Originally Posted by localhost127
so if i am reading you correctly, psycho-acoustic research has been rendered invalid based simply on being "30 or more years old"
? can you please provide any citation to this? what else has been rendered invalid by basis of simply being "discovered in the past".
and you do realize that anyone on this forum or elsewhere attenuating destructive early arriving, high-gain indirect specular reflections (forming effectively anechoic ISD) - and reintroducing later-arriving energy as a lateral, semi-diffused soundfield via the use of reflection phase gratings is actually emulating the LEDE response, yes?
maybe you missed this thread: Who needs a Haas Kicker?
the root of all of your confusion is you still simply do not even understand what "LEDE" is - yet you pretend to speak with such authority!
i believe FTB and boggy's MyRoom design use diffusers on the rear wall? yes? the same rear wall diffusers that you insist "collapse the stereo image"
It is correct we have diffusers on the back wall (and ceiling) of FTB Rooms but they do not perform to the LEDE/RFZ criteria, and are very specific - they are purpose designed for a unique function.
Their interaction with the speakers is engineered to be minimal (pretty close to non-existent in fact). They are aimed at self-noises interactions with the mix/recording engineer. You will notice they cover a very small area of the back wall - a ratio that follows a strict rule/equation based on room size, distance to cue, and so on.
So while it is correct that there are diffusors there, you simply cannot put all the eggs in the same bag.
I would not agree to a -12dB return à la LEDE or RFZ as some suggest in any of my designs - I do believe this is detrimental. Once you've learned to hear what that does, you realize a few things. And start questioning. It's this questioning that kick started research that led to FTB.
Before the FTB concept was finalized and tested + approved on the first builds, we were designing RFZ/LEDE. So this statement is not based on theory only. But on a practical knowledge and experience of building quite a few of these too.
LEDE/RFZ are not bad rooms - but in my opinion are far from optimized and do have a series of issues that need to be addressed. I think what DanDan means is that since these were created, and no one will deny they were very important steps in our small field of studio acoustics, a lot of progress was made.
It's like in any other fields, you learn from what was done 30, 20 or 10 years and even 6 months ago, and you build on it. Some things you may drop because in retrospect they are not all that good or needed. Maybe because for ex. the available data 30/20 years ago was "incomplete" or not detailed enough to allow to segregate between particular phenomena (when you knew about their existence) and made acoustic engineers honestly think this one thing was a good thing when in fact, while it indeed had some good to it there were some significant downsides to it too that simply cannot be ignored. Today with more advanced knowledge, we know better how to try and retain what is good and drop what is not needed or actually detrimental.
At one point, in a few decades maybe, the knowledge in this small field will be such that we'll reach a point where we'll more or less hit a glass wall in terms of what can be practically achieved.
For now, some have chosen to go forward and try news things, building on the knowledge accumulated so far. And going forward sometimes means dropping things that in retrospect were not optimum and trying new things.
FTB is doing well. We are building a lot of rooms. I also think that what Boggy came up with is very clever. I have a lot of respect for what he does. It's not easy to survive in this small area of engineering where research means are very limited and the market a niche of a niche.
I can only hope that more models will emerge and thus keep things moving forward. And keep things interesting.