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Post by urwi on Aug 19, 2014 15:00:09 GMT -5
If the EQ was tied together, you'd want it split... Can't win.  Actually the ideal setup with a true mono design would be to get each one as flat as possible (independent) then EQ the pair as one unit for the room. No, that's not how it works. Just because each response is more or less flat doesn't ensure that the combined response is also flat (this is caused by different phase responses). You would want to set level, delay and EQ for each subwoofer in a way so their COMBINED response matches the optimization target (flatness, seat to seat variance, max output or any combination of the 3). This approach is not practical because you would need to try thousands of combinations. Harman's SFM method works that way. It is the optimum though. A more practical approach is to set level and distance of each sub individually trying to optimize seat to seat variance. Then EQ all subs AS ONE for maximum flatness. |
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klinemj
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Post by klinemj on Aug 19, 2014 15:21:14 GMT -5
igorzep and bootmanThanks for the info - quite informative on both counts. I get it now. I currently only have 1 sub but I am planning to get a new sub and had been curious about >1 sub. With my room, implementing a DBA would be a challenge (there's a french door leading to outside right where 2 of the 4 rear drivers would need to be). But, at least now I understand that concept and why some people are saying the XMC's PEQ approach is still not quite right yet. It does seem that if they could send the test tone through both subs at once in the dual mono mode while maintaining the separate distance/etc that this would be a step in the right direction. And, it sounds like that is what Dirac will do (to be confirmed). Maybe they can at least enable this with the PEQ also. Mark
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bootman
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Post by bootman on Aug 19, 2014 15:51:51 GMT -5
Actually the ideal setup with a true mono design would be to get each one as flat as possible (independent) then EQ the pair as one unit for the room. No, that's not how it works. Just because each response is more or less flat doesn't ensure that the combined response is also flat (this is caused by different phase responses). You would want to set level, delay and EQ for each subwoofer in a way so their COMBINED response matches the optimization target (flatness, seat to seat variance, max output or any combination of the 3). This approach is not practical because you would need to try thousands of combinations. Harman's SFM method works that way. It is the optimum though. A more practical approach is to set level and distance of each sub individually trying to optimize seat to seat variance. Then EQ all subs AS ONE for maximum flatness. Yes EQing the set as one is the best approach, (as I alluded to in my post after the one you quoted) and again if this is confirmed via Dirac, I think this issue can be put to bed. |
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Post by SticknStones on Aug 19, 2014 17:00:52 GMT -5
I would think by their individual room position that they would each engage unique boundary reenforcement, but I'm sure they thought a lot about it. If I have two mono subs in opposite ends, I would think at least adjusting distance/phase would be a useful feature. Look's like stereo is the better choice if you are running dual subs and want to control each individually. Time to start horsing around!! You know your going to buy it!  |
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bootman
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Post by bootman on Aug 19, 2014 17:21:25 GMT -5
If I have two mono subs in opposite ends, I would think at least adjusting distance/phase would be a useful feature. Look's like stereo is the better choice if you are running dual subs and want to control each individually. Time to start horsing around!! You know your going to buy it! Me? I'm on the list. |
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Post by igorzep on Aug 19, 2014 17:44:36 GMT -5
Igorzep, can you explain how your DBA setup applies to those with two box subs? You keep bringing up DBAs but in all honestly that is a very rare setup and should be treated as such if the setup routine doesn't really work that well with normal box subs that >99% of enthuthiast have. So can you clarify the dual box setup routine? I think if Dirac treats the dual subs as one unit after setting up levels and distance independently, we are good to go for 99.99% of all home applications. Why should I repeat the same things again and again? We get repetitive... What the point if my points will be again ignored... I've said already that the DBA is a perfect concept to demonstrate the issue. It doesn't mean the issue does not exists in other setups. It is just show itself so clear and obvious with this example that there could be no questions about why it is wrong way to do it. The DBA is just a special case of two subwoofers optimally placed. Perfect one. So perfect that it solves all room problems in the bass region at the same time. This is a VALID case of two subwoofers! And this case is handled completely suboptimal and incorrectly by the proposed 'independent' procedure. So, it is just one special case. There is a myriad of other cases. They are not so perfect, but it doesn't mean they magically become optimal and fitting to the proposed 'independent' procedure. Some of them may be not so perfect but any front/rear sub setup (or two subs at front, two at the back, or one in the middle two at the sides, etc.) are simplifications of DBA case, meaning it cannot solve all room problems, but can be setup to solve most problematic ones, acoustically, by actively killing some of the reflections. The routine is the same and universal. Just not perfect as with DBA case, but optimal (or very close to that). There are actually subset of setups that will fit the proposed 'independent' procedure. And this subset is... putting both subs at the front wall symmetrically. What is interesting is that this special case works optimally (or very close to that)... with delay/phase/level/EQ all equal... so, it works optimally with just one sub output. The other 0.01% will usually find a custom solution anyway don't you think? The 0.01% of users have more than one sub in the first place. And so, then the question is - why do we have two separate (not Y-connected) subwoofer outputs in XMC-1? To make a buzz "we can manage two subs", but it appears you still need to find a custom solution if you need something more than Y-connector? Or for a real non-marketing reason? I hope high quality DAC should be accompanied by high quality stream of audio samples fitted to it... There are already so many words have been written... A lot less effort than that is really needed to implement it properly... with just a wish to do it from the Emotiva. Either they have a real wish... or just are making of visibility of wishing it. |
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Post by igorzep on Aug 19, 2014 17:53:10 GMT -5
why some people are saying the XMC's PEQ approach is still not quite right yet The PEQ approach is quite OK. Just inconvenient. But it is OK because a man can always choose to adjust just one sub setting or same setting at both of subs at the same time. Automatic (Dirac) will not be able to do it and this will present a choice between Dirac and dual sub Bass Management. |
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Post by foggy1956 on Aug 19, 2014 17:53:54 GMT -5
Maybe its time to buy something else.
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Post by Dan Laufman on Aug 19, 2014 17:57:25 GMT -5
I think the point has been made....
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Post by igorzep on Aug 19, 2014 18:01:21 GMT -5
Something else is either significantly more expensive... or does not have Dirac as the Room EQ. Well XMC-1 doesn't have it also... yet. But we are assuming it has it... in some (hopefully near) future.
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Post by foggy1956 on Aug 19, 2014 18:06:27 GMT -5
Something else is either significantly more expensive... or does not have Dirac as the Room EQ. Well XMC-1 doesn't have it also... yet. But we are assuming it has it... in some (hopefully near) future. My point is if you don't like the product buy something else that has your feature set, if it is expensive that is the price you pay! |
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Post by bluescale on Aug 19, 2014 18:20:06 GMT -5
Something else is either significantly more expensive... or does not have Dirac as the Room EQ. Well XMC-1 doesn't have it also... yet. But we are assuming it has it... in some (hopefully near) future. My point is if you don't like the product buy something else that has your feature set, if it is expensive that is the price you pay! What an odd response. Igorzep and others (like me) who are talking about this this are only trying to help improve the feature set on the XMC-1. We're excited by this product (in fact, mine is arriving today). Constructive criticism is a good thing, not a negative thing. |
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Post by foggy1956 on Aug 19, 2014 18:22:51 GMT -5
My point is if you don't like the product buy something else that has your feature set, if it is expensive that is the price you pay! What an odd response. Igorzep and others (like me) who are talking about this this are only trying to help improve the feature set on the XMC-1. We're excited by this product (in fact, mine is arriving today). Constructive criticism is a good thing, not a negative thing. Agreed, I just think this has been beat to death. |
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bootman
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Post by bootman on Aug 19, 2014 18:27:59 GMT -5
What an odd response. Igorzep and others (like me) who are talking about this this are only trying to help improve the feature set on the XMC-1. We're excited by this product (in fact, mine is arriving today). Constructive criticism is a good thing, not a negative thing. Agreed, I just think this has been beat to death. Not quite. The question of how Dirac handles the two subs has yet to be answered. Why does it seem we will have to wait until it comes out and independently verified until we know for sure? We should know this now, no? |
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Post by foggy1956 on Aug 19, 2014 18:29:09 GMT -5
Agreed, I just think this has been beat to death. Not quite. The question of how Dirac handles the two subs has yet to be answered. Why does it seem we will have to wait until it comes out and independently verified until we know for sure? We should know this now, no? What would that change? |
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Post by bluescale on Aug 19, 2014 18:47:23 GMT -5
Not quite. The question of how Dirac handles the two subs has yet to be answered. Why does it seem we will have to wait until it comes out and independently verified until we know for sure? We should know this now, no? What would that change? It would put a lot of questions to bed. The fact of the matter is, so far, this is the only thing any of us have had to complain about. That's a remarkable thing. A lot of the naysayers on AVS and elsewhere are pretty quiet as they watch how this is handled (and yes, there is quite a bit of curiosity outside of the lounge). The sooner this can be put to bed, the better. |
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Post by foggy1956 on Aug 19, 2014 18:50:06 GMT -5
It would put a lot of questions to bed. The fact of the matter is, so far, this is the only thing any of us have had to complain about. That's a remarkable thing. A lot of the naysayers on AVS and elsewhere are pretty quiet as they watch how this is handled (and yes, there is quite a bit of curiosity outside of the lounge). The sooner this can be put to bed, the better. It is 1 freaking awesome unit whether or not they do anything different about bass management! |
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bootman
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Post by bootman on Aug 19, 2014 18:57:34 GMT -5
I'm not even complaining.
I just want some more info for a unit I'm in the market for.
The questions asked here are valid ones.
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Post by music1st on Aug 19, 2014 21:18:32 GMT -5
I agree that an answer would be very appreciated. I'm following this thread closely because I have two subs and the XMC-1 is a very possible replacement for my UMC-200.
I appreciate all of the knowledge that people have shared. I don't mind repetitive posts when they contain useful technical information. I'm not a pro with this stuff, so I could use the extra instruction.
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bootman
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Post by bootman on Aug 19, 2014 21:28:15 GMT -5
why some people are saying the XMC's PEQ approach is still not quite right yet The PEQ approach is quite OK. Just inconvenient. But it is OK because a man can always choose to adjust just one sub setting or same setting at both of subs at the same time. Automatic (Dirac) will not be able to do it and this will present a choice between Dirac and dual sub Bass Management. I think this is where I don't understand when you say Dirac won't be able to EQ both as one unit. Why do you think it won't? Sorry if this isn't what you meant. |
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