gainphile said:Interesting link. Thanks.
I'm thinking of this for my pluto. One question: would the signals for sub be summed or Left-right as it is?
May start collecting those 5" DSE woofers. Cheap and able to do 30Hz.
Move sub2 to the lower left corner of the picture and connect it out of phase. Just try it.
soongsc said:
Obviously low frequencies means something different to you than to me. An e-bass produces very low frequency sine tones with little overtones.
The problems get even worse when the room becomes smaller, so what is the point you're trying to make?
What do you hear when you switch polarities while playing back a 40Hz sine wave?
markus76 said:
Markus ,
I'm old in this game , the game has no winners and one can spin the science anyway one would like , there will be no unanimous winner.
It will be my way and likes vs yours , my answer is not to say what you like is wrong , it is to say , Relax brother ! this is my rendition , enjoy , as i have yours, there are many knowledgeable individuals here , it's a great vast community , listen and enjoy , I have .....
Now to your question , i never disagreed about multiple subs , i was a bit taken aback by this being the " Gedlee setup ", when this has been common knowledge in the business for over 20 yrs .
. My work on such has also proven E/Q and servo recovery Subwoofers was the worst approach , again IMHO...
Regards,
a.wayne, if you want to have a discussion about subjectivity in science then this is probably the wrong thread.
Maybe I'm too young but I still believe that it's not about your way or mine or likes and dislikes. So if you have arguments I really would love to hear them.
I've never seen Earl's approach decribed before in literature so what's the problem with calling it "the Geddes approach" or "Gedlee setup" (as you did)? Can you provide us an insight into who was talking about using multiple subs in 1989?
Best, Markus
Maybe I'm too young but I still believe that it's not about your way or mine or likes and dislikes. So if you have arguments I really would love to hear them.
I've never seen Earl's approach decribed before in literature so what's the problem with calling it "the Geddes approach" or "Gedlee setup" (as you did)? Can you provide us an insight into who was talking about using multiple subs in 1989?
Best, Markus
Markus ,
I'm sure the info is there , Myself personally have been doing multiple subs from the 70's ...
In the 80's i was involved in a project mainly for recording studios that led to multiple sub , application in respect to high DB levels in a realatively small room ...
this led to a patent application in 1988 , i can tell you others where already doing it , but mostly servo control , our method attacked the localization problems by taking the mass of the radiated output form the floor boundaries to mid room , the item was marketed as the Bass Column Circa 1988...
This information is available ( yes there was knowledge before Interweb) and out their quite a few did venture , you will be amazed how much of Audio today is old rehash with a spin and it's funny to hear your comments as you still believe your interpretation of the science( your way ) to be better than others , hence my original comment
there will be no winners .. Enjoy !
I'm sure the info is there , Myself personally have been doing multiple subs from the 70's ...
In the 80's i was involved in a project mainly for recording studios that led to multiple sub , application in respect to high DB levels in a realatively small room ...
this led to a patent application in 1988 , i can tell you others where already doing it , but mostly servo control , our method attacked the localization problems by taking the mass of the radiated output form the floor boundaries to mid room , the item was marketed as the Bass Column Circa 1988...
This information is available ( yes there was knowledge before Interweb) and out their quite a few did venture , you will be amazed how much of Audio today is old rehash with a spin and it's funny to hear your comments as you still believe your interpretation of the science( your way ) to be better than others , hence my original comment
there will be no winners .. Enjoy !Ah now you're harsh Wayne, let them have fun believing they are breaking new ground!
Here's a little test and article a guy did to get better understanding. It's in Swedish but the pics and graphs should be interesting for some of you.
In Sweden I know people that have been doing multiple subs for decades.
http://www.lts.a.se/Portals/0/artiklar/Rummet2.pdf
/Peter
Here's a little test and article a guy did to get better understanding. It's in Swedish but the pics and graphs should be interesting for some of you.
In Sweden I know people that have been doing multiple subs for decades.
http://www.lts.a.se/Portals/0/artiklar/Rummet2.pdf
/Peter
I was never given the impression from Dr. Geddes that he felt he was breaking new ground. I don't know that he believed that multiple subs in a room was a brand new idea to him. Nor do I ever recall him saying that he only recently discovered this. He's mentioned doing thing for quite some time himself as well. I believe his innovation to the idea was a better understanding of the physics behind why it works, and thus an ability to standardize the setup of multiple subs for the smoothest response in room.
I think it's important that this information be put out there, regardless of what you call it, because most people aren't doing this. This isn't common knowledge amongst pro's and average users alike. It's good to know that there are others who believe in the method, and utilize it, but I am glad to see this view being put out there more and more. One look at the recommendation of most subwoofer companies, or worse yet, the general dogma over at places like AVS Forum, and you rather quickly see that most people are doing it wrong. Even if they have multiple subs, they stack them all in one corner, or spread them across the front of the room.
I do keep hearing an argument from them that makes little sense to me, and I would like some clarification here if I could. When I suggest this method the comment becomes that if you move subs around the room like this, they don't sum to increase spl ability, and thus small subs are a bad idea. Additionally, a lot of people want to stack them up in one area as they believe that doing so gains 6db's for each sub, that you don't get otherwise. When people ask how to setup subs, thats what they are told, that they will have increased spl with one arrangement, but smoother bass with the other (sometimes they say that, other times they say it offers no gain). I've even heard people say it makes the smoothness worse, and that for best integration it has to be right near the main speakers. I can't seem to shake the idea that doing this is wrong, and so, what is the truth here? I know what I've measured, I know what I've experienced, I know what Harman and Dr. Geddes has written on the subject.
I think it's important that this information be put out there, regardless of what you call it, because most people aren't doing this. This isn't common knowledge amongst pro's and average users alike. It's good to know that there are others who believe in the method, and utilize it, but I am glad to see this view being put out there more and more. One look at the recommendation of most subwoofer companies, or worse yet, the general dogma over at places like AVS Forum, and you rather quickly see that most people are doing it wrong. Even if they have multiple subs, they stack them all in one corner, or spread them across the front of the room.
I do keep hearing an argument from them that makes little sense to me, and I would like some clarification here if I could. When I suggest this method the comment becomes that if you move subs around the room like this, they don't sum to increase spl ability, and thus small subs are a bad idea. Additionally, a lot of people want to stack them up in one area as they believe that doing so gains 6db's for each sub, that you don't get otherwise. When people ask how to setup subs, thats what they are told, that they will have increased spl with one arrangement, but smoother bass with the other (sometimes they say that, other times they say it offers no gain). I've even heard people say it makes the smoothness worse, and that for best integration it has to be right near the main speakers. I can't seem to shake the idea that doing this is wrong, and so, what is the truth here? I know what I've measured, I know what I've experienced, I know what Harman and Dr. Geddes has written on the subject.
Gainphile,
Please go back and read through the other thread. A good bit of questions are answered there. For a quickie, yes, the dipole vs others has been discussed.
My take on the rest of the comments are one to which Geddes has not stated that the use of multiple subs was his idea. Welti said four was great at these locations. These locations are usually not possible. Geddes says that three is almost as good and here are the restrictions; corner, adjacent wall not in corner and non-corner above the mid-point of the room. Use measurements and spacially average these three subs, however they best fit into your environment, and tune using plate amp controls starting with corner sub. Measurement results have shown supporting success that it's possible. John K. is asking for information regarding modeling to support Geddes claims. Geddes is saying that most modeling is not real world applicable so I am not interested in helping.
This is a brief summary as to what I feel has transpired. Everyone is right here if you ask me. Welti is correct but most can not use this strategy. John K is correct in wanting a model that will tell you outcomes before application. Geddes is right in offering up a real world possibility and stating that this sub placement/arrangement will allow sufficiiently flat response over a spacially averaged area.
Am I missing a whole lot here??
Please go back and read through the other thread. A good bit of questions are answered there. For a quickie, yes, the dipole vs others has been discussed.
My take on the rest of the comments are one to which Geddes has not stated that the use of multiple subs was his idea. Welti said four was great at these locations. These locations are usually not possible. Geddes says that three is almost as good and here are the restrictions; corner, adjacent wall not in corner and non-corner above the mid-point of the room. Use measurements and spacially average these three subs, however they best fit into your environment, and tune using plate amp controls starting with corner sub. Measurement results have shown supporting success that it's possible. John K. is asking for information regarding modeling to support Geddes claims. Geddes is saying that most modeling is not real world applicable so I am not interested in helping.
This is a brief summary as to what I feel has transpired. Everyone is right here if you ask me. Welti is correct but most can not use this strategy. John K is correct in wanting a model that will tell you outcomes before application. Geddes is right in offering up a real world possibility and stating that this sub placement/arrangement will allow sufficiiently flat response over a spacially averaged area.
Am I missing a whole lot here??
gainphile, I played around with a dipole sub in the nearfield (<40cm from head) which was amazingly good with lower levels. When using it in a "normal" way it had the same problems one closed sub showed.
a.wayne, "it doesn't matter where you take it from, it matters where you take it to". Does it really matter that our ancestor had the ability to travel to mars but we don't know anything about it anymore?
3rd and last time—after that I'm giving up: please post references to literature.
Best, Markus
a.wayne, "it doesn't matter where you take it from, it matters where you take it to". Does it really matter that our ancestor had the ability to travel to mars but we don't know anything about it anymore?
3rd and last time—after that I'm giving up: please post references to literature.
Best, Markus
pjpoes said:
Matt
Two "coherent" source add 6 dB and two incoherent sources will add 3 dB. The real situation in a real room is somewhere between these two values, but its never zero.
My point about multiple subs is simply that as an AES reviewer I am very aware of the literature in audio. To my knowledge, prior to Todd's work, there was no publication that proposed using subs placed around the room. I had studied this concept well before Todd's paper as evidenced by my Letter To the Editor regarding his paper and my own conclusions on the approach. Now if there actually is a "discoverable" discussion about using subs placed around the room (multiple subs all at one location IS NOT what is being recommended here) then I would love to know about it as it would be new to many of us.
goskers said:
I think that is mostly correct. Except maybe the modeling point.
I've done as much modeling as anyone, and, I would actually claim a lot more. There are things that one can get from these models, but at some point you have to move to the real situation to adapt and refine the concepts there. That is where I am at now. Everytime I have a discussion with John about his modeles I get attacked over what I believe are small insignificant aspects and he never takes my advise or admits to any mistakes. Would anyone help in a situation like that?
markus76 said:
Hello Markus,
I would strongly disagree, bass localization is absolutely affected by it , so is port location ( on vented cabinets ) ...
If you have never tried or tested it ( i have ) then how can you be so absolute ...
Why in the old 4 ch era (70's), before it matured and became that fancy new invention "surround sound" why some audiophiles even had 4 "subwoofers" , well it could have been my imagination, maybe multiple subs have never been tried before ...
You must be on to something Markus , keep us informed ...
Regards ,
pjpoes said:
Yes !
" location " mitigates the issue, singular and or plural. Read back, that was never in dispute , nor do i dispute Mr Gedlee approach , just the tone of discussion .
Audio is funny and the science can be spun many ways , there will be no absolute winners .........Just enjoy the discussions..