Since Dr. Floyd E. Toole seems to be the last word on sound reproduction, I thought I would get his book to help me with my new room/speaker setup. The first thing that I found out, for a number of reasons, Dr. Toole is not a fan of "Computerized Room Correction" he believes it has no value and doesn't solve the problem of speaker/room relationship. "Just another Corporate Gimmick"
So I'm on the path of bliss with Dr. Toole when I run into my first problem. Getting the anechoic data set for the speakers I purchase. Since they don't come with the speakers, not much information, I decided to write the company.
First Email: "I just bought some Focal speakers, and I'm trying to get the anechoic data set for loudspeaker for the Focal Aria 936 CC900, 906. I need the data, so I can set the speakers up properly. Thank you, and I await your response."
Focal Response: "Unfortunately, we do not have such data available for sharing, Please let me know if I can help with anything else."
Second email: "Without that data, how can the speakers/room be setup?"
Focal Response: "Your Room is not an anechoic chamber, therefore the data is useless, the readings are done during Transducer Design in order to make sure they attain the design spec. When placing in your room, it comes down to personal taste, and if you need that level of detail, the need for a professional reading is recommended for each different location you may place them, because once the readings are done, and the room is treated, you can never move the speakers unless you re-read the room at the new location, and re-treat (diffusers, sound traps, etc.).
Third Email: "According to Dr. Floyd E, Toole's Sound Reproduction 3rd Edition, I will need the anechoic data set for these loudspeakers. The test data you provide is nonexistent, other than specs, with the speaker. In order for me to set up the speaker/room, speaker naturality, will be needed. Thank you and I await your response.
I' waiting for a response. Do I really require the data; haven't gotten that far into the book.
I'm glad you are educating yourself from an authority such as Dr. O'Toole.
Unfortunately this area is awash in misinformation, and I regret to say some of it on these forums, and it continues.
Focal are right to a degree, but they should publish that information. I firmly believe that you should NOT purchase any speaker where full measurement data are unavailable. The problem is that there is not much you can do with an aberrant speaker. Dr. O'Toole is right about that. If you have a lousy speaker, you cat bet there will be mismatches between on and off axis response, not correctable by any form of Eq. Also there likely will be resonant issues of retained energy not amenable to Eq.
Now you can get close to anechoic measurements in your room, at least above 300 Hz. Often the information below that is not far off, especially of you have a good room. It requires special pulsed signals. I use the Omnimic system. I have been very pleased with it.
In addition there is not much you can do with your room, as these to an overwhelming degree are determined by the physical dimensions of the room. The issues are confined to the frequencies below 100 Hz for most rooms. The issue arises because at certain frequencies in the bass decade, at some frequencies these reflections will reinforce and cause a peak, and at others cancel and cause a null. Now Eq, can help reduce a peak, but trying to Eq a null is misguided and prone to overload components and increase distortion. Changing the location of subs can help here, but add to the disassociation of fundamentals and harmonics.
I have long maintained that subs should be as close as possible to the main speakers. In addition having speakers of sufficient quality they can be crossed at 40 Hz rather than 80 Hz is advantageous.
The big issue where Eq falls apart is that so much of this room issue does come from speaker problems. Reflections from the room are a very good thing. Dead rooms DO NOT sound good. Normal speech human speech from a talking human in pretty much any room will sound fine. If you know the person, they will sound the same from one room to another. So a speaker should, but most don't. The problem is the speaker and not the rooms.
This issue arises because the direct first response, has a different frequency envelope form the secondary reflections. This is why a speakers with an off axis response out to over 60 degrees that does not very closely match the first on axis response will be a poor performer. The more reverberant the room the more apparent the problem.
Having had speakers in huge variety of rooms in my years doing on location recording and monitoring from speakers, I can tell you that is true. Good speakers will not be fussy about their environment to a very large degree.
This brings me to the last point, that you can not correct for this with Eq, only make it worse. The reason being that you can not apply the frequency correction to both the axis and off axis response with an equalizer, because the two responses require different correction! This also applies to automated Eq programs.
So this is why I harp on the fact the choosing or building good accurate speakers is essential to good reproduction. If the speakers are not accurate, you are out of luck. There is nothing you can do about it.
So if your speakers are not accurate you are stuck with them. To that extent Focal are correct. Having data that would show problems with your speakers, that I have referenced, would just tell you, you should not have bought them in the first place.