Thomas Jouanjean wrote on Mon, 30 August 2010 12:24 |
"You can't fix a time domain problem in the frequency domain" |
bruno putzeys wrote on Mon, 30 August 2010 06:30 | ||
Of course you can. Time and frequency domain are the same thing seen from different angles. One reason why people don't believe it is because traditionally EQ's are minimum phase whereas acoustical problems are not, meaning that after correction you still have a smeared impulse response. If the EQ is a full FIR correction you can, in principle, correct everything... BUT ONLY... ...in one spot in the room. Or n spots if you have n speakers. The issue has nothing to do with time vs frequency domain but with the fact that the room is a space and you have only two points (a pair of speakers) to control it by. If you have a dip at a certain frequency / spot, you will have a bump at the same frequency elsewhere. Correct the dip and the bump elsewhere gets worse. Room correction restricts you to sitting in one exact spot. That is why it doesn't work practically. However, if you are happy to have your head nailed down in one precise location you can remove everything. Echos, everything. Just don't move your head. |
Thomas Jouanjean wrote on Mon, 30 August 2010 13:53 |
And thus, in my book it doesn't work in practice and has no real interest in studios. A good room should be quasi isotropic. Not a mediocre nail head sized sweet spot with everything even worse everywhere else. |
Thomas Jouanjean wrote on Mon, 30 August 2010 13:53 |
Sorry I always sound like an old grumpy grandpa when these systems pop out |
bruno putzeys wrote on Mon, 30 August 2010 09:35 |
Indeed, I only wanted to point out that time vs frequency domain is not what lies at the root of this. Which doesn't mean that it works, unfortunately! (sorry for the hordes who hawk these things, and even sorrier for those who buy them). |
bruno putzeys wrote on Mon, 30 August 2010 07:30 |
BUT ONLY... ...in one spot in the room. |
brett wrote on Mon, 30 August 2010 10:09 |
that turned out outstanding in my opinion. |
Ethan Winer wrote on Mon, 30 August 2010 12:38 |
Exactly. Yet people often report positive results with these products. --Ethan |
Ethan Winer wrote on Mon, 30 August 2010 18:38 | ||
Of course I'm totally with you, and the main point is that EQ improvements that help in one place are made worse somewhere else. Even a few inches away in many cases. --Ethan |
brett wrote on Mon, 30 August 2010 23:36 |
This thread was sort of about external eq vs internal eq and doing it for free. However, it was not about using it in place of acoustic design and I don't know how many times I need to repeat that. |
martindale wrote on Mon, 30 August 2010 23:36 |
However, I would take some exception to the thread's seeming "slant" towards external eq in the monitor chain being "evil". I do totally agree (and really like the phrase) that the goal in acoustic design should be to build (or fix) rooms to be "quasi isotropic." But it is a fact that most of the studio designers and room tuning gurus ( at least in the US) use some external eq to fine tune the room---not to correct large modal problems, but sometimes to make small corrections and/ or achieve a certain "curve", which can be VERY important to some engineers in some facets of studio monitoring. |
martindale wrote on Mon, 30 August 2010 23:36 |
Try talking to Dolby about a film mix room that does not conform to an "X" curve....you won't get very far. I don't think any designer could build a room and install speakers that conformed to an "X" curve without any eq. Having worked on a lot of film rooms, in close cooperation with Dolby, I understand the powerful need for standardization of monitor curves. You may say, "but we're talking about music studios, not film rooms", but I would ask what about the many "music guys" who are more and more starting to add TV and indie film mixing to their scope, in order to open up additional income streams and get hip to the changing definition of "recorded sound media." ...should these people tune their speakers to a small room "X"; or have multiple eq settings (shudder)?....these are additional thread topics, food for thought, but speak to the necessary use of external eq's. |
brett wrote on Mon, 30 August 2010 19:30 |
not in this case. |
Ethan Winer wrote on Wed, 01 September 2010 20:16 |
^^^ That room is 16 by 11.5 by 8 feet, which is typical for a lot of home studios. Of course it has "serious modal and null issues." All such rooms do! Those graphs are absolutely typical. In any event, those graphs were taken with the room empty as part of this exhaustive comparison: EQ Versus Bass Traps --Ethan |
bruno putzeys wrote on Mon, 30 August 2010 13:30 |
If the EQ is a full FIR correction you can, in principle, correct everything... BUT ONLY... ...in one spot in the room. Or n spots if you have n speakers. The issue has nothing to do with time vs frequency domain but with the fact that the room is a space and you have only two points (a pair of speakers) to control it by. If you have a dip at a certain frequency / spot, you will have a bump at the same frequency elsewhere. Correct the dip and the bump elsewhere gets worse. Room correction restricts you to sitting in one exact spot. That is why it doesn't work practically. However, if you are happy to have your head nailed down in one precise location you can remove everything. Echos, everything. Just don't move your head. |
bruno putzeys wrote on Mon, 30 August 2010 13:30 |
....................... If the EQ is a full FIR correction you can, in principle, correct everything... ....... |
bruno putzeys wrote on Mon, 30 August 2010 13:30 |
With all other BUT ONLY... ...in one spot in the room. Or n spots if you have n speakers. The issue has nothing to do with time vs frequency domain but with the fact that the room is a space and you have only two points (a pair of speakers) to control it by. If you have a dip at a certain frequency / spot, you will have a bump at the same frequency elsewhere. Correct the dip and the bump elsewhere gets worse. Room correction restricts you to sitting in one exact spot. That is why it doesn't work practically. However, if you are happy to have your head nailed down in one precise location you can remove everything. Echos, everything. Just don't move your head. |