john k... said:
Why do you ask? Earls approach is to have 3 more or less fixed sub positions in a real room and then get the spatially flattest frequency response out of it. Nothing more nothing less.
You guys start to lose sight of the actual problem: low frequency reproduction in a small space. Obviously there's no agreement what the priorities are—flattest frequency response, shortest decay rate, smallest seat to seat variation, etc.?
It makes no sense discussing methods to achieve a certain goal if nobody knows what the goal is.
Best, Markus
Personally I see nothing off topic with john k trying to investigate your method of placing subs from an achademic research point of view. Why so defensive? I'm sure john k would not attempt to do this unless it's seemed worthwhile. Ask him whether he wants to get technical with EnABL and see how he responds.gedlee said:
gedlee said:
If my question (it's been consistently the same one which you fail to answer) was disingenuous then I would simply post a bunch of simulations for source and listening positions placed arbitrarily. I haven't done that because THAT would be disingenuous. I have asked for guidance. Gotten none.
Were my comments to Todd in the other thread that I could not find agreement with his data disingenuous as well? I continued to question, investigate, and found that I had made an error. While my sims are not fully in agreement with Todd's (unless I include the erroneous direct term) I don't see Todd reacting as you are. Seems to me you also agreed that the direct term was erroneous. Todd didn't call foul.
And I am not even in disagreement that 3 woofers may result in something acceptable (or "good enough" as you put it). Certainly it should be better than 1 or 2. I just don't necessarily accept you definition of good enough, which really isn't relevant. But certainly if your approach is so successful in the arena of real rooms then the simple problem my sims address should be a no brainer. A rectangular room, sealed or otherwise, should have a fairly unique arrangement for the optimum placement of an array of woofers, be it 2, 3, 4,...,n woofers. It seems to for 4 woofers. I find it difficult to understand your continued objections to my request for guidance. Moving to the real world where modes interact, wall flex, everything is more complex, can only make the problem more difficult.
So let me ask a different way. I have a REAL listening room which measure 12' 3" x 19' 5" x 7' 8". Where should I place the subs?
As for hijacking the thread, I'll leave it to the moderators to decide whether I can post to this thread or not. It's not your board/thread. It's a discussion group. Perhaps you would prefer to have it censored? I haven't seen anyone ask to have your comments stricken from other thread because they were critical or contrarian, and Lord knows that you disagree with just about everthing that isn't Geddes. And I notice you don't seem to mind at all if I am in agreement with you, as I have been in some of other other threads.
Perhaps you feel I am trying to engage you in argument because I have repeatedly asked the same question which you have refused to answer. But while you claim that all you do is based on science, all you have presents is discussion: move the the woofers around, add damping, try this, try that. Soongc was correct when he said, "You're sounding more like a normal audiophile now."
I'm actually very happy that JohnK asks these question.
I have a problem now where I really love my Pluto clone, but dislike the typical boomy low-frequency, as written here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=138487
Multiple sub interest me but I'm not too convinced yet to invest on more subwoofer at the moment. Is this simply a "trial and error" approach and what kind of success rate can we expect from multiple sub?
As with anything, what is the drawback aside from cost? phase, localization, etc?
Thanks...
I have a problem now where I really love my Pluto clone, but dislike the typical boomy low-frequency, as written here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=138487
Multiple sub interest me but I'm not too convinced yet to invest on more subwoofer at the moment. Is this simply a "trial and error" approach and what kind of success rate can we expect from multiple sub?
As with anything, what is the drawback aside from cost? phase, localization, etc?
Thanks...
John, why do you keep asking a question that was already answered multiple times??
http://www.mehlau.net/audio/multisub_geddes/
Earl's method does not find the best locations for 3 subs in a given room but the best settings (volume, delay and cut off frequency) that yield the smoothest overall frequency response for 3 (more or less) random sub locations. The same is true for Todd's SFM.
Best, Markus
http://www.mehlau.net/audio/multisub_geddes/
Earl's method does not find the best locations for 3 subs in a given room but the best settings (volume, delay and cut off frequency) that yield the smoothest overall frequency response for 3 (more or less) random sub locations. The same is true for Todd's SFM.
Best, Markus
Pan said:
Agree and find this very ironic ...... Science one day and audiophile "Optimization " the next...
It seems Earl is the only one allowed to feel something is better ....
Multiple subs work earl because you reduce localization , i had mentioned this to you awhile back and it was brushed off , when i tried to explain to you that low frequency is omni-directional but radiating output is not... By spreading the field out with 3 subs you have reduced the localization creating better integration ...
This information and the science behind it was filed in my patent application in 1989..........................
Oh no! EQ is used.markus76 said:
Good thing is that this can cause decay long enough to mask the not-so-good transient onsets. boooom all around you with no localization, that is great. Gives good ear massage too.Seriously, two people moving around in the room helps breakup some of the modes. How can the measurement be accurate? And if you sweep the wand, how do you know you don't get wind effect in the measurements?
We're talking about low frequencies. Are you aware that 40Hz equals a wavelength of 8.6m. That's 25ms for one period. Your hearing needs a couple of periods to be able to determine pitch. What use has the concept of "transient onset" within these physical measures?
Regarding the sensation of "booming" bass notes: haven't you followed the discussion about minimum phase systems??
By the way this response at my listening position doesn't make use of any EQ at all—just 3 subs:
Regarding the sensation of "booming" bass notes: haven't you followed the discussion about minimum phase systems??
By the way this response at my listening position doesn't make use of any EQ at all—just 3 subs:
An externally hosted image should be here but it was not working when we last tested it.
Bear in mind that we are listening to musical instruments not just a single tone, and the definition of "small room" is very different depending on where you live. Where I live rooms can be as small as 3Mx3M.markus76 said:
Regarding "transient onset", if you currently cannot hear the difference when switching absolute polarity in both channels. Then there is nothing I can say to let you understand.
markus76 said:
Hello Markus ,
Not sure if you want one , your tone seems confrontational as oppose to wanting any banter technical or not , seems you have it all figured out anyway .
I can only leave you with a quote from our mutual friend Mr Gedlee
"I'll leave the academic "proof" of the ideal to others."
Regards,