And what will be the critical distance in the far field for a point source radiator, where the direct sound field will still hold any meaningful percentage of the reverberation field? How longer an oblate guided near piston can ''throw'' than naked, and how longer will be for a floor to ceiling line source? Or even for a tall Bessel power tapped 3/4 inch small flange tweeter array for that.
If you are talking about modal frequencies then fine, but people need to understand the problems with "room EQ" above this range.
"Critical Distance" is a steady state concept and doesn't apply to the first arrival sound field. The rest of the comment is rather garbled and I cannot understand what you are trying to say.
In other words I mean for how long a distance in a room a typical direct radiator home speaker can be considered throwing enough direct sound proportion for we perceive the flatness or not of first arrival, was the first part of the question. Isn't that critical to decide applying room EQ for far enough distances being valid or not?
The second part of the question was about how longer can that be for an oblate guided speaker like a 12 incher from your line VS the former example and VS a true line source?
The second part of the question was about how longer can that be for an oblate guided speaker like a 12 incher from your line VS the former example and VS a true line source?
I am still unclear on the question and I don't want to presume to understand it and give a faulty answer. I don't see what distance has to do with the first arival sound. There is a first arrival at any distance. The time difference between the first arrival and the build-up of the reverberant field and the "critical distance" will vary with distance, but that's a different thing.
So please be more precise in your comment.
So please be more precise in your comment.
OK. After several meters the power of the reflections has to overcome the power of the direct sound enough, doesn't it? For what we must cater to be flatter? What the subject mostly perceives? The room sound dominates or not when far away?
Power can only be defined in the steady state - its a time average measure, so in terms of power yes, but I am still lost about what it is your are trying to say.
Again, I'm sorry but the English of this this sentence eludes me.
We perceive both the direct sound and the steady state sound, but in different ways. There is no "mostly" one way or the other. They are different things and lead to different effects. The transient direct sound affects mostly "image", while the steady state is timbre, coloration and spaciousness.
Audyssey has come a long way, have you ever discussed this with Chris from Audyssey.
There are other high end EQing products too that Harman has shown to be very effective in room
Different topic though so a new thread on this if there is interest? Just in case the OP hates for his thread to go off topic.
So you do not believe in a product like Audyssey? I think I have read that you have not used Audyssey PRO, correct?
In theory of course but do the measurements the OP shows us the difference you are describing?
Sorry, I meant both measurements gated, One gated in room vs outside response that can have much longer gates.
From what I have read and learned from many, many Expert DIY builds is that both measurements can be used to desgin great crossovers.
Thanks. So if we EQ with an RTA for flatter, say in a big studio down towards its back wall, ''tembre, coloration and spaciuosness'' will be perceived better, but we will destroy imaging?. So RTA DSP EQ is bad practice in large theaters, big HT rooms, and live events in stadiums even? Since the direct sound will always be there strong enough and we must not alter the natural flatness of a good PA system?
P.S. Sorry if I gave you a hard time with my English.
Opps, Im confused on my reply and I can not edit it.
I meant that in the in room responses....
the gated response vs the non-gated show little changes since the room is a well treated room there isnt a huge difference but are the small changes still enough?
I don't think that it is OT as a reference. Though if it gets expanded, it will really become a new topic, so we better open new. It relates about taking measurements for designing an active home speaker that will have known position and distance in a known room. Which is the current topic. Do we compensate for RTA measurements at listening position on its controller at all, or not? Gated at 1m is all we must take notice above modal region, is what I understood by now. Extending this, a good passive crossover is all we need, right? Cheaper and simpler, less equipment and amps and cables.
Salas
It's not that simple. You might want to read
http://harman.com/EN-US/OurCompany/Technologyleadership/Documents/Scientific Publications/13686.pdf
Best, Markus
There is only so much detail that one can get into in thread posts. At some point you have to go to the literature if you really want to figure things out.
Thanks for that post Markus.
Thanks for that post Markus.
Here is what I was getting at all
Here are my in room measurements
Gated at .8ms, ignore the red measurement I was testing polarity.
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Gated at 4 ms
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Gated at 8 ms (almost raw measurements)
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The only changes are really in the lower frequencies, Gating shifts from about 1200Hz down to 100Hz.
Even the raw measurement is usable in crossover simulation.
Doug, what are you doing to treat your room and what type of speakers are those? Looks pretty darn good to me.
Dan
Dan
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