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Post by ansat on Jan 1, 2015 19:27:15 GMT -5
but additional equipment would not need to be purchased. Exactly my point. The unit was originally designed as a true .2 unit so why are we buying extra gear to fix it?  impatient  But I have given a lot of thought to this and I to implement correctly, 1 of two things need to happen, Either emotiva applies dsp and delay on the subwoofers BEFORE dirac (which I am not sure can be done and would require a complete rework of the bass management) or the better option, put additional functionality into the upgrade. At this point, the only thing I think that emotiva could do would be to add delay after dirac, and this would not completely solve the issue of two flat curves will usually not produce a flat sum. But we probably don't want to start this conversation over again here. Tony |
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Post by Mike Ronesia on Jan 1, 2015 19:48:30 GMT -5
Is there any room correction SW that can do .2 properly?
Cheers
Mark
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Post by ansat on Jan 1, 2015 19:59:24 GMT -5
Is there any room correction SW that can do .2 properly? Cheers Mark SUB EQ HT from Audyssey is supposed to do pretty good out of the box and with the pro calibration, there are some who swear by it. The issue is that to get the subwoofer response good across multiple seats, decisions have to be made and ARC cannot correct sub frequencies over multiple seats as each adjustment will effect all seats and errors in seating near walls will usually not exist in the middle of the room. This is something that the user needs to decide. I want mine and my wifes seating as good as possible and I really don't care about the other 5 seats in the theater as they are empty most of the time. But at the same time, I don't want to eq the room to just two seats as I can get good results with the middle and upper frequencies across all seating. Thanks Tony |
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Post by Mike Ronesia on Jan 1, 2015 20:10:07 GMT -5
Is there any room correction SW that can do .2 properly? Cheers Mark SUB EQ HT from Audyssey is supposed to do pretty good out of the box and with the pro calibration, there are some who swear by it. The issue is that to get the subwoofer response good across multiple seats, decisions have to be made and ARC cannot correct sub frequencies over multiple seats as each adjustment will effect all seats and errors in seating near walls will usually not exist in the middle of the room. This is something that the user needs to decide. I want mine and my wifes seating as good as possible and I really don't care about the other 5 seats in the theater as they are empty most of the time. But at the same time, I don't want to eq the room to just two seats as I can get good results with the middle and upper frequencies across all seating. Thanks Tony Well I guess they needed to save something for the reference line. I am more than happy with the current package at this price point. With all you've put into this I'll be able to make sure the subs are dialed in as much as roomanly possible. Thanks for all of your help in understanding this stuff. You are the first person to explain it in a way that I can start to grasp the issues and the process to correct them. Cheers Mark |
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Post by smfins on Jan 1, 2015 20:51:45 GMT -5
Doesn't Audysey XT32 take care of time alignment with dual subs? I haven't read any threads about xt32 lately, but I think I remember reading that it does.
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Post by smfins on Jan 1, 2015 20:55:00 GMT -5
Tony, I didnt see your post regarding Sub EQ HT. Both my Marantz 8801 and Denon AVR X4000 have this, and to me its great. I fall into the category of only worrying about the main listening area.
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Post by ansat on Jan 1, 2015 21:05:19 GMT -5
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Post by ansat on Jan 1, 2015 21:11:56 GMT -5
From Audyssey, - Bass in small rooms is notoriously difficult to get right. Bass lovers apply various techniques to enhance bass output. Many see the addition of a second subwoofer as the solution – this is true in part, but only if the second subwoofer is properly integrated, not simply added on to an existing set-up. Audyssey Sub EQ HT ensures that the level and delay for each subwoofer is correct before integrating them into the equalization solution. The process takes only a few minutes and results in rich, full bass that covers a wide listening area. From myself - even if all this is done -- what is missing as phase alignment. One of my favorite threads where Mark Seaton shares some of his wisdom. www.avsforum.com/forum/113-subwoofers-bass-transducers/1633729-six-6-seaton-submersive-install-exceptional-service-mark-seaton.html |
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PAC
Minor Hero
Posts: 38
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Post by PAC on Jan 4, 2015 21:36:09 GMT -5
Tony, I really appreciate all that you have done in this (and other) threads to help with sub placement and using REW. You gave me the incentive (despite having no time to mess with this stuff - due to work!)to download REW and check my HT room for any difficulties I had with bass management. (I had always suspected I had a problem with decreased bass response - but was not and still am not sure.) This is a graph of my main sub in its location in the HT room.  I moved the sub around and the 30 - 45 hz null persisted no matter where I placed the sub. I have two other subs and placed them in the back of the room behind the sofa. The three subs all together (with phase adjusted on two subs) seemed to even out the room response. Here is a graph of the three subs (blue) together over the main sub.  Here is a graph of the main sub alone with the mic in front of the cone.  Any thoughts? (The REW files are too big to attach here) I'm thinking about getting a miniDSP to help with the 30 - 45hz dip and other problems with the room. My room is well treated (bass traps and wall panels, acoustic ceiling panels, carpet, ect). Interesting though, I do not hear much difference in the XMC-1 with DIRAC on vs Preset 1 with a manual calibration. Still working with DIRAC though. Thanks again for all that you have done! |
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Post by ansat on Jan 4, 2015 22:35:27 GMT -5
I think your charts look pretty good. Your on the right track. There is a couple of things that I am seeing though. The 3 sub graph should be 6-12 db higher then the sub alone. - So try this. Using a spl meter get the spl the same on each subwoofer first. Then with just 2 subs (1 front and 1 rear) take a measurement. Move the phase knob 10 - 15 degrees and take another measurement, Then go the other direction 10-15 degrees and take a measurement (and keep repeating until you see the most even response)(at this point just try to eliminate as many dips as you can and don't worry about the humps). Now on your final subwoofer. you are going to do the same as you did for the first two, but leave the first two subs on and just change the phase on the 3rd subwoofer. Now you are looking for even response. Your final set of measurements should look similar to this.  But with the three subs you have now, thanks to having a phase alignment on 2 subs, I don't think that you will need a minidsp just yet. Tony |
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Post by nickwin on Mar 11, 2015 22:03:39 GMT -5
From Audyssey, - Bass in small rooms is notoriously difficult to get right. Bass lovers apply various techniques to enhance bass output. Many see the addition of a second subwoofer as the solution – this is true in part, but only if the second subwoofer is properly integrated, not simply added on to an existing set-up. Audyssey Sub EQ HT ensures that the level and delay for each subwoofer is correct before integrating them into the equalization solution. The process takes only a few minutes and results in rich, full bass that covers a wide listening area. From myself - even if all this is done -- what is missing as phase alignment. One of my favorite threads where Mark Seaton shares some of his wisdom. www.avsforum.com/forum/113-subwoofers-bass-transducers/1633729-six-6-seaton-submersive-install-exceptional-service-mark-seaton.htmlTony, I was under the assumption that delay (time allignent) and phase alignment were the same thing. If two subs are time aligned are they not in phase? Also, I'm trying to understand when/why someone would need a external DSP, is the issue that you cannot manually adjust the delays (distance) for each sub when using the Dirac preset? If you have a manual phase knob on your sub can you do the same thing with that you would with the miniDSP? Or does a phase knob not give you enough delay to play with? Thanks for the info! |
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Post by ansat on Mar 11, 2015 23:02:18 GMT -5
From Audyssey, - Bass in small rooms is notoriously difficult to get right. Bass lovers apply various techniques to enhance bass output. Many see the addition of a second subwoofer as the solution – this is true in part, but only if the second subwoofer is properly integrated, not simply added on to an existing set-up. Audyssey Sub EQ HT ensures that the level and delay for each subwoofer is correct before integrating them into the equalization solution. The process takes only a few minutes and results in rich, full bass that covers a wide listening area. From myself - even if all this is done -- what is missing as phase alignment. One of my favorite threads where Mark Seaton shares some of his wisdom. www.avsforum.com/forum/113-subwoofers-bass-transducers/1633729-six-6-seaton-submersive-install-exceptional-service-mark-seaton.htmlTony, I was under the assumption that delay (time allignent) and phase alignment were the same thing. If two subs are time aligned are they not in phase? Also, I'm trying to understand when/why someone would need a external DSP, is the issue that you cannot manually adjust the delays (distance) for each sub when using the Dirac preset? If you have a manual phase knob on your sub can you do the same thing with that you would with the miniDSP? Or does a phase knob not give you enough delay to play with? Thanks for the info! A phase knob can work. Where I would diffreciate between phase and time alignment is aligning the initial impulse (which would ensure that the sub reaches your ear at the same time that the other speakers would) vs aligning by phase (which would ensure most of the frequency range is combining instead of cancelling) If you have a phase knob, then there is a good chance that you can get away without a minidsp. The advantage of the minidsp is that you can easily time align to xover point post dirac. (Its a little more difficult with the phase knob). Tony |
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Post by socketman on Mar 11, 2015 23:23:29 GMT -5
Is there a tutorial of some sort on how to accomplish this . Tony  |
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Post by Mike Ronesia on Mar 12, 2015 0:21:50 GMT -5
Is there a tutorial of some sort on how to accomplish this . Tony Please let us know when you have it all filled out.    Cheers Mark |
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Post by deltadube on Mar 12, 2015 0:27:37 GMT -5
I think your charts look pretty good. Your on the right track. There is a couple of things that I am seeing though. The 3 sub graph should be 6-12 db higher then the sub alone. - So try this. Using a spl meter get the spl the same on each subwoofer first. Then with just 2 subs (1 front and 1 rear) take a measurement. Move the phase knob 10 - 15 degrees and take another measurement, Then go the other direction 10-15 degrees and take a measurement (and keep repeating until you see the most even response)(at this point just try to eliminate as many dips as you can and don't worry about the humps). Now on your final subwoofer. you are going to do the same as you did for the first two, but leave the first two subs on and just change the phase on the 3rd subwoofer. Now you are looking for even response. Your final set of measurements should look similar to this. But with the three subs you have now, thanks to having a phase alignment on 2 subs, I don't think that you will need a minidsp just yet. Tony wow .. confusing charts.. looks like a big null at 45hz |
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Post by barrak on Mar 12, 2015 10:55:45 GMT -5
Tony, I was under the assumption that delay (time allignent) and phase alignment were the same thing. If two subs are time aligned are they not in phase? Also, I'm trying to understand when/why someone would need a external DSP, is the issue that you cannot manually adjust the delays (distance) for each sub when using the Dirac preset? If you have a manual phase knob on your sub can you do the same thing with that you would with the miniDSP? Or does a phase knob not give you enough delay to play with? Thanks for the info! A phase knob can work. Where I would diffreciate between phase and time alignment is aligning the initial impulse (which would ensure that the sub reaches your ear at the same time that the other speakers would) vs aligning by phase (which would ensure most of the frequency range is combining instead of cancelling) If you have a phase knob, then there is a good chance that you can get away without a minidsp. The advantage of the minidsp is that you can easily time align to xover point post dirac. (Its a little more difficult with the phase knob). Tony If a setup produces a nasty room mode (resonance), then phase aligning the subs could make things worse (and harder for the mostly automated Dirac to deal with). With Dirac and similar time-domain EQ, time aligning is the way to go, especially if you have high-quality subs. To be a bit technical; phase aligning attempts to coincide peaks and valleys together. For a resonant mode, this could be accomplished at multiple inter-signal time shifts (think of how many ways you could stack two sheets of corrugated metal). Time aligning, on the other hand, makes sure that bass transients start (and hopefully stop) simultaneously at the listening position. For the new initiate into room correction, I would suggest stacking the subs and leaving multi-position sub optimization until sufficient experience is accumulated and room treatment is finalized. I would also suggest solo-employing the higher quality sub if you have a mixed bag of subs available. |
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Post by nickwin on Mar 12, 2015 11:33:02 GMT -5
I have an oddly shaped small room and I'm one case where adding a second (not identical but comparable) sub was a major improvment from one. I tried the single sub at every possible position in the room and could not get a decent response. Even after EQing with an antimode and Audyssey over top of that in the ideal position I had massive peaks and a ton of resinance. A few years down the road a second sub came available to play with so decided to try it out. I first tried mid side walls and that was terrible, tried a few different location and found that front right and back left corner produces a way flatter response without much noticeble loss of output. After fine tuning with the phase knob on one of the subs and adding some bass traps to my room the bass is awesome with no eq. Exponentialy better than I ever thought I would ever achieve in my house. It makes my Hifiman he500s bass sound downright mediocre. I can't wait to see what Dirac will do.
I'm not sure exactly what the second sub is doing acoustically because its taking away a HUGE peak at 40hz, maybe acting as an active bass trap? I'm going to try and set up REW for the first time today and see if I can get some visuals of what's going on. I just thought I would share my case of a second sub bing a big improvement. If your a person who has put time into experimenting and can't seem to get a good response from your single sub it's defintly worth a shot.
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Post by bestboy on Mar 12, 2015 16:26:16 GMT -5
Well, here is what happens more or less:  from the Welti/Devantir paperYou want your room (or at least your main listening position) as uniform and as light as possible. As you can see the difference between one and two subs is very significant. These diagrams show why people use 2 or more subwoofers. It's not to brag. It's not to get more "fat" bass. It's usually not even to get a higher bass output level. It's just because 2 (or more) subs create a more uniform spatial bass distribution and a flatter spectral bass response. |
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Post by nickwin on Mar 13, 2015 15:53:45 GMT -5
I finally broke down and decided to try out REW again. I had trouble getting it to work 10 years ago on a macbook, Its not working out as easy as I hoped this time either, but I did manage to get some measurements of my subs during the brief time that It was working for me. The first picture is each sub playing on its own over laid with both together. The combined graph is how I had previously set up the position and phase by ear, I think it sounds significantly better than either on there own. The 2nd graph is both subs playing together with different phase settings on the MFW15. I was kind of surprised how these looked. I playing with this a little by ear and the 7 o'clock (green) setting sounded the best to me, yet just looking at them the the other ones appear to be more in phase and flatter. I think I must have been picking up on that peak at 75hz which I don't get with the setting I had. What you guys think? Which setting should I use before I run Dirac? Do I need a miniDSP? |
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Post by ansat on Mar 13, 2015 15:58:17 GMT -5
I finally broke down and decided to try out REW again. I had trouble getting it to work 10 years ago on a macbook, Its not working out as easy as I hoped this time either, but I did manage to get some measurements of my subs during the brief time that It was working for me. The first picture is each sub playing on its own over laid with both together. The combined graph is how I had previously set up the position and phase by ear, I think it sounds significantly better than either on there own. The 2nd graph is both subs playing together with different phase settings on the MFW15. I was kind of surprised how these looked. I playing with this a little by ear and the 7 o'clock (green) setting sounded the best to me, yet just looking at them the the other ones appear to be more in phase and flatter. Looking at the 3rd graph explains a little bit because with no smoothing my original setting produces a much smoother response. I think I must have been picking up on that peak at 75hz which I don't get with the setting I had. What you guys think? Which setting should I use before I run Dirac? Do I need a miniDSP? I think your good with no minidsp. Try the 3rd, for max output and allow dirac do its thing over it. Tony |
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But I have given a lot of thought to this and I to implement correctly, 1 of two things need to happen, Either emotiva applies dsp and delay on the subwoofers BEFORE dirac (which I am not sure can be done and would require a complete rework of the bass management) or the better option, put additional functionality into the upgrade. At this point, the only thing I think that emotiva could do would be to add delay after dirac, and this would not completely solve the issue of two flat curves will usually not produce a flat sum. 
