bass is mono below 80Hz, and I adjust the LFE level so it's 10db above the level of BM. I think what would fix this is if bass management were to be stereo and not mono. Small speaker bass for left channels would go to the left front, and right channels to the right front. MAYBE that would fix it. It would be more correct too because some of us have small speakers that go up to 200Hz. But if BM has to stay Mono, the processor should drop it 3db. I'm certain Stereo Bass would be a fix because the increase is only due to both fronts summing to play the bass. XMC-1 had Stereo Subs. If you had two subs, Bass Management was sent to them in stereo. Now we have subs called Left and Right that are always mono.
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Post by megash0n on Jan 17, 2021 11:23:40 GMT -5
I'm certain Stereo Bass would be a fix because the increase is only due to both fronts summing to play the bass. XMC-1 had Stereo Subs. If you had two subs, Bass Management was sent to them in stereo. Now we have subs called Left and Right that are always mono. that still only addresses the sub output though. Not the underlying, "blind" bass management, correct? In other words, Emotiva would need to apply any and all changes to BM regardless of the channel BM was directed to. Then, one could have an option to enable a reduction of 3dB per virtual BM channel for those instances where BM was mono. Hopefully the made sense.
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Post by ttocs on Jan 17, 2021 12:05:42 GMT -5
XMC-1 had Stereo Subs. If you had two subs, Bass Management was sent to them in stereo. Now we have subs called Left and Right that are always mono. that still only addresses the sub output though. Not the underlying, "blind" bass management, correct? In other words, Emotiva would need to apply any and all changes to BM regardless of the channel BM was directed to. Then, one could have an option to enable a reduction of 3dB per virtual BM channel for those instances where BM was mono. Hopefully the made sense. I'm pretty sure I get what you're saying. But I think with the XMC-1, since it had stereo subs, BM in the XMC-1 sent the Right side to the Right sub, and Left to Left. Anyone out there who has a XMC-1 to test with? And yes, I think a 3dB option would be nice toggle to have.
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Post by megash0n on Jan 17, 2021 12:22:20 GMT -5
that still only addresses the sub output though. Not the underlying, "blind" bass management, correct? In other words, Emotiva would need to apply any and all changes to BM regardless of the channel BM was directed to. Then, one could have an option to enable a reduction of 3dB per virtual BM channel for those instances where BM was mono. Hopefully the made sense. I'm pretty sure I get what you're saying. But I think with the XMC-1, since it had stereo subs, BM in the XMC-1 sent the Right side to the Right sub, and Left to Left. Anyone out there who has a XMC-1 to test with? Any yes, I think a 3dB option would be nice toggle to have. I follow. I guess I should have said.. I wasn't sure if it was dependant upon the channel, in this case a subwoofer, or if it was dependant upon the logical output of bass management whether it be stereo or not. One would only impact subwoofers, which wouldn't fully satisfy you. The other would.
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Post by marcl on Jan 17, 2021 12:47:23 GMT -5
that still only addresses the sub output though. Not the underlying, "blind" bass management, correct? In other words, Emotiva would need to apply any and all changes to BM regardless of the channel BM was directed to. Then, one could have an option to enable a reduction of 3dB per virtual BM channel for those instances where BM was mono. Hopefully the made sense. I'm pretty sure I get what you're saying. But I think with the XMC-1, since it had stereo subs, BM in the XMC-1 sent the Right side to the Right sub, and Left to Left. Anyone out there who has a XMC-1 to test with? Any yes, I think a 3dB option would be nice toggle to have. I looked at my XMC-1 manual. If you have two subs and configure them for Stereo, Bass Management does what we would want ... all left to left, all right to right. It doesn't mention the center and I bet it sends center bass to both and you get the 3db rise. Interestingly, not a word in the manual that I could find about Bass Management if you have no subs. I assume it goes to large speakers, but this is not stated explicitly anywhere I could find.
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Post by ttocs on Jan 17, 2021 13:12:03 GMT -5
I hate typos when they're mine. Any = And ^^^
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Post by ttocs on Jan 17, 2021 22:49:02 GMT -5
Well it looks like I'm down to 5 subs. Four Martin Logan 1100X and one 800X seems to do the trick, and I get the end of my dining table back. The Left and Right Speakers, in addition to Left/Right duties, also handle the bass that Bass Management sends to them for all speakers designated as Small. These speakers are now actually speaker groups consisting of a main speaker, Martin Logan 13A, and two subwoofers connected via the Speaker Level connections, so they are connected directly to the Left or Right speakers. The bottom subwoofer of each stack is also tasked with LFE duties. The LFE Group consists of one left ML 1100X, one right ML 1100X, and one ML 800X located at the rear of the room. The Martin Logan subwoofers are pretty flexible in how they can be setup, and they seem to perform very well! I'm very surprised at how quick they respond. I'm so happy with them that I have no use for my other old subs, they simply cannot compete with these new subwoofers. This is how the Left/Right speaker setup looks. The arrangement for LFE consists of the bottom left and bottom right subs plus the sub at the back of the room. There is tweaking still to happen, but the initial results are improved from using the system in a "normal" configuration with multiple subs when I was using the twin Sumiko subs and a Rel. This new setup is much better by measurement, but is waaaay better in terms of dynamics and instantaneous impact!!
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Post by hsamwel on Jan 17, 2021 23:59:46 GMT -5
So when do we have elevated bass signal?
1. Center sub - LFE, R/L sub none, LR -large
2. Center sub - mono, L/R sub none, all speakers small
3. Center sub - LFE, L/R sub mono or dual mono, all speakers small
4. Center sub - none, L/R sub mono or dual mono, all speakers small
Don’t know if I have missed some setting..
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Post by ttocs on Jan 18, 2021 1:21:49 GMT -5
So when do we have elevated bass signal? 1. Center sub - LFE, R/L sub none, LR -large 2. Center sub - mono, L/R sub none, all speakers small 3. Center sub - LFE, L/R sub mono or dual mono, all speakers small 4. Center sub - none, L/R sub mono or dual mono, all speakers small Don’t know if I have missed some setting.. I think it's easier to conceive the setup this way. 7.1.4, Fronts Large, all others Small, the only sub output used is Center Sub. Now toggle between Center Sub LFE and Center Sub Mono. There is around a 6dB difference in volume from the Fronts, but NOT Surrounds and Tops. The Surrounds and Tops never change in volume, this part is easy for my system because I just turn off the subs and the amp for the Fronts/Center. With the Fronts/Center on, Surrounds/Tops on, Subwoofers off, when I toggle the Center Sub between LFE and Mono the volume of the electrostatic panel which only carries frequencies above 300Hz gets louder when the Center Sub is set as Mono, and back to lower volume when set as LFE. The Center speaker never changes volume. To recap, the Center, Surrounds, and Tops never change volume when toggling the Center Sub between LFE and Mono. The Fronts get louder when the Center Sub is set as Mono, and quieter when set as LFE. I'm not getting into anything about the bass because that is much harder for me to separate because I don't currently have subs connected to the Left/Right Subs outputs, but maybe I'll do that in the next few days because I have some to use, just need to have the time to do it. Also, with my Fronts set as Large, this is where BM goes to when the Center Sub is set for LFE, so I need to have another avenue for the bass as a control to test.
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